diff --git a/.gitignore b/.gitignore
index 89bd7bd..b2a1ae4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -35,6 +35,7 @@
 /git-clone
 /git-column
 /git-commit
+/git-commit-graph
 /git-commit-tree
 /git-config
 /git-count-objects
@@ -141,6 +142,7 @@
 /git-rm
 /git-send-email
 /git-send-pack
+/git-serve
 /git-sh-i18n
 /git-sh-i18n--envsubst
 /git-sh-setup
diff --git a/Documentation/Makefile b/Documentation/Makefile
index 6232143..fa9e5c0 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -78,6 +78,7 @@
 TECH_DOCS += technical/pack-protocol
 TECH_DOCS += technical/protocol-capabilities
 TECH_DOCS += technical/protocol-common
+TECH_DOCS += technical/protocol-v2
 TECH_DOCS += technical/racy-git
 TECH_DOCS += technical/send-pack-pipeline
 TECH_DOCS += technical/shallow
diff --git a/Documentation/RelNotes/2.18.0.txt b/Documentation/RelNotes/2.18.0.txt
index 5f16516..31c3f6d 100644
--- a/Documentation/RelNotes/2.18.0.txt
+++ b/Documentation/RelNotes/2.18.0.txt
@@ -21,6 +21,29 @@
  * When built with more recent cURL, GIT_SSL_VERSION can now specify
    "tlsv1.3" as its value.
 
+ * "git gui" learned that "~/.ssh/id_ecdsa.pub" and
+   "~/.ssh/id_ed25519.pub" are also possible SSH key files.
+   (merge 2e2f0288ef bb/git-gui-ssh-key-files later to maint).
+
+ * "git gui" performs commit upon CTRL/CMD+ENTER but the
+   CTRL/CMD+KP_ENTER (i.e. enter key on the numpad) did not have the
+   same key binding.  It now does.
+   (merge 28a1d94a06 bp/git-gui-bind-kp-enter later to maint).
+
+ * "git gui" has been taught to work with old versions of tk (like
+   8.5.7) that do not support "ttk::style theme use" as a way to query
+   the current theme.
+   (merge 4891961105 cb/git-gui-ttk-style later to maint).
+
+ * "git rebase" has learned to honor "--signoff" option when using
+   backends other than "am" (but not "--preserve-merges").
+
+ * "git branch --list" during an interrupted "rebase -i" now lets
+   users distinguish the case where a detached HEAD is being rebased
+   and a normal branch is being rebased.
+
+ * "git mergetools" learned talking to guiffy.
+
 
 Performance, Internal Implementation, Development Support etc.
 
@@ -76,6 +99,25 @@
  * Small test-helper programs have been consolidated into a single
    binary.
 
+ * API clean-up around ref-filter code.
+
+ * Shell completion (in contrib) that gives list of paths have been
+   optimized somewhat.
+
+ * The index file is updated to record the fsmonitor section after a
+   full scan was made, to avoid wasting the effort that has already
+   spent.
+
+ * Performance measuring framework in t/perf learned to help bisecting
+   performance regressions.
+
+ * Some multi-word source filenames are being renamed to separate
+   words with dashes instead of underscores.
+
+ * An reusable "memory pool" implementation has been extracted from
+   fast-import.c, which in turn has become the first user of the
+   mem-pool API.
+
 Also contains various documentation updates and code clean-ups.
 
 
@@ -115,8 +157,44 @@
    fixed.
    (merge a0d51e8d0e eb/cred-helper-ignore-sigpipe later to maint).
 
+ * "git rebase --keep-empty" still removed an empty commit if the
+   other side contained an empty commit (due to the "does an
+   equivalent patch exist already?" check), which has been corrected.
+   (merge 3d946165e1 pw/rebase-keep-empty-fixes later to maint).
+
+ * Some codepaths, including the refs API, get and keep relative
+   paths, that go out of sync when the process does chdir(2).  The
+   chdir-notify API is introduced to let these codepaths adjust these
+   cached paths to the new current directory.
+   (merge fb9c2d2703 jk/relative-directory-fix later to maint).
+
+ * "cd sub/dir && git commit ../path" ought to record the changes to
+   the file "sub/path", but this regressed long time ago.
+   (merge 86238e07ef bw/commit-partial-from-subdirectory-fix later to maint).
+
+ * Recent introduction of "--log-destination" option to "git daemon"
+   did not work well when the daemon was run under "--inetd" mode.
+   (merge e67d906d73 lw/daemon-log-destination later to maint).
+
+ * Small fix to the autoconf build procedure.
+   (merge 249482daf0 es/fread-reads-dir-autoconf-fix later to maint).
+
+ * Fix an unexploitable (because the oversized contents are not under
+   attacker's control) buffer overflow.
+   (merge d8579accfa bp/fsmonitor-bufsize-fix later to maint).
+
  * Other minor doc, test and build updates and code cleanups.
    (merge 248f66ed8e nd/trace-with-env later to maint).
    (merge 14ced5562c ys/bisect-object-id-missing-conversion-fix later to maint).
    (merge 5988eb631a ab/doc-hash-brokenness later to maint).
    (merge a4d4e32a70 pk/test-avoid-pipe-hiding-exit-status later to maint).
+   (merge 05e293c1ac jk/flockfile-stdio later to maint).
+   (merge e9184b0789 jk/t5561-missing-curl later to maint).
+   (merge b1801b85a3 nd/worktree-move later to maint).
+   (merge bbd374dd20 ak/bisect-doc-typofix later to maint).
+   (merge 4855f06fb3 mn/send-email-credential-doc later to maint).
+   (merge 8523b1e355 en/doc-typoes later to maint).
+   (merge 43b44ccfe7 js/t5404-path-fix later to maint).
+   (merge decf711fc1 ps/test-chmtime-get later to maint).
+   (merge 22d11a6e8e es/worktree-docs later to maint).
+   (merge 92a5dbbc22 tg/use-git-contacts later to maint).
diff --git a/Documentation/SubmittingPatches b/Documentation/SubmittingPatches
index a1d0fec..945f8ed 100644
--- a/Documentation/SubmittingPatches
+++ b/Documentation/SubmittingPatches
@@ -260,8 +260,8 @@
 not a text/plain, it's something else.
 
 Send your patch with "To:" set to the mailing list, with "cc:" listing
-people who are involved in the area you are touching (the output from
-`git blame $path` and `git shortlog --no-merges $path` would help to
+people who are involved in the area you are touching (the `git
+contacts` command in `contrib/contacts/` can help to
 identify them), to solicit comments and reviews.
 
 :1: footnote:[The current maintainer: gitster@pobox.com]
diff --git a/Documentation/config.txt b/Documentation/config.txt
index 2659153..a05a88f 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -530,6 +530,12 @@
 	This variable can be set to 'input',
 	in which case no output conversion is performed.
 
+core.checkRoundtripEncoding::
+	A comma and/or whitespace separated list of encodings that Git
+	performs UTF-8 round trip checks on if they are used in an
+	`working-tree-encoding` attribute (see linkgit:gitattributes[5]).
+	The default value is `SHIFT-JIS`.
+
 core.symlinks::
 	If false, symbolic links are checked out as small plain files that
 	contain the link text. linkgit:git-update-index[1] and
@@ -898,6 +904,10 @@
 This setting defaults to "refs/notes/commits", and it can be overridden by
 the `GIT_NOTES_REF` environment variable.  See linkgit:git-notes[1].
 
+core.commitGraph::
+	Enable git commit graph feature. Allows reading from the
+	commit-graph file.
+
 core.sparseCheckout::
 	Enable "sparse checkout" feature. See section "Sparse checkout" in
 	linkgit:git-read-tree[1] for more information.
@@ -1088,6 +1098,16 @@
 	A boolean to make git-clean do nothing unless given -f,
 	-i or -n.   Defaults to true.
 
+color.advice::
+	A boolean to enable/disable color in hints (e.g. when a push
+	failed, see `advice.*` for a list).  May be set to `always`,
+	`false` (or `never`) or `auto` (or `true`), in which case colors
+	are used only when the error output goes to a terminal. If
+	unset, then the value of `color.ui` is used (`auto` by default).
+
+color.advice.hint::
+	Use customized color for hints.
+
 color.branch::
 	A boolean to enable/disable color in the output of
 	linkgit:git-branch[1]. May be set to `always`,
@@ -1190,6 +1210,15 @@
 	A boolean to enable/disable colored output when the pager is in
 	use (default is true).
 
+color.push::
+	A boolean to enable/disable color in push errors. May be set to
+	`always`, `false` (or `never`) or `auto` (or `true`), in which
+	case colors are used only when the error output goes to a terminal.
+	If unset, then the value of `color.ui` is used (`auto` by default).
+
+color.push.error::
+	Use customized color for push errors.
+
 color.showBranch::
 	A boolean to enable/disable color in the output of
 	linkgit:git-show-branch[1]. May be set to `always`,
@@ -1218,6 +1247,15 @@
 	status short-format), or
 	`unmerged` (files which have unmerged changes).
 
+color.transport::
+	A boolean to enable/disable color when pushes are rejected. May be
+	set to `always`, `false` (or `never`) or `auto` (or `true`), in which
+	case colors are used only when the error output goes to a terminal.
+	If unset, then the value of `color.ui` is used (`auto` by default).
+
+color.transport.rejected::
+	Use customized color when a push was rejected.
+
 color.ui::
 	This variable determines the default value for variables such
 	as `color.diff` and `color.grep` that control the use of color
diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index e3a44f0..f466600 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -568,7 +568,7 @@
 --
 +
 Patterns have the same syntax and semantics as patterns used for
-fnmantch(3) without the FNM_PATHNAME flag, except a pathname also
+fnmatch(3) without the FNM_PATHNAME flag, except a pathname also
 matches a pattern if removing any number of the final pathname
 components matches the pattern.  For example, the pattern "`foo*bar`"
 matches "`fooasdfbar`" and "`foo/bar/baz/asdf`" but not "`foobarx`".
@@ -592,7 +592,7 @@
 	Treat all files as text.
 
 --ignore-cr-at-eol::
-	Ignore carrige-return at the end of line when doing a comparison.
+	Ignore carriage-return at the end of line when doing a comparison.
 
 --ignore-space-at-eol::
 	Ignore changes in whitespace at EOL.
diff --git a/Documentation/git-bisect.txt b/Documentation/git-bisect.txt
index 4a1417b..4b45d83 100644
--- a/Documentation/git-bisect.txt
+++ b/Documentation/git-bisect.txt
@@ -165,8 +165,8 @@
 git bisect terms
 ------------------------------------------------
 
-You can get just the old (respectively new) term with `git bisect term
---term-old` or `git bisect term --term-good`.
+You can get just the old (respectively new) term with `git bisect terms
+--term-old` or `git bisect terms --term-good`.
 
 If you would like to use your own terms instead of "bad"/"good" or
 "new"/"old", you can choose any names you like (except existing bisect
diff --git a/Documentation/git-clone.txt b/Documentation/git-clone.txt
index 42ca7b5..b844b99 100644
--- a/Documentation/git-clone.txt
+++ b/Documentation/git-clone.txt
@@ -260,7 +260,7 @@
 
 <repository>::
 	The (possibly remote) repository to clone from.  See the
-	<<URLS,URLS>> section below for more information on specifying
+	<<URLS,GIT URLS>> section below for more information on specifying
 	repositories.
 
 <directory>::
diff --git a/Documentation/git-commit-graph.txt b/Documentation/git-commit-graph.txt
new file mode 100644
index 0000000..4c97b55
--- /dev/null
+++ b/Documentation/git-commit-graph.txt
@@ -0,0 +1,94 @@
+git-commit-graph(1)
+===================
+
+NAME
+----
+git-commit-graph - Write and verify Git commit graph files
+
+
+SYNOPSIS
+--------
+[verse]
+'git commit-graph read' [--object-dir <dir>]
+'git commit-graph write' <options> [--object-dir <dir>]
+
+
+DESCRIPTION
+-----------
+
+Manage the serialized commit graph file.
+
+
+OPTIONS
+-------
+--object-dir::
+	Use given directory for the location of packfiles and commit graph
+	file. This parameter exists to specify the location of an alternate
+	that only has the objects directory, not a full .git directory. The
+	commit graph file is expected to be at <dir>/info/commit-graph and
+	the packfiles are expected to be in <dir>/pack.
+
+
+COMMANDS
+--------
+'write'::
+
+Write a commit graph file based on the commits found in packfiles.
++
+With the `--stdin-packs` option, generate the new commit graph by
+walking objects only in the specified pack-indexes. (Cannot be combined
+with --stdin-commits.)
++
+With the `--stdin-commits` option, generate the new commit graph by
+walking commits starting at the commits specified in stdin as a list
+of OIDs in hex, one OID per line. (Cannot be combined with
+--stdin-packs.)
++
+With the `--append` option, include all commits that are present in the
+existing commit-graph file.
+
+'read'::
+
+Read a graph file given by the commit-graph file and output basic
+details about the graph file. Used for debugging purposes.
+
+
+EXAMPLES
+--------
+
+* Write a commit graph file for the packed commits in your local .git folder.
++
+------------------------------------------------
+$ git commit-graph write
+------------------------------------------------
+
+* Write a graph file, extending the current graph file using commits
+* in <pack-index>.
++
+------------------------------------------------
+$ echo <pack-index> | git commit-graph write --stdin-packs
+------------------------------------------------
+
+* Write a graph file containing all reachable commits.
++
+------------------------------------------------
+$ git show-ref -s | git commit-graph write --stdin-commits
+------------------------------------------------
+
+* Write a graph file containing all commits in the current
+* commit-graph file along with those reachable from HEAD.
++
+------------------------------------------------
+$ git rev-parse HEAD | git commit-graph write --stdin-commits --append
+------------------------------------------------
+
+* Read basic information from the commit-graph file.
++
+------------------------------------------------
+$ git commit-graph read
+------------------------------------------------
+
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/Documentation/git-config.txt b/Documentation/git-config.txt
index e09ed5d..18ddc78 100644
--- a/Documentation/git-config.txt
+++ b/Documentation/git-config.txt
@@ -9,13 +9,13 @@
 SYNOPSIS
 --------
 [verse]
-'git config' [<file-option>] [type] [--show-origin] [-z|--null] name [value [value_regex]]
-'git config' [<file-option>] [type] --add name value
-'git config' [<file-option>] [type] --replace-all name value [value_regex]
-'git config' [<file-option>] [type] [--show-origin] [-z|--null] --get name [value_regex]
-'git config' [<file-option>] [type] [--show-origin] [-z|--null] --get-all name [value_regex]
-'git config' [<file-option>] [type] [--show-origin] [-z|--null] [--name-only] --get-regexp name_regex [value_regex]
-'git config' [<file-option>] [type] [-z|--null] --get-urlmatch name URL
+'git config' [<file-option>] [--type=<type>] [--show-origin] [-z|--null] name [value [value_regex]]
+'git config' [<file-option>] [--type=<type>] --add name value
+'git config' [<file-option>] [--type=<type>] --replace-all name value [value_regex]
+'git config' [<file-option>] [--type=<type>] [--show-origin] [-z|--null] --get name [value_regex]
+'git config' [<file-option>] [--type=<type>] [--show-origin] [-z|--null] --get-all name [value_regex]
+'git config' [<file-option>] [--type=<type>] [--show-origin] [-z|--null] [--name-only] --get-regexp name_regex [value_regex]
+'git config' [<file-option>] [--type=<type>] [-z|--null] --get-urlmatch name URL
 'git config' [<file-option>] --unset name [value_regex]
 'git config' [<file-option>] --unset-all name [value_regex]
 'git config' [<file-option>] --rename-section old_name new_name
@@ -38,12 +38,10 @@
 you want to handle the lines that do *not* match the regex, just
 prepend a single exclamation mark in front (see also <<EXAMPLES>>).
 
-The type specifier can be either `--int` or `--bool`, to make
-'git config' ensure that the variable(s) are of the given type and
-convert the value to the canonical form (simple decimal number for int,
-a "true" or "false" string for bool), or `--path`, which does some
-path expansion (see `--path` below).  If no type specifier is passed, no
-checks or transformations are performed on the value.
+The `--type=<type>` option instructs 'git config' to ensure that incoming and
+outgoing values are canonicalize-able under the given <type>.  If no
+`--type=<type>` is given, no canonicalization will be performed. Callers may
+unset an existing `--type` specifier with `--no-type`.
 
 When reading, the values are read from the system, global and
 repository local configuration files by default, and options
@@ -160,30 +158,43 @@
 --list::
 	List all variables set in config file, along with their values.
 
+--type <type>::
+  'git config' will ensure that any input or output is valid under the given
+  type constraint(s), and will canonicalize outgoing values in `<type>`'s
+  canonical form.
++
+Valid `<type>`'s include:
++
+- 'bool': canonicalize values as either "true" or "false".
+- 'int': canonicalize values as simple decimal numbers. An optional suffix of
+  'k', 'm', or 'g' will cause the value to be multiplied by 1024, 1048576, or
+  1073741824 upon input.
+- 'bool-or-int': canonicalize according to either 'bool' or 'int', as described
+  above.
+- 'path': canonicalize by adding a leading `~` to the value of `$HOME` and
+  `~user` to the home directory for the specified user. This specifier has no
+  effect when setting the value (but you can use `git config section.variable
+  ~/` from the command line to let your shell do the expansion.)
+- 'expiry-date': canonicalize by converting from a fixed or relative date-string
+  to a timestamp. This specifier has no effect when setting the value.
+- 'color': When getting a value, canonicalize by converting to an ANSI color
+  escape sequence. When setting a value, a sanity-check is performed to ensure
+  that the given value is canonicalize-able as an ANSI color, but it is written
+  as-is.
++
+
 --bool::
-	'git config' will ensure that the output is "true" or "false"
-
 --int::
-	'git config' will ensure that the output is a simple
-	decimal number.  An optional value suffix of 'k', 'm', or 'g'
-	in the config file will cause the value to be multiplied
-	by 1024, 1048576, or 1073741824 prior to output.
-
 --bool-or-int::
-	'git config' will ensure that the output matches the format of
-	either --bool or --int, as described above.
-
 --path::
-	`git config` will expand a leading `~` to the value of
-	`$HOME`, and `~user` to the home directory for the
-	specified user.  This option has no effect when setting the
-	value (but you can use `git config section.variable ~/`
-	from the command line to let your shell do the expansion).
-
 --expiry-date::
-	`git config` will ensure that the output is converted from
-	a fixed or relative date-string to a timestamp. This option
-	has no effect when setting the value.
+  Historical options for selecting a type specifier. Prefer instead `--type`,
+  (see: above).
+
+--no-type::
+  Un-sets the previously set type specifier (if one was previously set). This
+  option requests that 'git config' not canonicalize the retrieved variable.
+  `--no-type` has no effect without `--type=<type>` or `--<type>`.
 
 -z::
 --null::
@@ -221,6 +232,8 @@
 	output it as the ANSI color escape sequence to the standard
 	output.  The optional `default` parameter is used instead, if
 	there is no color configured for `name`.
++
+`--type=color [--default=<default>]` is preferred over `--get-color`.
 
 -e::
 --edit::
@@ -233,6 +246,10 @@
 	using `--file`, `--global`, etc) and `on` when searching all
 	config files.
 
+--default <value>::
+  When using `--get`, and the requested variable is not found, behave as if
+  <value> were the value assigned to the that variable.
+
 CONFIGURATION
 -------------
 `pager.config` is only respected when listing configuration, i.e., when
diff --git a/Documentation/git-fetch-pack.txt b/Documentation/git-fetch-pack.txt
index f7ebe36..c975884 100644
--- a/Documentation/git-fetch-pack.txt
+++ b/Documentation/git-fetch-pack.txt
@@ -88,7 +88,7 @@
 	infinite even if there is an ancestor-chain that long.
 
 --shallow-since=<date>::
-	Deepen or shorten the history of a shallow'repository to
+	Deepen or shorten the history of a shallow repository to
 	include all reachable commits after <date>.
 
 --shallow-exclude=<revision>::
diff --git a/Documentation/git-for-each-ref.txt b/Documentation/git-for-each-ref.txt
index dffa14a..085d177 100644
--- a/Documentation/git-for-each-ref.txt
+++ b/Documentation/git-for-each-ref.txt
@@ -121,7 +121,7 @@
 	stripping with positive <N>, or it becomes the full refname if
 	stripping with negative <N>.  Neither is an error.
 +
-`strip` can be used as a synomym to `lstrip`.
+`strip` can be used as a synonym to `lstrip`.
 
 objecttype::
 	The type of the object (`blob`, `tree`, `commit`, `tag`).
diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
index 6cbe462..b41e132 100644
--- a/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@ -47,7 +47,7 @@
 
 The first rule takes precedence in the case of a single <commit>.  To
 apply the second rule, i.e., format everything since the beginning of
-history up until <commit>, use the '\--root' option: `git format-patch
+history up until <commit>, use the `--root` option: `git format-patch
 --root <commit>`.  If you want to format only <commit> itself, you
 can do this with `git format-patch -1 <commit>`.
 
diff --git a/Documentation/git-gc.txt b/Documentation/git-gc.txt
index 3126e0d..7c8a2ed 100644
--- a/Documentation/git-gc.txt
+++ b/Documentation/git-gc.txt
@@ -129,7 +129,7 @@
 much time is spent optimizing the delta compression of the objects in
 the repository when the --aggressive option is specified.  The larger
 the value, the more time is spent optimizing the delta compression.  See
-the documentation for the --window' option in linkgit:git-repack[1] for
+the documentation for the --window option in linkgit:git-repack[1] for
 more details.  This defaults to 250.
 
 Similarly, the optional configuration variable `gc.aggressiveDepth`
diff --git a/Documentation/git-log.txt b/Documentation/git-log.txt
index 5437f8b..90761f1 100644
--- a/Documentation/git-log.txt
+++ b/Documentation/git-log.txt
@@ -9,7 +9,7 @@
 SYNOPSIS
 --------
 [verse]
-'git log' [<options>] [<revision range>] [[\--] <path>...]
+'git log' [<options>] [<revision range>] [[--] <path>...]
 
 DESCRIPTION
 -----------
@@ -90,13 +90,13 @@
 	ways to spell <revision range>, see the 'Specifying Ranges'
 	section of linkgit:gitrevisions[7].
 
-[\--] <path>...::
+[--] <path>...::
 	Show only commits that are enough to explain how the files
 	that match the specified paths came to be.  See 'History
 	Simplification' below for details and other simplification
 	modes.
 +
-Paths may need to be prefixed with ``\-- '' to separate them from
+Paths may need to be prefixed with `--` to separate them from
 options or the revision range, when confusion arises.
 
 include::rev-list-options.txt[]
@@ -125,7 +125,7 @@
 `git log --since="2 weeks ago" -- gitk`::
 
 	Show the changes during the last two weeks to the file 'gitk'.
-	The ``--'' is necessary to avoid confusion with the *branch* named
+	The `--` is necessary to avoid confusion with the *branch* named
 	'gitk'
 
 `git log --name-status release..test`::
diff --git a/Documentation/git-ls-remote.txt b/Documentation/git-ls-remote.txt
index 5f2628c..6ad1e34 100644
--- a/Documentation/git-ls-remote.txt
+++ b/Documentation/git-ls-remote.txt
@@ -10,7 +10,7 @@
 --------
 [verse]
 'git ls-remote' [--heads] [--tags] [--refs] [--upload-pack=<exec>]
-	      [-q | --quiet] [--exit-code] [--get-url]
+	      [-q | --quiet] [--exit-code] [--get-url] [--sort=<key>]
 	      [--symref] [<repository> [<refs>...]]
 
 DESCRIPTION
@@ -60,6 +60,16 @@
 	upload-pack only shows the symref HEAD, so it will be the only
 	one shown by ls-remote.
 
+--sort=<key>::
+	Sort based on the key given. Prefix `-` to sort in descending order
+	of the value. Supports "version:refname" or "v:refname" (tag names
+	are treated as versions). The "version:refname" sort order can also
+	be affected by the "versionsort.suffix" configuration variable.
+	See linkgit:git-for-each-ref[1] for more sort options, but be aware
+	keys like `committerdate` that require access to the objects
+	themselves will not work for refs whose objects have not yet been
+	fetched from the remote, and will give a `missing object` error.
+
 <repository>::
 	The "remote" repository to query.  This parameter can be
 	either a URL or the name of a remote (see the GIT URLS and
@@ -90,6 +100,10 @@
 	c5db5456ae3b0873fc659c19fafdde22313cc441	refs/tags/v0.99.2
 	7ceca275d047c90c0c7d5afb13ab97efdf51bd6e	refs/tags/v0.99.3
 
+SEE ALSO
+--------
+linkgit:git-check-ref-format[1].
+
 GIT
 ---
 Part of the linkgit:git[1] suite
diff --git a/Documentation/git-mktree.txt b/Documentation/git-mktree.txt
index c3616e7..27fe2b3 100644
--- a/Documentation/git-mktree.txt
+++ b/Documentation/git-mktree.txt
@@ -14,7 +14,7 @@
 DESCRIPTION
 -----------
 Reads standard input in non-recursive `ls-tree` output format, and creates
-a tree object.  The order of the tree entries is normalised by mktree so
+a tree object.  The order of the tree entries is normalized by mktree so
 pre-sorting the input is not required.  The object name of the tree object
 built is written to the standard output.
 
diff --git a/Documentation/git-push.txt b/Documentation/git-push.txt
index 5b08302..34410f9 100644
--- a/Documentation/git-push.txt
+++ b/Documentation/git-push.txt
@@ -300,7 +300,7 @@
 	These options are passed to linkgit:git-send-pack[1]. A thin transfer
 	significantly reduces the amount of sent data when the sender and
 	receiver share many of the same objects in common. The default is
-	\--thin.
+	`--thin`.
 
 -q::
 --quiet::
diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index 3277ca1..dd85206 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -364,9 +364,10 @@
 	Incompatible with the --interactive option.
 
 --signoff::
-	This flag is passed to 'git am' to sign off all the rebased
-	commits (see linkgit:git-am[1]). Incompatible with the
-	--interactive option.
+	Add a Signed-off-by: trailer to all the rebased commits. Note
+	that if `--interactive` is given then only commits marked to be
+	picked, edited or reworded will have the trailer added. Incompatible
+	with the `--preserve-merges` option.
 
 -i::
 --interactive::
diff --git a/Documentation/git-send-email.txt b/Documentation/git-send-email.txt
index 71ef97b..60cf96f 100644
--- a/Documentation/git-send-email.txt
+++ b/Documentation/git-send-email.txt
@@ -255,7 +255,7 @@
 
 --batch-size=<num>::
 	Some email servers (e.g. smtp.163.com) limit the number emails to be
-	sent per session (connection) and this will lead to a faliure when
+	sent per session (connection) and this will lead to a failure when
 	sending many messages.  With this option, send-email will disconnect after
 	sending $<num> messages and wait for a few seconds (see --relogin-delay)
 	and reconnect, to work around such a limit.  You may want to
@@ -473,16 +473,7 @@
 
 If you have multifactor authentication setup on your gmail account, you will
 need to generate an app-specific password for use with 'git send-email'. Visit
-https://security.google.com/settings/security/apppasswords to setup an
-app-specific password.  Once setup, you can store it with the credentials
-helper:
-
-	$ git credential fill
-	protocol=smtp
-	host=smtp.gmail.com
-	username=youname@gmail.com
-	password=app-password
-
+https://security.google.com/settings/security/apppasswords to create it.
 
 Once your commits are ready to be sent to the mailing list, run the
 following commands:
@@ -491,6 +482,11 @@
 	$ edit outgoing/0000-*
 	$ git send-email outgoing/*
 
+The first time you run it, you will be prompted for your credentials.  Enter the
+app-specific or your regular password as appropriate.  If you have credential
+helper configured (see linkgit:git-credential[1]), the password will be saved in
+the credential store so you won't have to type it the next time.
+
 Note: the following perl modules are required
       Net::SMTP::SSL, MIME::Base64 and Authen::SASL
 
diff --git a/Documentation/git-shortlog.txt b/Documentation/git-shortlog.txt
index 5e35ea1..bc80905 100644
--- a/Documentation/git-shortlog.txt
+++ b/Documentation/git-shortlog.txt
@@ -8,7 +8,7 @@
 SYNOPSIS
 --------
 [verse]
-'git shortlog' [<options>] [<revision range>] [[\--] <path>...]
+'git shortlog' [<options>] [<revision range>] [[--] <path>...]
 git log --pretty=short | 'git shortlog' [<options>]
 
 DESCRIPTION
@@ -69,11 +69,11 @@
 	ways to spell <revision range>, see the "Specifying Ranges"
 	section of linkgit:gitrevisions[7].
 
-[\--] <path>...::
+[--] <path>...::
 	Consider only commits that are enough to explain how the files
 	that match the specified paths came to be.
 +
-Paths may need to be prefixed with "\-- " to separate them from
+Paths may need to be prefixed with `--` to separate them from
 options or the revision range, when confusion arises.
 
 MAPPING AUTHORS
diff --git a/Documentation/git-status.txt b/Documentation/git-status.txt
index 6c230c0..c16e27e 100644
--- a/Documentation/git-status.txt
+++ b/Documentation/git-status.txt
@@ -113,7 +113,7 @@
 	- 'matching'    - Shows ignored files and directories matching an
 			  ignore pattern.
 +
-When 'matching' mode is specified, paths that explicity match an
+When 'matching' mode is specified, paths that explicitly match an
 ignored pattern are shown. If a directory matches an ignore pattern,
 then it is shown, but not paths contained in the ignored directory. If
 a directory does not match an ignore pattern, but all contents are
diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index 71c5618..630999f 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -213,8 +213,8 @@
 	submodule URLs change upstream and you need to update your local
 	repositories accordingly.
 +
-"git submodule sync" synchronizes all submodules while
-"git submodule sync \-- A" synchronizes submodule "A" only.
+`git submodule sync` synchronizes all submodules while
+`git submodule sync -- A` synchronizes submodule "A" only.
 +
 If `--recursive` is specified, this command will recurse into the
 registered submodules, and sync any nested submodules within.
diff --git a/Documentation/git-svn.txt b/Documentation/git-svn.txt
index 636e090..d59379e 100644
--- a/Documentation/git-svn.txt
+++ b/Documentation/git-svn.txt
@@ -635,7 +635,8 @@
 
 -A<filename>::
 --authors-file=<filename>::
-	Syntax is compatible with the file used by 'git cvsimport':
+	Syntax is compatible with the file used by 'git cvsimport' but
+	an empty email address can be supplied with '<>':
 +
 ------------------------------------------------------------------------
 	loginname = Joe User <user@example.com>
@@ -654,8 +655,14 @@
 	If this option is specified, for each SVN committer name that
 	does not exist in the authors file, the given file is executed
 	with the committer name as the first argument.  The program is
-	expected to return a single line of the form "Name <email>",
-	which will be treated as if included in the authors file.
+	expected to return a single line of the form "Name <email>" or
+	"Name <>", which will be treated as if included in the authors
+	file.
++
+Due to historical reasons a relative 'filename' is first searched
+relative to the current directory for 'init' and 'clone' and relative
+to the root of the working tree for 'fetch'. If 'filename' is
+not found, it is searched like any other command in '$PATH'.
 +
 [verse]
 config key: svn.authorsProg
diff --git a/Documentation/git-worktree.txt b/Documentation/git-worktree.txt
index e7eb24a..9920d9c 100644
--- a/Documentation/git-worktree.txt
+++ b/Documentation/git-worktree.txt
@@ -14,7 +14,7 @@
 'git worktree lock' [--reason <string>] <worktree>
 'git worktree move' <worktree> <new-path>
 'git worktree prune' [-n] [-v] [--expire <expire>]
-'git worktree remove' [--force] <worktree>
+'git worktree remove' [-f] <worktree>
 'git worktree unlock' <worktree>
 
 DESCRIPTION
@@ -27,11 +27,12 @@
 tree is associated with the repository.  This new working tree is called a
 "linked working tree" as opposed to the "main working tree" prepared by "git
 init" or "git clone".  A repository has one main working tree (if it's not a
-bare repository) and zero or more linked working trees.
+bare repository) and zero or more linked working trees. When you are done
+with a linked working tree, remove it with `git worktree remove`.
 
-When you are done with a linked working tree you can simply delete it.
-The working tree's administrative files in the repository (see
-"DETAILS" below) will eventually be removed automatically (see
+If a working tree is deleted without using `git worktree remove`, then
+its associated administrative files, which reside in the repository
+(see "DETAILS" below), will eventually be removed automatically (see
 `gc.worktreePruneExpire` in linkgit:git-config[1]), or you can run
 `git worktree prune` in the main or any linked working tree to
 clean up any stale administrative files.
@@ -106,7 +107,7 @@
 	By default, `add` refuses to create a new working tree when
 	`<commit-ish>` is a branch name and is already checked out by
 	another working tree and `remove` refuses to remove an unclean
-	working tree. This option overrides that safeguard.
+	working tree. This option overrides these safeguards.
 
 -b <new-branch>::
 -B <new-branch>::
@@ -232,7 +233,7 @@
 details on a single line with columns.  For example:
 
 ------------
-S git worktree list
+$ git worktree list
 /path/to/bare-source            (bare)
 /path/to/linked-worktree        abcd1234 [master]
 /path/to/other-linked-worktree  1234abc  (detached HEAD)
@@ -247,7 +248,7 @@
 example:
 
 ------------
-S git worktree list --porcelain
+$ git worktree list --porcelain
 worktree /path/to/bare-source
 bare
 
@@ -278,8 +279,7 @@
 # ... hack hack hack ...
 $ git commit -a -m 'emergency fix for boss'
 $ popd
-$ rm -rf ../temp
-$ git worktree prune
+$ git worktree remove ../temp
 ------------
 
 BUGS
diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt
index 1094fe2..ee210be 100644
--- a/Documentation/gitattributes.txt
+++ b/Documentation/gitattributes.txt
@@ -279,6 +279,94 @@
   catch potential problems early, safety triggers.
 
 
+`working-tree-encoding`
+^^^^^^^^^^^^^^^^^^^^^^^
+
+Git recognizes files encoded in ASCII or one of its supersets (e.g.
+UTF-8, ISO-8859-1, ...) as text files. Files encoded in certain other
+encodings (e.g. UTF-16) are interpreted as binary and consequently
+built-in Git text processing tools (e.g. 'git diff') as well as most Git
+web front ends do not visualize the contents of these files by default.
+
+In these cases you can tell Git the encoding of a file in the working
+directory with the `working-tree-encoding` attribute. If a file with this
+attribute is added to Git, then Git reencodes the content from the
+specified encoding to UTF-8. Finally, Git stores the UTF-8 encoded
+content in its internal data structure (called "the index"). On checkout
+the content is reencoded back to the specified encoding.
+
+Please note that using the `working-tree-encoding` attribute may have a
+number of pitfalls:
+
+- Alternative Git implementations (e.g. JGit or libgit2) and older Git
+  versions (as of March 2018) do not support the `working-tree-encoding`
+  attribute. If you decide to use the `working-tree-encoding` attribute
+  in your repository, then it is strongly recommended to ensure that all
+  clients working with the repository support it.
+
+  For example, Microsoft Visual Studio resources files (`*.rc`) or
+  PowerShell script files (`*.ps1`) are sometimes encoded in UTF-16.
+  If you declare `*.ps1` as files as UTF-16 and you add `foo.ps1` with
+  a `working-tree-encoding` enabled Git client, then `foo.ps1` will be
+  stored as UTF-8 internally. A client without `working-tree-encoding`
+  support will checkout `foo.ps1` as UTF-8 encoded file. This will
+  typically cause trouble for the users of this file.
+
+  If a Git client, that does not support the `working-tree-encoding`
+  attribute, adds a new file `bar.ps1`, then `bar.ps1` will be
+  stored "as-is" internally (in this example probably as UTF-16).
+  A client with `working-tree-encoding` support will interpret the
+  internal contents as UTF-8 and try to convert it to UTF-16 on checkout.
+  That operation will fail and cause an error.
+
+- Reencoding content to non-UTF encodings can cause errors as the
+  conversion might not be UTF-8 round trip safe. If you suspect your
+  encoding to not be round trip safe, then add it to
+  `core.checkRoundtripEncoding` to make Git check the round trip
+  encoding (see linkgit:git-config[1]). SHIFT-JIS (Japanese character
+  set) is known to have round trip issues with UTF-8 and is checked by
+  default.
+
+- Reencoding content requires resources that might slow down certain
+  Git operations (e.g 'git checkout' or 'git add').
+
+Use the `working-tree-encoding` attribute only if you cannot store a file
+in UTF-8 encoding and if you want Git to be able to process the content
+as text.
+
+As an example, use the following attributes if your '*.ps1' files are
+UTF-16 encoded with byte order mark (BOM) and you want Git to perform
+automatic line ending conversion based on your platform.
+
+------------------------
+*.ps1		text working-tree-encoding=UTF-16
+------------------------
+
+Use the following attributes if your '*.ps1' files are UTF-16 little
+endian encoded without BOM and you want Git to use Windows line endings
+in the working directory. Please note, it is highly recommended to
+explicitly define the line endings with `eol` if the `working-tree-encoding`
+attribute is used to avoid ambiguity.
+
+------------------------
+*.ps1		text working-tree-encoding=UTF-16LE eol=CRLF
+------------------------
+
+You can get a list of all available encodings on your platform with the
+following command:
+
+------------------------
+iconv --list
+------------------------
+
+If you do not know the encoding of a file, then you can use the `file`
+command to guess the encoding:
+
+------------------------
+file foo.ps1
+------------------------
+
+
 `ident`
 ^^^^^^^
 
diff --git a/Documentation/gitk.txt b/Documentation/gitk.txt
index ca96c28..244cd01 100644
--- a/Documentation/gitk.txt
+++ b/Documentation/gitk.txt
@@ -8,7 +8,7 @@
 SYNOPSIS
 --------
 [verse]
-'gitk' [<options>] [<revision range>] [\--] [<path>...]
+'gitk' [<options>] [<revision range>] [--] [<path>...]
 
 DESCRIPTION
 -----------
diff --git a/Documentation/gitremote-helpers.txt b/Documentation/gitremote-helpers.txt
index 4b8c93e..9d1459a 100644
--- a/Documentation/gitremote-helpers.txt
+++ b/Documentation/gitremote-helpers.txt
@@ -102,6 +102,14 @@
 +
 Supported commands: 'connect'.
 
+'stateless-connect'::
+	Experimental; for internal use only.
+	Can attempt to connect to a remote server for communication
+	using git's wire-protocol version 2.  See the documentation
+	for the stateless-connect command for more information.
++
+Supported commands: 'stateless-connect'.
+
 'push'::
 	Can discover remote refs and push local commits and the
 	history leading up to them to new or existing remote refs.
@@ -136,6 +144,14 @@
 +
 Supported commands: 'connect'.
 
+'stateless-connect'::
+	Experimental; for internal use only.
+	Can attempt to connect to a remote server for communication
+	using git's wire-protocol version 2.  See the documentation
+	for the stateless-connect command for more information.
++
+Supported commands: 'stateless-connect'.
+
 'fetch'::
 	Can discover remote refs and transfer objects reachable from
 	them to the local object store.
@@ -375,6 +391,22 @@
 +
 Supported if the helper has the "connect" capability.
 
+'stateless-connect' <service>::
+	Experimental; for internal use only.
+	Connects to the given remote service for communication using
+	git's wire-protocol version 2.  Valid replies to this command
+	are empty line (connection established), 'fallback' (no smart
+	transport support, fall back to dumb transports) and just
+	exiting with error message printed (can't connect, don't bother
+	trying to fall back).  After line feed terminating the positive
+	(empty) response, the output of the service starts.  Messages
+	(both request and response) must consist of zero or more
+	PKT-LINEs, terminating in a flush packet. The client must not
+	expect the server to store any state in between request-response
+	pairs.  After the connection ends, the remote helper exits.
++
+Supported if the helper has the "stateless-connect" capability.
+
 If a fatal error occurs, the program writes the error message to
 stderr and exits. The caller should expect that a suitable error
 message has been printed if the child closes the connection without
diff --git a/Documentation/glossary-content.txt b/Documentation/glossary-content.txt
index 6b8888d..6c2d23d 100644
--- a/Documentation/glossary-content.txt
+++ b/Documentation/glossary-content.txt
@@ -463,7 +463,7 @@
 [[def_push]]push::
 	Pushing a <<def_branch,branch>> means to get the branch's
 	<<def_head_ref,head ref>> from a remote <<def_repository,repository>>,
-	find out if it is a direct ancestor to the branch's local
+	find out if it is an ancestor to the branch's local
 	head ref, and in that case, putting all
 	objects, which are <<def_reachable,reachable>> from the local
 	head ref, and which are missing from the remote
diff --git a/Documentation/technical/api-directory-listing.txt b/Documentation/technical/api-directory-listing.txt
index 7fae00f..4f44ca2 100644
--- a/Documentation/technical/api-directory-listing.txt
+++ b/Documentation/technical/api-directory-listing.txt
@@ -53,7 +53,7 @@
 	not be returned even if all of its contents are ignored. In
 	this case, the contents are returned as individual entries.
 +
-If this is set, files and directories that explicity match an ignore
+If this is set, files and directories that explicitly match an ignore
 pattern are reported. Implicity ignored directories (directories that
 do not match an ignore pattern, but whose contents are all ignored)
 are not reported, instead all of the contents are reported.
diff --git a/Documentation/technical/api-object-access.txt b/Documentation/technical/api-object-access.txt
index a1162e5..5b29622 100644
--- a/Documentation/technical/api-object-access.txt
+++ b/Documentation/technical/api-object-access.txt
@@ -1,7 +1,7 @@
 object access API
 =================
 
-Talk about <sha1_file.c> and <object.h> family, things like
+Talk about <sha1-file.c> and <object.h> family, things like
 
 * read_sha1_file()
 * read_object_with_reference()
diff --git a/Documentation/technical/api-submodule-config.txt b/Documentation/technical/api-submodule-config.txt
index ee907c4..fb06089 100644
--- a/Documentation/technical/api-submodule-config.txt
+++ b/Documentation/technical/api-submodule-config.txt
@@ -38,7 +38,7 @@
 Functions
 ---------
 
-`void submodule_free()`::
+`void submodule_free(struct repository *r)`::
 
 	Use these to free the internally cached values.
 
diff --git a/Documentation/technical/commit-graph-format.txt b/Documentation/technical/commit-graph-format.txt
new file mode 100644
index 0000000..ad6af81
--- /dev/null
+++ b/Documentation/technical/commit-graph-format.txt
@@ -0,0 +1,97 @@
+Git commit graph format
+=======================
+
+The Git commit graph stores a list of commit OIDs and some associated
+metadata, including:
+
+- The generation number of the commit. Commits with no parents have
+  generation number 1; commits with parents have generation number
+  one more than the maximum generation number of its parents. We
+  reserve zero as special, and can be used to mark a generation
+  number invalid or as "not computed".
+
+- The root tree OID.
+
+- The commit date.
+
+- The parents of the commit, stored using positional references within
+  the graph file.
+
+These positional references are stored as unsigned 32-bit integers
+corresponding to the array position withing the list of commit OIDs. We
+use the most-significant bit for special purposes, so we can store at most
+(1 << 31) - 1 (around 2 billion) commits.
+
+== Commit graph files have the following format:
+
+In order to allow extensions that add extra data to the graph, we organize
+the body into "chunks" and provide a binary lookup table at the beginning
+of the body. The header includes certain values, such as number of chunks
+and hash type.
+
+All 4-byte numbers are in network order.
+
+HEADER:
+
+  4-byte signature:
+      The signature is: {'C', 'G', 'P', 'H'}
+
+  1-byte version number:
+      Currently, the only valid version is 1.
+
+  1-byte Hash Version (1 = SHA-1)
+      We infer the hash length (H) from this value.
+
+  1-byte number (C) of "chunks"
+
+  1-byte (reserved for later use)
+     Current clients should ignore this value.
+
+CHUNK LOOKUP:
+
+  (C + 1) * 12 bytes listing the table of contents for the chunks:
+      First 4 bytes describe the chunk id. Value 0 is a terminating label.
+      Other 8 bytes provide the byte-offset in current file for chunk to
+      start. (Chunks are ordered contiguously in the file, so you can infer
+      the length using the next chunk position if necessary.) Each chunk
+      ID appears at most once.
+
+  The remaining data in the body is described one chunk at a time, and
+  these chunks may be given in any order. Chunks are required unless
+  otherwise specified.
+
+CHUNK DATA:
+
+  OID Fanout (ID: {'O', 'I', 'D', 'F'}) (256 * 4 bytes)
+      The ith entry, F[i], stores the number of OIDs with first
+      byte at most i. Thus F[255] stores the total
+      number of commits (N).
+
+  OID Lookup (ID: {'O', 'I', 'D', 'L'}) (N * H bytes)
+      The OIDs for all commits in the graph, sorted in ascending order.
+
+  Commit Data (ID: {'C', 'G', 'E', 'T' }) (N * (H + 16) bytes)
+    * The first H bytes are for the OID of the root tree.
+    * The next 8 bytes are for the positions of the first two parents
+      of the ith commit. Stores value 0xffffffff if no parent in that
+      position. If there are more than two parents, the second value
+      has its most-significant bit on and the other bits store an array
+      position into the Large Edge List chunk.
+    * The next 8 bytes store the generation number of the commit and
+      the commit time in seconds since EPOCH. The generation number
+      uses the higher 30 bits of the first 4 bytes, while the commit
+      time uses the 32 bits of the second 4 bytes, along with the lowest
+      2 bits of the lowest byte, storing the 33rd and 34th bit of the
+      commit time.
+
+  Large Edge List (ID: {'E', 'D', 'G', 'E'}) [Optional]
+      This list of 4-byte values store the second through nth parents for
+      all octopus merges. The second parent value in the commit data stores
+      an array position within this list along with the most-significant bit
+      on. Starting at that array position, iterate through this list of commit
+      positions for the parents until reaching a value with the most-significant
+      bit on. The other bits correspond to the position of the last parent.
+
+TRAILER:
+
+	H-byte HASH-checksum of all of the above.
diff --git a/Documentation/technical/commit-graph.txt b/Documentation/technical/commit-graph.txt
new file mode 100644
index 0000000..0550c6d
--- /dev/null
+++ b/Documentation/technical/commit-graph.txt
@@ -0,0 +1,163 @@
+Git Commit Graph Design Notes
+=============================
+
+Git walks the commit graph for many reasons, including:
+
+1. Listing and filtering commit history.
+2. Computing merge bases.
+
+These operations can become slow as the commit count grows. The merge
+base calculation shows up in many user-facing commands, such as 'merge-base'
+or 'status' and can take minutes to compute depending on history shape.
+
+There are two main costs here:
+
+1. Decompressing and parsing commits.
+2. Walking the entire graph to satisfy topological order constraints.
+
+The commit graph file is a supplemental data structure that accelerates
+commit graph walks. If a user downgrades or disables the 'core.commitGraph'
+config setting, then the existing ODB is sufficient. The file is stored
+as "commit-graph" either in the .git/objects/info directory or in the info
+directory of an alternate.
+
+The commit graph file stores the commit graph structure along with some
+extra metadata to speed up graph walks. By listing commit OIDs in lexi-
+cographic order, we can identify an integer position for each commit and
+refer to the parents of a commit using those integer positions. We use
+binary search to find initial commits and then use the integer positions
+for fast lookups during the walk.
+
+A consumer may load the following info for a commit from the graph:
+
+1. The commit OID.
+2. The list of parents, along with their integer position.
+3. The commit date.
+4. The root tree OID.
+5. The generation number (see definition below).
+
+Values 1-4 satisfy the requirements of parse_commit_gently().
+
+Define the "generation number" of a commit recursively as follows:
+
+ * A commit with no parents (a root commit) has generation number one.
+
+ * A commit with at least one parent has generation number one more than
+   the largest generation number among its parents.
+
+Equivalently, the generation number of a commit A is one more than the
+length of a longest path from A to a root commit. The recursive definition
+is easier to use for computation and observing the following property:
+
+    If A and B are commits with generation numbers N and M, respectively,
+    and N <= M, then A cannot reach B. That is, we know without searching
+    that B is not an ancestor of A because it is further from a root commit
+    than A.
+
+    Conversely, when checking if A is an ancestor of B, then we only need
+    to walk commits until all commits on the walk boundary have generation
+    number at most N. If we walk commits using a priority queue seeded by
+    generation numbers, then we always expand the boundary commit with highest
+    generation number and can easily detect the stopping condition.
+
+This property can be used to significantly reduce the time it takes to
+walk commits and determine topological relationships. Without generation
+numbers, the general heuristic is the following:
+
+    If A and B are commits with commit time X and Y, respectively, and
+    X < Y, then A _probably_ cannot reach B.
+
+This heuristic is currently used whenever the computation is allowed to
+violate topological relationships due to clock skew (such as "git log"
+with default order), but is not used when the topological order is
+required (such as merge base calculations, "git log --graph").
+
+In practice, we expect some commits to be created recently and not stored
+in the commit graph. We can treat these commits as having "infinite"
+generation number and walk until reaching commits with known generation
+number.
+
+Design Details
+--------------
+
+- The commit graph file is stored in a file named 'commit-graph' in the
+  .git/objects/info directory. This could be stored in the info directory
+  of an alternate.
+
+- The core.commitGraph config setting must be on to consume graph files.
+
+- The file format includes parameters for the object ID hash function,
+  so a future change of hash algorithm does not require a change in format.
+
+Future Work
+-----------
+
+- The commit graph feature currently does not honor commit grafts. This can
+  be remedied by duplicating or refactoring the current graft logic.
+
+- The 'commit-graph' subcommand does not have a "verify" mode that is
+  necessary for integration with fsck.
+
+- The file format includes room for precomputed generation numbers. These
+  are not currently computed, so all generation numbers will be marked as
+  0 (or "uncomputed"). A later patch will include this calculation.
+
+- After computing and storing generation numbers, we must make graph
+  walks aware of generation numbers to gain the performance benefits they
+  enable. This will mostly be accomplished by swapping a commit-date-ordered
+  priority queue with one ordered by generation number. The following
+  operations are important candidates:
+
+    - paint_down_to_common()
+    - 'log --topo-order'
+
+- Currently, parse_commit_gently() requires filling in the root tree
+  object for a commit. This passes through lookup_tree() and consequently
+  lookup_object(). Also, it calls lookup_commit() when loading the parents.
+  These method calls check the ODB for object existence, even if the
+  consumer does not need the content. For example, we do not need the
+  tree contents when computing merge bases. Now that commit parsing is
+  removed from the computation time, these lookup operations are the
+  slowest operations keeping graph walks from being fast. Consider
+  loading these objects without verifying their existence in the ODB and
+  only loading them fully when consumers need them. Consider a method
+  such as "ensure_tree_loaded(commit)" that fully loads a tree before
+  using commit->tree.
+
+- The current design uses the 'commit-graph' subcommand to generate the graph.
+  When this feature stabilizes enough to recommend to most users, we should
+  add automatic graph writes to common operations that create many commits.
+  For example, one could compute a graph on 'clone', 'fetch', or 'repack'
+  commands.
+
+- A server could provide a commit graph file as part of the network protocol
+  to avoid extra calculations by clients. This feature is only of benefit if
+  the user is willing to trust the file, because verifying the file is correct
+  is as hard as computing it from scratch.
+
+Related Links
+-------------
+[0] https://bugs.chromium.org/p/git/issues/detail?id=8
+    Chromium work item for: Serialized Commit Graph
+
+[1] https://public-inbox.org/git/20110713070517.GC18566@sigill.intra.peff.net/
+    An abandoned patch that introduced generation numbers.
+
+[2] https://public-inbox.org/git/20170908033403.q7e6dj7benasrjes@sigill.intra.peff.net/
+    Discussion about generation numbers on commits and how they interact
+    with fsck.
+
+[3] https://public-inbox.org/git/20170908034739.4op3w4f2ma5s65ku@sigill.intra.peff.net/
+    More discussion about generation numbers and not storing them inside
+    commit objects. A valuable quote:
+
+    "I think we should be moving more in the direction of keeping
+     repo-local caches for optimizations. Reachability bitmaps have been
+     a big performance win. I think we should be doing the same with our
+     properties of commits. Not just generation numbers, but making it
+     cheap to access the graph structure without zlib-inflating whole
+     commit objects (i.e., packv4 or something like the "metapacks" I
+     proposed a few years ago)."
+
+[4] https://public-inbox.org/git/20180108154822.54829-1-git@jeffhostetler.com/T/#u
+    A patch to remove the ahead-behind calculation from 'status'.
diff --git a/Documentation/technical/protocol-v2.txt b/Documentation/technical/protocol-v2.txt
new file mode 100644
index 0000000..136179d
--- /dev/null
+++ b/Documentation/technical/protocol-v2.txt
@@ -0,0 +1,395 @@
+ Git Wire Protocol, Version 2
+==============================
+
+This document presents a specification for a version 2 of Git's wire
+protocol.  Protocol v2 will improve upon v1 in the following ways:
+
+  * Instead of multiple service names, multiple commands will be
+    supported by a single service
+  * Easily extendable as capabilities are moved into their own section
+    of the protocol, no longer being hidden behind a NUL byte and
+    limited by the size of a pkt-line
+  * Separate out other information hidden behind NUL bytes (e.g. agent
+    string as a capability and symrefs can be requested using 'ls-refs')
+  * Reference advertisement will be omitted unless explicitly requested
+  * ls-refs command to explicitly request some refs
+  * Designed with http and stateless-rpc in mind.  With clear flush
+    semantics the http remote helper can simply act as a proxy
+
+In protocol v2 communication is command oriented.  When first contacting a
+server a list of capabilities will advertised.  Some of these capabilities
+will be commands which a client can request be executed.  Once a command
+has completed, a client can reuse the connection and request that other
+commands be executed.
+
+ Packet-Line Framing
+---------------------
+
+All communication is done using packet-line framing, just as in v1.  See
+`Documentation/technical/pack-protocol.txt` and
+`Documentation/technical/protocol-common.txt` for more information.
+
+In protocol v2 these special packets will have the following semantics:
+
+  * '0000' Flush Packet (flush-pkt) - indicates the end of a message
+  * '0001' Delimiter Packet (delim-pkt) - separates sections of a message
+
+ Initial Client Request
+------------------------
+
+In general a client can request to speak protocol v2 by sending
+`version=2` through the respective side-channel for the transport being
+used which inevitably sets `GIT_PROTOCOL`.  More information can be
+found in `pack-protocol.txt` and `http-protocol.txt`.  In all cases the
+response from the server is the capability advertisement.
+
+ Git Transport
+~~~~~~~~~~~~~~~
+
+When using the git:// transport, you can request to use protocol v2 by
+sending "version=2" as an extra parameter:
+
+   003egit-upload-pack /project.git\0host=myserver.com\0\0version=2\0
+
+ SSH and File Transport
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+When using either the ssh:// or file:// transport, the GIT_PROTOCOL
+environment variable must be set explicitly to include "version=2".
+
+ HTTP Transport
+~~~~~~~~~~~~~~~~
+
+When using the http:// or https:// transport a client makes a "smart"
+info/refs request as described in `http-protocol.txt` and requests that
+v2 be used by supplying "version=2" in the `Git-Protocol` header.
+
+   C: Git-Protocol: version=2
+   C:
+   C: GET $GIT_URL/info/refs?service=git-upload-pack HTTP/1.0
+
+A v2 server would reply:
+
+   S: 200 OK
+   S: <Some headers>
+   S: ...
+   S:
+   S: 000eversion 2\n
+   S: <capability-advertisement>
+
+Subsequent requests are then made directly to the service
+`$GIT_URL/git-upload-pack`. (This works the same for git-receive-pack).
+
+ Capability Advertisement
+--------------------------
+
+A server which decides to communicate (based on a request from a client)
+using protocol version 2, notifies the client by sending a version string
+in its initial response followed by an advertisement of its capabilities.
+Each capability is a key with an optional value.  Clients must ignore all
+unknown keys.  Semantics of unknown values are left to the definition of
+each key.  Some capabilities will describe commands which can be requested
+to be executed by the client.
+
+    capability-advertisement = protocol-version
+			       capability-list
+			       flush-pkt
+
+    protocol-version = PKT-LINE("version 2" LF)
+    capability-list = *capability
+    capability = PKT-LINE(key[=value] LF)
+
+    key = 1*(ALPHA | DIGIT | "-_")
+    value = 1*(ALPHA | DIGIT | " -_.,?\/{}[]()<>!@#$%^&*+=:;")
+
+ Command Request
+-----------------
+
+After receiving the capability advertisement, a client can then issue a
+request to select the command it wants with any particular capabilities
+or arguments.  There is then an optional section where the client can
+provide any command specific parameters or queries.  Only a single
+command can be requested at a time.
+
+    request = empty-request | command-request
+    empty-request = flush-pkt
+    command-request = command
+		      capability-list
+		      [command-args]
+		      flush-pkt
+    command = PKT-LINE("command=" key LF)
+    command-args = delim-pkt
+		   *command-specific-arg
+
+    command-specific-args are packet line framed arguments defined by
+    each individual command.
+
+The server will then check to ensure that the client's request is
+comprised of a valid command as well as valid capabilities which were
+advertised.  If the request is valid the server will then execute the
+command.  A server MUST wait till it has received the client's entire
+request before issuing a response.  The format of the response is
+determined by the command being executed, but in all cases a flush-pkt
+indicates the end of the response.
+
+When a command has finished, and the client has received the entire
+response from the server, a client can either request that another
+command be executed or can terminate the connection.  A client may
+optionally send an empty request consisting of just a flush-pkt to
+indicate that no more requests will be made.
+
+ Capabilities
+--------------
+
+There are two different types of capabilities: normal capabilities,
+which can be used to to convey information or alter the behavior of a
+request, and commands, which are the core actions that a client wants to
+perform (fetch, push, etc).
+
+Protocol version 2 is stateless by default.  This means that all commands
+must only last a single round and be stateless from the perspective of the
+server side, unless the client has requested a capability indicating that
+state should be maintained by the server.  Clients MUST NOT require state
+management on the server side in order to function correctly.  This
+permits simple round-robin load-balancing on the server side, without
+needing to worry about state management.
+
+ agent
+~~~~~~~
+
+The server can advertise the `agent` capability with a value `X` (in the
+form `agent=X`) to notify the client that the server is running version
+`X`.  The client may optionally send its own agent string by including
+the `agent` capability with a value `Y` (in the form `agent=Y`) in its
+request to the server (but it MUST NOT do so if the server did not
+advertise the agent capability). The `X` and `Y` strings may contain any
+printable ASCII characters except space (i.e., the byte range 32 < x <
+127), and are typically of the form "package/version" (e.g.,
+"git/1.8.3.1"). The agent strings are purely informative for statistics
+and debugging purposes, and MUST NOT be used to programmatically assume
+the presence or absence of particular features.
+
+ ls-refs
+~~~~~~~~~
+
+`ls-refs` is the command used to request a reference advertisement in v2.
+Unlike the current reference advertisement, ls-refs takes in arguments
+which can be used to limit the refs sent from the server.
+
+Additional features not supported in the base command will be advertised
+as the value of the command in the capability advertisement in the form
+of a space separated list of features: "<command>=<feature 1> <feature 2>"
+
+ls-refs takes in the following arguments:
+
+    symrefs
+	In addition to the object pointed by it, show the underlying ref
+	pointed by it when showing a symbolic ref.
+    peel
+	Show peeled tags.
+    ref-prefix <prefix>
+	When specified, only references having a prefix matching one of
+	the provided prefixes are displayed.
+
+The output of ls-refs is as follows:
+
+    output = *ref
+	     flush-pkt
+    ref = PKT-LINE(obj-id SP refname *(SP ref-attribute) LF)
+    ref-attribute = (symref | peeled)
+    symref = "symref-target:" symref-target
+    peeled = "peeled:" obj-id
+
+ fetch
+~~~~~~~
+
+`fetch` is the command used to fetch a packfile in v2.  It can be looked
+at as a modified version of the v1 fetch where the ref-advertisement is
+stripped out (since the `ls-refs` command fills that role) and the
+message format is tweaked to eliminate redundancies and permit easy
+addition of future extensions.
+
+Additional features not supported in the base command will be advertised
+as the value of the command in the capability advertisement in the form
+of a space separated list of features: "<command>=<feature 1> <feature 2>"
+
+A `fetch` request can take the following arguments:
+
+    want <oid>
+	Indicates to the server an object which the client wants to
+	retrieve.  Wants can be anything and are not limited to
+	advertised objects.
+
+    have <oid>
+	Indicates to the server an object which the client has locally.
+	This allows the server to make a packfile which only contains
+	the objects that the client needs. Multiple 'have' lines can be
+	supplied.
+
+    done
+	Indicates to the server that negotiation should terminate (or
+	not even begin if performing a clone) and that the server should
+	use the information supplied in the request to construct the
+	packfile.
+
+    thin-pack
+	Request that a thin pack be sent, which is a pack with deltas
+	which reference base objects not contained within the pack (but
+	are known to exist at the receiving end). This can reduce the
+	network traffic significantly, but it requires the receiving end
+	to know how to "thicken" these packs by adding the missing bases
+	to the pack.
+
+    no-progress
+	Request that progress information that would normally be sent on
+	side-band channel 2, during the packfile transfer, should not be
+	sent.  However, the side-band channel 3 is still used for error
+	responses.
+
+    include-tag
+	Request that annotated tags should be sent if the objects they
+	point to are being sent.
+
+    ofs-delta
+	Indicate that the client understands PACKv2 with delta referring
+	to its base by position in pack rather than by an oid.  That is,
+	they can read OBJ_OFS_DELTA (ake type 6) in a packfile.
+
+If the 'shallow' feature is advertised the following arguments can be
+included in the clients request as well as the potential addition of the
+'shallow-info' section in the server's response as explained below.
+
+    shallow <oid>
+	A client must notify the server of all commits for which it only
+	has shallow copies (meaning that it doesn't have the parents of
+	a commit) by supplying a 'shallow <oid>' line for each such
+	object so that the server is aware of the limitations of the
+	client's history.  This is so that the server is aware that the
+	client may not have all objects reachable from such commits.
+
+    deepen <depth>
+	Requests that the fetch/clone should be shallow having a commit
+	depth of <depth> relative to the remote side.
+
+    deepen-relative
+	Requests that the semantics of the "deepen" command be changed
+	to indicate that the depth requested is relative to the client's
+	current shallow boundary, instead of relative to the requested
+	commits.
+
+    deepen-since <timestamp>
+	Requests that the shallow clone/fetch should be cut at a
+	specific time, instead of depth.  Internally it's equivalent to
+	doing "git rev-list --max-age=<timestamp>". Cannot be used with
+	"deepen".
+
+    deepen-not <rev>
+	Requests that the shallow clone/fetch should be cut at a
+	specific revision specified by '<rev>', instead of a depth.
+	Internally it's equivalent of doing "git rev-list --not <rev>".
+	Cannot be used with "deepen", but can be used with
+	"deepen-since".
+
+The response of `fetch` is broken into a number of sections separated by
+delimiter packets (0001), with each section beginning with its section
+header.
+
+    output = *section
+    section = (acknowledgments | shallow-info | packfile)
+	      (flush-pkt | delim-pkt)
+
+    acknowledgments = PKT-LINE("acknowledgments" LF)
+		      (nak | *ack)
+		      (ready)
+    ready = PKT-LINE("ready" LF)
+    nak = PKT-LINE("NAK" LF)
+    ack = PKT-LINE("ACK" SP obj-id LF)
+
+    shallow-info = PKT-LINE("shallow-info" LF)
+		   *PKT-LINE((shallow | unshallow) LF)
+    shallow = "shallow" SP obj-id
+    unshallow = "unshallow" SP obj-id
+
+    packfile = PKT-LINE("packfile" LF)
+	       *PKT-LINE(%x01-03 *%x00-ff)
+
+    acknowledgments section
+	* If the client determines that it is finished with negotiations
+	  by sending a "done" line, the acknowledgments sections MUST be
+	  omitted from the server's response.
+
+	* Always begins with the section header "acknowledgments"
+
+	* The server will respond with "NAK" if none of the object ids sent
+	  as have lines were common.
+
+	* The server will respond with "ACK obj-id" for all of the
+	  object ids sent as have lines which are common.
+
+	* A response cannot have both "ACK" lines as well as a "NAK"
+	  line.
+
+	* The server will respond with a "ready" line indicating that
+	  the server has found an acceptable common base and is ready to
+	  make and send a packfile (which will be found in the packfile
+	  section of the same response)
+
+	* If the server has found a suitable cut point and has decided
+	  to send a "ready" line, then the server can decide to (as an
+	  optimization) omit any "ACK" lines it would have sent during
+	  its response.  This is because the server will have already
+	  determined the objects it plans to send to the client and no
+	  further negotiation is needed.
+
+    shallow-info section
+	* If the client has requested a shallow fetch/clone, a shallow
+	  client requests a fetch or the server is shallow then the
+	  server's response may include a shallow-info section.  The
+	  shallow-info section will be included if (due to one of the
+	  above conditions) the server needs to inform the client of any
+	  shallow boundaries or adjustments to the clients already
+	  existing shallow boundaries.
+
+	* Always begins with the section header "shallow-info"
+
+	* If a positive depth is requested, the server will compute the
+	  set of commits which are no deeper than the desired depth.
+
+	* The server sends a "shallow obj-id" line for each commit whose
+	  parents will not be sent in the following packfile.
+
+	* The server sends an "unshallow obj-id" line for each commit
+	  which the client has indicated is shallow, but is no longer
+	  shallow as a result of the fetch (due to its parents being
+	  sent in the following packfile).
+
+	* The server MUST NOT send any "unshallow" lines for anything
+	  which the client has not indicated was shallow as a part of
+	  its request.
+
+	* This section is only included if a packfile section is also
+	  included in the response.
+
+    packfile section
+	* This section is only included if the client has sent 'want'
+	  lines in its request and either requested that no more
+	  negotiation be done by sending 'done' or if the server has
+	  decided it has found a sufficient cut point to produce a
+	  packfile.
+
+	* Always begins with the section header "packfile"
+
+	* The transmission of the packfile begins immediately after the
+	  section header
+
+	* The data transfer of the packfile is always multiplexed, using
+	  the same semantics of the 'side-band-64k' capability from
+	  protocol version 1.  This means that each packet, during the
+	  packfile data stream, is made up of a leading 4-byte pkt-line
+	  length (typical of the pkt-line format), followed by a 1-byte
+	  stream code, followed by the actual data.
+
+	  The stream code can be one of:
+		1 - pack data
+		2 - progress messages
+		3 - fatal error message just before stream aborts
diff --git a/Makefile b/Makefile
index 068a22f..ad880d1 100644
--- a/Makefile
+++ b/Makefile
@@ -464,6 +464,26 @@
 # When using RUNTIME_PREFIX, define HAVE_WPGMPTR if your platform offers
 # the global variable _wpgmptr containing the absolute path of the current
 # executable (this is the case on Windows).
+#
+# Define DEVELOPER to enable more compiler warnings. Compiler version
+# and family are auto detected, but could be overridden by defining
+# COMPILER_FEATURES (see config.mak.dev)
+#
+# When DEVELOPER is set, DEVOPTS can be used to control compiler
+# options.  This variable contains keywords separated by
+# whitespace. The following keywords are are recognized:
+#
+#    no-error:
+#
+#        suppresses the -Werror that implicitly comes with
+#        DEVELOPER=1. Useful for getting the full set of errors
+#        without immediately dying, or for logging them.
+#
+#    extra-all:
+#
+#        The DEVELOPER mode enables -Wextra with a few exceptions. By
+#        setting this flag the exceptions are removed, and all of
+#        -Wextra is used.
 
 GIT-VERSION-FILE: FORCE
 	@$(SHELL_PATH) ./GIT-VERSION-GEN
@@ -472,15 +492,6 @@
 # CFLAGS and LDFLAGS are for the users to override from the command line.
 
 CFLAGS = -g -O2 -Wall
-DEVELOPER_CFLAGS = -Werror \
-	-Wdeclaration-after-statement \
-	-Wno-format-zero-length \
-	-Wold-style-definition \
-	-Woverflow \
-	-Wpointer-arith \
-	-Wstrict-prototypes \
-	-Wunused \
-	-Wvla
 LDFLAGS =
 ALL_CFLAGS = $(CPPFLAGS) $(CFLAGS)
 ALL_LDFLAGS = $(LDFLAGS)
@@ -679,7 +690,6 @@
 PROGRAM_OBJS += sh-i18n--envsubst.o
 PROGRAM_OBJS += shell.o
 PROGRAM_OBJS += show-index.o
-PROGRAM_OBJS += upload-pack.o
 PROGRAM_OBJS += remote-testsvn.o
 
 # Binary suffix, set to .exe for Windows builds
@@ -728,6 +738,7 @@
 TEST_PROGRAMS_NEED_X += test-fake-ssh
 TEST_PROGRAMS_NEED_X += test-line-buffer
 TEST_PROGRAMS_NEED_X += test-parse-options
+TEST_PROGRAMS_NEED_X += test-pkt-line
 TEST_PROGRAMS_NEED_X += test-svn-fe
 TEST_PROGRAMS_NEED_X += test-tool
 
@@ -810,11 +821,13 @@
 LIB_OBJS += bulk-checkin.o
 LIB_OBJS += bundle.o
 LIB_OBJS += cache-tree.o
+LIB_OBJS += chdir-notify.o
 LIB_OBJS += checkout.o
 LIB_OBJS += color.o
 LIB_OBJS += column.o
 LIB_OBJS += combine-diff.o
 LIB_OBJS += commit.o
+LIB_OBJS += commit-graph.o
 LIB_OBJS += compat/obstack.o
 LIB_OBJS += compat/terminal.o
 LIB_OBJS += config.o
@@ -845,7 +858,7 @@
 LIB_OBJS += ewah/ewah_bitmap.o
 LIB_OBJS += ewah/ewah_io.o
 LIB_OBJS += ewah/ewah_rlw.o
-LIB_OBJS += exec_cmd.o
+LIB_OBJS += exec-cmd.o
 LIB_OBJS += fetch-object.o
 LIB_OBJS += fetch-pack.o
 LIB_OBJS += fsck.o
@@ -868,9 +881,11 @@
 LIB_OBJS += ll-merge.o
 LIB_OBJS += lockfile.o
 LIB_OBJS += log-tree.o
+LIB_OBJS += ls-refs.o
 LIB_OBJS += mailinfo.o
 LIB_OBJS += mailmap.o
 LIB_OBJS += match-trees.o
+LIB_OBJS += mem-pool.o
 LIB_OBJS += merge.o
 LIB_OBJS += merge-blobs.o
 LIB_OBJS += merge-recursive.o
@@ -915,7 +930,7 @@
 LIB_OBJS += refs/ref-cache.o
 LIB_OBJS += ref-filter.o
 LIB_OBJS += remote.o
-LIB_OBJS += replace_object.o
+LIB_OBJS += replace-object.o
 LIB_OBJS += repository.o
 LIB_OBJS += rerere.o
 LIB_OBJS += resolve-undo.o
@@ -923,12 +938,13 @@
 LIB_OBJS += run-command.o
 LIB_OBJS += send-pack.o
 LIB_OBJS += sequencer.o
+LIB_OBJS += serve.o
 LIB_OBJS += server-info.o
 LIB_OBJS += setup.o
 LIB_OBJS += sha1-array.o
 LIB_OBJS += sha1-lookup.o
-LIB_OBJS += sha1_file.o
-LIB_OBJS += sha1_name.o
+LIB_OBJS += sha1-file.o
+LIB_OBJS += sha1-name.o
 LIB_OBJS += shallow.o
 LIB_OBJS += sideband.o
 LIB_OBJS += sigchain.o
@@ -951,6 +967,7 @@
 LIB_OBJS += tree.o
 LIB_OBJS += tree-walk.o
 LIB_OBJS += unpack-trees.o
+LIB_OBJS += upload-pack.o
 LIB_OBJS += url.o
 LIB_OBJS += urlmatch.o
 LIB_OBJS += usage.o
@@ -963,7 +980,7 @@
 LIB_OBJS += wildmatch.o
 LIB_OBJS += worktree.o
 LIB_OBJS += wrapper.o
-LIB_OBJS += write_or_die.o
+LIB_OBJS += write-or-die.o
 LIB_OBJS += ws.o
 LIB_OBJS += wt-status.o
 LIB_OBJS += xdiff-interface.o
@@ -990,6 +1007,7 @@
 BUILTIN_OBJS += builtin/column.o
 BUILTIN_OBJS += builtin/commit-tree.o
 BUILTIN_OBJS += builtin/commit.o
+BUILTIN_OBJS += builtin/commit-graph.o
 BUILTIN_OBJS += builtin/config.o
 BUILTIN_OBJS += builtin/count-objects.o
 BUILTIN_OBJS += builtin/credential.o
@@ -1055,6 +1073,7 @@
 BUILTIN_OBJS += builtin/revert.o
 BUILTIN_OBJS += builtin/rm.o
 BUILTIN_OBJS += builtin/send-pack.o
+BUILTIN_OBJS += builtin/serve.o
 BUILTIN_OBJS += builtin/shortlog.o
 BUILTIN_OBJS += builtin/show-branch.o
 BUILTIN_OBJS += builtin/show-ref.o
@@ -1068,6 +1087,7 @@
 BUILTIN_OBJS += builtin/update-ref.o
 BUILTIN_OBJS += builtin/update-server-info.o
 BUILTIN_OBJS += builtin/upload-archive.o
+BUILTIN_OBJS += builtin/upload-pack.o
 BUILTIN_OBJS += builtin/var.o
 BUILTIN_OBJS += builtin/verify-commit.o
 BUILTIN_OBJS += builtin/verify-pack.o
@@ -1089,7 +1109,7 @@
 -include config.mak
 
 ifdef DEVELOPER
-CFLAGS += $(DEVELOPER_CFLAGS)
+include config.mak.dev
 endif
 
 comma := ,
@@ -2108,14 +2128,17 @@
 	INSTLIBDIR_EXTRA='$(PERLLIB_EXTRA_SQ)' && \
 	INSTLIBDIR="$$INSTLIBDIR$${INSTLIBDIR_EXTRA:+:$$INSTLIBDIR_EXTRA}" && \
 	sed -e 's=@@PATHSEP@@=$(pathsep)=g' \
-	    -e 's=@@INSTLIBDIR@@='$$INSTLIBDIR'=g' \
-	    -e 's=@@PERLLIBDIR@@='$(perllibdir_SQ)'=g' \
+	    -e "s=@@INSTLIBDIR@@=$$INSTLIBDIR=g" \
 	    -e 's=@@PERLLIBDIR_REL@@=$(perllibdir_relative_SQ)=g' \
 	    -e 's=@@GITEXECDIR_REL@@=$(gitexecdir_relative_SQ)=g' \
 	    -e 's=@@LOCALEDIR_REL@@=$(localedir_relative_SQ)=g' \
 	    $< >$@+ && \
 	mv $@+ $@
 
+.PHONY: perllibdir
+perllibdir:
+	@echo '$(perllibdir_SQ)'
+
 .PHONY: gitweb
 gitweb:
 	$(QUIET_SUBDIR0)gitweb $(QUIET_SUBDIR1) all
@@ -2256,8 +2279,8 @@
 $(OBJECTS): $(LIB_H)
 endif
 
-exec_cmd.sp exec_cmd.s exec_cmd.o: GIT-PREFIX
-exec_cmd.sp exec_cmd.s exec_cmd.o: EXTRA_CPPFLAGS = \
+exec-cmd.sp exec-cmd.s exec-cmd.o: GIT-PREFIX
+exec-cmd.sp exec-cmd.s exec-cmd.o: EXTRA_CPPFLAGS = \
 	'-DGIT_EXEC_PATH="$(gitexecdir_SQ)"' \
 	'-DGIT_LOCALE_PATH="$(localedir_relative_SQ)"' \
 	'-DBINDIR="$(bindir_relative_SQ)"' \
diff --git a/advice.c b/advice.c
index 406efc1..89fda1d 100644
--- a/advice.c
+++ b/advice.c
@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "config.h"
+#include "color.h"
 
 int advice_push_update_rejected = 1;
 int advice_push_non_ff_current = 1;
@@ -20,6 +21,33 @@
 int advice_ignored_hook = 1;
 int advice_waiting_for_editor = 1;
 
+static int advice_use_color = -1;
+static char advice_colors[][COLOR_MAXLEN] = {
+	GIT_COLOR_RESET,
+	GIT_COLOR_YELLOW,	/* HINT */
+};
+
+enum color_advice {
+	ADVICE_COLOR_RESET = 0,
+	ADVICE_COLOR_HINT = 1,
+};
+
+static int parse_advise_color_slot(const char *slot)
+{
+	if (!strcasecmp(slot, "reset"))
+		return ADVICE_COLOR_RESET;
+	if (!strcasecmp(slot, "hint"))
+		return ADVICE_COLOR_HINT;
+	return -1;
+}
+
+static const char *advise_get_color(enum color_advice ix)
+{
+	if (want_color_stderr(advice_use_color))
+		return advice_colors[ix];
+	return "";
+}
+
 static struct {
 	const char *name;
 	int *preference;
@@ -59,7 +87,10 @@
 
 	for (cp = buf.buf; *cp; cp = np) {
 		np = strchrnul(cp, '\n');
-		fprintf(stderr,	_("hint: %.*s\n"), (int)(np - cp), cp);
+		fprintf(stderr,	_("%shint: %.*s%s\n"),
+			advise_get_color(ADVICE_COLOR_HINT),
+			(int)(np - cp), cp,
+			advise_get_color(ADVICE_COLOR_RESET));
 		if (*np)
 			np++;
 	}
@@ -68,9 +99,23 @@
 
 int git_default_advice_config(const char *var, const char *value)
 {
-	const char *k;
+	const char *k, *slot_name;
 	int i;
 
+	if (!strcmp(var, "color.advice")) {
+		advice_use_color = git_config_colorbool(var, value);
+		return 0;
+	}
+
+	if (skip_prefix(var, "color.advice.", &slot_name)) {
+		int slot = parse_advise_color_slot(slot_name);
+		if (slot < 0)
+			return 0;
+		if (!value)
+			return config_error_nonbool(var);
+		return color_parse(value, advice_colors[slot]);
+	}
+
 	if (!skip_prefix(var, "advice.", &k))
 		return 0;
 
diff --git a/alloc.c b/alloc.c
index 12afadf..cf4f8b6 100644
--- a/alloc.c
+++ b/alloc.c
@@ -93,6 +93,7 @@
 	struct commit *c = alloc_node(&commit_state, sizeof(struct commit));
 	c->object.type = OBJ_COMMIT;
 	c->index = alloc_commit_index();
+	c->graph_pos = COMMIT_NOT_FROM_GRAPH;
 	return c;
 }
 
diff --git a/attr.c b/attr.c
index dfc3a55..03a678f 100644
--- a/attr.c
+++ b/attr.c
@@ -10,7 +10,7 @@
 #define NO_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "attr.h"
 #include "dir.h"
 #include "utf8.h"
diff --git a/builtin.h b/builtin.h
index 42378f3..4e0f647 100644
--- a/builtin.h
+++ b/builtin.h
@@ -149,6 +149,7 @@
 extern int cmd_clean(int argc, const char **argv, const char *prefix);
 extern int cmd_column(int argc, const char **argv, const char *prefix);
 extern int cmd_commit(int argc, const char **argv, const char *prefix);
+extern int cmd_commit_graph(int argc, const char **argv, const char *prefix);
 extern int cmd_commit_tree(int argc, const char **argv, const char *prefix);
 extern int cmd_config(int argc, const char **argv, const char *prefix);
 extern int cmd_count_objects(int argc, const char **argv, const char *prefix);
@@ -215,6 +216,7 @@
 extern int cmd_revert(int argc, const char **argv, const char *prefix);
 extern int cmd_rm(int argc, const char **argv, const char *prefix);
 extern int cmd_send_pack(int argc, const char **argv, const char *prefix);
+extern int cmd_serve(int argc, const char **argv, const char *prefix);
 extern int cmd_shortlog(int argc, const char **argv, const char *prefix);
 extern int cmd_show(int argc, const char **argv, const char *prefix);
 extern int cmd_show_branch(int argc, const char **argv, const char *prefix);
@@ -231,6 +233,7 @@
 extern int cmd_update_server_info(int argc, const char **argv, const char *prefix);
 extern int cmd_upload_archive(int argc, const char **argv, const char *prefix);
 extern int cmd_upload_archive_writer(int argc, const char **argv, const char *prefix);
+extern int cmd_upload_pack(int argc, const char **argv, const char *prefix);
 extern int cmd_var(int argc, const char **argv, const char *prefix);
 extern int cmd_verify_commit(int argc, const char **argv, const char *prefix);
 extern int cmd_verify_tag(int argc, const char **argv, const char *prefix);
diff --git a/builtin/add.c b/builtin/add.c
index 9ef7fb0..c9e2619 100644
--- a/builtin/add.c
+++ b/builtin/add.c
@@ -9,7 +9,7 @@
 #include "lockfile.h"
 #include "dir.h"
 #include "pathspec.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "cache-tree.h"
 #include "run-command.h"
 #include "parse-options.h"
diff --git a/builtin/am.c b/builtin/am.c
index 9c82603..d834f9e 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -6,7 +6,7 @@
 #include "cache.h"
 #include "config.h"
 #include "builtin.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "parse-options.h"
 #include "dir.h"
 #include "run-command.h"
diff --git a/builtin/branch.c b/builtin/branch.c
index 5bd2a0d..efc9ac1 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -391,7 +391,6 @@
 	struct ref_array array;
 	int maxwidth = 0;
 	const char *remote_prefix = "";
-	struct strbuf out = STRBUF_INIT;
 	char *to_free = NULL;
 
 	/*
@@ -419,7 +418,10 @@
 	ref_array_sort(sorting, &array);
 
 	for (i = 0; i < array.nr; i++) {
-		format_ref_array_item(array.items[i], format, &out);
+		struct strbuf out = STRBUF_INIT;
+		struct strbuf err = STRBUF_INIT;
+		if (format_ref_array_item(array.items[i], format, &out, &err))
+			die("%s", err.buf);
 		if (column_active(colopts)) {
 			assert(!filter->verbose && "--column and --verbose are incompatible");
 			 /* format to a string_list to let print_columns() do its job */
@@ -428,6 +430,7 @@
 			fwrite(out.buf, 1, out.len, stdout);
 			putchar('\n');
 		}
+		strbuf_release(&err);
 		strbuf_release(&out);
 	}
 
diff --git a/builtin/clone.c b/builtin/clone.c
index 7df5932..84f1473 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -1135,7 +1135,7 @@
 	if (transport->smart_options && !deepen && !filter_options.choice)
 		transport->smart_options->check_self_contained_and_connected = 1;
 
-	refs = transport_get_remote_refs(transport);
+	refs = transport_get_remote_refs(transport, NULL);
 
 	if (refs) {
 		mapped_refs = wanted_peer_refs(refs, refspec);
diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
new file mode 100644
index 0000000..37420ae
--- /dev/null
+++ b/builtin/commit-graph.c
@@ -0,0 +1,171 @@
+#include "builtin.h"
+#include "config.h"
+#include "dir.h"
+#include "lockfile.h"
+#include "parse-options.h"
+#include "commit-graph.h"
+
+static char const * const builtin_commit_graph_usage[] = {
+	N_("git commit-graph [--object-dir <objdir>]"),
+	N_("git commit-graph read [--object-dir <objdir>]"),
+	N_("git commit-graph write [--object-dir <objdir>] [--append] [--stdin-packs|--stdin-commits]"),
+	NULL
+};
+
+static const char * const builtin_commit_graph_read_usage[] = {
+	N_("git commit-graph read [--object-dir <objdir>]"),
+	NULL
+};
+
+static const char * const builtin_commit_graph_write_usage[] = {
+	N_("git commit-graph write [--object-dir <objdir>] [--append] [--stdin-packs|--stdin-commits]"),
+	NULL
+};
+
+static struct opts_commit_graph {
+	const char *obj_dir;
+	int stdin_packs;
+	int stdin_commits;
+	int append;
+} opts;
+
+static int graph_read(int argc, const char **argv)
+{
+	struct commit_graph *graph = NULL;
+	char *graph_name;
+
+	static struct option builtin_commit_graph_read_options[] = {
+		OPT_STRING(0, "object-dir", &opts.obj_dir,
+			N_("dir"),
+			N_("The object directory to store the graph")),
+		OPT_END(),
+	};
+
+	argc = parse_options(argc, argv, NULL,
+			     builtin_commit_graph_read_options,
+			     builtin_commit_graph_read_usage, 0);
+
+	if (!opts.obj_dir)
+		opts.obj_dir = get_object_directory();
+
+	graph_name = get_commit_graph_filename(opts.obj_dir);
+	graph = load_commit_graph_one(graph_name);
+
+	if (!graph)
+		die("graph file %s does not exist", graph_name);
+	FREE_AND_NULL(graph_name);
+
+	printf("header: %08x %d %d %d %d\n",
+		ntohl(*(uint32_t*)graph->data),
+		*(unsigned char*)(graph->data + 4),
+		*(unsigned char*)(graph->data + 5),
+		*(unsigned char*)(graph->data + 6),
+		*(unsigned char*)(graph->data + 7));
+	printf("num_commits: %u\n", graph->num_commits);
+	printf("chunks:");
+
+	if (graph->chunk_oid_fanout)
+		printf(" oid_fanout");
+	if (graph->chunk_oid_lookup)
+		printf(" oid_lookup");
+	if (graph->chunk_commit_data)
+		printf(" commit_metadata");
+	if (graph->chunk_large_edges)
+		printf(" large_edges");
+	printf("\n");
+
+	return 0;
+}
+
+static int graph_write(int argc, const char **argv)
+{
+	const char **pack_indexes = NULL;
+	int packs_nr = 0;
+	const char **commit_hex = NULL;
+	int commits_nr = 0;
+	const char **lines = NULL;
+	int lines_nr = 0;
+	int lines_alloc = 0;
+
+	static struct option builtin_commit_graph_write_options[] = {
+		OPT_STRING(0, "object-dir", &opts.obj_dir,
+			N_("dir"),
+			N_("The object directory to store the graph")),
+		OPT_BOOL(0, "stdin-packs", &opts.stdin_packs,
+			N_("scan pack-indexes listed by stdin for commits")),
+		OPT_BOOL(0, "stdin-commits", &opts.stdin_commits,
+			N_("start walk at commits listed by stdin")),
+		OPT_BOOL(0, "append", &opts.append,
+			N_("include all commits already in the commit-graph file")),
+		OPT_END(),
+	};
+
+	argc = parse_options(argc, argv, NULL,
+			     builtin_commit_graph_write_options,
+			     builtin_commit_graph_write_usage, 0);
+
+	if (opts.stdin_packs && opts.stdin_commits)
+		die(_("cannot use both --stdin-commits and --stdin-packs"));
+	if (!opts.obj_dir)
+		opts.obj_dir = get_object_directory();
+
+	if (opts.stdin_packs || opts.stdin_commits) {
+		struct strbuf buf = STRBUF_INIT;
+		lines_nr = 0;
+		lines_alloc = 128;
+		ALLOC_ARRAY(lines, lines_alloc);
+
+		while (strbuf_getline(&buf, stdin) != EOF) {
+			ALLOC_GROW(lines, lines_nr + 1, lines_alloc);
+			lines[lines_nr++] = strbuf_detach(&buf, NULL);
+		}
+
+		if (opts.stdin_packs) {
+			pack_indexes = lines;
+			packs_nr = lines_nr;
+		}
+		if (opts.stdin_commits) {
+			commit_hex = lines;
+			commits_nr = lines_nr;
+		}
+	}
+
+	write_commit_graph(opts.obj_dir,
+			   pack_indexes,
+			   packs_nr,
+			   commit_hex,
+			   commits_nr,
+			   opts.append);
+
+	return 0;
+}
+
+int cmd_commit_graph(int argc, const char **argv, const char *prefix)
+{
+	static struct option builtin_commit_graph_options[] = {
+		OPT_STRING(0, "object-dir", &opts.obj_dir,
+			N_("dir"),
+			N_("The object directory to store the graph")),
+		OPT_END(),
+	};
+
+	if (argc == 2 && !strcmp(argv[1], "-h"))
+		usage_with_options(builtin_commit_graph_usage,
+				   builtin_commit_graph_options);
+
+	git_config(git_default_config, NULL);
+	argc = parse_options(argc, argv, prefix,
+			     builtin_commit_graph_options,
+			     builtin_commit_graph_usage,
+			     PARSE_OPT_STOP_AT_NON_OPTION);
+
+	if (argc > 0) {
+		if (!strcmp(argv[0], "read"))
+			return graph_read(argc, argv);
+		if (!strcmp(argv[0], "write"))
+			return graph_write(argc, argv);
+	}
+
+	usage_with_options(builtin_commit_graph_usage,
+			   builtin_commit_graph_options);
+}
diff --git a/builtin/commit.c b/builtin/commit.c
index 37fcb55..5571d4a 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -218,8 +218,7 @@
 
 	if (with_tree) {
 		char *max_prefix = common_prefix(pattern);
-		overlay_tree_on_index(&the_index, with_tree,
-				      max_prefix ? max_prefix : prefix);
+		overlay_tree_on_index(&the_index, with_tree, max_prefix);
 		free(max_prefix);
 	}
 
diff --git a/builtin/config.c b/builtin/config.c
index 01169dd..69e7270 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -25,7 +25,8 @@
 
 static int use_global_config, use_system_config, use_local_config;
 static struct git_config_source given_config_source;
-static int actions, types;
+static int actions, type;
+static char *default_value;
 static int end_null;
 static int respect_includes_opt = -1;
 static struct config_options config_options;
@@ -55,11 +56,68 @@
 #define PAGING_ACTIONS (ACTION_LIST | ACTION_GET_ALL | \
 			ACTION_GET_REGEXP | ACTION_GET_URLMATCH)
 
-#define TYPE_BOOL (1<<0)
-#define TYPE_INT (1<<1)
-#define TYPE_BOOL_OR_INT (1<<2)
-#define TYPE_PATH (1<<3)
-#define TYPE_EXPIRY_DATE (1<<4)
+#define TYPE_BOOL		1
+#define TYPE_INT		2
+#define TYPE_BOOL_OR_INT	3
+#define TYPE_PATH		4
+#define TYPE_EXPIRY_DATE	5
+#define TYPE_COLOR		6
+
+#define OPT_CALLBACK_VALUE(s, l, v, h, i) \
+	{ OPTION_CALLBACK, (s), (l), (v), NULL, (h), PARSE_OPT_NOARG | \
+	PARSE_OPT_NONEG, option_parse_type, (i) }
+
+static struct option builtin_config_options[];
+
+static int option_parse_type(const struct option *opt, const char *arg,
+			     int unset)
+{
+	int new_type, *to_type;
+
+	if (unset) {
+		*((int *) opt->value) = 0;
+		return 0;
+	}
+
+	/*
+	 * To support '--<type>' style flags, begin with new_type equal to
+	 * opt->defval.
+	 */
+	new_type = opt->defval;
+	if (!new_type) {
+		if (!strcmp(arg, "bool"))
+			new_type = TYPE_BOOL;
+		else if (!strcmp(arg, "int"))
+			new_type = TYPE_INT;
+		else if (!strcmp(arg, "bool-or-int"))
+			new_type = TYPE_BOOL_OR_INT;
+		else if (!strcmp(arg, "path"))
+			new_type = TYPE_PATH;
+		else if (!strcmp(arg, "expiry-date"))
+			new_type = TYPE_EXPIRY_DATE;
+		else if (!strcmp(arg, "color"))
+			new_type = TYPE_COLOR;
+		else
+			die(_("unrecognized --type argument, %s"), arg);
+	}
+
+	to_type = opt->value;
+	if (*to_type && *to_type != new_type) {
+		/*
+		 * Complain when there is a new type not equal to the old type.
+		 * This allows for combinations like '--int --type=int' and
+		 * '--type=int --type=int', but disallows ones like '--type=bool
+		 * --int' and '--type=bool
+		 * --type=int'.
+		 */
+		error("only one type at a time.");
+		usage_with_options(builtin_config_usage,
+			builtin_config_options);
+	}
+	*to_type = new_type;
+
+	return 0;
+}
 
 static struct option builtin_config_options[] = {
 	OPT_GROUP(N_("Config file location")),
@@ -84,16 +142,18 @@
 	OPT_BIT(0, "get-color", &actions, N_("find the color configured: slot [default]"), ACTION_GET_COLOR),
 	OPT_BIT(0, "get-colorbool", &actions, N_("find the color setting: slot [stdout-is-tty]"), ACTION_GET_COLORBOOL),
 	OPT_GROUP(N_("Type")),
-	OPT_BIT(0, "bool", &types, N_("value is \"true\" or \"false\""), TYPE_BOOL),
-	OPT_BIT(0, "int", &types, N_("value is decimal number"), TYPE_INT),
-	OPT_BIT(0, "bool-or-int", &types, N_("value is --bool or --int"), TYPE_BOOL_OR_INT),
-	OPT_BIT(0, "path", &types, N_("value is a path (file or directory name)"), TYPE_PATH),
-	OPT_BIT(0, "expiry-date", &types, N_("value is an expiry date"), TYPE_EXPIRY_DATE),
+	OPT_CALLBACK('t', "type", &type, "", N_("value is given this type"), option_parse_type),
+	OPT_CALLBACK_VALUE(0, "bool", &type, N_("value is \"true\" or \"false\""), TYPE_BOOL),
+	OPT_CALLBACK_VALUE(0, "int", &type, N_("value is decimal number"), TYPE_INT),
+	OPT_CALLBACK_VALUE(0, "bool-or-int", &type, N_("value is --bool or --int"), TYPE_BOOL_OR_INT),
+	OPT_CALLBACK_VALUE(0, "path", &type, N_("value is a path (file or directory name)"), TYPE_PATH),
+	OPT_CALLBACK_VALUE(0, "expiry-date", &type, N_("value is an expiry date"), TYPE_EXPIRY_DATE),
 	OPT_GROUP(N_("Other")),
 	OPT_BOOL('z', "null", &end_null, N_("terminate values with NUL byte")),
 	OPT_BOOL(0, "name-only", &omit_values, N_("show variable names only")),
 	OPT_BOOL(0, "includes", &respect_includes_opt, N_("respect include directives on lookup")),
 	OPT_BOOL(0, "show-origin", &show_origin, N_("show origin of config (file, standard input, blob, command line)")),
+	OPT_STRING(0, "default", &default_value, N_("value"), N_("with --get, use default value when missing entry")),
 	OPT_END(),
 };
 
@@ -149,30 +209,35 @@
 		if (show_keys)
 			strbuf_addch(buf, key_delim);
 
-		if (types == TYPE_INT)
+		if (type == TYPE_INT)
 			strbuf_addf(buf, "%"PRId64,
 				    git_config_int64(key_, value_ ? value_ : ""));
-		else if (types == TYPE_BOOL)
+		else if (type == TYPE_BOOL)
 			strbuf_addstr(buf, git_config_bool(key_, value_) ?
 				      "true" : "false");
-		else if (types == TYPE_BOOL_OR_INT) {
+		else if (type == TYPE_BOOL_OR_INT) {
 			int is_bool, v;
 			v = git_config_bool_or_int(key_, value_, &is_bool);
 			if (is_bool)
 				strbuf_addstr(buf, v ? "true" : "false");
 			else
 				strbuf_addf(buf, "%d", v);
-		} else if (types == TYPE_PATH) {
+		} else if (type == TYPE_PATH) {
 			const char *v;
 			if (git_config_pathname(&v, key_, value_) < 0)
 				return -1;
 			strbuf_addstr(buf, v);
 			free((char *)v);
-		} else if (types == TYPE_EXPIRY_DATE) {
+		} else if (type == TYPE_EXPIRY_DATE) {
 			timestamp_t t;
 			if (git_config_expiry_date(&t, key_, value_) < 0)
 				return -1;
 			strbuf_addf(buf, "%"PRItime, t);
+		} else if (type == TYPE_COLOR) {
+			char v[COLOR_MAXLEN];
+			if (git_config_color(v, key_, value_) < 0)
+				return -1;
+			strbuf_addstr(buf, v);
 		} else if (value_) {
 			strbuf_addstr(buf, value_);
 		} else {
@@ -258,6 +323,16 @@
 	config_with_options(collect_config, &values,
 			    &given_config_source, &config_options);
 
+	if (!values.nr && default_value) {
+		struct strbuf *item;
+		ALLOC_GROW(values.items, values.nr + 1, values.alloc);
+		item = &values.items[values.nr++];
+		strbuf_init(item, 0);
+		if (format_config(item, key_, default_value) < 0)
+			die(_("failed to format default config value: %s"),
+				default_value);
+	}
+
 	ret = !values.nr;
 
 	for (i = 0; i < values.nr; i++) {
@@ -287,7 +362,7 @@
 	if (!value)
 		return NULL;
 
-	if (types == 0 || types == TYPE_PATH || types == TYPE_EXPIRY_DATE)
+	if (type == 0 || type == TYPE_PATH || type == TYPE_EXPIRY_DATE)
 		/*
 		 * We don't do normalization for TYPE_PATH here: If
 		 * the path is like ~/foobar/, we prefer to store
@@ -296,11 +371,11 @@
 		 * Also don't do normalization for expiry dates.
 		 */
 		return xstrdup(value);
-	if (types == TYPE_INT)
+	if (type == TYPE_INT)
 		return xstrfmt("%"PRId64, git_config_int64(key, value));
-	if (types == TYPE_BOOL)
+	if (type == TYPE_BOOL)
 		return xstrdup(git_config_bool(key, value) ?  "true" : "false");
-	if (types == TYPE_BOOL_OR_INT) {
+	if (type == TYPE_BOOL_OR_INT) {
 		int is_bool, v;
 		v = git_config_bool_or_int(key, value, &is_bool);
 		if (!is_bool)
@@ -308,8 +383,22 @@
 		else
 			return xstrdup(v ? "true" : "false");
 	}
+	if (type == TYPE_COLOR) {
+		char v[COLOR_MAXLEN];
+		if (git_config_color(v, key, value))
+			die("cannot parse color '%s'", value);
 
-	die("BUG: cannot normalize type %d", types);
+		/*
+		 * The contents of `v` now contain an ANSI escape
+		 * sequence, not suitable for including within a
+		 * configuration file. Treat the above as a
+		 * "sanity-check", and return the given value, which we
+		 * know is representable as valid color code.
+		 */
+		return xstrdup(value);
+	}
+
+	die("BUG: cannot normalize type %d", type);
 }
 
 static int get_color_found;
@@ -566,12 +655,7 @@
 		key_delim = '\n';
 	}
 
-	if (HAS_MULTI_BITS(types)) {
-		error("only one type at a time.");
-		usage_with_options(builtin_config_usage, builtin_config_options);
-	}
-
-	if ((actions & (ACTION_GET_COLOR|ACTION_GET_COLORBOOL)) && types) {
+	if ((actions & (ACTION_GET_COLOR|ACTION_GET_COLORBOOL)) && type) {
 		error("--get-color and variable type are incoherent");
 		usage_with_options(builtin_config_usage, builtin_config_options);
 	}
@@ -601,6 +685,12 @@
 		usage_with_options(builtin_config_usage, builtin_config_options);
 	}
 
+	if (default_value && !(actions & ACTION_GET)) {
+		error("--default is only applicable to --get");
+		usage_with_options(builtin_config_usage,
+			builtin_config_options);
+	}
+
 	if (actions & PAGING_ACTIONS)
 		setup_auto_pager("config", 1);
 
diff --git a/builtin/describe.c b/builtin/describe.c
index de840f9..b5afc45 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -6,7 +6,7 @@
 #include "blob.h"
 #include "refs.h"
 #include "builtin.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "parse-options.h"
 #include "revision.h"
 #include "diff.h"
diff --git a/builtin/difftool.c b/builtin/difftool.c
index ee8dce0..aad0e07 100644
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -15,7 +15,7 @@
 #include "config.h"
 #include "builtin.h"
 #include "run-command.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "parse-options.h"
 #include "argv-array.h"
 #include "strbuf.h"
diff --git a/builtin/fast-export.c b/builtin/fast-export.c
index a15898d..530df12 100644
--- a/builtin/fast-export.c
+++ b/builtin/fast-export.c
@@ -651,8 +651,11 @@
 	struct commit *commit;
 	while (commits->nr) {
 		commit = (struct commit *)object_array_pop(commits);
-		if (has_unshown_parent(commit))
+		if (has_unshown_parent(commit)) {
+			/* Queue again, to be handled later */
+			add_object_array(&commit->object, NULL, commits);
 			return;
+		}
 		handle_commit(commit, revs, paths_of_changed_objects);
 	}
 }
diff --git a/builtin/fetch-pack.c b/builtin/fetch-pack.c
index a7bc136..1a1bc63 100644
--- a/builtin/fetch-pack.c
+++ b/builtin/fetch-pack.c
@@ -4,6 +4,7 @@
 #include "remote.h"
 #include "connect.h"
 #include "sha1-array.h"
+#include "protocol.h"
 
 static const char fetch_pack_usage[] =
 "git fetch-pack [--all] [--stdin] [--quiet | -q] [--keep | -k] [--thin] "
@@ -52,6 +53,7 @@
 	struct fetch_pack_args args;
 	struct oid_array shallow = OID_ARRAY_INIT;
 	struct string_list deepen_not = STRING_LIST_INIT_DUP;
+	struct packet_reader reader;
 
 	fetch_if_missing = 0;
 
@@ -211,10 +213,24 @@
 		if (!conn)
 			return args.diag_url ? 0 : 1;
 	}
-	get_remote_heads(fd[0], NULL, 0, &ref, 0, NULL, &shallow);
+
+	packet_reader_init(&reader, fd[0], NULL, 0,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_GENTLE_ON_EOF);
+
+	switch (discover_version(&reader)) {
+	case protocol_v2:
+		die("support for protocol v2 not implemented yet");
+	case protocol_v1:
+	case protocol_v0:
+		get_remote_heads(&reader, &ref, 0, NULL, &shallow);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
 
 	ref = fetch_pack(&args, fd, conn, ref, dest, sought, nr_sought,
-			 &shallow, pack_lockfile_ptr);
+			 &shallow, pack_lockfile_ptr, protocol_v0);
 	if (pack_lockfile) {
 		printf("lock %s\n", pack_lockfile);
 		fflush(stdout);
diff --git a/builtin/fetch.c b/builtin/fetch.c
index dcdfc66..7ee83ac 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -264,7 +264,7 @@
 	struct string_list_item *item = NULL;
 
 	for_each_ref(add_existing, &existing_refs);
-	for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
+	for (ref = transport_get_remote_refs(transport, NULL); ref; ref = ref->next) {
 		if (!starts_with(ref->name, "refs/tags/"))
 			continue;
 
@@ -346,11 +346,28 @@
 	struct ref *rm;
 	struct ref *ref_map = NULL;
 	struct ref **tail = &ref_map;
+	struct argv_array ref_prefixes = ARGV_ARRAY_INIT;
 
 	/* opportunistically-updated references: */
 	struct ref *orefs = NULL, **oref_tail = &orefs;
 
-	const struct ref *remote_refs = transport_get_remote_refs(transport);
+	const struct ref *remote_refs;
+
+	for (i = 0; i < refspec_count; i++) {
+		if (!refspecs[i].exact_sha1) {
+			const char *glob = strchr(refspecs[i].src, '*');
+			if (glob)
+				argv_array_pushf(&ref_prefixes, "%.*s",
+						 (int)(glob - refspecs[i].src),
+						 refspecs[i].src);
+			else
+				expand_ref_prefix(&ref_prefixes, refspecs[i].src);
+		}
+	}
+
+	remote_refs = transport_get_remote_refs(transport, &ref_prefixes);
+
+	argv_array_clear(&ref_prefixes);
 
 	if (refspec_count) {
 		struct refspec *fetch_refspec;
diff --git a/builtin/gc.c b/builtin/gc.c
index 3e67124..d604940 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -354,6 +354,7 @@
 	const char *name;
 	pid_t pid;
 	int daemonized = 0;
+	timestamp_t dummy;
 
 	struct option builtin_gc_options[] = {
 		OPT__QUIET(&quiet, N_("suppress progress reporting")),
@@ -382,7 +383,7 @@
 	/* default expiry time, overwritten in gc_config */
 	gc_config();
 	if (parse_expiry_date(gc_log_expire, &gc_log_expire_time))
-		die(_("Failed to parse gc.logexpiry value %s"), gc_log_expire);
+		die(_("failed to parse gc.logexpiry value %s"), gc_log_expire);
 
 	if (pack_refs < 0)
 		pack_refs = !is_bare_repository();
@@ -392,6 +393,9 @@
 	if (argc > 0)
 		usage_with_options(builtin_gc_usage, builtin_gc_options);
 
+	if (prune_expire && parse_expiry_date(prune_expire, &dummy))
+		die(_("failed to parse prune expiry value %s"), prune_expire);
+
 	if (aggressive) {
 		argv_array_push(&repack, "-f");
 		if (aggressive_depth > 0)
diff --git a/builtin/grep.c b/builtin/grep.c
index 5f32d2c..6e7bc76 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -602,8 +602,7 @@
 }
 
 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
-		       struct object *obj, const char *name, const char *path,
-		       struct repository *repo)
+		       struct object *obj, const char *name, const char *path)
 {
 	if (obj->type == OBJ_BLOB)
 		return grep_oid(opt, &obj->oid, name, 0, path);
@@ -630,7 +629,7 @@
 		}
 		init_tree_desc(&tree, data, size);
 		hit = grep_tree(opt, pathspec, &tree, &base, base.len,
-				obj->type == OBJ_COMMIT, repo);
+				obj->type == OBJ_COMMIT, the_repository);
 		strbuf_release(&base);
 		free(data);
 		return hit;
@@ -639,7 +638,6 @@
 }
 
 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
-			struct repository *repo,
 			const struct object_array *list)
 {
 	unsigned int i;
@@ -652,11 +650,11 @@
 
 		/* load the gitmodules file for this rev */
 		if (recurse_submodules) {
-			submodule_free();
+			submodule_free(the_repository);
 			gitmodules_config_oid(&real_obj->oid);
 		}
-		if (grep_object(opt, pathspec, real_obj, list->objects[i].name, list->objects[i].path,
-				repo)) {
+		if (grep_object(opt, pathspec, real_obj, list->objects[i].name,
+				list->objects[i].path)) {
 			hit = 1;
 			if (opt->status_only)
 				break;
@@ -1108,7 +1106,7 @@
 		if (cached)
 			die(_("both --cached and trees are given."));
 
-		hit = grep_objects(&opt, &pathspec, the_repository, &list);
+		hit = grep_objects(&opt, &pathspec, &list);
 	}
 
 	if (num_threads)
diff --git a/builtin/hash-object.c b/builtin/hash-object.c
index 526da5c..a9a3a19 100644
--- a/builtin/hash-object.c
+++ b/builtin/hash-object.c
@@ -9,7 +9,7 @@
 #include "blob.h"
 #include "quote.h"
 #include "parse-options.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 
 /*
  * This is to create corrupt objects for debugging and as such it
diff --git a/builtin/help.c b/builtin/help.c
index 598867c..2d51071 100644
--- a/builtin/help.c
+++ b/builtin/help.c
@@ -4,7 +4,7 @@
 #include "cache.h"
 #include "config.h"
 #include "builtin.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "parse-options.h"
 #include "run-command.h"
 #include "column.h"
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index d81473e..a2cd29d 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -9,7 +9,7 @@
 #include "tree.h"
 #include "progress.h"
 #include "fsck.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "streaming.h"
 #include "thread-utils.h"
 #include "packfile.h"
@@ -1271,7 +1271,7 @@
 			    nr_objects - nr_objects_initial);
 		stop_progress_msg(&progress, msg.buf);
 		strbuf_release(&msg);
-		hashclose(f, tail_hash, 0);
+		finalize_hashfile(f, tail_hash, 0);
 		hashcpy(read_hash, pack_hash);
 		fixup_pack_header_footer(output_fd, pack_hash,
 					 curr_pack, nr_objects,
@@ -1593,7 +1593,7 @@
 	/*
 	 * Get rid of the idx file as we do not need it anymore.
 	 * NEEDSWORK: extract this bit from free_pack_by_name() in
-	 * sha1_file.c, perhaps?  It shouldn't matter very much as we
+	 * sha1-file.c, perhaps?  It shouldn't matter very much as we
 	 * know we haven't installed this pack (hence we never have
 	 * read anything from it).
 	 */
diff --git a/builtin/init-db.c b/builtin/init-db.c
index 68ff4ad..2542c52 100644
--- a/builtin/init-db.c
+++ b/builtin/init-db.c
@@ -7,7 +7,7 @@
 #include "config.h"
 #include "refs.h"
 #include "builtin.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "parse-options.h"
 
 #ifndef DEFAULT_GIT_TEMPLATE_DIR
diff --git a/builtin/ls-remote.c b/builtin/ls-remote.c
index 540d564..ca3f04a 100644
--- a/builtin/ls-remote.c
+++ b/builtin/ls-remote.c
@@ -1,7 +1,9 @@
 #include "builtin.h"
 #include "cache.h"
 #include "transport.h"
+#include "ref-filter.h"
 #include "remote.h"
+#include "refs.h"
 
 static const char * const ls_remote_usage[] = {
 	N_("git ls-remote [--heads] [--tags] [--refs] [--upload-pack=<exec>]\n"
@@ -43,10 +45,14 @@
 	int show_symref_target = 0;
 	const char *uploadpack = NULL;
 	const char **pattern = NULL;
+	struct argv_array ref_prefixes = ARGV_ARRAY_INIT;
+	int i;
 
 	struct remote *remote;
 	struct transport *transport;
 	const struct ref *ref;
+	struct ref_array ref_array;
+	static struct ref_sorting *sorting = NULL, **sorting_tail = &sorting;
 
 	struct option options[] = {
 		OPT__QUIET(&quiet, N_("do not print remote URL")),
@@ -60,6 +66,8 @@
 		OPT_BIT(0, "refs", &flags, N_("do not show peeled tags"), REF_NORMAL),
 		OPT_BOOL(0, "get-url", &get_url,
 			 N_("take url.<base>.insteadOf into account")),
+		OPT_CALLBACK(0 , "sort", sorting_tail, N_("key"),
+			     N_("field name to sort on"), &parse_opt_ref_sorting),
 		OPT_SET_INT_F(0, "exit-code", &status,
 			      N_("exit with exit code 2 if no matching refs are found"),
 			      2, PARSE_OPT_NOCOMPLETE),
@@ -68,6 +76,8 @@
 		OPT_END()
 	};
 
+	memset(&ref_array, 0, sizeof(ref_array));
+
 	argc = parse_options(argc, argv, prefix, options, ls_remote_usage,
 			     PARSE_OPT_STOP_AT_NON_OPTION);
 	dest = argv[0];
@@ -75,8 +85,17 @@
 	if (argc > 1) {
 		int i;
 		pattern = xcalloc(argc, sizeof(const char *));
-		for (i = 1; i < argc; i++)
+		for (i = 1; i < argc; i++) {
+			const char *glob;
 			pattern[i - 1] = xstrfmt("*/%s", argv[i]);
+
+			glob = strchr(argv[i], '*');
+			if (glob)
+				argv_array_pushf(&ref_prefixes, "%.*s",
+						 (int)(glob - argv[i]), argv[i]);
+			else
+				expand_ref_prefix(&ref_prefixes, argv[i]);
+		}
 	}
 
 	remote = remote_get(dest);
@@ -90,6 +109,7 @@
 
 	if (get_url) {
 		printf("%s\n", *remote->url);
+		UNLEAK(sorting);
 		return 0;
 	}
 
@@ -97,21 +117,36 @@
 	if (uploadpack != NULL)
 		transport_set_option(transport, TRANS_OPT_UPLOADPACK, uploadpack);
 
-	ref = transport_get_remote_refs(transport);
-	if (transport_disconnect(transport))
+	ref = transport_get_remote_refs(transport, &ref_prefixes);
+	if (transport_disconnect(transport)) {
+		UNLEAK(sorting);
 		return 1;
+	}
 
 	if (!dest && !quiet)
 		fprintf(stderr, "From %s\n", *remote->url);
 	for ( ; ref; ref = ref->next) {
+		struct ref_array_item *item;
 		if (!check_ref_type(ref, flags))
 			continue;
 		if (!tail_match(pattern, ref->name))
 			continue;
+		item = ref_array_push(&ref_array, ref->name, &ref->old_oid);
+		item->symref = xstrdup_or_null(ref->symref);
+	}
+
+	if (sorting)
+		ref_array_sort(sorting, &ref_array);
+
+	for (i = 0; i < ref_array.nr; i++) {
+		const struct ref_array_item *ref = ref_array.items[i];
 		if (show_symref_target && ref->symref)
-			printf("ref: %s\t%s\n", ref->symref, ref->name);
-		printf("%s\t%s\n", oid_to_hex(&ref->old_oid), ref->name);
+			printf("ref: %s\t%s\n", ref->symref, ref->refname);
+		printf("%s\t%s\n", oid_to_hex(&ref->objectname), ref->refname);
 		status = 0; /* we found something */
 	}
+
+	UNLEAK(sorting);
+	UNLEAK(ref_array);
 	return status;
 }
diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index 32736e0..bf01e05 100644
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -2,7 +2,7 @@
 #include "tree-walk.h"
 #include "xdiff-interface.h"
 #include "blob.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "merge-blobs.h"
 
 static const char merge_tree_usage[] = "git merge-tree <base-tree> <branch1> <branch2>";
diff --git a/builtin/mktag.c b/builtin/mktag.c
index 9f5a50a..82a6e86 100644
--- a/builtin/mktag.c
+++ b/builtin/mktag.c
@@ -1,5 +1,6 @@
 #include "builtin.h"
 #include "tag.h"
+#include "replace-object.h"
 
 /*
  * A signature file has a very simple fixed format: four lines
@@ -24,7 +25,7 @@
 	enum object_type type;
 	unsigned long size;
 	void *buffer = read_object_file(oid, &type, &size);
-	const struct object_id *repl = lookup_replace_object(oid);
+	const struct object_id *repl = lookup_replace_object(the_repository, oid);
 
 	if (buffer) {
 		if (type == type_from_string(expected_type))
diff --git a/builtin/mv.c b/builtin/mv.c
index 6d141f7..7a63667 100644
--- a/builtin/mv.c
+++ b/builtin/mv.c
@@ -276,10 +276,12 @@
 			die_errno(_("renaming '%s' failed"), src);
 		}
 		if (submodule_gitfile[i]) {
-			if (submodule_gitfile[i] != SUBMODULE_WITH_GITDIR)
-				connect_work_tree_and_git_dir(dst, submodule_gitfile[i]);
 			if (!update_path_in_gitmodules(src, dst))
 				gitmodules_modified = 1;
+			if (submodule_gitfile[i] != SUBMODULE_WITH_GITDIR)
+				connect_work_tree_and_git_dir(dst,
+							      submodule_gitfile[i],
+							      1);
 		}
 
 		if (mode == WORKING_DIRECTORY)
diff --git a/builtin/notes.c b/builtin/notes.c
index 921e08d..e5bf80e 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -14,7 +14,7 @@
 #include "blob.h"
 #include "pretty.h"
 #include "refs.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "run-command.h"
 #include "parse-options.h"
 #include "string-list.h"
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 4bdae5a..24b1c6c 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -837,11 +837,11 @@
 		 * If so, rewrite it like in fast-import
 		 */
 		if (pack_to_stdout) {
-			hashclose(f, oid.hash, CSUM_CLOSE);
+			finalize_hashfile(f, oid.hash, CSUM_HASH_IN_STREAM | CSUM_CLOSE);
 		} else if (nr_written == nr_remaining) {
-			hashclose(f, oid.hash, CSUM_FSYNC);
+			finalize_hashfile(f, oid.hash, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE);
 		} else {
-			int fd = hashclose(f, oid.hash, 0);
+			int fd = finalize_hashfile(f, oid.hash, 0);
 			fixup_pack_header_footer(fd, oid.hash, pack_tmp_name,
 						 nr_written, oid.hash, offset);
 			close(fd);
diff --git a/builtin/pack-refs.c b/builtin/pack-refs.c
index b106a39..f335356 100644
--- a/builtin/pack-refs.c
+++ b/builtin/pack-refs.c
@@ -1,6 +1,7 @@
 #include "builtin.h"
 #include "parse-options.h"
 #include "refs.h"
+#include "repository.h"
 
 static char const * const pack_refs_usage[] = {
 	N_("git pack-refs [<options>]"),
@@ -17,5 +18,5 @@
 	};
 	if (parse_options(argc, argv, prefix, opts, pack_refs_usage, 0))
 		usage_with_options(pack_refs_usage, opts);
-	return refs_pack_refs(get_main_ref_store(), flags);
+	return refs_pack_refs(get_main_ref_store(the_repository), flags);
 }
diff --git a/builtin/pull.c b/builtin/pull.c
index e32d6cd..71aac50 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -9,7 +9,7 @@
 #include "config.h"
 #include "builtin.h"
 #include "parse-options.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "run-command.h"
 #include "sha1-array.h"
 #include "remote.h"
diff --git a/builtin/push.c b/builtin/push.c
index 013c20d..ac37053 100644
--- a/builtin/push.c
+++ b/builtin/push.c
@@ -12,12 +12,40 @@
 #include "submodule.h"
 #include "submodule-config.h"
 #include "send-pack.h"
+#include "color.h"
 
 static const char * const push_usage[] = {
 	N_("git push [<options>] [<repository> [<refspec>...]]"),
 	NULL,
 };
 
+static int push_use_color = -1;
+static char push_colors[][COLOR_MAXLEN] = {
+	GIT_COLOR_RESET,
+	GIT_COLOR_RED,	/* ERROR */
+};
+
+enum color_push {
+	PUSH_COLOR_RESET = 0,
+	PUSH_COLOR_ERROR = 1
+};
+
+static int parse_push_color_slot(const char *slot)
+{
+	if (!strcasecmp(slot, "reset"))
+		return PUSH_COLOR_RESET;
+	if (!strcasecmp(slot, "error"))
+		return PUSH_COLOR_ERROR;
+	return -1;
+}
+
+static const char *push_get_color(enum color_push ix)
+{
+	if (want_color_stderr(push_use_color))
+		return push_colors[ix];
+	return "";
+}
+
 static int thin = 1;
 static int deleterefs;
 static const char *receivepack;
@@ -337,8 +365,11 @@
 		fprintf(stderr, _("Pushing to %s\n"), transport->url);
 	err = transport_push(transport, refspec_nr, refspec, flags,
 			     &reject_reasons);
-	if (err != 0)
+	if (err != 0) {
+		fprintf(stderr, "%s", push_get_color(PUSH_COLOR_ERROR));
 		error(_("failed to push some refs to '%s'"), transport->url);
+		fprintf(stderr, "%s", push_get_color(PUSH_COLOR_RESET));
+	}
 
 	err |= transport_disconnect(transport);
 	if (!err)
@@ -467,6 +498,7 @@
 
 static int git_push_config(const char *k, const char *v, void *cb)
 {
+	const char *slot_name;
 	int *flags = cb;
 	int status;
 
@@ -514,6 +546,16 @@
 			else
 				string_list_append(&push_options_config, v);
 		return 0;
+	} else if (!strcmp(k, "color.push")) {
+		push_use_color = git_config_colorbool(k, v);
+		return 0;
+	} else if (skip_prefix(k, "color.push.", &slot_name)) {
+		int slot = parse_push_color_slot(slot_name);
+		if (slot < 0)
+			return 0;
+		if (!v)
+			return config_error_nonbool(k);
+		return color_parse(v, push_colors[slot]);
 	}
 
 	return git_default_config(k, v, NULL);
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index c4272fb..0dd1632 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -7,7 +7,7 @@
 #include "pkt-line.h"
 #include "sideband.h"
 #include "run-command.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "commit.h"
 #include "object.h"
 #include "remote.h"
@@ -1965,6 +1965,12 @@
 		unpack_limit = receive_unpack_limit;
 
 	switch (determine_protocol_version_server()) {
+	case protocol_v2:
+		/*
+		 * push support for protocol v2 has not been implemented yet,
+		 * so ignore the request to use v2 and fallback to using v0.
+		 */
+		break;
 	case protocol_v1:
 		/*
 		 * v1 is just the original protocol with a version string,
diff --git a/builtin/remote.c b/builtin/remote.c
index 805ffc0..8708e58 100644
--- a/builtin/remote.c
+++ b/builtin/remote.c
@@ -862,7 +862,7 @@
 	if (query) {
 		transport = transport_get(states->remote, states->remote->url_nr > 0 ?
 			states->remote->url[0] : NULL);
-		remote_refs = transport_get_remote_refs(transport);
+		remote_refs = transport_get_remote_refs(transport, NULL);
 		transport_disconnect(transport);
 
 		states->queried = 1;
diff --git a/builtin/replace.c b/builtin/replace.c
index 935647b..237ea65 100644
--- a/builtin/replace.c
+++ b/builtin/replace.c
@@ -14,6 +14,8 @@
 #include "refs.h"
 #include "parse-options.h"
 #include "run-command.h"
+#include "object-store.h"
+#include "repository.h"
 #include "tag.h"
 
 static const char * const git_replace_usage[] = {
@@ -83,7 +85,7 @@
 		    "valid formats are 'short', 'medium' and 'long'\n",
 		    format);
 
-	for_each_replace_ref(show_reference, (void *)&data);
+	for_each_replace_ref(the_repository, show_reference, (void *)&data);
 
 	return 0;
 }
diff --git a/builtin/send-pack.c b/builtin/send-pack.c
index fc4f0bb..b5427f7 100644
--- a/builtin/send-pack.c
+++ b/builtin/send-pack.c
@@ -14,6 +14,7 @@
 #include "sha1-array.h"
 #include "gpg-interface.h"
 #include "gettext.h"
+#include "protocol.h"
 
 static const char * const send_pack_usage[] = {
 	N_("git send-pack [--all | --mirror] [--dry-run] [--force] "
@@ -154,6 +155,7 @@
 	int progress = -1;
 	int from_stdin = 0;
 	struct push_cas_option cas = {0};
+	struct packet_reader reader;
 
 	struct option options[] = {
 		OPT__VERBOSITY(&verbose),
@@ -256,8 +258,22 @@
 			args.verbose ? CONNECT_VERBOSE : 0);
 	}
 
-	get_remote_heads(fd[0], NULL, 0, &remote_refs, REF_NORMAL,
-			 &extra_have, &shallow);
+	packet_reader_init(&reader, fd[0], NULL, 0,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_GENTLE_ON_EOF);
+
+	switch (discover_version(&reader)) {
+	case protocol_v2:
+		die("support for protocol v2 not implemented yet");
+		break;
+	case protocol_v1:
+	case protocol_v0:
+		get_remote_heads(&reader, &remote_refs, REF_NORMAL,
+				 &extra_have, &shallow);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
 
 	transport_verify_remote_names(nr_refspecs, refspecs);
 
diff --git a/builtin/serve.c b/builtin/serve.c
new file mode 100644
index 0000000..d3fd240
--- /dev/null
+++ b/builtin/serve.c
@@ -0,0 +1,30 @@
+#include "cache.h"
+#include "builtin.h"
+#include "parse-options.h"
+#include "serve.h"
+
+static char const * const serve_usage[] = {
+	N_("git serve [<options>]"),
+	NULL
+};
+
+int cmd_serve(int argc, const char **argv, const char *prefix)
+{
+	struct serve_options opts = SERVE_OPTIONS_INIT;
+
+	struct option options[] = {
+		OPT_BOOL(0, "stateless-rpc", &opts.stateless_rpc,
+			 N_("quit after a single request/response exchange")),
+		OPT_BOOL(0, "advertise-capabilities", &opts.advertise_capabilities,
+			 N_("exit immediately after advertising capabilities")),
+		OPT_END()
+	};
+
+	/* ignore all unknown cmdline switches for now */
+	argc = parse_options(argc, argv, prefix, options, serve_usage,
+			     PARSE_OPT_KEEP_DASHDASH |
+			     PARSE_OPT_KEEP_UNKNOWN);
+	serve(&opts);
+
+	return 0;
+}
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index a404df3..c2403a9 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -455,7 +455,7 @@
 
 	displaypath = get_submodule_displaypath(path, prefix);
 
-	sub = submodule_from_path(&null_oid, path);
+	sub = submodule_from_path(the_repository, &null_oid, path);
 
 	if (!sub)
 		die(_("No url found for submodule path '%s' in .gitmodules"),
@@ -596,8 +596,12 @@
 
 	printf("%c%s %s", state, oid_to_hex(oid), displaypath);
 
-	if (state == ' ' || state == '+')
-		printf(" (%s)", compute_rev_name(path, oid_to_hex(oid)));
+	if (state == ' ' || state == '+') {
+		const char *name = compute_rev_name(path, oid_to_hex(oid));
+
+		if (name)
+			printf(" (%s)", name);
+	}
 
 	printf("\n");
 }
@@ -622,7 +626,7 @@
 	struct rev_info rev;
 	int diff_files_result;
 
-	if (!submodule_from_path(&null_oid, path))
+	if (!submodule_from_path(the_repository, &null_oid, path))
 		die(_("no submodule mapping found in .gitmodules for path '%s'"),
 		      path);
 
@@ -746,7 +750,7 @@
 	if (argc != 2)
 		usage(_("git submodule--helper name <path>"));
 
-	sub = submodule_from_path(&null_oid, argv[1]);
+	sub = submodule_from_path(the_repository, &null_oid, argv[1]);
 
 	if (!sub)
 		die(_("no submodule mapping found in .gitmodules for path '%s'"),
@@ -777,7 +781,7 @@
 	if (!is_submodule_active(the_repository, path))
 		return;
 
-	sub = submodule_from_path(&null_oid, path);
+	sub = submodule_from_path(the_repository, &null_oid, path);
 
 	if (sub && sub->url) {
 		if (starts_with_dot_dot_slash(sub->url) ||
@@ -930,7 +934,7 @@
 	struct strbuf sb_config = STRBUF_INIT;
 	char *sub_git_dir = xstrfmt("%s/.git", path);
 
-	sub = submodule_from_path(&null_oid, path);
+	sub = submodule_from_path(the_repository, &null_oid, path);
 
 	if (!sub || !sub->name)
 		goto cleanup;
@@ -1264,8 +1268,7 @@
 		strbuf_reset(&sb);
 	}
 
-	/* Connect module worktree and git dir */
-	connect_work_tree_and_git_dir(path, sm_gitdir);
+	connect_work_tree_and_git_dir(path, sm_gitdir, 0);
 
 	p = git_pathdup_submodule(path, "config");
 	if (!p)
@@ -1372,7 +1375,7 @@
 		goto cleanup;
 	}
 
-	sub = submodule_from_path(&null_oid, ce->name);
+	sub = submodule_from_path(the_repository, &null_oid, ce->name);
 
 	if (suc->recursive_prefix)
 		displaypath = relative_path(suc->recursive_prefix,
@@ -1655,7 +1658,7 @@
 	const char *branch = NULL;
 	char *key;
 
-	sub = submodule_from_path(&null_oid, path);
+	sub = submodule_from_path(the_repository, &null_oid, path);
 	if (!sub)
 		return NULL;
 
diff --git a/builtin/tag.c b/builtin/tag.c
index 8cff6d0..46a5c6a 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -118,7 +118,7 @@
 		return -1;
 
 	if (format->format)
-		pretty_print_ref(name, oid->hash, format);
+		pretty_print_ref(name, oid, format);
 
 	return 0;
 }
diff --git a/builtin/upload-pack.c b/builtin/upload-pack.c
new file mode 100644
index 0000000..decde5a
--- /dev/null
+++ b/builtin/upload-pack.c
@@ -0,0 +1,74 @@
+#include "cache.h"
+#include "builtin.h"
+#include "exec-cmd.h"
+#include "pkt-line.h"
+#include "parse-options.h"
+#include "protocol.h"
+#include "upload-pack.h"
+#include "serve.h"
+
+static const char * const upload_pack_usage[] = {
+	N_("git upload-pack [<options>] <dir>"),
+	NULL
+};
+
+int cmd_upload_pack(int argc, const char **argv, const char *prefix)
+{
+	const char *dir;
+	int strict = 0;
+	struct upload_pack_options opts = { 0 };
+	struct serve_options serve_opts = SERVE_OPTIONS_INIT;
+	struct option options[] = {
+		OPT_BOOL(0, "stateless-rpc", &opts.stateless_rpc,
+			 N_("quit after a single request/response exchange")),
+		OPT_BOOL(0, "advertise-refs", &opts.advertise_refs,
+			 N_("exit immediately after initial ref advertisement")),
+		OPT_BOOL(0, "strict", &strict,
+			 N_("do not try <directory>/.git/ if <directory> is no Git directory")),
+		OPT_INTEGER(0, "timeout", &opts.timeout,
+			    N_("interrupt transfer after <n> seconds of inactivity")),
+		OPT_END()
+	};
+
+	packet_trace_identity("upload-pack");
+	check_replace_refs = 0;
+
+	argc = parse_options(argc, argv, NULL, options, upload_pack_usage, 0);
+
+	if (argc != 1)
+		usage_with_options(upload_pack_usage, options);
+
+	if (opts.timeout)
+		opts.daemon_mode = 1;
+
+	setup_path();
+
+	dir = argv[0];
+
+	if (!enter_repo(dir, strict))
+		die("'%s' does not appear to be a git repository", dir);
+
+	switch (determine_protocol_version_server()) {
+	case protocol_v2:
+		serve_opts.advertise_capabilities = opts.advertise_refs;
+		serve_opts.stateless_rpc = opts.stateless_rpc;
+		serve(&serve_opts);
+		break;
+	case protocol_v1:
+		/*
+		 * v1 is just the original protocol with a version string,
+		 * so just fall through after writing the version string.
+		 */
+		if (opts.advertise_refs || !opts.stateless_rpc)
+			packet_write_fmt(1, "version 1\n");
+
+		/* fallthrough */
+	case protocol_v0:
+		upload_pack(&opts);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
+
+	return 0;
+}
diff --git a/builtin/verify-tag.c b/builtin/verify-tag.c
index ad7b79f..6fa04b7 100644
--- a/builtin/verify-tag.c
+++ b/builtin/verify-tag.c
@@ -72,7 +72,7 @@
 		}
 
 		if (format.format)
-			pretty_print_ref(name, oid.hash, &format);
+			pretty_print_ref(name, &oid, &format);
 	}
 	return had_error;
 }
diff --git a/builtin/worktree.c b/builtin/worktree.c
index 40a438e..30647b3 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -783,8 +783,9 @@
 {
 	int force = 0;
 	struct option options[] = {
-		OPT_BOOL(0, "force", &force,
-			 N_("force removing even if the worktree is dirty")),
+		OPT__FORCE(&force,
+			 N_("force removing even if the worktree is dirty"),
+			 PARSE_OPT_NOCOMPLETE),
 		OPT_END()
 	};
 	struct worktree **worktrees, *wt;
diff --git a/bulk-checkin.c b/bulk-checkin.c
index de1f404..c0bc8de 100644
--- a/bulk-checkin.c
+++ b/bulk-checkin.c
@@ -36,9 +36,9 @@
 		unlink(state->pack_tmp_name);
 		goto clear_exit;
 	} else if (state->nr_written == 1) {
-		hashclose(state->f, oid.hash, CSUM_FSYNC);
+		finalize_hashfile(state->f, oid.hash, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE);
 	} else {
-		int fd = hashclose(state->f, oid.hash, 0);
+		int fd = finalize_hashfile(state->f, oid.hash, 0);
 		fixup_pack_header_footer(fd, oid.hash, state->pack_tmp_name,
 					 state->nr_written, oid.hash,
 					 state->offset);
diff --git a/cache.h b/cache.h
index bc6636b..0c1fb9f 100644
--- a/cache.h
+++ b/cache.h
@@ -478,7 +478,7 @@
 extern char *get_object_directory(void);
 extern char *get_index_file(void);
 extern char *get_graft_file(void);
-extern int set_git_dir(const char *path);
+extern void set_git_dir(const char *path);
 extern int get_common_dir_noenv(struct strbuf *sb, const char *gitdir);
 extern int get_common_dir(struct strbuf *sb, const char *gitdir);
 extern const char *get_git_namespace(void);
@@ -806,6 +806,7 @@
 
 extern int fsync_object_files;
 extern int core_preload_index;
+extern int core_commit_graph;
 extern int core_apply_sparse_checkout;
 extern int precomposed_unicode;
 extern int protect_hfs;
@@ -1192,25 +1193,6 @@
 	return read_object_file_extended(oid, type, size, 1);
 }
 
-/*
- * This internal function is only declared here for the benefit of
- * lookup_replace_object().  Please do not call it directly.
- */
-extern const struct object_id *do_lookup_replace_object(const struct object_id *oid);
-
-/*
- * If object sha1 should be replaced, return the replacement object's
- * name (replaced recursively, if necessary).  The return value is
- * either sha1 or a pointer to a permanently-allocated value.  When
- * object replacement is suppressed, always return sha1.
- */
-static inline const struct object_id *lookup_replace_object(const struct object_id *oid)
-{
-	if (!check_replace_refs)
-		return oid;
-	return do_lookup_replace_object(oid);
-}
-
 /* Read and unpack an object file into memory, write memory to an object file */
 extern int oid_object_info(const struct object_id *, unsigned long *);
 
diff --git a/chdir-notify.c b/chdir-notify.c
new file mode 100644
index 0000000..5f7f2c2
--- /dev/null
+++ b/chdir-notify.c
@@ -0,0 +1,93 @@
+#include "cache.h"
+#include "chdir-notify.h"
+#include "list.h"
+#include "strbuf.h"
+
+struct chdir_notify_entry {
+	const char *name;
+	chdir_notify_callback cb;
+	void *data;
+	struct list_head list;
+};
+static LIST_HEAD(chdir_notify_entries);
+
+void chdir_notify_register(const char *name,
+			   chdir_notify_callback cb,
+			   void *data)
+{
+	struct chdir_notify_entry *e = xmalloc(sizeof(*e));
+	e->name = name;
+	e->cb = cb;
+	e->data = data;
+	list_add_tail(&e->list, &chdir_notify_entries);
+}
+
+static void reparent_cb(const char *name,
+			const char *old_cwd,
+			const char *new_cwd,
+			void *data)
+{
+	char **path = data;
+	char *tmp = *path;
+
+	if (!tmp)
+		return;
+
+	*path = reparent_relative_path(old_cwd, new_cwd, tmp);
+	free(tmp);
+
+	if (name) {
+		trace_printf_key(&trace_setup_key,
+				 "setup: reparent %s to '%s'",
+				 name, *path);
+	}
+}
+
+void chdir_notify_reparent(const char *name, char **path)
+{
+	chdir_notify_register(name, reparent_cb, path);
+}
+
+int chdir_notify(const char *new_cwd)
+{
+	struct strbuf old_cwd = STRBUF_INIT;
+	struct list_head *pos;
+
+	if (strbuf_getcwd(&old_cwd) < 0)
+		return -1;
+	if (chdir(new_cwd) < 0) {
+		int saved_errno = errno;
+		strbuf_release(&old_cwd);
+		errno = saved_errno;
+		return -1;
+	}
+
+	trace_printf_key(&trace_setup_key,
+			 "setup: chdir from '%s' to '%s'",
+			 old_cwd.buf, new_cwd);
+
+	list_for_each(pos, &chdir_notify_entries) {
+		struct chdir_notify_entry *e =
+			list_entry(pos, struct chdir_notify_entry, list);
+		e->cb(e->name, old_cwd.buf, new_cwd, e->data);
+	}
+
+	strbuf_release(&old_cwd);
+	return 0;
+}
+
+char *reparent_relative_path(const char *old_cwd,
+			     const char *new_cwd,
+			     const char *path)
+{
+	char *ret, *full;
+
+	if (is_absolute_path(path))
+		return xstrdup(path);
+
+	full = xstrfmt("%s/%s", old_cwd, path);
+	ret = xstrdup(remove_leading_path(full, new_cwd));
+	free(full);
+
+	return ret;
+}
diff --git a/chdir-notify.h b/chdir-notify.h
new file mode 100644
index 0000000..366e4c1
--- /dev/null
+++ b/chdir-notify.h
@@ -0,0 +1,73 @@
+#ifndef CHDIR_NOTIFY_H
+#define CHDIR_NOTIFY_H
+
+/*
+ * An API to let code "subscribe" to changes to the current working directory.
+ * The general idea is that some code asks to be notified when the working
+ * directory changes, and other code that calls chdir uses a special wrapper
+ * that notifies everyone.
+ */
+
+/*
+ * Callers who need to know about changes can do:
+ *
+ *   void foo(const char *old_path, const char *new_path, void *data)
+ *   {
+ *	warning("switched from %s to %s!", old_path, new_path);
+ *   }
+ *   ...
+ *   chdir_notify_register("description", foo, data);
+ *
+ * In practice most callers will want to move a relative path to the new root;
+ * they can use the reparent_relative_path() helper for that. If that's all
+ * you're doing, you can also use the convenience function:
+ *
+ *   chdir_notify_reparent("description", &my_path);
+ *
+ * Whenever a chdir event occurs, that will update my_path (if it's relative)
+ * to adjust for the new cwd by freeing any existing string and allocating a
+ * new one.
+ *
+ * Registered functions are called in the order in which they were added. Note
+ * that there's currently no way to remove a function, so make sure that the
+ * data parameter remains valid for the rest of the program.
+ *
+ * The "name" argument is used only for printing trace output from
+ * $GIT_TRACE_SETUP. It may be NULL, but if non-NULL should point to
+ * storage which lasts as long as the registration is active.
+ */
+typedef void (*chdir_notify_callback)(const char *name,
+				      const char *old_cwd,
+				      const char *new_cwd,
+				      void *data);
+void chdir_notify_register(const char *name, chdir_notify_callback cb, void *data);
+void chdir_notify_reparent(const char *name, char **path);
+
+/*
+ *
+ * Callers that want to chdir:
+ *
+ *   chdir_notify(new_path);
+ *
+ * to switch to the new path and notify any callbacks.
+ *
+ * Note that you don't need to chdir_notify() if you're just temporarily moving
+ * to a directory and back, as long as you don't call any subscribed code in
+ * between (but it should be safe to do so if you're unsure).
+ */
+int chdir_notify(const char *new_cwd);
+
+/*
+ * Reparent a relative path from old_root to new_root. For example:
+ *
+ *   reparent_relative_path("/a", "/a/b", "b/rel");
+ *
+ * would return the (newly allocated) string "rel". Note that we may return an
+ * absolute path in some cases (e.g., if the resulting path is not inside
+ * new_cwd).
+ */
+char *reparent_relative_path(const char *old_cwd,
+			     const char *new_cwd,
+			     const char *path);
+
+#endif /* CHDIR_NOTIFY_H */
diff --git a/color.c b/color.c
index f277e72..c6c6c4f 100644
--- a/color.c
+++ b/color.c
@@ -319,18 +319,20 @@
 	return GIT_COLOR_AUTO;
 }
 
-static int check_auto_color(void)
+static int check_auto_color(int fd)
 {
-	if (color_stdout_is_tty < 0)
-		color_stdout_is_tty = isatty(1);
-	if (color_stdout_is_tty || (pager_in_use() && pager_use_color)) {
+	static int color_stderr_is_tty = -1;
+	int *is_tty_p = fd == 1 ? &color_stdout_is_tty : &color_stderr_is_tty;
+	if (*is_tty_p < 0)
+		*is_tty_p = isatty(fd);
+	if (*is_tty_p || (fd == 1 && pager_in_use() && pager_use_color)) {
 		if (!is_terminal_dumb())
 			return 1;
 	}
 	return 0;
 }
 
-int want_color(int var)
+int want_color_fd(int fd, int var)
 {
 	/*
 	 * NEEDSWORK: This function is sometimes used from multiple threads, and
@@ -339,15 +341,15 @@
 	 * is listed in .tsan-suppressions for the time being.
 	 */
 
-	static int want_auto = -1;
+	static int want_auto[3] = { -1, -1, -1 };
 
 	if (var < 0)
 		var = git_use_color_default;
 
 	if (var == GIT_COLOR_AUTO) {
-		if (want_auto < 0)
-			want_auto = check_auto_color();
-		return want_auto;
+		if (want_auto[fd] < 0)
+			want_auto[fd] = check_auto_color(fd);
+		return want_auto[fd];
 	}
 	return var;
 }
diff --git a/color.h b/color.h
index cd0bced..5b744e1 100644
--- a/color.h
+++ b/color.h
@@ -88,7 +88,9 @@
  * Return a boolean whether to use color, where the argument 'var' is
  * one of GIT_COLOR_UNKNOWN, GIT_COLOR_NEVER, GIT_COLOR_ALWAYS, GIT_COLOR_AUTO.
  */
-int want_color(int var);
+int want_color_fd(int fd, int var);
+#define want_color(colorbool) want_color_fd(1, (colorbool))
+#define want_color_stderr(colorbool) want_color_fd(2, (colorbool))
 
 /*
  * Translate a Git color from 'value' into a string that the terminal can
diff --git a/command-list.txt b/command-list.txt
index a1fad28..835c589 100644
--- a/command-list.txt
+++ b/command-list.txt
@@ -34,6 +34,7 @@
 git-clone                               mainporcelain           init
 git-column                              purehelpers
 git-commit                              mainporcelain           history
+git-commit-graph                        plumbingmanipulators
 git-commit-tree                         plumbingmanipulators
 git-config                              ancillarymanipulators
 git-count-objects                       ancillaryinterrogators
diff --git a/commit-graph.c b/commit-graph.c
new file mode 100644
index 0000000..3fc1e0d
--- /dev/null
+++ b/commit-graph.c
@@ -0,0 +1,741 @@
+#include "cache.h"
+#include "config.h"
+#include "git-compat-util.h"
+#include "lockfile.h"
+#include "pack.h"
+#include "packfile.h"
+#include "commit.h"
+#include "object.h"
+#include "revision.h"
+#include "sha1-lookup.h"
+#include "commit-graph.h"
+#include "object-store.h"
+
+#define GRAPH_SIGNATURE 0x43475048 /* "CGPH" */
+#define GRAPH_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */
+#define GRAPH_CHUNKID_OIDLOOKUP 0x4f49444c /* "OIDL" */
+#define GRAPH_CHUNKID_DATA 0x43444154 /* "CDAT" */
+#define GRAPH_CHUNKID_LARGEEDGES 0x45444745 /* "EDGE" */
+
+#define GRAPH_DATA_WIDTH 36
+
+#define GRAPH_VERSION_1 0x1
+#define GRAPH_VERSION GRAPH_VERSION_1
+
+#define GRAPH_OID_VERSION_SHA1 1
+#define GRAPH_OID_LEN_SHA1 GIT_SHA1_RAWSZ
+#define GRAPH_OID_VERSION GRAPH_OID_VERSION_SHA1
+#define GRAPH_OID_LEN GRAPH_OID_LEN_SHA1
+
+#define GRAPH_OCTOPUS_EDGES_NEEDED 0x80000000
+#define GRAPH_PARENT_MISSING 0x7fffffff
+#define GRAPH_EDGE_LAST_MASK 0x7fffffff
+#define GRAPH_PARENT_NONE 0x70000000
+
+#define GRAPH_LAST_EDGE 0x80000000
+
+#define GRAPH_FANOUT_SIZE (4 * 256)
+#define GRAPH_CHUNKLOOKUP_WIDTH 12
+#define GRAPH_MIN_SIZE (5 * GRAPH_CHUNKLOOKUP_WIDTH + GRAPH_FANOUT_SIZE + \
+			GRAPH_OID_LEN + 8)
+
+char *get_commit_graph_filename(const char *obj_dir)
+{
+	return xstrfmt("%s/info/commit-graph", obj_dir);
+}
+
+static struct commit_graph *alloc_commit_graph(void)
+{
+	struct commit_graph *g = xcalloc(1, sizeof(*g));
+	g->graph_fd = -1;
+
+	return g;
+}
+
+struct commit_graph *load_commit_graph_one(const char *graph_file)
+{
+	void *graph_map;
+	const unsigned char *data, *chunk_lookup;
+	size_t graph_size;
+	struct stat st;
+	uint32_t i;
+	struct commit_graph *graph;
+	int fd = git_open(graph_file);
+	uint64_t last_chunk_offset;
+	uint32_t last_chunk_id;
+	uint32_t graph_signature;
+	unsigned char graph_version, hash_version;
+
+	if (fd < 0)
+		return NULL;
+	if (fstat(fd, &st)) {
+		close(fd);
+		return NULL;
+	}
+	graph_size = xsize_t(st.st_size);
+
+	if (graph_size < GRAPH_MIN_SIZE) {
+		close(fd);
+		die("graph file %s is too small", graph_file);
+	}
+	graph_map = xmmap(NULL, graph_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	data = (const unsigned char *)graph_map;
+
+	graph_signature = get_be32(data);
+	if (graph_signature != GRAPH_SIGNATURE) {
+		error("graph signature %X does not match signature %X",
+		      graph_signature, GRAPH_SIGNATURE);
+		goto cleanup_fail;
+	}
+
+	graph_version = *(unsigned char*)(data + 4);
+	if (graph_version != GRAPH_VERSION) {
+		error("graph version %X does not match version %X",
+		      graph_version, GRAPH_VERSION);
+		goto cleanup_fail;
+	}
+
+	hash_version = *(unsigned char*)(data + 5);
+	if (hash_version != GRAPH_OID_VERSION) {
+		error("hash version %X does not match version %X",
+		      hash_version, GRAPH_OID_VERSION);
+		goto cleanup_fail;
+	}
+
+	graph = alloc_commit_graph();
+
+	graph->hash_len = GRAPH_OID_LEN;
+	graph->num_chunks = *(unsigned char*)(data + 6);
+	graph->graph_fd = fd;
+	graph->data = graph_map;
+	graph->data_len = graph_size;
+
+	last_chunk_id = 0;
+	last_chunk_offset = 8;
+	chunk_lookup = data + 8;
+	for (i = 0; i < graph->num_chunks; i++) {
+		uint32_t chunk_id = get_be32(chunk_lookup + 0);
+		uint64_t chunk_offset = get_be64(chunk_lookup + 4);
+		int chunk_repeated = 0;
+
+		chunk_lookup += GRAPH_CHUNKLOOKUP_WIDTH;
+
+		if (chunk_offset > graph_size - GIT_MAX_RAWSZ) {
+			error("improper chunk offset %08x%08x", (uint32_t)(chunk_offset >> 32),
+			      (uint32_t)chunk_offset);
+			goto cleanup_fail;
+		}
+
+		switch (chunk_id) {
+		case GRAPH_CHUNKID_OIDFANOUT:
+			if (graph->chunk_oid_fanout)
+				chunk_repeated = 1;
+			else
+				graph->chunk_oid_fanout = (uint32_t*)(data + chunk_offset);
+			break;
+
+		case GRAPH_CHUNKID_OIDLOOKUP:
+			if (graph->chunk_oid_lookup)
+				chunk_repeated = 1;
+			else
+				graph->chunk_oid_lookup = data + chunk_offset;
+			break;
+
+		case GRAPH_CHUNKID_DATA:
+			if (graph->chunk_commit_data)
+				chunk_repeated = 1;
+			else
+				graph->chunk_commit_data = data + chunk_offset;
+			break;
+
+		case GRAPH_CHUNKID_LARGEEDGES:
+			if (graph->chunk_large_edges)
+				chunk_repeated = 1;
+			else
+				graph->chunk_large_edges = data + chunk_offset;
+			break;
+		}
+
+		if (chunk_repeated) {
+			error("chunk id %08x appears multiple times", chunk_id);
+			goto cleanup_fail;
+		}
+
+		if (last_chunk_id == GRAPH_CHUNKID_OIDLOOKUP)
+		{
+			graph->num_commits = (chunk_offset - last_chunk_offset)
+					     / graph->hash_len;
+		}
+
+		last_chunk_id = chunk_id;
+		last_chunk_offset = chunk_offset;
+	}
+
+	return graph;
+
+cleanup_fail:
+	munmap(graph_map, graph_size);
+	close(fd);
+	exit(1);
+}
+
+/* global storage */
+static struct commit_graph *commit_graph = NULL;
+
+static void prepare_commit_graph_one(const char *obj_dir)
+{
+	char *graph_name;
+
+	if (commit_graph)
+		return;
+
+	graph_name = get_commit_graph_filename(obj_dir);
+	commit_graph = load_commit_graph_one(graph_name);
+
+	FREE_AND_NULL(graph_name);
+}
+
+static int prepare_commit_graph_run_once = 0;
+static void prepare_commit_graph(void)
+{
+	struct alternate_object_database *alt;
+	char *obj_dir;
+
+	if (prepare_commit_graph_run_once)
+		return;
+	prepare_commit_graph_run_once = 1;
+
+	obj_dir = get_object_directory();
+	prepare_commit_graph_one(obj_dir);
+	prepare_alt_odb(the_repository);
+	for (alt = the_repository->objects->alt_odb_list;
+	     !commit_graph && alt;
+	     alt = alt->next)
+		prepare_commit_graph_one(alt->path);
+}
+
+static void close_commit_graph(void)
+{
+	if (!commit_graph)
+		return;
+
+	if (commit_graph->graph_fd >= 0) {
+		munmap((void *)commit_graph->data, commit_graph->data_len);
+		commit_graph->data = NULL;
+		close(commit_graph->graph_fd);
+	}
+
+	FREE_AND_NULL(commit_graph);
+}
+
+static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t *pos)
+{
+	return bsearch_hash(oid->hash, g->chunk_oid_fanout,
+			    g->chunk_oid_lookup, g->hash_len, pos);
+}
+
+static struct commit_list **insert_parent_or_die(struct commit_graph *g,
+						 uint64_t pos,
+						 struct commit_list **pptr)
+{
+	struct commit *c;
+	struct object_id oid;
+	hashcpy(oid.hash, g->chunk_oid_lookup + g->hash_len * pos);
+	c = lookup_commit(&oid);
+	if (!c)
+		die("could not find commit %s", oid_to_hex(&oid));
+	c->graph_pos = pos;
+	return &commit_list_insert(c, pptr)->next;
+}
+
+static int fill_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t pos)
+{
+	struct object_id oid;
+	uint32_t edge_value;
+	uint32_t *parent_data_ptr;
+	uint64_t date_low, date_high;
+	struct commit_list **pptr;
+	const unsigned char *commit_data = g->chunk_commit_data + (g->hash_len + 16) * pos;
+
+	item->object.parsed = 1;
+	item->graph_pos = pos;
+
+	hashcpy(oid.hash, commit_data);
+	item->tree = lookup_tree(&oid);
+
+	date_high = get_be32(commit_data + g->hash_len + 8) & 0x3;
+	date_low = get_be32(commit_data + g->hash_len + 12);
+	item->date = (timestamp_t)((date_high << 32) | date_low);
+
+	pptr = &item->parents;
+
+	edge_value = get_be32(commit_data + g->hash_len);
+	if (edge_value == GRAPH_PARENT_NONE)
+		return 1;
+	pptr = insert_parent_or_die(g, edge_value, pptr);
+
+	edge_value = get_be32(commit_data + g->hash_len + 4);
+	if (edge_value == GRAPH_PARENT_NONE)
+		return 1;
+	if (!(edge_value & GRAPH_OCTOPUS_EDGES_NEEDED)) {
+		pptr = insert_parent_or_die(g, edge_value, pptr);
+		return 1;
+	}
+
+	parent_data_ptr = (uint32_t*)(g->chunk_large_edges +
+			  4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
+	do {
+		edge_value = get_be32(parent_data_ptr);
+		pptr = insert_parent_or_die(g,
+					    edge_value & GRAPH_EDGE_LAST_MASK,
+					    pptr);
+		parent_data_ptr++;
+	} while (!(edge_value & GRAPH_LAST_EDGE));
+
+	return 1;
+}
+
+int parse_commit_in_graph(struct commit *item)
+{
+	if (!core_commit_graph)
+		return 0;
+	if (item->object.parsed)
+		return 1;
+
+	prepare_commit_graph();
+	if (commit_graph) {
+		uint32_t pos;
+		int found;
+		if (item->graph_pos != COMMIT_NOT_FROM_GRAPH) {
+			pos = item->graph_pos;
+			found = 1;
+		} else {
+			found = bsearch_graph(commit_graph, &(item->object.oid), &pos);
+		}
+
+		if (found)
+			return fill_commit_in_graph(item, commit_graph, pos);
+	}
+
+	return 0;
+}
+
+static void write_graph_chunk_fanout(struct hashfile *f,
+				     struct commit **commits,
+				     int nr_commits)
+{
+	int i, count = 0;
+	struct commit **list = commits;
+
+	/*
+	 * Write the first-level table (the list is sorted,
+	 * but we use a 256-entry lookup to be able to avoid
+	 * having to do eight extra binary search iterations).
+	 */
+	for (i = 0; i < 256; i++) {
+		while (count < nr_commits) {
+			if ((*list)->object.oid.hash[0] != i)
+				break;
+			count++;
+			list++;
+		}
+
+		hashwrite_be32(f, count);
+	}
+}
+
+static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
+				   struct commit **commits, int nr_commits)
+{
+	struct commit **list = commits;
+	int count;
+	for (count = 0; count < nr_commits; count++, list++)
+		hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
+}
+
+static const unsigned char *commit_to_sha1(size_t index, void *table)
+{
+	struct commit **commits = table;
+	return commits[index]->object.oid.hash;
+}
+
+static void write_graph_chunk_data(struct hashfile *f, int hash_len,
+				   struct commit **commits, int nr_commits)
+{
+	struct commit **list = commits;
+	struct commit **last = commits + nr_commits;
+	uint32_t num_extra_edges = 0;
+
+	while (list < last) {
+		struct commit_list *parent;
+		int edge_value;
+		uint32_t packedDate[2];
+
+		parse_commit(*list);
+		hashwrite(f, (*list)->tree->object.oid.hash, hash_len);
+
+		parent = (*list)->parents;
+
+		if (!parent)
+			edge_value = GRAPH_PARENT_NONE;
+		else {
+			edge_value = sha1_pos(parent->item->object.oid.hash,
+					      commits,
+					      nr_commits,
+					      commit_to_sha1);
+
+			if (edge_value < 0)
+				edge_value = GRAPH_PARENT_MISSING;
+		}
+
+		hashwrite_be32(f, edge_value);
+
+		if (parent)
+			parent = parent->next;
+
+		if (!parent)
+			edge_value = GRAPH_PARENT_NONE;
+		else if (parent->next)
+			edge_value = GRAPH_OCTOPUS_EDGES_NEEDED | num_extra_edges;
+		else {
+			edge_value = sha1_pos(parent->item->object.oid.hash,
+					      commits,
+					      nr_commits,
+					      commit_to_sha1);
+			if (edge_value < 0)
+				edge_value = GRAPH_PARENT_MISSING;
+		}
+
+		hashwrite_be32(f, edge_value);
+
+		if (edge_value & GRAPH_OCTOPUS_EDGES_NEEDED) {
+			do {
+				num_extra_edges++;
+				parent = parent->next;
+			} while (parent);
+		}
+
+		if (sizeof((*list)->date) > 4)
+			packedDate[0] = htonl(((*list)->date >> 32) & 0x3);
+		else
+			packedDate[0] = 0;
+
+		packedDate[1] = htonl((*list)->date);
+		hashwrite(f, packedDate, 8);
+
+		list++;
+	}
+}
+
+static void write_graph_chunk_large_edges(struct hashfile *f,
+					  struct commit **commits,
+					  int nr_commits)
+{
+	struct commit **list = commits;
+	struct commit **last = commits + nr_commits;
+	struct commit_list *parent;
+
+	while (list < last) {
+		int num_parents = 0;
+		for (parent = (*list)->parents; num_parents < 3 && parent;
+		     parent = parent->next)
+			num_parents++;
+
+		if (num_parents <= 2) {
+			list++;
+			continue;
+		}
+
+		/* Since num_parents > 2, this initializer is safe. */
+		for (parent = (*list)->parents->next; parent; parent = parent->next) {
+			int edge_value = sha1_pos(parent->item->object.oid.hash,
+						  commits,
+						  nr_commits,
+						  commit_to_sha1);
+
+			if (edge_value < 0)
+				edge_value = GRAPH_PARENT_MISSING;
+			else if (!parent->next)
+				edge_value |= GRAPH_LAST_EDGE;
+
+			hashwrite_be32(f, edge_value);
+		}
+
+		list++;
+	}
+}
+
+static int commit_compare(const void *_a, const void *_b)
+{
+	const struct object_id *a = (const struct object_id *)_a;
+	const struct object_id *b = (const struct object_id *)_b;
+	return oidcmp(a, b);
+}
+
+struct packed_commit_list {
+	struct commit **list;
+	int nr;
+	int alloc;
+};
+
+struct packed_oid_list {
+	struct object_id *list;
+	int nr;
+	int alloc;
+};
+
+static int add_packed_commits(const struct object_id *oid,
+			      struct packed_git *pack,
+			      uint32_t pos,
+			      void *data)
+{
+	struct packed_oid_list *list = (struct packed_oid_list*)data;
+	enum object_type type;
+	off_t offset = nth_packed_object_offset(pack, pos);
+	struct object_info oi = OBJECT_INFO_INIT;
+
+	oi.typep = &type;
+	if (packed_object_info(pack, offset, &oi) < 0)
+		die("unable to get type of object %s", oid_to_hex(oid));
+
+	if (type != OBJ_COMMIT)
+		return 0;
+
+	ALLOC_GROW(list->list, list->nr + 1, list->alloc);
+	oidcpy(&(list->list[list->nr]), oid);
+	list->nr++;
+
+	return 0;
+}
+
+static void add_missing_parents(struct packed_oid_list *oids, struct commit *commit)
+{
+	struct commit_list *parent;
+	for (parent = commit->parents; parent; parent = parent->next) {
+		if (!(parent->item->object.flags & UNINTERESTING)) {
+			ALLOC_GROW(oids->list, oids->nr + 1, oids->alloc);
+			oidcpy(&oids->list[oids->nr], &(parent->item->object.oid));
+			oids->nr++;
+			parent->item->object.flags |= UNINTERESTING;
+		}
+	}
+}
+
+static void close_reachable(struct packed_oid_list *oids)
+{
+	int i;
+	struct commit *commit;
+
+	for (i = 0; i < oids->nr; i++) {
+		commit = lookup_commit(&oids->list[i]);
+		if (commit)
+			commit->object.flags |= UNINTERESTING;
+	}
+
+	/*
+	 * As this loop runs, oids->nr may grow, but not more
+	 * than the number of missing commits in the reachable
+	 * closure.
+	 */
+	for (i = 0; i < oids->nr; i++) {
+		commit = lookup_commit(&oids->list[i]);
+
+		if (commit && !parse_commit(commit))
+			add_missing_parents(oids, commit);
+	}
+
+	for (i = 0; i < oids->nr; i++) {
+		commit = lookup_commit(&oids->list[i]);
+
+		if (commit)
+			commit->object.flags &= ~UNINTERESTING;
+	}
+}
+
+void write_commit_graph(const char *obj_dir,
+			const char **pack_indexes,
+			int nr_packs,
+			const char **commit_hex,
+			int nr_commits,
+			int append)
+{
+	struct packed_oid_list oids;
+	struct packed_commit_list commits;
+	struct hashfile *f;
+	uint32_t i, count_distinct = 0;
+	char *graph_name;
+	int fd;
+	struct lock_file lk = LOCK_INIT;
+	uint32_t chunk_ids[5];
+	uint64_t chunk_offsets[5];
+	int num_chunks;
+	int num_extra_edges;
+	struct commit_list *parent;
+
+	oids.nr = 0;
+	oids.alloc = approximate_object_count() / 4;
+
+	if (append) {
+		prepare_commit_graph_one(obj_dir);
+		if (commit_graph)
+			oids.alloc += commit_graph->num_commits;
+	}
+
+	if (oids.alloc < 1024)
+		oids.alloc = 1024;
+	ALLOC_ARRAY(oids.list, oids.alloc);
+
+	if (append && commit_graph) {
+		for (i = 0; i < commit_graph->num_commits; i++) {
+			const unsigned char *hash = commit_graph->chunk_oid_lookup +
+				commit_graph->hash_len * i;
+			hashcpy(oids.list[oids.nr++].hash, hash);
+		}
+	}
+
+	if (pack_indexes) {
+		struct strbuf packname = STRBUF_INIT;
+		int dirlen;
+		strbuf_addf(&packname, "%s/pack/", obj_dir);
+		dirlen = packname.len;
+		for (i = 0; i < nr_packs; i++) {
+			struct packed_git *p;
+			strbuf_setlen(&packname, dirlen);
+			strbuf_addstr(&packname, pack_indexes[i]);
+			p = add_packed_git(packname.buf, packname.len, 1);
+			if (!p)
+				die("error adding pack %s", packname.buf);
+			if (open_pack_index(p))
+				die("error opening index for %s", packname.buf);
+			for_each_object_in_pack(p, add_packed_commits, &oids);
+			close_pack(p);
+		}
+		strbuf_release(&packname);
+	}
+
+	if (commit_hex) {
+		for (i = 0; i < nr_commits; i++) {
+			const char *end;
+			struct object_id oid;
+			struct commit *result;
+
+			if (commit_hex[i] && parse_oid_hex(commit_hex[i], &oid, &end))
+				continue;
+
+			result = lookup_commit_reference_gently(&oid, 1);
+
+			if (result) {
+				ALLOC_GROW(oids.list, oids.nr + 1, oids.alloc);
+				oidcpy(&oids.list[oids.nr], &(result->object.oid));
+				oids.nr++;
+			}
+		}
+	}
+
+	if (!pack_indexes && !commit_hex)
+		for_each_packed_object(add_packed_commits, &oids, 0);
+
+	close_reachable(&oids);
+
+	QSORT(oids.list, oids.nr, commit_compare);
+
+	count_distinct = 1;
+	for (i = 1; i < oids.nr; i++) {
+		if (oidcmp(&oids.list[i-1], &oids.list[i]))
+			count_distinct++;
+	}
+
+	if (count_distinct >= GRAPH_PARENT_MISSING)
+		die(_("the commit graph format cannot write %d commits"), count_distinct);
+
+	commits.nr = 0;
+	commits.alloc = count_distinct;
+	ALLOC_ARRAY(commits.list, commits.alloc);
+
+	num_extra_edges = 0;
+	for (i = 0; i < oids.nr; i++) {
+		int num_parents = 0;
+		if (i > 0 && !oidcmp(&oids.list[i-1], &oids.list[i]))
+			continue;
+
+		commits.list[commits.nr] = lookup_commit(&oids.list[i]);
+		parse_commit(commits.list[commits.nr]);
+
+		for (parent = commits.list[commits.nr]->parents;
+		     parent; parent = parent->next)
+			num_parents++;
+
+		if (num_parents > 2)
+			num_extra_edges += num_parents - 1;
+
+		commits.nr++;
+	}
+	num_chunks = num_extra_edges ? 4 : 3;
+
+	if (commits.nr >= GRAPH_PARENT_MISSING)
+		die(_("too many commits to write graph"));
+
+	graph_name = get_commit_graph_filename(obj_dir);
+	fd = hold_lock_file_for_update(&lk, graph_name, 0);
+
+	if (fd < 0) {
+		struct strbuf folder = STRBUF_INIT;
+		strbuf_addstr(&folder, graph_name);
+		strbuf_setlen(&folder, strrchr(folder.buf, '/') - folder.buf);
+
+		if (mkdir(folder.buf, 0777) < 0)
+			die_errno(_("cannot mkdir %s"), folder.buf);
+		strbuf_release(&folder);
+
+		fd = hold_lock_file_for_update(&lk, graph_name, LOCK_DIE_ON_ERROR);
+
+		if (fd < 0)
+			die_errno("unable to create '%s'", graph_name);
+	}
+
+	f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
+
+	hashwrite_be32(f, GRAPH_SIGNATURE);
+
+	hashwrite_u8(f, GRAPH_VERSION);
+	hashwrite_u8(f, GRAPH_OID_VERSION);
+	hashwrite_u8(f, num_chunks);
+	hashwrite_u8(f, 0); /* unused padding byte */
+
+	chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;
+	chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
+	chunk_ids[2] = GRAPH_CHUNKID_DATA;
+	if (num_extra_edges)
+		chunk_ids[3] = GRAPH_CHUNKID_LARGEEDGES;
+	else
+		chunk_ids[3] = 0;
+	chunk_ids[4] = 0;
+
+	chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
+	chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
+	chunk_offsets[2] = chunk_offsets[1] + GRAPH_OID_LEN * commits.nr;
+	chunk_offsets[3] = chunk_offsets[2] + (GRAPH_OID_LEN + 16) * commits.nr;
+	chunk_offsets[4] = chunk_offsets[3] + 4 * num_extra_edges;
+
+	for (i = 0; i <= num_chunks; i++) {
+		uint32_t chunk_write[3];
+
+		chunk_write[0] = htonl(chunk_ids[i]);
+		chunk_write[1] = htonl(chunk_offsets[i] >> 32);
+		chunk_write[2] = htonl(chunk_offsets[i] & 0xffffffff);
+		hashwrite(f, chunk_write, 12);
+	}
+
+	write_graph_chunk_fanout(f, commits.list, commits.nr);
+	write_graph_chunk_oids(f, GRAPH_OID_LEN, commits.list, commits.nr);
+	write_graph_chunk_data(f, GRAPH_OID_LEN, commits.list, commits.nr);
+	write_graph_chunk_large_edges(f, commits.list, commits.nr);
+
+	close_commit_graph();
+	finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
+	commit_lock_file(&lk);
+
+	free(oids.list);
+	oids.alloc = 0;
+	oids.nr = 0;
+}
diff --git a/commit-graph.h b/commit-graph.h
new file mode 100644
index 0000000..e1d8580
--- /dev/null
+++ b/commit-graph.h
@@ -0,0 +1,46 @@
+#ifndef COMMIT_GRAPH_H
+#define COMMIT_GRAPH_H
+
+#include "git-compat-util.h"
+
+char *get_commit_graph_filename(const char *obj_dir);
+
+/*
+ * Given a commit struct, try to fill the commit struct info, including:
+ *  1. tree object
+ *  2. date
+ *  3. parents.
+ *
+ * Returns 1 if and only if the commit was found in the packed graph.
+ *
+ * See parse_commit_buffer() for the fallback after this call.
+ */
+int parse_commit_in_graph(struct commit *item);
+
+struct commit_graph {
+	int graph_fd;
+
+	const unsigned char *data;
+	size_t data_len;
+
+	unsigned char hash_len;
+	unsigned char num_chunks;
+	uint32_t num_commits;
+	struct object_id oid;
+
+	const uint32_t *chunk_oid_fanout;
+	const unsigned char *chunk_oid_lookup;
+	const unsigned char *chunk_commit_data;
+	const unsigned char *chunk_large_edges;
+};
+
+struct commit_graph *load_commit_graph_one(const char *graph_file);
+
+void write_commit_graph(const char *obj_dir,
+			const char **pack_indexes,
+			int nr_packs,
+			const char **commit_hex,
+			int nr_commits,
+			int append);
+
+#endif
diff --git a/commit.c b/commit.c
index ca474a7..5704911 100644
--- a/commit.c
+++ b/commit.c
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "tag.h"
 #include "commit.h"
+#include "commit-graph.h"
 #include "pkt-line.h"
 #include "utf8.h"
 #include "diff.h"
@@ -383,6 +384,8 @@
 		return -1;
 	if (item->object.parsed)
 		return 0;
+	if (parse_commit_in_graph(item))
+		return 0;
 	buffer = read_object_file(&item->object.oid, &type, &size);
 	if (!buffer)
 		return quiet_on_missing ? -1 :
diff --git a/commit.h b/commit.h
index 0fb8271..e57ae4b 100644
--- a/commit.h
+++ b/commit.h
@@ -9,6 +9,8 @@
 #include "string-list.h"
 #include "pretty.h"
 
+#define COMMIT_NOT_FROM_GRAPH 0xFFFFFFFF
+
 struct commit_list {
 	struct commit *item;
 	struct commit_list *next;
@@ -21,6 +23,7 @@
 	timestamp_t date;
 	struct commit_list *parents;
 	struct tree *tree;
+	uint32_t graph_pos;
 };
 
 extern int save_commit_buffer;
diff --git a/common-main.c b/common-main.c
index b2e5a86..3728f66 100644
--- a/common-main.c
+++ b/common-main.c
@@ -1,5 +1,5 @@
 #include "cache.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "attr.h"
 
 /*
diff --git a/config.c b/config.c
index c698988..6f8f1d8 100644
--- a/config.c
+++ b/config.c
@@ -9,13 +9,14 @@
 #include "config.h"
 #include "repository.h"
 #include "lockfile.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "strbuf.h"
 #include "quote.h"
 #include "hashmap.h"
 #include "string-list.h"
 #include "utf8.h"
 #include "dir.h"
+#include "color.h"
 
 struct config_source {
 	struct config_source *prev;
@@ -653,7 +654,45 @@
 	}
 }
 
-static int git_parse_source(config_fn_t fn, void *data)
+struct parse_event_data {
+	enum config_event_t previous_type;
+	size_t previous_offset;
+	const struct config_options *opts;
+};
+
+static int do_event(enum config_event_t type, struct parse_event_data *data)
+{
+	size_t offset;
+
+	if (!data->opts || !data->opts->event_fn)
+		return 0;
+
+	if (type == CONFIG_EVENT_WHITESPACE &&
+	    data->previous_type == type)
+		return 0;
+
+	offset = cf->do_ftell(cf);
+	/*
+	 * At EOF, the parser always "inserts" an extra '\n', therefore
+	 * the end offset of the event is the current file position, otherwise
+	 * we will already have advanced to the next event.
+	 */
+	if (type != CONFIG_EVENT_EOF)
+		offset--;
+
+	if (data->previous_type != CONFIG_EVENT_EOF &&
+	    data->opts->event_fn(data->previous_type, data->previous_offset,
+				 offset, data->opts->event_fn_data) < 0)
+		return -1;
+
+	data->previous_type = type;
+	data->previous_offset = offset;
+
+	return 0;
+}
+
+static int git_parse_source(config_fn_t fn, void *data,
+			    const struct config_options *opts)
 {
 	int comment = 0;
 	int baselen = 0;
@@ -664,8 +703,15 @@
 	/* U+FEFF Byte Order Mark in UTF8 */
 	const char *bomptr = utf8_bom;
 
+	/* For the parser event callback */
+	struct parse_event_data event_data = {
+		CONFIG_EVENT_EOF, 0, opts
+	};
+
 	for (;;) {
-		int c = get_next_char();
+		int c;
+
+		c = get_next_char();
 		if (bomptr && *bomptr) {
 			/* We are at the file beginning; skip UTF8-encoded BOM
 			 * if present. Sane editors won't put this in on their
@@ -682,18 +728,33 @@
 			}
 		}
 		if (c == '\n') {
-			if (cf->eof)
+			if (cf->eof) {
+				if (do_event(CONFIG_EVENT_EOF, &event_data) < 0)
+					return -1;
 				return 0;
+			}
+			if (do_event(CONFIG_EVENT_WHITESPACE, &event_data) < 0)
+				return -1;
 			comment = 0;
 			continue;
 		}
-		if (comment || isspace(c))
+		if (comment)
 			continue;
+		if (isspace(c)) {
+			if (do_event(CONFIG_EVENT_WHITESPACE, &event_data) < 0)
+					return -1;
+			continue;
+		}
 		if (c == '#' || c == ';') {
+			if (do_event(CONFIG_EVENT_COMMENT, &event_data) < 0)
+					return -1;
 			comment = 1;
 			continue;
 		}
 		if (c == '[') {
+			if (do_event(CONFIG_EVENT_SECTION, &event_data) < 0)
+					return -1;
+
 			/* Reset prior to determining a new stem */
 			strbuf_reset(var);
 			if (get_base_var(var) < 0 || var->len < 1)
@@ -704,6 +765,10 @@
 		}
 		if (!isalpha(c))
 			break;
+
+		if (do_event(CONFIG_EVENT_ENTRY, &event_data) < 0)
+			return -1;
+
 		/*
 		 * Truncate the var name back to the section header
 		 * stem prior to grabbing the suffix part of the name
@@ -715,6 +780,9 @@
 			break;
 	}
 
+	if (do_event(CONFIG_EVENT_ERROR, &event_data) < 0)
+		return -1;
+
 	switch (cf->origin_type) {
 	case CONFIG_ORIGIN_BLOB:
 		error_msg = xstrfmt(_("bad config line %d in blob %s"),
@@ -1000,6 +1068,15 @@
 	return 0;
 }
 
+int git_config_color(char *dest, const char *var, const char *value)
+{
+	if (!value)
+		return config_error_nonbool(var);
+	if (color_parse(value, dest) < 0)
+		return -1;
+	return 0;
+}
+
 static int git_default_core_config(const char *var, const char *value)
 {
 	/* This needs a better name */
@@ -1172,6 +1249,11 @@
 		return 0;
 	}
 
+	if (!strcmp(var, "core.checkroundtripencoding")) {
+		check_roundtrip_encoding = xstrdup(value);
+		return 0;
+	}
+
 	if (!strcmp(var, "core.notesref")) {
 		notes_ref_name = xstrdup(value);
 		return 0;
@@ -1226,6 +1308,11 @@
 		return 0;
 	}
 
+	if (!strcmp(var, "core.commitgraph")) {
+		core_commit_graph = git_config_bool(var, value);
+		return 0;
+	}
+
 	if (!strcmp(var, "core.sparsecheckout")) {
 		core_apply_sparse_checkout = git_config_bool(var, value);
 		return 0;
@@ -1365,7 +1452,7 @@
 	if (starts_with(var, "mailmap."))
 		return git_default_mailmap_config(var, value);
 
-	if (starts_with(var, "advice."))
+	if (starts_with(var, "advice.") || starts_with(var, "color.advice"))
 		return git_default_advice_config(var, value);
 
 	if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
@@ -1398,7 +1485,8 @@
  * fgetc, ungetc, ftell of top need to be initialized before calling
  * this function.
  */
-static int do_config_from(struct config_source *top, config_fn_t fn, void *data)
+static int do_config_from(struct config_source *top, config_fn_t fn, void *data,
+			  const struct config_options *opts)
 {
 	int ret;
 
@@ -1410,7 +1498,7 @@
 	strbuf_init(&top->var, 1024);
 	cf = top;
 
-	ret = git_parse_source(fn, data);
+	ret = git_parse_source(fn, data, opts);
 
 	/* pop config-file parsing state stack */
 	strbuf_release(&top->value);
@@ -1423,9 +1511,10 @@
 static int do_config_from_file(config_fn_t fn,
 		const enum config_origin_type origin_type,
 		const char *name, const char *path, FILE *f,
-		void *data)
+		void *data, const struct config_options *opts)
 {
 	struct config_source top;
+	int ret;
 
 	top.u.file = f;
 	top.origin_type = origin_type;
@@ -1436,29 +1525,39 @@
 	top.do_ungetc = config_file_ungetc;
 	top.do_ftell = config_file_ftell;
 
-	return do_config_from(&top, fn, data);
+	flockfile(f);
+	ret = do_config_from(&top, fn, data, opts);
+	funlockfile(f);
+	return ret;
 }
 
 static int git_config_from_stdin(config_fn_t fn, void *data)
 {
-	return do_config_from_file(fn, CONFIG_ORIGIN_STDIN, "", NULL, stdin, data);
+	return do_config_from_file(fn, CONFIG_ORIGIN_STDIN, "", NULL, stdin,
+				   data, NULL);
 }
 
-int git_config_from_file(config_fn_t fn, const char *filename, void *data)
+int git_config_from_file_with_options(config_fn_t fn, const char *filename,
+				      void *data,
+				      const struct config_options *opts)
 {
 	int ret = -1;
 	FILE *f;
 
 	f = fopen_or_warn(filename, "r");
 	if (f) {
-		flockfile(f);
-		ret = do_config_from_file(fn, CONFIG_ORIGIN_FILE, filename, filename, f, data);
-		funlockfile(f);
+		ret = do_config_from_file(fn, CONFIG_ORIGIN_FILE, filename,
+					  filename, f, data, opts);
 		fclose(f);
 	}
 	return ret;
 }
 
+int git_config_from_file(config_fn_t fn, const char *filename, void *data)
+{
+	return git_config_from_file_with_options(fn, filename, data, NULL);
+}
+
 int git_config_from_mem(config_fn_t fn, const enum config_origin_type origin_type,
 			const char *name, const char *buf, size_t len, void *data)
 {
@@ -1475,7 +1574,7 @@
 	top.do_ungetc = config_buf_ungetc;
 	top.do_ftell = config_buf_ftell;
 
-	return do_config_from(&top, fn, data);
+	return do_config_from(&top, fn, data, NULL);
 }
 
 int git_config_from_blob_oid(config_fn_t fn,
@@ -2219,96 +2318,98 @@
  * Find all the stuff for git_config_set() below.
  */
 
-static struct {
+struct config_store_data {
 	int baselen;
 	char *key;
 	int do_not_match;
 	regex_t *value_regex;
 	int multi_replace;
-	size_t *offset;
-	unsigned int offset_alloc;
-	enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
-	unsigned int seen;
-} store;
+	struct {
+		size_t begin, end;
+		enum config_event_t type;
+		int is_keys_section;
+	} *parsed;
+	unsigned int parsed_nr, parsed_alloc, *seen, seen_nr, seen_alloc;
+	unsigned int key_seen:1, section_seen:1, is_keys_section:1;
+};
 
-static int matches(const char *key, const char *value)
+static int matches(const char *key, const char *value,
+		   const struct config_store_data *store)
 {
-	if (strcmp(key, store.key))
+	if (strcmp(key, store->key))
 		return 0; /* not ours */
-	if (!store.value_regex)
+	if (!store->value_regex)
 		return 1; /* always matches */
-	if (store.value_regex == CONFIG_REGEX_NONE)
+	if (store->value_regex == CONFIG_REGEX_NONE)
 		return 0; /* never matches */
 
-	return store.do_not_match ^
-		(value && !regexec(store.value_regex, value, 0, NULL, 0));
+	return store->do_not_match ^
+		(value && !regexec(store->value_regex, value, 0, NULL, 0));
+}
+
+static int store_aux_event(enum config_event_t type,
+			   size_t begin, size_t end, void *data)
+{
+	struct config_store_data *store = data;
+
+	ALLOC_GROW(store->parsed, store->parsed_nr + 1, store->parsed_alloc);
+	store->parsed[store->parsed_nr].begin = begin;
+	store->parsed[store->parsed_nr].end = end;
+	store->parsed[store->parsed_nr].type = type;
+
+	if (type == CONFIG_EVENT_SECTION) {
+		if (cf->var.len < 2 || cf->var.buf[cf->var.len - 1] != '.')
+			BUG("Invalid section name '%s'", cf->var.buf);
+
+		/* Is this the section we were looking for? */
+		store->is_keys_section =
+			store->parsed[store->parsed_nr].is_keys_section =
+			cf->var.len - 1 == store->baselen &&
+			!strncasecmp(cf->var.buf, store->key, store->baselen);
+		if (store->is_keys_section) {
+			store->section_seen = 1;
+			ALLOC_GROW(store->seen, store->seen_nr + 1,
+				   store->seen_alloc);
+			store->seen[store->seen_nr] = store->parsed_nr;
+		}
+	}
+
+	store->parsed_nr++;
+
+	return 0;
 }
 
 static int store_aux(const char *key, const char *value, void *cb)
 {
-	const char *ep;
-	size_t section_len;
+	struct config_store_data *store = cb;
 
-	switch (store.state) {
-	case KEY_SEEN:
-		if (matches(key, value)) {
-			if (store.seen == 1 && store.multi_replace == 0) {
+	if (store->key_seen) {
+		if (matches(key, value, store)) {
+			if (store->seen_nr == 1 && store->multi_replace == 0) {
 				warning(_("%s has multiple values"), key);
 			}
 
-			ALLOC_GROW(store.offset, store.seen + 1,
-				   store.offset_alloc);
+			ALLOC_GROW(store->seen, store->seen_nr + 1,
+				   store->seen_alloc);
 
-			store.offset[store.seen] = cf->do_ftell(cf);
-			store.seen++;
+			store->seen[store->seen_nr] = store->parsed_nr;
+			store->seen_nr++;
 		}
-		break;
-	case SECTION_SEEN:
+	} else if (store->is_keys_section) {
 		/*
-		 * What we are looking for is in store.key (both
-		 * section and var), and its section part is baselen
-		 * long.  We found key (again, both section and var).
-		 * We would want to know if this key is in the same
-		 * section as what we are looking for.  We already
-		 * know we are in the same section as what should
-		 * hold store.key.
+		 * Do not increment matches yet: this may not be a match, but we
+		 * are in the desired section.
 		 */
-		ep = strrchr(key, '.');
-		section_len = ep - key;
+		ALLOC_GROW(store->seen, store->seen_nr + 1, store->seen_alloc);
+		store->seen[store->seen_nr] = store->parsed_nr;
+		store->section_seen = 1;
 
-		if ((section_len != store.baselen) ||
-		    memcmp(key, store.key, section_len+1)) {
-			store.state = SECTION_END_SEEN;
-			break;
-		}
-
-		/*
-		 * Do not increment matches: this is no match, but we
-		 * just made sure we are in the desired section.
-		 */
-		ALLOC_GROW(store.offset, store.seen + 1,
-			   store.offset_alloc);
-		store.offset[store.seen] = cf->do_ftell(cf);
-		/* fallthru */
-	case SECTION_END_SEEN:
-	case START:
-		if (matches(key, value)) {
-			ALLOC_GROW(store.offset, store.seen + 1,
-				   store.offset_alloc);
-			store.offset[store.seen] = cf->do_ftell(cf);
-			store.state = KEY_SEEN;
-			store.seen++;
-		} else {
-			if (strrchr(key, '.') - key == store.baselen &&
-			      !strncmp(key, store.key, store.baselen)) {
-					store.state = SECTION_SEEN;
-					ALLOC_GROW(store.offset,
-						   store.seen + 1,
-						   store.offset_alloc);
-					store.offset[store.seen] = cf->do_ftell(cf);
-			}
+		if (matches(key, value, store)) {
+			store->seen_nr++;
+			store->key_seen = 1;
 		}
 	}
+
 	return 0;
 }
 
@@ -2320,31 +2421,33 @@
 	return 4;
 }
 
-static struct strbuf store_create_section(const char *key)
+static struct strbuf store_create_section(const char *key,
+					  const struct config_store_data *store)
 {
 	const char *dot;
 	int i;
 	struct strbuf sb = STRBUF_INIT;
 
-	dot = memchr(key, '.', store.baselen);
+	dot = memchr(key, '.', store->baselen);
 	if (dot) {
 		strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
-		for (i = dot - key + 1; i < store.baselen; i++) {
+		for (i = dot - key + 1; i < store->baselen; i++) {
 			if (key[i] == '"' || key[i] == '\\')
 				strbuf_addch(&sb, '\\');
 			strbuf_addch(&sb, key[i]);
 		}
 		strbuf_addstr(&sb, "\"]\n");
 	} else {
-		strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
+		strbuf_addf(&sb, "[%.*s]\n", store->baselen, key);
 	}
 
 	return sb;
 }
 
-static ssize_t write_section(int fd, const char *key)
+static ssize_t write_section(int fd, const char *key,
+			     const struct config_store_data *store)
 {
-	struct strbuf sb = store_create_section(key);
+	struct strbuf sb = store_create_section(key, store);
 	ssize_t ret;
 
 	ret = write_in_full(fd, sb.buf, sb.len);
@@ -2353,11 +2456,12 @@
 	return ret;
 }
 
-static ssize_t write_pair(int fd, const char *key, const char *value)
+static ssize_t write_pair(int fd, const char *key, const char *value,
+			  const struct config_store_data *store)
 {
 	int i;
 	ssize_t ret;
-	int length = strlen(key + store.baselen + 1);
+	int length = strlen(key + store->baselen + 1);
 	const char *quote = "";
 	struct strbuf sb = STRBUF_INIT;
 
@@ -2377,7 +2481,7 @@
 		quote = "\"";
 
 	strbuf_addf(&sb, "\t%.*s = %s",
-		    length, key + store.baselen + 1, quote);
+		    length, key + store->baselen + 1, quote);
 
 	for (i = 0; value[i]; i++)
 		switch (value[i]) {
@@ -2403,30 +2507,85 @@
 	return ret;
 }
 
-static ssize_t find_beginning_of_line(const char *contents, size_t size,
-	size_t offset_, int *found_bracket)
+/*
+ * If we are about to unset the last key(s) in a section, and if there are
+ * no comments surrounding (or included in) the section, we will want to
+ * extend begin/end to remove the entire section.
+ *
+ * Note: the parameter `seen_ptr` points to the index into the store.seen
+ * array.  * This index may be incremented if a section has more than one
+ * entry (which all are to be removed).
+ */
+static void maybe_remove_section(struct config_store_data *store,
+				 const char *contents,
+				 size_t *begin_offset, size_t *end_offset,
+				 int *seen_ptr)
 {
-	size_t equal_offset = size, bracket_offset = size;
-	ssize_t offset;
+	size_t begin;
+	int i, seen, section_seen = 0;
 
-contline:
-	for (offset = offset_-2; offset > 0
-			&& contents[offset] != '\n'; offset--)
-		switch (contents[offset]) {
-			case '=': equal_offset = offset; break;
-			case ']': bracket_offset = offset; break;
+	/*
+	 * First, ensure that this is the first key, and that there are no
+	 * comments before the entry nor before the section header.
+	 */
+	seen = *seen_ptr;
+	for (i = store->seen[seen]; i > 0; i--) {
+		enum config_event_t type = store->parsed[i - 1].type;
+
+		if (type == CONFIG_EVENT_COMMENT)
+			/* There is a comment before this entry or section */
+			return;
+		if (type == CONFIG_EVENT_ENTRY) {
+			if (!section_seen)
+				/* This is not the section's first entry. */
+				return;
+			/* We encountered no comment before the section. */
+			break;
 		}
-	if (offset > 0 && contents[offset-1] == '\\') {
-		offset_ = offset;
-		goto contline;
+		if (type == CONFIG_EVENT_SECTION) {
+			if (!store->parsed[i - 1].is_keys_section)
+				break;
+			section_seen = 1;
+		}
 	}
-	if (bracket_offset < equal_offset) {
-		*found_bracket = 1;
-		offset = bracket_offset+1;
-	} else
-		offset++;
+	begin = store->parsed[i].begin;
 
-	return offset;
+	/*
+	 * Next, make sure that we are removing he last key(s) in the section,
+	 * and that there are no comments that are possibly about the current
+	 * section.
+	 */
+	for (i = store->seen[seen] + 1; i < store->parsed_nr; i++) {
+		enum config_event_t type = store->parsed[i].type;
+
+		if (type == CONFIG_EVENT_COMMENT)
+			return;
+		if (type == CONFIG_EVENT_SECTION) {
+			if (store->parsed[i].is_keys_section)
+				continue;
+			break;
+		}
+		if (type == CONFIG_EVENT_ENTRY) {
+			if (++seen < store->seen_nr &&
+			    i == store->seen[seen])
+				/* We want to remove this entry, too */
+				continue;
+			/* There is another entry in this section. */
+			return;
+		}
+	}
+
+	/*
+	 * We are really removing the last entry/entries from this section, and
+	 * there are no enclosed or surrounding comments. Remove the entire,
+	 * now-empty section.
+	 */
+	*seen_ptr = seen;
+	*begin_offset = begin;
+	if (i < store->parsed_nr)
+		*end_offset = store->parsed[i].begin;
+	else
+		*end_offset = store->parsed[store->parsed_nr - 1].end;
 }
 
 int git_config_set_in_file_gently(const char *config_filename,
@@ -2487,6 +2646,9 @@
 	char *filename_buf = NULL;
 	char *contents = NULL;
 	size_t contents_sz;
+	struct config_store_data store;
+
+	memset(&store, 0, sizeof(store));
 
 	/* parse-key returns negative; flip the sign to feed exit(3) */
 	ret = 0 - git_config_parse_key(key, &store.key, &store.baselen);
@@ -2529,13 +2691,14 @@
 		}
 
 		store.key = (char *)key;
-		if (write_section(fd, key) < 0 ||
-		    write_pair(fd, key, value) < 0)
+		if (write_section(fd, key, &store) < 0 ||
+		    write_pair(fd, key, value, &store) < 0)
 			goto write_err_out;
 	} else {
 		struct stat st;
 		size_t copy_begin, copy_end;
 		int i, new_line = 0;
+		struct config_options opts;
 
 		if (value_regex == NULL)
 			store.value_regex = NULL;
@@ -2558,18 +2721,24 @@
 			}
 		}
 
-		ALLOC_GROW(store.offset, 1, store.offset_alloc);
-		store.offset[0] = 0;
-		store.state = START;
-		store.seen = 0;
+		ALLOC_GROW(store.parsed, 1, store.parsed_alloc);
+		store.parsed[0].end = 0;
+
+		memset(&opts, 0, sizeof(opts));
+		opts.event_fn = store_aux_event;
+		opts.event_fn_data = &store;
 
 		/*
-		 * After this, store.offset will contain the *end* offset
-		 * of the last match, or remain at 0 if no match was found.
+		 * After this, store.parsed will contain offsets of all the
+		 * parsed elements, and store.seen will contain a list of
+		 * matches, as indices into store.parsed.
+		 *
 		 * As a side effect, we make sure to transform only a valid
 		 * existing config file.
 		 */
-		if (git_config_from_file(store_aux, config_filename, NULL)) {
+		if (git_config_from_file_with_options(store_aux,
+						      config_filename,
+						      &store, &opts)) {
 			error("invalid config file %s", config_filename);
 			free(store.key);
 			if (store.value_regex != NULL &&
@@ -2589,8 +2758,8 @@
 		}
 
 		/* if nothing to unset, or too many matches, error out */
-		if ((store.seen == 0 && value == NULL) ||
-				(store.seen > 1 && multi_replace == 0)) {
+		if ((store.seen_nr == 0 && value == NULL) ||
+		    (store.seen_nr > 1 && multi_replace == 0)) {
 			ret = CONFIG_NOTHING_SET;
 			goto out_free;
 		}
@@ -2621,18 +2790,49 @@
 			goto out_free;
 		}
 
-		if (store.seen == 0)
-			store.seen = 1;
+		if (store.seen_nr == 0) {
+			if (!store.seen_alloc) {
+				/* Did not see key nor section */
+				ALLOC_GROW(store.seen, 1, store.seen_alloc);
+				store.seen[0] = store.parsed_nr
+					- !!store.parsed_nr;
+			}
+			store.seen_nr = 1;
+		}
 
-		for (i = 0, copy_begin = 0; i < store.seen; i++) {
-			if (store.offset[i] == 0) {
-				store.offset[i] = copy_end = contents_sz;
-			} else if (store.state != KEY_SEEN) {
-				copy_end = store.offset[i];
-			} else
-				copy_end = find_beginning_of_line(
-					contents, contents_sz,
-					store.offset[i]-2, &new_line);
+		for (i = 0, copy_begin = 0; i < store.seen_nr; i++) {
+			size_t replace_end;
+			int j = store.seen[i];
+
+			new_line = 0;
+			if (!store.key_seen) {
+				copy_end = store.parsed[j].end;
+				/* include '\n' when copying section header */
+				if (copy_end > 0 && copy_end < contents_sz &&
+				    contents[copy_end - 1] != '\n' &&
+				    contents[copy_end] == '\n')
+					copy_end++;
+				replace_end = copy_end;
+			} else {
+				replace_end = store.parsed[j].end;
+				copy_end = store.parsed[j].begin;
+				if (!value)
+					maybe_remove_section(&store, contents,
+							     &copy_end,
+							     &replace_end, &i);
+				/*
+				 * Swallow preceding white-space on the same
+				 * line.
+				 */
+				while (copy_end > 0 ) {
+					char c = contents[copy_end - 1];
+
+					if (isspace(c) && c != '\n')
+						copy_end--;
+					else
+						break;
+				}
+			}
 
 			if (copy_end > 0 && contents[copy_end-1] != '\n')
 				new_line = 1;
@@ -2646,16 +2846,16 @@
 				    write_str_in_full(fd, "\n") < 0)
 					goto write_err_out;
 			}
-			copy_begin = store.offset[i];
+			copy_begin = replace_end;
 		}
 
 		/* write the pair (value == NULL means unset) */
 		if (value != NULL) {
-			if (store.state == START) {
-				if (write_section(fd, key) < 0)
+			if (!store.section_seen) {
+				if (write_section(fd, key, &store) < 0)
 					goto write_err_out;
 			}
-			if (write_pair(fd, key, value) < 0)
+			if (write_pair(fd, key, value, &store) < 0)
 				goto write_err_out;
 		}
 
@@ -2779,7 +2979,8 @@
 
 /* if new_name == NULL, the section is removed instead */
 static int git_config_copy_or_rename_section_in_file(const char *config_filename,
-				      const char *old_name, const char *new_name, int copy)
+				      const char *old_name,
+				      const char *new_name, int copy)
 {
 	int ret = 0, remove = 0;
 	char *filename_buf = NULL;
@@ -2789,6 +2990,9 @@
 	FILE *config_file = NULL;
 	struct stat st;
 	struct strbuf copystr = STRBUF_INIT;
+	struct config_store_data store;
+
+	memset(&store, 0, sizeof(store));
 
 	if (new_name && !section_name_is_ok(new_name)) {
 		ret = error("invalid section name: %s", new_name);
@@ -2858,7 +3062,7 @@
 				}
 				store.baselen = strlen(new_name);
 				if (!copy) {
-					if (write_section(out_fd, new_name) < 0) {
+					if (write_section(out_fd, new_name, &store) < 0) {
 						ret = write_error(get_lock_file_path(&lock));
 						goto out;
 					}
@@ -2879,7 +3083,7 @@
 						output[0] = '\t';
 					}
 				} else {
-					copystr = store_create_section(new_name);
+					copystr = store_create_section(new_name, &store);
 				}
 			}
 			remove = 0;
diff --git a/config.h b/config.h
index ef70a9c..cdac2fc 100644
--- a/config.h
+++ b/config.h
@@ -28,15 +28,40 @@
 	CONFIG_ORIGIN_CMDLINE
 };
 
+enum config_event_t {
+	CONFIG_EVENT_SECTION,
+	CONFIG_EVENT_ENTRY,
+	CONFIG_EVENT_WHITESPACE,
+	CONFIG_EVENT_COMMENT,
+	CONFIG_EVENT_EOF,
+	CONFIG_EVENT_ERROR
+};
+
+/*
+ * The parser event function (if not NULL) is called with the event type and
+ * the begin/end offsets of the parsed elements.
+ *
+ * Note: for CONFIG_EVENT_ENTRY (i.e. config variables), the trailing newline
+ * character is considered part of the element.
+ */
+typedef int (*config_parser_event_fn_t)(enum config_event_t type,
+					size_t begin_offset, size_t end_offset,
+					void *event_fn_data);
+
 struct config_options {
 	unsigned int respect_includes : 1;
 	const char *commondir;
 	const char *git_dir;
+	config_parser_event_fn_t event_fn;
+	void *event_fn_data;
 };
 
 typedef int (*config_fn_t)(const char *, const char *, void *);
 extern int git_default_config(const char *, const char *, void *);
 extern int git_config_from_file(config_fn_t fn, const char *, void *);
+extern int git_config_from_file_with_options(config_fn_t fn, const char *,
+					     void *,
+					     const struct config_options *);
 extern int git_config_from_mem(config_fn_t fn, const enum config_origin_type,
 					const char *name, const char *buf, size_t len, void *data);
 extern int git_config_from_blob_oid(config_fn_t fn, const char *name,
@@ -59,6 +84,7 @@
 extern int git_config_string(const char **, const char *, const char *);
 extern int git_config_pathname(const char **, const char *, const char *);
 extern int git_config_expiry_date(timestamp_t *, const char *, const char *);
+extern int git_config_color(char *, const char *, const char *);
 extern int git_config_set_in_file_gently(const char *, const char *, const char *);
 extern void git_config_set_in_file(const char *, const char *, const char *);
 extern int git_config_set_gently(const char *, const char *);
diff --git a/config.mak.dev b/config.mak.dev
new file mode 100644
index 0000000..2d244ca
--- /dev/null
+++ b/config.mak.dev
@@ -0,0 +1,42 @@
+ifeq ($(filter no-error,$(DEVOPTS)),)
+CFLAGS += -Werror
+endif
+CFLAGS += -Wdeclaration-after-statement
+CFLAGS += -Wno-format-zero-length
+CFLAGS += -Wold-style-definition
+CFLAGS += -Woverflow
+CFLAGS += -Wpointer-arith
+CFLAGS += -Wstrict-prototypes
+CFLAGS += -Wunused
+CFLAGS += -Wvla
+
+ifndef COMPILER_FEATURES
+COMPILER_FEATURES := $(shell ./detect-compiler $(CC))
+endif
+
+ifneq ($(filter clang4,$(COMPILER_FEATURES)),)
+CFLAGS += -Wtautological-constant-out-of-range-compare
+endif
+
+ifneq ($(or $(filter gcc6,$(COMPILER_FEATURES)),$(filter clang4,$(COMPILER_FEATURES))),)
+CFLAGS += -Wextra
+# if a function is public, there should be a prototype and the right
+# header file should be included. If not, it should be static.
+CFLAGS += -Wmissing-prototypes
+ifeq ($(filter extra-all,$(DEVOPTS)),)
+# These are disabled because we have these all over the place.
+CFLAGS += -Wno-empty-body
+CFLAGS += -Wno-missing-field-initializers
+CFLAGS += -Wno-sign-compare
+CFLAGS += -Wno-unused-function
+CFLAGS += -Wno-unused-parameter
+endif
+endif
+
+# uninitialized warnings on gcc 4.9.2 in xdiff/xdiffi.c and config.c
+# not worth fixing since newer compilers correctly stop complaining
+ifneq ($(filter gcc4,$(COMPILER_FEATURES)),)
+ifeq ($(filter gcc5,$(COMPILER_FEATURES)),)
+CFLAGS += -Wno-uninitialized
+endif
+endif
diff --git a/configure.ac b/configure.ac
index 6f1fd9d..e11b797 100644
--- a/configure.ac
+++ b/configure.ac
@@ -927,7 +927,7 @@
 	[AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT],
 		[[
 		FILE *f = fopen(".", "r");
-		return f)]])],
+		return f != NULL;]])],
 	[ac_cv_fread_reads_directories=no],
 	[ac_cv_fread_reads_directories=yes])
 ])
diff --git a/connect.c b/connect.c
index c3a014c..b34dc80 100644
--- a/connect.c
+++ b/connect.c
@@ -12,9 +12,11 @@
 #include "sha1-array.h"
 #include "transport.h"
 #include "strbuf.h"
+#include "version.h"
 #include "protocol.h"
 
-static char *server_capabilities;
+static char *server_capabilities_v1;
+static struct argv_array server_capabilities_v2 = ARGV_ARRAY_INIT;
 static const char *parse_feature_value(const char *, const char *, int *);
 
 static int check_ref(const char *name, unsigned int flags)
@@ -46,8 +48,14 @@
 	return check_ref(ref->name, flags);
 }
 
-static void die_initial_contact(int unexpected)
+static NORETURN void die_initial_contact(int unexpected)
 {
+	/*
+	 * A hang-up after seeing some response from the other end
+	 * means that it is unexpected, as we know the other end is
+	 * willing to talk to us.  A hang-up before seeing any
+	 * response does not necessarily mean an ACL problem, though.
+	 */
 	if (unexpected)
 		die(_("The remote end hung up upon initial contact"));
 	else
@@ -56,6 +64,92 @@
 		      "and the repository exists."));
 }
 
+/* Checks if the server supports the capability 'c' */
+int server_supports_v2(const char *c, int die_on_error)
+{
+	int i;
+
+	for (i = 0; i < server_capabilities_v2.argc; i++) {
+		const char *out;
+		if (skip_prefix(server_capabilities_v2.argv[i], c, &out) &&
+		    (!*out || *out == '='))
+			return 1;
+	}
+
+	if (die_on_error)
+		die("server doesn't support '%s'", c);
+
+	return 0;
+}
+
+int server_supports_feature(const char *c, const char *feature,
+			    int die_on_error)
+{
+	int i;
+
+	for (i = 0; i < server_capabilities_v2.argc; i++) {
+		const char *out;
+		if (skip_prefix(server_capabilities_v2.argv[i], c, &out) &&
+		    (!*out || *(out++) == '=')) {
+			if (parse_feature_request(out, feature))
+				return 1;
+			else
+				break;
+		}
+	}
+
+	if (die_on_error)
+		die("server doesn't support feature '%s'", feature);
+
+	return 0;
+}
+
+static void process_capabilities_v2(struct packet_reader *reader)
+{
+	while (packet_reader_read(reader) == PACKET_READ_NORMAL)
+		argv_array_push(&server_capabilities_v2, reader->line);
+
+	if (reader->status != PACKET_READ_FLUSH)
+		die("expected flush after capabilities");
+}
+
+enum protocol_version discover_version(struct packet_reader *reader)
+{
+	enum protocol_version version = protocol_unknown_version;
+
+	/*
+	 * Peek the first line of the server's response to
+	 * determine the protocol version the server is speaking.
+	 */
+	switch (packet_reader_peek(reader)) {
+	case PACKET_READ_EOF:
+		die_initial_contact(0);
+	case PACKET_READ_FLUSH:
+	case PACKET_READ_DELIM:
+		version = protocol_v0;
+		break;
+	case PACKET_READ_NORMAL:
+		version = determine_protocol_version_client(reader->line);
+		break;
+	}
+
+	switch (version) {
+	case protocol_v2:
+		process_capabilities_v2(reader);
+		break;
+	case protocol_v1:
+		/* Read the peeked version line */
+		packet_reader_read(reader);
+		break;
+	case protocol_v0:
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
+
+	return version;
+}
+
 static void parse_one_symref_info(struct string_list *symref, const char *val, int len)
 {
 	char *sym, *target;
@@ -85,7 +179,7 @@
 static void annotate_refs_with_symref_info(struct ref *ref)
 {
 	struct string_list symref = STRING_LIST_INIT_DUP;
-	const char *feature_list = server_capabilities;
+	const char *feature_list = server_capabilities_v1;
 
 	while (feature_list) {
 		int len;
@@ -109,60 +203,21 @@
 	string_list_clear(&symref, 0);
 }
 
-/*
- * Read one line of a server's ref advertisement into packet_buffer.
- */
-static int read_remote_ref(int in, char **src_buf, size_t *src_len,
-			   int *responded)
+static void process_capabilities(const char *line, int *len)
 {
-	int len = packet_read(in, src_buf, src_len,
-			      packet_buffer, sizeof(packet_buffer),
-			      PACKET_READ_GENTLE_ON_EOF |
-			      PACKET_READ_CHOMP_NEWLINE);
-	const char *arg;
-	if (len < 0)
-		die_initial_contact(*responded);
-	if (len > 4 && skip_prefix(packet_buffer, "ERR ", &arg))
-		die("remote error: %s", arg);
-
-	*responded = 1;
-
-	return len;
-}
-
-#define EXPECTING_PROTOCOL_VERSION 0
-#define EXPECTING_FIRST_REF 1
-#define EXPECTING_REF 2
-#define EXPECTING_SHALLOW 3
-
-/* Returns 1 if packet_buffer is a protocol version pkt-line, 0 otherwise. */
-static int process_protocol_version(void)
-{
-	switch (determine_protocol_version_client(packet_buffer)) {
-	case protocol_v1:
-		return 1;
-	case protocol_v0:
-		return 0;
-	default:
-		die("server is speaking an unknown protocol");
-	}
-}
-
-static void process_capabilities(int *len)
-{
-	int nul_location = strlen(packet_buffer);
+	int nul_location = strlen(line);
 	if (nul_location == *len)
 		return;
-	server_capabilities = xstrdup(packet_buffer + nul_location + 1);
+	server_capabilities_v1 = xstrdup(line + nul_location + 1);
 	*len = nul_location;
 }
 
-static int process_dummy_ref(void)
+static int process_dummy_ref(const char *line)
 {
 	struct object_id oid;
 	const char *name;
 
-	if (parse_oid_hex(packet_buffer, &oid, &name))
+	if (parse_oid_hex(line, &oid, &name))
 		return 0;
 	if (*name != ' ')
 		return 0;
@@ -171,20 +226,20 @@
 	return !oidcmp(&null_oid, &oid) && !strcmp(name, "capabilities^{}");
 }
 
-static void check_no_capabilities(int len)
+static void check_no_capabilities(const char *line, int len)
 {
-	if (strlen(packet_buffer) != len)
+	if (strlen(line) != len)
 		warning("Ignoring capabilities after first line '%s'",
-			packet_buffer + strlen(packet_buffer));
+			line + strlen(line));
 }
 
-static int process_ref(int len, struct ref ***list, unsigned int flags,
-		       struct oid_array *extra_have)
+static int process_ref(const char *line, int len, struct ref ***list,
+		       unsigned int flags, struct oid_array *extra_have)
 {
 	struct object_id old_oid;
 	const char *name;
 
-	if (parse_oid_hex(packet_buffer, &old_oid, &name))
+	if (parse_oid_hex(line, &old_oid, &name))
 		return 0;
 	if (*name != ' ')
 		return 0;
@@ -200,16 +255,17 @@
 		**list = ref;
 		*list = &ref->next;
 	}
-	check_no_capabilities(len);
+	check_no_capabilities(line, len);
 	return 1;
 }
 
-static int process_shallow(int len, struct oid_array *shallow_points)
+static int process_shallow(const char *line, int len,
+			   struct oid_array *shallow_points)
 {
 	const char *arg;
 	struct object_id old_oid;
 
-	if (!skip_prefix(packet_buffer, "shallow ", &arg))
+	if (!skip_prefix(line, "shallow ", &arg))
 		return 0;
 
 	if (get_oid_hex(arg, &old_oid))
@@ -217,60 +273,68 @@
 	if (!shallow_points)
 		die("repository on the other end cannot be shallow");
 	oid_array_append(shallow_points, &old_oid);
-	check_no_capabilities(len);
+	check_no_capabilities(line, len);
 	return 1;
 }
 
+enum get_remote_heads_state {
+	EXPECTING_FIRST_REF = 0,
+	EXPECTING_REF,
+	EXPECTING_SHALLOW,
+	EXPECTING_DONE,
+};
+
 /*
  * Read all the refs from the other end
  */
-struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
+struct ref **get_remote_heads(struct packet_reader *reader,
 			      struct ref **list, unsigned int flags,
 			      struct oid_array *extra_have,
 			      struct oid_array *shallow_points)
 {
 	struct ref **orig_list = list;
-
-	/*
-	 * A hang-up after seeing some response from the other end
-	 * means that it is unexpected, as we know the other end is
-	 * willing to talk to us.  A hang-up before seeing any
-	 * response does not necessarily mean an ACL problem, though.
-	 */
-	int responded = 0;
-	int len;
-	int state = EXPECTING_PROTOCOL_VERSION;
+	int len = 0;
+	enum get_remote_heads_state state = EXPECTING_FIRST_REF;
+	const char *arg;
 
 	*list = NULL;
 
-	while ((len = read_remote_ref(in, &src_buf, &src_len, &responded))) {
+	while (state != EXPECTING_DONE) {
+		switch (packet_reader_read(reader)) {
+		case PACKET_READ_EOF:
+			die_initial_contact(1);
+		case PACKET_READ_NORMAL:
+			len = reader->pktlen;
+			if (len > 4 && skip_prefix(reader->line, "ERR ", &arg))
+				die("remote error: %s", arg);
+			break;
+		case PACKET_READ_FLUSH:
+			state = EXPECTING_DONE;
+			break;
+		case PACKET_READ_DELIM:
+			die("invalid packet");
+		}
+
 		switch (state) {
-		case EXPECTING_PROTOCOL_VERSION:
-			if (process_protocol_version()) {
-				state = EXPECTING_FIRST_REF;
-				break;
-			}
-			state = EXPECTING_FIRST_REF;
-			/* fallthrough */
 		case EXPECTING_FIRST_REF:
-			process_capabilities(&len);
-			if (process_dummy_ref()) {
+			process_capabilities(reader->line, &len);
+			if (process_dummy_ref(reader->line)) {
 				state = EXPECTING_SHALLOW;
 				break;
 			}
 			state = EXPECTING_REF;
 			/* fallthrough */
 		case EXPECTING_REF:
-			if (process_ref(len, &list, flags, extra_have))
+			if (process_ref(reader->line, len, &list, flags, extra_have))
 				break;
 			state = EXPECTING_SHALLOW;
 			/* fallthrough */
 		case EXPECTING_SHALLOW:
-			if (process_shallow(len, shallow_points))
+			if (process_shallow(reader->line, len, shallow_points))
 				break;
-			die("protocol error: unexpected '%s'", packet_buffer);
-		default:
-			die("unexpected state %d", state);
+			die("protocol error: unexpected '%s'", reader->line);
+		case EXPECTING_DONE:
+			break;
 		}
 	}
 
@@ -279,6 +343,105 @@
 	return list;
 }
 
+/* Returns 1 when a valid ref has been added to `list`, 0 otherwise */
+static int process_ref_v2(const char *line, struct ref ***list)
+{
+	int ret = 1;
+	int i = 0;
+	struct object_id old_oid;
+	struct ref *ref;
+	struct string_list line_sections = STRING_LIST_INIT_DUP;
+	const char *end;
+
+	/*
+	 * Ref lines have a number of fields which are space deliminated.  The
+	 * first field is the OID of the ref.  The second field is the ref
+	 * name.  Subsequent fields (symref-target and peeled) are optional and
+	 * don't have a particular order.
+	 */
+	if (string_list_split(&line_sections, line, ' ', -1) < 2) {
+		ret = 0;
+		goto out;
+	}
+
+	if (parse_oid_hex(line_sections.items[i++].string, &old_oid, &end) ||
+	    *end) {
+		ret = 0;
+		goto out;
+	}
+
+	ref = alloc_ref(line_sections.items[i++].string);
+
+	oidcpy(&ref->old_oid, &old_oid);
+	**list = ref;
+	*list = &ref->next;
+
+	for (; i < line_sections.nr; i++) {
+		const char *arg = line_sections.items[i].string;
+		if (skip_prefix(arg, "symref-target:", &arg))
+			ref->symref = xstrdup(arg);
+
+		if (skip_prefix(arg, "peeled:", &arg)) {
+			struct object_id peeled_oid;
+			char *peeled_name;
+			struct ref *peeled;
+			if (parse_oid_hex(arg, &peeled_oid, &end) || *end) {
+				ret = 0;
+				goto out;
+			}
+
+			peeled_name = xstrfmt("%s^{}", ref->name);
+			peeled = alloc_ref(peeled_name);
+
+			oidcpy(&peeled->old_oid, &peeled_oid);
+			**list = peeled;
+			*list = &peeled->next;
+
+			free(peeled_name);
+		}
+	}
+
+out:
+	string_list_clear(&line_sections, 0);
+	return ret;
+}
+
+struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
+			     struct ref **list, int for_push,
+			     const struct argv_array *ref_prefixes)
+{
+	int i;
+	*list = NULL;
+
+	if (server_supports_v2("ls-refs", 1))
+		packet_write_fmt(fd_out, "command=ls-refs\n");
+
+	if (server_supports_v2("agent", 0))
+		packet_write_fmt(fd_out, "agent=%s", git_user_agent_sanitized());
+
+	packet_delim(fd_out);
+	/* When pushing we don't want to request the peeled tags */
+	if (!for_push)
+		packet_write_fmt(fd_out, "peel\n");
+	packet_write_fmt(fd_out, "symrefs\n");
+	for (i = 0; ref_prefixes && i < ref_prefixes->argc; i++) {
+		packet_write_fmt(fd_out, "ref-prefix %s\n",
+				 ref_prefixes->argv[i]);
+	}
+	packet_flush(fd_out);
+
+	/* Process response from server */
+	while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
+		if (!process_ref_v2(reader->line, &list))
+			die("invalid ls-refs response: %s", reader->line);
+	}
+
+	if (reader->status != PACKET_READ_FLUSH)
+		die("expected flush after ref listing");
+
+	return list;
+}
+
 static const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp)
 {
 	int len;
@@ -323,7 +486,7 @@
 
 const char *server_feature_value(const char *feature, int *len)
 {
-	return parse_feature_value(server_capabilities, feature, len);
+	return parse_feature_value(server_capabilities_v1, feature, len);
 }
 
 int server_supports(const char *feature)
@@ -872,6 +1035,7 @@
  */
 static struct child_process *git_connect_git(int fd[2], char *hostandport,
 					     const char *path, const char *prog,
+					     enum protocol_version version,
 					     int flags)
 {
 	struct child_process *conn;
@@ -910,10 +1074,10 @@
 		    target_host, 0);
 
 	/* If using a new version put that stuff here after a second null byte */
-	if (get_protocol_version_config() > 0) {
+	if (version > 0) {
 		strbuf_addch(&request, '\0');
 		strbuf_addf(&request, "version=%d%c",
-			    get_protocol_version_config(), '\0');
+			    version, '\0');
 	}
 
 	packet_write(fd[1], request.buf, request.len);
@@ -929,14 +1093,14 @@
  */
 static void push_ssh_options(struct argv_array *args, struct argv_array *env,
 			     enum ssh_variant variant, const char *port,
-			     int flags)
+			     enum protocol_version version, int flags)
 {
 	if (variant == VARIANT_SSH &&
-	    get_protocol_version_config() > 0) {
+	    version > 0) {
 		argv_array_push(args, "-o");
 		argv_array_push(args, "SendEnv=" GIT_PROTOCOL_ENVIRONMENT);
 		argv_array_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
-				 get_protocol_version_config());
+				 version);
 	}
 
 	if (flags & CONNECT_IPV4) {
@@ -989,7 +1153,8 @@
 
 /* Prepare a child_process for use by Git's SSH-tunneled transport. */
 static void fill_ssh_args(struct child_process *conn, const char *ssh_host,
-			  const char *port, int flags)
+			  const char *port, enum protocol_version version,
+			  int flags)
 {
 	const char *ssh;
 	enum ssh_variant variant;
@@ -1023,14 +1188,14 @@
 		argv_array_push(&detect.args, ssh);
 		argv_array_push(&detect.args, "-G");
 		push_ssh_options(&detect.args, &detect.env_array,
-				 VARIANT_SSH, port, flags);
+				 VARIANT_SSH, port, version, flags);
 		argv_array_push(&detect.args, ssh_host);
 
 		variant = run_command(&detect) ? VARIANT_SIMPLE : VARIANT_SSH;
 	}
 
 	argv_array_push(&conn->args, ssh);
-	push_ssh_options(&conn->args, &conn->env_array, variant, port, flags);
+	push_ssh_options(&conn->args, &conn->env_array, variant, port, version, flags);
 	argv_array_push(&conn->args, ssh_host);
 }
 
@@ -1051,6 +1216,15 @@
 	char *hostandport, *path;
 	struct child_process *conn;
 	enum protocol protocol;
+	enum protocol_version version = get_protocol_version_config();
+
+	/*
+	 * NEEDSWORK: If we are trying to use protocol v2 and we are planning
+	 * to perform a push, then fallback to v0 since the client doesn't know
+	 * how to push yet using v2.
+	 */
+	if (version == protocol_v2 && !strcmp("git-receive-pack", prog))
+		version = protocol_v0;
 
 	/* Without this we cannot rely on waitpid() to tell
 	 * what happened to our children.
@@ -1065,7 +1239,7 @@
 		printf("Diag: path=%s\n", path ? path : "NULL");
 		conn = NULL;
 	} else if (protocol == PROTO_GIT) {
-		conn = git_connect_git(fd, hostandport, path, prog, flags);
+		conn = git_connect_git(fd, hostandport, path, prog, version, flags);
 	} else {
 		struct strbuf cmd = STRBUF_INIT;
 		const char *const *var;
@@ -1108,12 +1282,12 @@
 				strbuf_release(&cmd);
 				return NULL;
 			}
-			fill_ssh_args(conn, ssh_host, port, flags);
+			fill_ssh_args(conn, ssh_host, port, version, flags);
 		} else {
 			transport_check_allowed("file");
-			if (get_protocol_version_config() > 0) {
+			if (version > 0) {
 				argv_array_pushf(&conn->env_array, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
-						 get_protocol_version_config());
+						 version);
 			}
 		}
 		argv_array_push(&conn->args, cmd.buf);
diff --git a/connect.h b/connect.h
index 01f14cd..0e69c67 100644
--- a/connect.h
+++ b/connect.h
@@ -13,4 +13,11 @@
 extern const char *server_feature_value(const char *feature, int *len_ret);
 extern int url_is_local_not_ssh(const char *url);
 
+struct packet_reader;
+extern enum protocol_version discover_version(struct packet_reader *reader);
+
+extern int server_supports_v2(const char *c, int die_on_error);
+extern int server_supports_feature(const char *c, const char *feature,
+				   int die_on_error);
+
 #endif
diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index a757073..46047e1 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -284,7 +284,11 @@
 
 # Clear the variables caching builtins' options when (re-)sourcing
 # the completion script.
-unset $(set |sed -ne 's/^\(__gitcomp_builtin_[a-zA-Z0-9_][a-zA-Z0-9_]*\)=.*/\1/p') 2>/dev/null
+if [[ -n ${ZSH_VERSION-} ]]; then
+	unset $(set |sed -ne 's/^\(__gitcomp_builtin_[a-zA-Z0-9_][a-zA-Z0-9_]*\)=.*/\1/p') 2>/dev/null
+else
+	unset $(compgen -v __gitcomp_builtin_)
+fi
 
 # This function is equivalent to
 #
@@ -390,12 +394,7 @@
 	local root="${2-.}" file
 
 	__git_ls_files_helper "$root" "$1" |
-	while read -r file; do
-		case "$file" in
-		?*/*) echo "${file%%/*}" ;;
-		*) echo "$file" ;;
-		esac
-	done | sort | uniq
+	cut -f1 -d/ | sort | uniq
 }
 
 # Lists branches from the local repository.
@@ -880,6 +879,7 @@
 		check-ref-format) : plumbing;;
 		checkout-index)   : plumbing;;
 		column)           : internal helper;;
+		commit-graph)     : plumbing;;
 		commit-tree)      : plumbing;;
 		count-objects)    : infrequent;;
 		credential)       : credentials;;
@@ -2350,6 +2350,7 @@
 		core.bigFileThreshold
 		core.checkStat
 		core.commentChar
+		core.commitGraph
 		core.compression
 		core.createObject
 		core.deltaBaseCacheLimit
@@ -2774,13 +2775,21 @@
 _git_stash ()
 {
 	local save_opts='--all --keep-index --no-keep-index --quiet --patch --include-untracked'
-	local subcommands='push save list show apply clear drop pop create branch'
-	local subcommand="$(__git_find_on_cmdline "$subcommands")"
+	local subcommands='push list show apply clear drop pop create branch'
+	local subcommand="$(__git_find_on_cmdline "$subcommands save")"
+	if [ -n "$(__git_find_on_cmdline "-p")" ]; then
+		subcommand="push"
+	fi
 	if [ -z "$subcommand" ]; then
 		case "$cur" in
 		--*)
 			__gitcomp "$save_opts"
 			;;
+		sa*)
+			if [ -z "$(__git_find_on_cmdline "$save_opts")" ]; then
+				__gitcomp "save"
+			fi
+			;;
 		*)
 			if [ -z "$(__git_find_on_cmdline "$save_opts")" ]; then
 				__gitcomp "$subcommands"
diff --git a/contrib/emacs/.gitignore b/contrib/emacs/.gitignore
deleted file mode 100644
index c531d98..0000000
--- a/contrib/emacs/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-*.elc
diff --git a/contrib/emacs/Makefile b/contrib/emacs/Makefile
deleted file mode 100644
index 24d9312..0000000
--- a/contrib/emacs/Makefile
+++ /dev/null
@@ -1,21 +0,0 @@
-## Build and install stuff
-
-EMACS = emacs
-
-ELC = git.elc git-blame.elc
-INSTALL ?= install
-INSTALL_ELC = $(INSTALL) -m 644
-prefix ?= $(HOME)
-emacsdir = $(prefix)/share/emacs/site-lisp
-RM ?= rm -f
-
-all: $(ELC)
-
-install: all
-	$(INSTALL) -d $(DESTDIR)$(emacsdir)
-	$(INSTALL_ELC) $(ELC:.elc=.el) $(ELC) $(DESTDIR)$(emacsdir)
-
-%.elc: %.el
-	$(EMACS) -batch -f batch-byte-compile $<
-
-clean:; $(RM) $(ELC)
diff --git a/contrib/emacs/README b/contrib/emacs/README
index 82368bd..977a16f 100644
--- a/contrib/emacs/README
+++ b/contrib/emacs/README
@@ -1,30 +1,24 @@
-This directory contains various modules for Emacs support.
+This directory used to contain various modules for Emacs support.
 
-To make the modules available to Emacs, you should add this directory
-to your load-path, and then require the modules you want. This can be
-done by adding to your .emacs something like this:
+These were added shortly after Git was first released. Since then
+Emacs's own support for Git got better than what was offered by these
+modes. There are also popular 3rd-party Git modes such as Magit which
+offer replacements for these.
 
-  (add-to-list 'load-path ".../git/contrib/emacs")
-  (require 'git)
-  (require 'git-blame)
-
-
-The following modules are available:
+The following modules were available, and can be dug up from the Git
+history:
 
 * git.el:
 
-  Status manager that displays the state of all the files of the
-  project, and provides easy access to the most frequently used git
-  commands. The user interface is as far as possible compatible with
-  the pcl-cvs mode. It can be started with `M-x git-status'.
+  Wrapper for "git status" that provided access to other git commands.
+
+  Modern alternatives to this include Magit, and VC mode that ships
+  with Emacs.
 
 * git-blame.el:
 
-  Emacs implementation of incremental git-blame.  When you turn it on
-  while viewing a file, the editor buffer will be updated by setting
-  the background of individual lines to a color that reflects which
-  commit it comes from.  And when you move around the buffer, a
-  one-line summary will be shown in the echo area.
+  A wrapper for "git blame" written before Emacs's own vc-annotate
+  mode learned to invoke git-blame, which can be done via C-x v g.
 
 * vc-git.el:
 
diff --git a/contrib/emacs/git-blame.el b/contrib/emacs/git-blame.el
index 510e0f7..6a8a2b8 100644
--- a/contrib/emacs/git-blame.el
+++ b/contrib/emacs/git-blame.el
@@ -1,483 +1,6 @@
-;;; git-blame.el --- Minor mode for incremental blame for Git  -*- coding: utf-8 -*-
-;;
-;; Copyright (C) 2007  David Kågedal
-;;
-;; Authors:    David Kågedal <davidk@lysator.liu.se>
-;; Created:    31 Jan 2007
-;; Message-ID: <87iren2vqx.fsf@morpheus.local>
-;; License:    GPL
-;; Keywords:   git, version control, release management
-;;
-;; Compatibility: Emacs21, Emacs22 and EmacsCVS
-;;                Git 1.5 and up
-
-;; This file is *NOT* part of GNU Emacs.
-;; This file is distributed under the same terms as GNU Emacs.
-
-;; This program is free software; you can redistribute it and/or
-;; modify it under the terms of the GNU General Public License as
-;; published by the Free Software Foundation; either version 2 of
-;; the License, or (at your option) any later version.
-
-;; This program is distributed in the hope that it will be
-;; useful, but WITHOUT ANY WARRANTY; without even the implied
-;; warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
-;; PURPOSE.  See the GNU General Public License for more details.
-
-;; You should have received a copy of the GNU General Public
-;; License along with this program; if not, see
-;; <http://www.gnu.org/licenses/>.
-
-;; http://www.fsf.org/copyleft/gpl.html
-
-
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;;
-;;; Commentary:
-;;
-;; Here is an Emacs implementation of incremental git-blame.  When you
-;; turn it on while viewing a file, the editor buffer will be updated by
-;; setting the background of individual lines to a color that reflects
-;; which commit it comes from.  And when you move around the buffer, a
-;; one-line summary will be shown in the echo area.
-
-;;; Installation:
-;;
-;; To use this package, put it somewhere in `load-path' (or add
-;; directory with git-blame.el to `load-path'), and add the following
-;; line to your .emacs:
-;;
-;;    (require 'git-blame)
-;;
-;; If you do not want to load this package before it is necessary, you
-;; can make use of the `autoload' feature, e.g. by adding to your .emacs
-;; the following lines
-;;
-;;    (autoload 'git-blame-mode "git-blame"
-;;              "Minor mode for incremental blame for Git." t)
-;;
-;; Then first use of `M-x git-blame-mode' would load the package.
-
-;;; Compatibility:
-;;
-;; It requires GNU Emacs 21 or later and Git 1.5.0 and up
-;;
-;; If you'are using Emacs 20, try changing this:
-;;
-;;            (overlay-put ovl 'face (list :background
-;;                                         (cdr (assq 'color (cddddr info)))))
-;;
-;; to
-;;
-;;            (overlay-put ovl 'face (cons 'background-color
-;;                                         (cdr (assq 'color (cddddr info)))))
-
-
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;;
-;;; Code:
-
-(eval-when-compile (require 'cl))			      ; to use `push', `pop'
-(require 'format-spec)
-
-(defface git-blame-prefix-face
-  '((((background dark)) (:foreground "gray"
-                          :background "black"))
-    (((background light)) (:foreground "gray"
-                           :background "white"))
-    (t (:weight bold)))
-  "The face used for the hash prefix."
-  :group 'git-blame)
-
-(defgroup git-blame nil
-  "A minor mode showing Git blame information."
-  :group 'git
-  :link '(function-link git-blame-mode))
-
-
-(defcustom git-blame-use-colors t
-  "Use colors to indicate commits in `git-blame-mode'."
-  :type 'boolean
-  :group 'git-blame)
-
-(defcustom git-blame-prefix-format
-  "%h %20A:"
-  "The format of the prefix added to each line in `git-blame'
-mode. The format is passed to `format-spec' with the following format keys:
-
-  %h - the abbreviated hash
-  %H - the full hash
-  %a - the author name
-  %A - the author email
-  %c - the committer name
-  %C - the committer email
-  %s - the commit summary
-"
-  :group 'git-blame)
-
-(defcustom git-blame-mouseover-format
-  "%h %a %A: %s"
-  "The format of the description shown when pointing at a line in
-`git-blame' mode. The format string is passed to `format-spec'
-with the following format keys:
-
-  %h - the abbreviated hash
-  %H - the full hash
-  %a - the author name
-  %A - the author email
-  %c - the committer name
-  %C - the committer email
-  %s - the commit summary
-"
-  :group 'git-blame)
-
-
-(defun git-blame-color-scale (&rest elements)
-  "Given a list, returns a list of triples formed with each
-elements of the list.
-
-a b => bbb bba bab baa abb aba aaa aab"
-  (let (result)
-    (dolist (a elements)
-      (dolist (b elements)
-        (dolist (c elements)
-          (setq result (cons (format "#%s%s%s" a b c) result)))))
-    result))
-
-;; (git-blame-color-scale "0c" "04" "24" "1c" "2c" "34" "14" "3c") =>
-;; ("#3c3c3c" "#3c3c14" "#3c3c34" "#3c3c2c" "#3c3c1c" "#3c3c24"
-;; "#3c3c04" "#3c3c0c" "#3c143c" "#3c1414" "#3c1434" "#3c142c" ...)
-
-(defmacro git-blame-random-pop (l)
-  "Select a random element from L and returns it. Also remove
-selected element from l."
-  ;; only works on lists with unique elements
-  `(let ((e (elt ,l (random (length ,l)))))
-     (setq ,l (remove e ,l))
-     e))
-
-(defvar git-blame-log-oneline-format
-  "format:[%cr] %cn: %s"
-  "*Formatting option used for describing current line in the minibuffer.
-
-This option is used to pass to git log --pretty= command-line option,
-and describe which commit the current line was made.")
-
-(defvar git-blame-dark-colors
-  (git-blame-color-scale "0c" "04" "24" "1c" "2c" "34" "14" "3c")
-  "*List of colors (format #RGB) to use in a dark environment.
-
-To check out the list, evaluate (list-colors-display git-blame-dark-colors).")
-
-(defvar git-blame-light-colors
-  (git-blame-color-scale "c4" "d4" "cc" "dc" "f4" "e4" "fc" "ec")
-  "*List of colors (format #RGB) to use in a light environment.
-
-To check out the list, evaluate (list-colors-display git-blame-light-colors).")
-
-(defvar git-blame-colors '()
-  "Colors used by git-blame. The list is built once when activating git-blame
-minor mode.")
-
-(defvar git-blame-ancient-color "dark green"
-  "*Color to be used for ancient commit.")
-
-(defvar git-blame-autoupdate t
-  "*Automatically update the blame display while editing")
-
-(defvar git-blame-proc nil
-  "The running git-blame process")
-(make-variable-buffer-local 'git-blame-proc)
-
-(defvar git-blame-overlays nil
-  "The git-blame overlays used in the current buffer.")
-(make-variable-buffer-local 'git-blame-overlays)
-
-(defvar git-blame-cache nil
-  "A cache of git-blame information for the current buffer")
-(make-variable-buffer-local 'git-blame-cache)
-
-(defvar git-blame-idle-timer nil
-  "An idle timer that updates the blame")
-(make-variable-buffer-local 'git-blame-cache)
-
-(defvar git-blame-update-queue nil
-  "A queue of update requests")
-(make-variable-buffer-local 'git-blame-update-queue)
-
-;; FIXME: docstrings
-(defvar git-blame-file nil)
-(defvar git-blame-current nil)
-
-(defvar git-blame-mode nil)
-(make-variable-buffer-local 'git-blame-mode)
-
-(defvar git-blame-mode-line-string " blame"
-  "String to display on the mode line when git-blame is active.")
-
-(or (assq 'git-blame-mode minor-mode-alist)
-    (setq minor-mode-alist
-	  (cons '(git-blame-mode git-blame-mode-line-string) minor-mode-alist)))
-
-;;;###autoload
-(defun git-blame-mode (&optional arg)
-  "Toggle minor mode for displaying Git blame
-
-With prefix ARG, turn the mode on if ARG is positive."
-  (interactive "P")
-  (cond
-   ((null arg)
-    (if git-blame-mode (git-blame-mode-off) (git-blame-mode-on)))
-   ((> (prefix-numeric-value arg) 0) (git-blame-mode-on))
-   (t (git-blame-mode-off))))
-
-(defun git-blame-mode-on ()
-  "Turn on git-blame mode.
-
-See also function `git-blame-mode'."
-  (make-local-variable 'git-blame-colors)
-  (if git-blame-autoupdate
-      (add-hook 'after-change-functions 'git-blame-after-change nil t)
-    (remove-hook 'after-change-functions 'git-blame-after-change t))
-  (git-blame-cleanup)
-  (let ((bgmode (cdr (assoc 'background-mode (frame-parameters)))))
-    (if (eq bgmode 'dark)
-	(setq git-blame-colors git-blame-dark-colors)
-      (setq git-blame-colors git-blame-light-colors)))
-  (setq git-blame-cache (make-hash-table :test 'equal))
-  (setq git-blame-mode t)
-  (git-blame-run))
-
-(defun git-blame-mode-off ()
-  "Turn off git-blame mode.
-
-See also function `git-blame-mode'."
-  (git-blame-cleanup)
-  (if git-blame-idle-timer (cancel-timer git-blame-idle-timer))
-  (setq git-blame-mode nil))
-
-;;;###autoload
-(defun git-reblame ()
-  "Recalculate all blame information in the current buffer"
-  (interactive)
-  (unless git-blame-mode
-    (error "Git-blame is not active"))
-
-  (git-blame-cleanup)
-  (git-blame-run))
-
-(defun git-blame-run (&optional startline endline)
-  (if git-blame-proc
-      ;; Should maybe queue up a new run here
-      (message "Already running git blame")
-    (let ((display-buf (current-buffer))
-          (blame-buf (get-buffer-create
-                      (concat " git blame for " (buffer-name))))
-          (args '("--incremental" "--contents" "-")))
-      (if startline
-          (setq args (append args
-                             (list "-L" (format "%d,%d" startline endline)))))
-      (setq args (append args
-                         (list (file-name-nondirectory buffer-file-name))))
-      (setq git-blame-proc
-            (apply 'start-process
-                   "git-blame" blame-buf
-                   "git" "blame"
-                   args))
-      (with-current-buffer blame-buf
-        (erase-buffer)
-        (make-local-variable 'git-blame-file)
-        (make-local-variable 'git-blame-current)
-        (setq git-blame-file display-buf)
-        (setq git-blame-current nil))
-      (set-process-filter git-blame-proc 'git-blame-filter)
-      (set-process-sentinel git-blame-proc 'git-blame-sentinel)
-      (process-send-region git-blame-proc (point-min) (point-max))
-      (process-send-eof git-blame-proc))))
-
-(defun remove-git-blame-text-properties (start end)
-  (let ((modified (buffer-modified-p))
-        (inhibit-read-only t))
-    (remove-text-properties start end '(point-entered nil))
-    (set-buffer-modified-p modified)))
-
-(defun git-blame-cleanup ()
-  "Remove all blame properties"
-    (mapc 'delete-overlay git-blame-overlays)
-    (setq git-blame-overlays nil)
-    (remove-git-blame-text-properties (point-min) (point-max)))
-
-(defun git-blame-update-region (start end)
-  "Rerun blame to get updates between START and END"
-  (let ((overlays (overlays-in start end)))
-    (while overlays
-      (let ((overlay (pop overlays)))
-        (if (< (overlay-start overlay) start)
-            (setq start (overlay-start overlay)))
-        (if (> (overlay-end overlay) end)
-            (setq end (overlay-end overlay)))
-        (setq git-blame-overlays (delete overlay git-blame-overlays))
-        (delete-overlay overlay))))
-  (remove-git-blame-text-properties start end)
-  ;; We can be sure that start and end are at line breaks
-  (git-blame-run (1+ (count-lines (point-min) start))
-                 (count-lines (point-min) end)))
-
-(defun git-blame-sentinel (proc status)
-  (with-current-buffer (process-buffer proc)
-    (with-current-buffer git-blame-file
-      (setq git-blame-proc nil)
-      (if git-blame-update-queue
-          (git-blame-delayed-update))))
-  ;;(kill-buffer (process-buffer proc))
-  ;;(message "git blame finished")
-  )
-
-(defvar in-blame-filter nil)
-
-(defun git-blame-filter (proc str)
-  (with-current-buffer (process-buffer proc)
-    (save-excursion
-      (goto-char (process-mark proc))
-      (insert-before-markers str)
-      (goto-char (point-min))
-      (unless in-blame-filter
-        (let ((more t)
-              (in-blame-filter t))
-          (while more
-            (setq more (git-blame-parse))))))))
-
-(defun git-blame-parse ()
-  (cond ((looking-at "\\([0-9a-f]\\{40\\}\\) \\([0-9]+\\) \\([0-9]+\\) \\([0-9]+\\)\n")
-         (let ((hash (match-string 1))
-               (src-line (string-to-number (match-string 2)))
-               (res-line (string-to-number (match-string 3)))
-               (num-lines (string-to-number (match-string 4))))
-           (delete-region (point) (match-end 0))
-           (setq git-blame-current (list (git-blame-new-commit hash)
-                                         src-line res-line num-lines)))
-         t)
-        ((looking-at "\\([a-z-]+\\) \\(.+\\)\n")
-         (let ((key (match-string 1))
-               (value (match-string 2)))
-           (delete-region (point) (match-end 0))
-           (git-blame-add-info (car git-blame-current) key value)
-           (when (string= key "filename")
-             (git-blame-create-overlay (car git-blame-current)
-                                       (caddr git-blame-current)
-                                       (cadddr git-blame-current))
-             (setq git-blame-current nil)))
-         t)
-        (t
-         nil)))
-
-(defun git-blame-new-commit (hash)
-  (with-current-buffer git-blame-file
-    (or (gethash hash git-blame-cache)
-        ;; Assign a random color to each new commit info
-        ;; Take care not to select the same color multiple times
-        (let* ((color (if git-blame-colors
-                          (git-blame-random-pop git-blame-colors)
-                        git-blame-ancient-color))
-               (info `(,hash (color . ,color))))
-          (puthash hash info git-blame-cache)
-          info))))
-
-(defun git-blame-create-overlay (info start-line num-lines)
-  (with-current-buffer git-blame-file
-    (save-excursion
-      (let ((inhibit-point-motion-hooks t)
-            (inhibit-modification-hooks t))
-        (goto-char (point-min))
-        (forward-line (1- start-line))
-        (let* ((start (point))
-               (end (progn (forward-line num-lines) (point)))
-               (ovl (make-overlay start end))
-               (hash (car info))
-               (spec `((?h . ,(substring hash 0 6))
-                       (?H . ,hash)
-                       (?a . ,(git-blame-get-info info 'author))
-                       (?A . ,(git-blame-get-info info 'author-mail))
-                       (?c . ,(git-blame-get-info info 'committer))
-                       (?C . ,(git-blame-get-info info 'committer-mail))
-                       (?s . ,(git-blame-get-info info 'summary)))))
-          (push ovl git-blame-overlays)
-          (overlay-put ovl 'git-blame info)
-          (overlay-put ovl 'help-echo
-                       (format-spec git-blame-mouseover-format spec))
-          (if git-blame-use-colors
-              (overlay-put ovl 'face (list :background
-                                           (cdr (assq 'color (cdr info))))))
-          (overlay-put ovl 'line-prefix
-                       (propertize (format-spec git-blame-prefix-format spec)
-                                   'face 'git-blame-prefix-face)))))))
-
-(defun git-blame-add-info (info key value)
-  (nconc info (list (cons (intern key) value))))
-
-(defun git-blame-get-info (info key)
-  (cdr (assq key (cdr info))))
-
-(defun git-blame-current-commit ()
-  (let ((info (get-char-property (point) 'git-blame)))
-    (if info
-        (car info)
-      (error "No commit info"))))
-
-(defun git-describe-commit (hash)
-  (with-temp-buffer
-    (call-process "git" nil t nil
-                  "log" "-1"
-		  (concat "--pretty=" git-blame-log-oneline-format)
-                  hash)
-    (buffer-substring (point-min) (point-max))))
-
-(defvar git-blame-last-identification nil)
-(make-variable-buffer-local 'git-blame-last-identification)
-(defun git-blame-identify (&optional hash)
-  (interactive)
-  (let ((info (gethash (or hash (git-blame-current-commit)) git-blame-cache)))
-    (when (and info (not (eq info git-blame-last-identification)))
-      (message "%s" (nth 4 info))
-      (setq git-blame-last-identification info))))
-
-;; (defun git-blame-after-save ()
-;;   (when git-blame-mode
-;;     (git-blame-cleanup)
-;;     (git-blame-run)))
-;; (add-hook 'after-save-hook 'git-blame-after-save)
-
-(defun git-blame-after-change (start end length)
-  (when git-blame-mode
-    (git-blame-enq-update start end)))
-
-(defvar git-blame-last-update nil)
-(make-variable-buffer-local 'git-blame-last-update)
-(defun git-blame-enq-update (start end)
-  "Mark the region between START and END as needing blame update"
-  ;; Try to be smart and avoid multiple callouts for sequential
-  ;; editing
-  (cond ((and git-blame-last-update
-              (= start (cdr git-blame-last-update)))
-         (setcdr git-blame-last-update end))
-        ((and git-blame-last-update
-              (= end (car git-blame-last-update)))
-         (setcar git-blame-last-update start))
-        (t
-         (setq git-blame-last-update (cons start end))
-         (setq git-blame-update-queue (nconc git-blame-update-queue
-                                             (list git-blame-last-update)))))
-  (unless (or git-blame-proc git-blame-idle-timer)
-    (setq git-blame-idle-timer
-          (run-with-idle-timer 0.5 nil 'git-blame-delayed-update))))
-
-(defun git-blame-delayed-update ()
-  (setq git-blame-idle-timer nil)
-  (if git-blame-update-queue
-      (let ((first (pop git-blame-update-queue))
-            (inhibit-point-motion-hooks t))
-        (git-blame-update-region (car first) (cdr first)))))
-
-(provide 'git-blame)
-
-;;; git-blame.el ends here
+(error "git-blame.el no longer ships with git. It's recommended
+to replace its use with Emacs's own vc-annotate. See
+contrib/emacs/README in git's
+sources (https://github.com/git/git/blob/master/contrib/emacs/README)
+for more info on suggested alternatives and for why this
+happened.")
diff --git a/contrib/emacs/git.el b/contrib/emacs/git.el
index 97919f2..03f9262 100644
--- a/contrib/emacs/git.el
+++ b/contrib/emacs/git.el
@@ -1,1704 +1,6 @@
-;;; git.el --- A user interface for git
-
-;; Copyright (C) 2005, 2006, 2007, 2008, 2009 Alexandre Julliard <julliard@winehq.org>
-
-;; Version: 1.0
-
-;; This program is free software; you can redistribute it and/or
-;; modify it under the terms of the GNU General Public License as
-;; published by the Free Software Foundation; either version 2 of
-;; the License, or (at your option) any later version.
-;;
-;; This program is distributed in the hope that it will be
-;; useful, but WITHOUT ANY WARRANTY; without even the implied
-;; warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
-;; PURPOSE.  See the GNU General Public License for more details.
-;;
-;; You should have received a copy of the GNU General Public
-;; License along with this program; if not, see
-;; <http://www.gnu.org/licenses/>.
-
-;;; Commentary:
-
-;; This file contains an interface for the git version control
-;; system. It provides easy access to the most frequently used git
-;; commands. The user interface is as far as possible identical to
-;; that of the PCL-CVS mode.
-;;
-;; To install: put this file on the load-path and place the following
-;; in your .emacs file:
-;;
-;;    (require 'git)
-;;
-;; To start: `M-x git-status'
-;;
-;; TODO
-;;  - diff against other branch
-;;  - renaming files from the status buffer
-;;  - creating tags
-;;  - fetch/pull
-;;  - revlist browser
-;;  - git-show-branch browser
-;;
-
-;;; Compatibility:
-;;
-;; This file works on GNU Emacs 21 or later. It may work on older
-;; versions but this is not guaranteed.
-;;
-;; It may work on XEmacs 21, provided that you first install the ewoc
-;; and log-edit packages.
-;;
-
-(eval-when-compile (require 'cl))
-(require 'ewoc)
-(require 'log-edit)
-(require 'easymenu)
-
-
-;;;; Customizations
-;;;; ------------------------------------------------------------
-
-(defgroup git nil
-  "A user interface for the git versioning system."
-  :group 'tools)
-
-(defcustom git-committer-name nil
-  "User name to use for commits.
-The default is to fall back to the repository config,
-then to `add-log-full-name' and then to `user-full-name'."
-  :group 'git
-  :type '(choice (const :tag "Default" nil)
-                 (string :tag "Name")))
-
-(defcustom git-committer-email nil
-  "Email address to use for commits.
-The default is to fall back to the git repository config,
-then to `add-log-mailing-address' and then to `user-mail-address'."
-  :group 'git
-  :type '(choice (const :tag "Default" nil)
-                 (string :tag "Email")))
-
-(defcustom git-commits-coding-system nil
-  "Default coding system for the log message of git commits."
-  :group 'git
-  :type '(choice (const :tag "From repository config" nil)
-                 (coding-system)))
-
-(defcustom git-append-signed-off-by nil
-  "Whether to append a Signed-off-by line to the commit message before editing."
-  :group 'git
-  :type 'boolean)
-
-(defcustom git-reuse-status-buffer t
-  "Whether `git-status' should try to reuse an existing buffer
-if there is already one that displays the same directory."
-  :group 'git
-  :type 'boolean)
-
-(defcustom git-per-dir-ignore-file ".gitignore"
-  "Name of the per-directory ignore file."
-  :group 'git
-  :type 'string)
-
-(defcustom git-show-uptodate nil
-  "Whether to display up-to-date files."
-  :group 'git
-  :type 'boolean)
-
-(defcustom git-show-ignored nil
-  "Whether to display ignored files."
-  :group 'git
-  :type 'boolean)
-
-(defcustom git-show-unknown t
-  "Whether to display unknown files."
-  :group 'git
-  :type 'boolean)
-
-
-(defface git-status-face
-  '((((class color) (background light)) (:foreground "purple"))
-    (((class color) (background dark)) (:foreground "salmon")))
-  "Git mode face used to highlight added and modified files."
-  :group 'git)
-
-(defface git-unmerged-face
-  '((((class color) (background light)) (:foreground "red" :bold t))
-    (((class color) (background dark)) (:foreground "red" :bold t)))
-  "Git mode face used to highlight unmerged files."
-  :group 'git)
-
-(defface git-unknown-face
-  '((((class color) (background light)) (:foreground "goldenrod" :bold t))
-    (((class color) (background dark)) (:foreground "goldenrod" :bold t)))
-  "Git mode face used to highlight unknown files."
-  :group 'git)
-
-(defface git-uptodate-face
-  '((((class color) (background light)) (:foreground "grey60"))
-    (((class color) (background dark)) (:foreground "grey40")))
-  "Git mode face used to highlight up-to-date files."
-  :group 'git)
-
-(defface git-ignored-face
-  '((((class color) (background light)) (:foreground "grey60"))
-    (((class color) (background dark)) (:foreground "grey40")))
-  "Git mode face used to highlight ignored files."
-  :group 'git)
-
-(defface git-mark-face
-  '((((class color) (background light)) (:foreground "red" :bold t))
-    (((class color) (background dark)) (:foreground "tomato" :bold t)))
-  "Git mode face used for the file marks."
-  :group 'git)
-
-(defface git-header-face
-  '((((class color) (background light)) (:foreground "blue"))
-    (((class color) (background dark)) (:foreground "blue")))
-  "Git mode face used for commit headers."
-  :group 'git)
-
-(defface git-separator-face
-  '((((class color) (background light)) (:foreground "brown"))
-    (((class color) (background dark)) (:foreground "brown")))
-  "Git mode face used for commit separator."
-  :group 'git)
-
-(defface git-permission-face
-  '((((class color) (background light)) (:foreground "green" :bold t))
-    (((class color) (background dark)) (:foreground "green" :bold t)))
-  "Git mode face used for permission changes."
-  :group 'git)
-
-
-;;;; Utilities
-;;;; ------------------------------------------------------------
-
-(defconst git-log-msg-separator "--- log message follows this line ---")
-
-(defvar git-log-edit-font-lock-keywords
-  `(("^\\(Author:\\|Date:\\|Merge:\\|Signed-off-by:\\)\\(.*\\)$"
-     (1 font-lock-keyword-face)
-     (2 font-lock-function-name-face))
-    (,(concat "^\\(" (regexp-quote git-log-msg-separator) "\\)$")
-     (1 font-lock-comment-face))))
-
-(defun git-get-env-strings (env)
-  "Build a list of NAME=VALUE strings from a list of environment strings."
-  (mapcar (lambda (entry) (concat (car entry) "=" (cdr entry))) env))
-
-(defun git-call-process (buffer &rest args)
-  "Wrapper for call-process that sets environment strings."
-  (apply #'call-process "git" nil buffer nil args))
-
-(defun git-call-process-display-error (&rest args)
-  "Wrapper for call-process that displays error messages."
-  (let* ((dir default-directory)
-         (buffer (get-buffer-create "*Git Command Output*"))
-         (ok (with-current-buffer buffer
-               (let ((default-directory dir)
-                     (buffer-read-only nil))
-                 (erase-buffer)
-                 (eq 0 (apply #'git-call-process (list buffer t) args))))))
-    (unless ok (display-message-or-buffer buffer))
-    ok))
-
-(defun git-call-process-string (&rest args)
-  "Wrapper for call-process that returns the process output as a string,
-or nil if the git command failed."
-  (with-temp-buffer
-    (and (eq 0 (apply #'git-call-process t args))
-         (buffer-string))))
-
-(defun git-call-process-string-display-error (&rest args)
-  "Wrapper for call-process that displays error message and returns
-the process output as a string, or nil if the git command failed."
-  (with-temp-buffer
-    (if (eq 0 (apply #'git-call-process (list t t) args))
-        (buffer-string)
-      (display-message-or-buffer (current-buffer))
-      nil)))
-
-(defun git-run-process-region (buffer start end program args)
-  "Run a git process with a buffer region as input."
-  (let ((output-buffer (current-buffer))
-        (dir default-directory))
-    (with-current-buffer buffer
-      (cd dir)
-      (apply #'call-process-region start end program
-             nil (list output-buffer t) nil args))))
-
-(defun git-run-command-buffer (buffer-name &rest args)
-  "Run a git command, sending the output to a buffer named BUFFER-NAME."
-  (let ((dir default-directory)
-        (buffer (get-buffer-create buffer-name)))
-    (message "Running git %s..." (car args))
-    (with-current-buffer buffer
-      (let ((default-directory dir)
-            (buffer-read-only nil))
-        (erase-buffer)
-        (apply #'git-call-process buffer args)))
-    (message "Running git %s...done" (car args))
-    buffer))
-
-(defun git-run-command-region (buffer start end env &rest args)
-  "Run a git command with specified buffer region as input."
-  (with-temp-buffer
-    (if (eq 0 (if env
-                  (git-run-process-region
-                   buffer start end "env"
-                   (append (git-get-env-strings env) (list "git") args))
-                (git-run-process-region buffer start end "git" args)))
-        (buffer-string)
-      (display-message-or-buffer (current-buffer))
-      nil)))
-
-(defun git-run-hook (hook env &rest args)
-  "Run a git hook and display its output if any."
-  (let ((dir default-directory)
-        (hook-name (expand-file-name (concat ".git/hooks/" hook))))
-    (or (not (file-executable-p hook-name))
-        (let (status (buffer (get-buffer-create "*Git Hook Output*")))
-          (with-current-buffer buffer
-            (erase-buffer)
-            (cd dir)
-            (setq status
-                  (if env
-                      (apply #'call-process "env" nil (list buffer t) nil
-                             (append (git-get-env-strings env) (list hook-name) args))
-                    (apply #'call-process hook-name nil (list buffer t) nil args))))
-          (display-message-or-buffer buffer)
-          (eq 0 status)))))
-
-(defun git-get-string-sha1 (string)
-  "Read a SHA1 from the specified string."
-  (and string
-       (string-match "[0-9a-f]\\{40\\}" string)
-       (match-string 0 string)))
-
-(defun git-get-committer-name ()
-  "Return the name to use as GIT_COMMITTER_NAME."
-  ; copied from log-edit
-  (or git-committer-name
-      (git-config "user.name")
-      (and (boundp 'add-log-full-name) add-log-full-name)
-      (and (fboundp 'user-full-name) (user-full-name))
-      (and (boundp 'user-full-name) user-full-name)))
-
-(defun git-get-committer-email ()
-  "Return the email address to use as GIT_COMMITTER_EMAIL."
-  ; copied from log-edit
-  (or git-committer-email
-      (git-config "user.email")
-      (and (boundp 'add-log-mailing-address) add-log-mailing-address)
-      (and (fboundp 'user-mail-address) (user-mail-address))
-      (and (boundp 'user-mail-address) user-mail-address)))
-
-(defun git-get-commits-coding-system ()
-  "Return the coding system to use for commits."
-  (let ((repo-config (git-config "i18n.commitencoding")))
-    (or git-commits-coding-system
-        (and repo-config
-             (fboundp 'locale-charset-to-coding-system)
-             (locale-charset-to-coding-system repo-config))
-      'utf-8)))
-
-(defun git-get-logoutput-coding-system ()
-  "Return the coding system used for git-log output."
-  (let ((repo-config (or (git-config "i18n.logoutputencoding")
-                         (git-config "i18n.commitencoding"))))
-    (or git-commits-coding-system
-        (and repo-config
-             (fboundp 'locale-charset-to-coding-system)
-             (locale-charset-to-coding-system repo-config))
-      'utf-8)))
-
-(defun git-escape-file-name (name)
-  "Escape a file name if necessary."
-  (if (string-match "[\n\t\"\\]" name)
-      (concat "\""
-              (mapconcat (lambda (c)
-                   (case c
-                     (?\n "\\n")
-                     (?\t "\\t")
-                     (?\\ "\\\\")
-                     (?\" "\\\"")
-                     (t (char-to-string c))))
-                 name "")
-              "\"")
-    name))
-
-(defun git-success-message (text files)
-  "Print a success message after having handled FILES."
-  (let ((n (length files)))
-    (if (equal n 1)
-        (message "%s %s" text (car files))
-      (message "%s %d files" text n))))
-
-(defun git-get-top-dir (dir)
-  "Retrieve the top-level directory of a git tree."
-  (let ((cdup (with-output-to-string
-                (with-current-buffer standard-output
-                  (cd dir)
-                  (unless (eq 0 (git-call-process t "rev-parse" "--show-cdup"))
-                    (error "cannot find top-level git tree for %s." dir))))))
-    (expand-file-name (concat (file-name-as-directory dir)
-                              (car (split-string cdup "\n"))))))
-
-;stolen from pcl-cvs
-(defun git-append-to-ignore (file)
-  "Add a file name to the ignore file in its directory."
-  (let* ((fullname (expand-file-name file))
-         (dir (file-name-directory fullname))
-         (name (file-name-nondirectory fullname))
-         (ignore-name (expand-file-name git-per-dir-ignore-file dir))
-         (created (not (file-exists-p ignore-name))))
-  (save-window-excursion
-    (set-buffer (find-file-noselect ignore-name))
-    (goto-char (point-max))
-    (unless (zerop (current-column)) (insert "\n"))
-    (insert "/" name "\n")
-    (sort-lines nil (point-min) (point-max))
-    (save-buffer))
-  (when created
-    (git-call-process nil "update-index" "--add" "--" (file-relative-name ignore-name)))
-  (git-update-status-files (list (file-relative-name ignore-name)))))
-
-; propertize definition for XEmacs, stolen from erc-compat
-(eval-when-compile
-  (unless (fboundp 'propertize)
-    (defun propertize (string &rest props)
-      (let ((string (copy-sequence string)))
-        (while props
-          (put-text-property 0 (length string) (nth 0 props) (nth 1 props) string)
-          (setq props (cddr props)))
-        string))))
-
-;;;; Wrappers for basic git commands
-;;;; ------------------------------------------------------------
-
-(defun git-rev-parse (rev)
-  "Parse a revision name and return its SHA1."
-  (git-get-string-sha1
-   (git-call-process-string "rev-parse" rev)))
-
-(defun git-config (key)
-  "Retrieve the value associated to KEY in the git repository config file."
-  (let ((str (git-call-process-string "config" key)))
-    (and str (car (split-string str "\n")))))
-
-(defun git-symbolic-ref (ref)
-  "Wrapper for the git-symbolic-ref command."
-  (let ((str (git-call-process-string "symbolic-ref" ref)))
-    (and str (car (split-string str "\n")))))
-
-(defun git-update-ref (ref newval &optional oldval reason)
-  "Update a reference by calling git-update-ref."
-  (let ((args (and oldval (list oldval))))
-    (when newval (push newval args))
-    (push ref args)
-    (when reason
-     (push reason args)
-     (push "-m" args))
-    (unless newval (push "-d" args))
-    (apply 'git-call-process-display-error "update-ref" args)))
-
-(defun git-for-each-ref (&rest specs)
-  "Return a list of refs using git-for-each-ref.
-Each entry is a cons of (SHORT-NAME . FULL-NAME)."
-  (let (refs)
-    (with-temp-buffer
-      (apply #'git-call-process t "for-each-ref" "--format=%(refname)" specs)
-      (goto-char (point-min))
-      (while (re-search-forward "^[^/\n]+/[^/\n]+/\\(.+\\)$" nil t)
-	(push (cons (match-string 1) (match-string 0)) refs)))
-    (nreverse refs)))
-
-(defun git-read-tree (tree &optional index-file)
-  "Read a tree into the index file."
-  (let ((process-environment
-         (append (and index-file (list (concat "GIT_INDEX_FILE=" index-file))) process-environment)))
-    (apply 'git-call-process-display-error "read-tree" (if tree (list tree)))))
-
-(defun git-write-tree (&optional index-file)
-  "Call git-write-tree and return the resulting tree SHA1 as a string."
-  (let ((process-environment
-         (append (and index-file (list (concat "GIT_INDEX_FILE=" index-file))) process-environment)))
-    (git-get-string-sha1
-     (git-call-process-string-display-error "write-tree"))))
-
-(defun git-commit-tree (buffer tree parent)
-  "Create a commit and possibly update HEAD.
-Create a commit with the message in BUFFER using the tree with hash TREE.
-Use PARENT as the parent of the new commit. If PARENT is the current \"HEAD\",
-update the \"HEAD\" reference to the new commit."
-  (let ((author-name (git-get-committer-name))
-        (author-email (git-get-committer-email))
-        (subject "commit (initial): ")
-        author-date log-start log-end args coding-system-for-write)
-    (when parent
-      (setq subject "commit: ")
-      (push "-p" args)
-      (push parent args))
-    (with-current-buffer buffer
-      (goto-char (point-min))
-      (if
-          (setq log-start (re-search-forward (concat "^" (regexp-quote git-log-msg-separator) "\n") nil t))
-          (save-restriction
-            (narrow-to-region (point-min) log-start)
-            (goto-char (point-min))
-            (when (re-search-forward "^Author: +\\(.*?\\) *<\\(.*\\)> *$" nil t)
-              (setq author-name (match-string 1)
-                    author-email (match-string 2)))
-            (goto-char (point-min))
-            (when (re-search-forward "^Date: +\\(.*\\)$" nil t)
-              (setq author-date (match-string 1)))
-            (goto-char (point-min))
-            (when (re-search-forward "^Merge: +\\(.*\\)" nil t)
-              (setq subject "commit (merge): ")
-              (dolist (parent (split-string (match-string 1) " +" t))
-                (push "-p" args)
-                (push parent args))))
-        (setq log-start (point-min)))
-      (setq log-end (point-max))
-      (goto-char log-start)
-      (when (re-search-forward ".*$" nil t)
-        (setq subject (concat subject (match-string 0))))
-      (setq coding-system-for-write buffer-file-coding-system))
-    (let ((commit
-           (git-get-string-sha1
-            (let ((env `(("GIT_AUTHOR_NAME" . ,author-name)
-                         ("GIT_AUTHOR_EMAIL" . ,author-email)
-                         ("GIT_COMMITTER_NAME" . ,(git-get-committer-name))
-                         ("GIT_COMMITTER_EMAIL" . ,(git-get-committer-email)))))
-              (when author-date (push `("GIT_AUTHOR_DATE" . ,author-date) env))
-              (apply #'git-run-command-region
-                     buffer log-start log-end env
-                     "commit-tree" tree (nreverse args))))))
-      (when commit (git-update-ref "HEAD" commit parent subject))
-      commit)))
-
-(defun git-empty-db-p ()
-  "Check if the git db is empty (no commit done yet)."
-  (not (eq 0 (git-call-process nil "rev-parse" "--verify" "HEAD"))))
-
-(defun git-get-merge-heads ()
-  "Retrieve the merge heads from the MERGE_HEAD file if present."
-  (let (heads)
-    (when (file-readable-p ".git/MERGE_HEAD")
-      (with-temp-buffer
-        (insert-file-contents ".git/MERGE_HEAD" nil nil nil t)
-        (goto-char (point-min))
-        (while (re-search-forward "[0-9a-f]\\{40\\}" nil t)
-          (push (match-string 0) heads))))
-    (nreverse heads)))
-
-(defun git-get-commit-description (commit)
-  "Get a one-line description of COMMIT."
-  (let ((coding-system-for-read (git-get-logoutput-coding-system)))
-    (let ((descr (git-call-process-string "log" "--max-count=1" "--pretty=oneline" commit)))
-      (if (and descr (string-match "\\`\\([0-9a-f]\\{40\\}\\) *\\(.*\\)$" descr))
-          (concat (substring (match-string 1 descr) 0 10) " - " (match-string 2 descr))
-        descr))))
-
-;;;; File info structure
-;;;; ------------------------------------------------------------
-
-; fileinfo structure stolen from pcl-cvs
-(defstruct (git-fileinfo
-            (:copier nil)
-            (:constructor git-create-fileinfo (state name &optional old-perm new-perm rename-state orig-name marked))
-            (:conc-name git-fileinfo->))
-  marked              ;; t/nil
-  state               ;; current state
-  name                ;; file name
-  old-perm new-perm   ;; permission flags
-  rename-state        ;; rename or copy state
-  orig-name           ;; original name for renames or copies
-  needs-update        ;; whether file needs to be updated
-  needs-refresh)      ;; whether file needs to be refreshed
-
-(defvar git-status nil)
-
-(defun git-set-fileinfo-state (info state)
-  "Set the state of a file info."
-  (unless (eq (git-fileinfo->state info) state)
-    (setf (git-fileinfo->state info) state
-	  (git-fileinfo->new-perm info) (git-fileinfo->old-perm info)
-          (git-fileinfo->rename-state info) nil
-          (git-fileinfo->orig-name info) nil
-          (git-fileinfo->needs-update info) nil
-          (git-fileinfo->needs-refresh info) t)))
-
-(defun git-status-filenames-map (status func files &rest args)
-  "Apply FUNC to the status files names in the FILES list.
-The list must be sorted."
-  (when files
-    (let ((file (pop files))
-          (node (ewoc-nth status 0)))
-      (while (and file node)
-        (let* ((info (ewoc-data node))
-               (name (git-fileinfo->name info)))
-          (if (string-lessp name file)
-              (setq node (ewoc-next status node))
-            (if (string-equal name file)
-                (apply func info args))
-            (setq file (pop files))))))))
-
-(defun git-set-filenames-state (status files state)
-  "Set the state of a list of named files. The list must be sorted"
-  (when files
-    (git-status-filenames-map status #'git-set-fileinfo-state files state)
-    (unless state  ;; delete files whose state has been set to nil
-      (ewoc-filter status (lambda (info) (git-fileinfo->state info))))))
-
-(defun git-state-code (code)
-  "Convert from a string to a added/deleted/modified state."
-  (case (string-to-char code)
-    (?M 'modified)
-    (?? 'unknown)
-    (?A 'added)
-    (?D 'deleted)
-    (?U 'unmerged)
-    (?T 'modified)
-    (t nil)))
-
-(defun git-status-code-as-string (code)
-  "Format a git status code as string."
-  (case code
-    ('modified (propertize "Modified" 'face 'git-status-face))
-    ('unknown  (propertize "Unknown " 'face 'git-unknown-face))
-    ('added    (propertize "Added   " 'face 'git-status-face))
-    ('deleted  (propertize "Deleted " 'face 'git-status-face))
-    ('unmerged (propertize "Unmerged" 'face 'git-unmerged-face))
-    ('uptodate (propertize "Uptodate" 'face 'git-uptodate-face))
-    ('ignored  (propertize "Ignored " 'face 'git-ignored-face))
-    (t "?       ")))
-
-(defun git-file-type-as-string (old-perm new-perm)
-  "Return a string describing the file type based on its permissions."
-  (let* ((old-type (lsh (or old-perm 0) -9))
-	 (new-type (lsh (or new-perm 0) -9))
-	 (str (case new-type
-		(64  ;; file
-		 (case old-type
-		   (64 nil)
-		   (80 "   (type change symlink -> file)")
-		   (112 "   (type change subproject -> file)")))
-		 (80  ;; symlink
-		  (case old-type
-		    (64 "   (type change file -> symlink)")
-		    (112 "   (type change subproject -> symlink)")
-		    (t "   (symlink)")))
-		  (112  ;; subproject
-		   (case old-type
-		     (64 "   (type change file -> subproject)")
-		     (80 "   (type change symlink -> subproject)")
-		     (t "   (subproject)")))
-                  (72 nil)  ;; directory (internal, not a real git state)
-		  (0  ;; deleted or unknown
-		   (case old-type
-		     (80 "   (symlink)")
-		     (112 "   (subproject)")))
-		  (t (format "   (unknown type %o)" new-type)))))
-    (cond (str (propertize str 'face 'git-status-face))
-          ((eq new-type 72) "/")
-          (t ""))))
-
-(defun git-rename-as-string (info)
-  "Return a string describing the copy or rename associated with INFO, or an empty string if none."
-  (let ((state (git-fileinfo->rename-state info)))
-    (if state
-        (propertize
-         (concat "   ("
-                 (if (eq state 'copy) "copied from "
-                   (if (eq (git-fileinfo->state info) 'added) "renamed from "
-                     "renamed to "))
-                 (git-escape-file-name (git-fileinfo->orig-name info))
-                 ")") 'face 'git-status-face)
-      "")))
-
-(defun git-permissions-as-string (old-perm new-perm)
-  "Format a permission change as string."
-  (propertize
-   (if (or (not old-perm)
-           (not new-perm)
-           (eq 0 (logand ?\111 (logxor old-perm new-perm))))
-       "  "
-     (if (eq 0 (logand ?\111 old-perm)) "+x" "-x"))
-  'face 'git-permission-face))
-
-(defun git-fileinfo-prettyprint (info)
-  "Pretty-printer for the git-fileinfo structure."
-  (let ((old-perm (git-fileinfo->old-perm info))
-	(new-perm (git-fileinfo->new-perm info)))
-    (insert (concat "   " (if (git-fileinfo->marked info) (propertize "*" 'face 'git-mark-face) " ")
-		    " " (git-status-code-as-string (git-fileinfo->state info))
-		    " " (git-permissions-as-string old-perm new-perm)
-		    "  " (git-escape-file-name (git-fileinfo->name info))
-		    (git-file-type-as-string old-perm new-perm)
-		    (git-rename-as-string info)))))
-
-(defun git-update-node-fileinfo (node info)
-  "Update the fileinfo of the specified node. The names are assumed to match already."
-  (let ((data (ewoc-data node)))
-    (setf
-     ;; preserve the marked flag
-     (git-fileinfo->marked info) (git-fileinfo->marked data)
-     (git-fileinfo->needs-update data) nil)
-    (when (not (equal info data))
-      (setf (git-fileinfo->needs-refresh info) t
-            (ewoc-data node) info))))
-
-(defun git-insert-info-list (status infolist files)
-  "Insert a sorted list of file infos in the status buffer, replacing existing ones if any."
-  (let* ((info (pop infolist))
-         (node (ewoc-nth status 0))
-         (name (and info (git-fileinfo->name info)))
-         remaining)
-    (while info
-      (let ((nodename (and node (git-fileinfo->name (ewoc-data node)))))
-        (while (and files (string-lessp (car files) name))
-          (push (pop files) remaining))
-        (when (and files (string-equal (car files) name))
-          (setq files (cdr files)))
-        (cond ((not nodename)
-               (setq node (ewoc-enter-last status info))
-               (setq info (pop infolist))
-               (setq name (and info (git-fileinfo->name info))))
-              ((string-lessp nodename name)
-               (setq node (ewoc-next status node)))
-              ((string-equal nodename name)
-               ;; preserve the marked flag
-               (git-update-node-fileinfo node info)
-               (setq info (pop infolist))
-               (setq name (and info (git-fileinfo->name info))))
-              (t
-               (setq node (ewoc-enter-before status node info))
-               (setq info (pop infolist))
-               (setq name (and info (git-fileinfo->name info)))))))
-    (nconc (nreverse remaining) files)))
-
-(defun git-run-diff-index (status files)
-  "Run git-diff-index on FILES and parse the results into STATUS.
-Return the list of files that haven't been handled."
-  (let (infolist)
-    (with-temp-buffer
-      (apply #'git-call-process t "diff-index" "-z" "-M" "HEAD" "--" files)
-      (goto-char (point-min))
-      (while (re-search-forward
-	      ":\\([0-7]\\{6\\}\\) \\([0-7]\\{6\\}\\) [0-9a-f]\\{40\\} [0-9a-f]\\{40\\} \\(\\([ADMUT]\\)\0\\([^\0]+\\)\\|\\([CR]\\)[0-9]*\0\\([^\0]+\\)\0\\([^\0]+\\)\\)\0"
-              nil t 1)
-        (let ((old-perm (string-to-number (match-string 1) 8))
-              (new-perm (string-to-number (match-string 2) 8))
-              (state (or (match-string 4) (match-string 6)))
-              (name (or (match-string 5) (match-string 7)))
-              (new-name (match-string 8)))
-          (if new-name  ; copy or rename
-              (if (eq ?C (string-to-char state))
-                  (push (git-create-fileinfo 'added new-name old-perm new-perm 'copy name) infolist)
-                (push (git-create-fileinfo 'deleted name 0 0 'rename new-name) infolist)
-                (push (git-create-fileinfo 'added new-name old-perm new-perm 'rename name) infolist))
-            (push (git-create-fileinfo (git-state-code state) name old-perm new-perm) infolist)))))
-    (setq infolist (sort (nreverse infolist)
-                         (lambda (info1 info2)
-                           (string-lessp (git-fileinfo->name info1)
-                                         (git-fileinfo->name info2)))))
-    (git-insert-info-list status infolist files)))
-
-(defun git-find-status-file (status file)
-  "Find a given file in the status ewoc and return its node."
-  (let ((node (ewoc-nth status 0)))
-    (while (and node (not (string= file (git-fileinfo->name (ewoc-data node)))))
-      (setq node (ewoc-next status node)))
-    node))
-
-(defun git-run-ls-files (status files default-state &rest options)
-  "Run git-ls-files on FILES and parse the results into STATUS.
-Return the list of files that haven't been handled."
-  (let (infolist)
-    (with-temp-buffer
-      (apply #'git-call-process t "ls-files" "-z" (append options (list "--") files))
-      (goto-char (point-min))
-      (while (re-search-forward "\\([^\0]*?\\)\\(/?\\)\0" nil t 1)
-        (let ((name (match-string 1)))
-          (push (git-create-fileinfo default-state name 0
-                                     (if (string-equal "/" (match-string 2)) (lsh ?\110 9) 0))
-                infolist))))
-    (setq infolist (nreverse infolist))  ;; assume it is sorted already
-    (git-insert-info-list status infolist files)))
-
-(defun git-run-ls-files-cached (status files default-state)
-  "Run git-ls-files -c on FILES and parse the results into STATUS.
-Return the list of files that haven't been handled."
-  (let (infolist)
-    (with-temp-buffer
-      (apply #'git-call-process t "ls-files" "-z" "-s" "-c" "--" files)
-      (goto-char (point-min))
-      (while (re-search-forward "\\([0-7]\\{6\\}\\) [0-9a-f]\\{40\\} 0\t\\([^\0]+\\)\0" nil t)
-	(let* ((new-perm (string-to-number (match-string 1) 8))
-	       (old-perm (if (eq default-state 'added) 0 new-perm))
-	       (name (match-string 2)))
-	  (push (git-create-fileinfo default-state name old-perm new-perm) infolist))))
-    (setq infolist (nreverse infolist))  ;; assume it is sorted already
-    (git-insert-info-list status infolist files)))
-
-(defun git-run-ls-unmerged (status files)
-  "Run git-ls-files -u on FILES and parse the results into STATUS."
-  (with-temp-buffer
-    (apply #'git-call-process t "ls-files" "-z" "-u" "--" files)
-    (goto-char (point-min))
-    (let (unmerged-files)
-      (while (re-search-forward "[0-7]\\{6\\} [0-9a-f]\\{40\\} [123]\t\\([^\0]+\\)\0" nil t)
-        (push (match-string 1) unmerged-files))
-      (setq unmerged-files (nreverse unmerged-files))  ;; assume it is sorted already
-      (git-set-filenames-state status unmerged-files 'unmerged))))
-
-(defun git-get-exclude-files ()
-  "Get the list of exclude files to pass to git-ls-files."
-  (let (files
-        (config (git-config "core.excludesfile")))
-    (when (file-readable-p ".git/info/exclude")
-      (push ".git/info/exclude" files))
-    (when (and config (file-readable-p config))
-      (push config files))
-    files))
-
-(defun git-run-ls-files-with-excludes (status files default-state &rest options)
-  "Run git-ls-files on FILES with appropriate --exclude-from options."
-  (let ((exclude-files (git-get-exclude-files)))
-    (apply #'git-run-ls-files status files default-state "--directory" "--no-empty-directory"
-           (concat "--exclude-per-directory=" git-per-dir-ignore-file)
-           (append options (mapcar (lambda (f) (concat "--exclude-from=" f)) exclude-files)))))
-
-(defun git-update-status-files (&optional files mark-files)
-  "Update the status of FILES from the index.
-The FILES list must be sorted."
-  (unless git-status (error "Not in git-status buffer."))
-  ;; set the needs-update flag on existing files
-  (if files
-      (git-status-filenames-map
-       git-status (lambda (info) (setf (git-fileinfo->needs-update info) t)) files)
-    (ewoc-map (lambda (info) (setf (git-fileinfo->needs-update info) t) nil) git-status)
-    (git-call-process nil "update-index" "--refresh")
-    (when git-show-uptodate
-      (git-run-ls-files-cached git-status nil 'uptodate)))
-  (let ((remaining-files
-          (if (git-empty-db-p) ; we need some special handling for an empty db
-	      (git-run-ls-files-cached git-status files 'added)
-            (git-run-diff-index git-status files))))
-    (git-run-ls-unmerged git-status files)
-    (when (or remaining-files (and git-show-unknown (not files)))
-      (setq remaining-files (git-run-ls-files-with-excludes git-status remaining-files 'unknown "-o")))
-    (when (or remaining-files (and git-show-ignored (not files)))
-      (setq remaining-files (git-run-ls-files-with-excludes git-status remaining-files 'ignored "-o" "-i")))
-    (unless files
-      (setq remaining-files (git-get-filenames (ewoc-collect git-status #'git-fileinfo->needs-update))))
-    (when remaining-files
-      (setq remaining-files (git-run-ls-files-cached git-status remaining-files 'uptodate)))
-    (git-set-filenames-state git-status remaining-files nil)
-    (when mark-files (git-mark-files git-status files))
-    (git-refresh-files)
-    (git-refresh-ewoc-hf git-status)))
-
-(defun git-mark-files (status files)
-  "Mark all the specified FILES, and unmark the others."
-  (let ((file (and files (pop files)))
-        (node (ewoc-nth status 0)))
-    (while node
-      (let ((info (ewoc-data node)))
-        (if (and file (string-equal (git-fileinfo->name info) file))
-            (progn
-              (unless (git-fileinfo->marked info)
-                (setf (git-fileinfo->marked info) t)
-                (setf (git-fileinfo->needs-refresh info) t))
-              (setq file (pop files))
-              (setq node (ewoc-next status node)))
-          (when (git-fileinfo->marked info)
-            (setf (git-fileinfo->marked info) nil)
-            (setf (git-fileinfo->needs-refresh info) t))
-          (if (and file (string-lessp file (git-fileinfo->name info)))
-              (setq file (pop files))
-            (setq node (ewoc-next status node))))))))
-
-(defun git-marked-files ()
-  "Return a list of all marked files, or if none a list containing just the file at cursor position."
-  (unless git-status (error "Not in git-status buffer."))
-  (or (ewoc-collect git-status (lambda (info) (git-fileinfo->marked info)))
-      (list (ewoc-data (ewoc-locate git-status)))))
-
-(defun git-marked-files-state (&rest states)
-  "Return a sorted list of marked files that are in the specified states."
-  (let ((files (git-marked-files))
-        result)
-    (dolist (info files)
-      (when (memq (git-fileinfo->state info) states)
-        (push info result)))
-    (nreverse result)))
-
-(defun git-refresh-files ()
-  "Refresh all files that need it and clear the needs-refresh flag."
-  (unless git-status (error "Not in git-status buffer."))
-  (ewoc-map
-   (lambda (info)
-     (let ((refresh (git-fileinfo->needs-refresh info)))
-       (setf (git-fileinfo->needs-refresh info) nil)
-       refresh))
-   git-status)
-  ; move back to goal column
-  (when goal-column (move-to-column goal-column)))
-
-(defun git-refresh-ewoc-hf (status)
-  "Refresh the ewoc header and footer."
-  (let ((branch (git-symbolic-ref "HEAD"))
-        (head (if (git-empty-db-p) "Nothing committed yet"
-                (git-get-commit-description "HEAD")))
-        (merge-heads (git-get-merge-heads)))
-    (ewoc-set-hf status
-                 (format "Directory:  %s\nBranch:     %s\nHead:       %s%s\n"
-                         default-directory
-                         (if branch
-                             (if (string-match "^refs/heads/" branch)
-                                 (substring branch (match-end 0))
-                               branch)
-                           "none (detached HEAD)")
-                         head
-                         (if merge-heads
-                             (concat "\nMerging:    "
-                                     (mapconcat (lambda (str) (git-get-commit-description str)) merge-heads "\n            "))
-                           ""))
-                 (if (ewoc-nth status 0) "" "    No changes."))))
-
-(defun git-get-filenames (files)
-  (mapcar (lambda (info) (git-fileinfo->name info)) files))
-
-(defun git-update-index (index-file files)
-  "Run git-update-index on a list of files."
-  (let ((process-environment (append (and index-file (list (concat "GIT_INDEX_FILE=" index-file)))
-                                     process-environment))
-        added deleted modified)
-    (dolist (info files)
-      (case (git-fileinfo->state info)
-        ('added (push info added))
-        ('deleted (push info deleted))
-        ('modified (push info modified))))
-    (and
-     (or (not added) (apply #'git-call-process-display-error "update-index" "--add" "--" (git-get-filenames added)))
-     (or (not deleted) (apply #'git-call-process-display-error "update-index" "--remove" "--" (git-get-filenames deleted)))
-     (or (not modified) (apply #'git-call-process-display-error "update-index" "--" (git-get-filenames modified))))))
-
-(defun git-run-pre-commit-hook ()
-  "Run the pre-commit hook if any."
-  (unless git-status (error "Not in git-status buffer."))
-  (let ((files (git-marked-files-state 'added 'deleted 'modified)))
-    (or (not files)
-        (not (file-executable-p ".git/hooks/pre-commit"))
-        (let ((index-file (make-temp-file "gitidx")))
-          (unwind-protect
-            (let ((head-tree (unless (git-empty-db-p) (git-rev-parse "HEAD^{tree}"))))
-              (git-read-tree head-tree index-file)
-              (git-update-index index-file files)
-              (git-run-hook "pre-commit" `(("GIT_INDEX_FILE" . ,index-file))))
-          (delete-file index-file))))))
-
-(defun git-do-commit ()
-  "Perform the actual commit using the current buffer as log message."
-  (interactive)
-  (let ((buffer (current-buffer))
-        (index-file (make-temp-file "gitidx")))
-    (with-current-buffer log-edit-parent-buffer
-      (if (git-marked-files-state 'unmerged)
-          (message "You cannot commit unmerged files, resolve them first.")
-        (unwind-protect
-            (let ((files (git-marked-files-state 'added 'deleted 'modified))
-                  head tree head-tree)
-              (unless (git-empty-db-p)
-                (setq head (git-rev-parse "HEAD")
-                      head-tree (git-rev-parse "HEAD^{tree}")))
-              (message "Running git commit...")
-              (when
-                  (and
-                   (git-read-tree head-tree index-file)
-                   (git-update-index nil files)         ;update both the default index
-                   (git-update-index index-file files)  ;and the temporary one
-                   (setq tree (git-write-tree index-file)))
-                (if (or (not (string-equal tree head-tree))
-                        (yes-or-no-p "The tree was not modified, do you really want to perform an empty commit? "))
-                    (let ((commit (git-commit-tree buffer tree head)))
-                      (when commit
-                        (condition-case nil (delete-file ".git/MERGE_HEAD") (error nil))
-                        (condition-case nil (delete-file ".git/MERGE_MSG") (error nil))
-                        (with-current-buffer buffer (erase-buffer))
-                        (git-update-status-files (git-get-filenames files))
-                        (git-call-process nil "rerere")
-                        (git-call-process nil "gc" "--auto")
-                        (message "Committed %s." commit)
-                        (git-run-hook "post-commit" nil)))
-                  (message "Commit aborted."))))
-          (delete-file index-file))))))
-
-
-;;;; Interactive functions
-;;;; ------------------------------------------------------------
-
-(defun git-mark-file ()
-  "Mark the file that the cursor is on and move to the next one."
-  (interactive)
-  (unless git-status (error "Not in git-status buffer."))
-  (let* ((pos (ewoc-locate git-status))
-         (info (ewoc-data pos)))
-    (setf (git-fileinfo->marked info) t)
-    (ewoc-invalidate git-status pos)
-    (ewoc-goto-next git-status 1)))
-
-(defun git-unmark-file ()
-  "Unmark the file that the cursor is on and move to the next one."
-  (interactive)
-  (unless git-status (error "Not in git-status buffer."))
-  (let* ((pos (ewoc-locate git-status))
-         (info (ewoc-data pos)))
-    (setf (git-fileinfo->marked info) nil)
-    (ewoc-invalidate git-status pos)
-    (ewoc-goto-next git-status 1)))
-
-(defun git-unmark-file-up ()
-  "Unmark the file that the cursor is on and move to the previous one."
-  (interactive)
-  (unless git-status (error "Not in git-status buffer."))
-  (let* ((pos (ewoc-locate git-status))
-         (info (ewoc-data pos)))
-    (setf (git-fileinfo->marked info) nil)
-    (ewoc-invalidate git-status pos)
-    (ewoc-goto-prev git-status 1)))
-
-(defun git-mark-all ()
-  "Mark all files."
-  (interactive)
-  (unless git-status (error "Not in git-status buffer."))
-  (ewoc-map (lambda (info) (unless (git-fileinfo->marked info)
-                             (setf (git-fileinfo->marked info) t))) git-status)
-  ; move back to goal column after invalidate
-  (when goal-column (move-to-column goal-column)))
-
-(defun git-unmark-all ()
-  "Unmark all files."
-  (interactive)
-  (unless git-status (error "Not in git-status buffer."))
-  (ewoc-map (lambda (info) (when (git-fileinfo->marked info)
-                             (setf (git-fileinfo->marked info) nil)
-                             t)) git-status)
-  ; move back to goal column after invalidate
-  (when goal-column (move-to-column goal-column)))
-
-(defun git-toggle-all-marks ()
-  "Toggle all file marks."
-  (interactive)
-  (unless git-status (error "Not in git-status buffer."))
-  (ewoc-map (lambda (info) (setf (git-fileinfo->marked info) (not (git-fileinfo->marked info))) t) git-status)
-  ; move back to goal column after invalidate
-  (when goal-column (move-to-column goal-column)))
-
-(defun git-next-file (&optional n)
-  "Move the selection down N files."
-  (interactive "p")
-  (unless git-status (error "Not in git-status buffer."))
-  (ewoc-goto-next git-status n))
-
-(defun git-prev-file (&optional n)
-  "Move the selection up N files."
-  (interactive "p")
-  (unless git-status (error "Not in git-status buffer."))
-  (ewoc-goto-prev git-status n))
-
-(defun git-next-unmerged-file (&optional n)
-  "Move the selection down N unmerged files."
-  (interactive "p")
-  (unless git-status (error "Not in git-status buffer."))
-  (let* ((last (ewoc-locate git-status))
-         (node (ewoc-next git-status last)))
-    (while (and node (> n 0))
-      (when (eq 'unmerged (git-fileinfo->state (ewoc-data node)))
-        (setq n (1- n))
-        (setq last node))
-      (setq node (ewoc-next git-status node)))
-    (ewoc-goto-node git-status last)))
-
-(defun git-prev-unmerged-file (&optional n)
-  "Move the selection up N unmerged files."
-  (interactive "p")
-  (unless git-status (error "Not in git-status buffer."))
-  (let* ((last (ewoc-locate git-status))
-         (node (ewoc-prev git-status last)))
-    (while (and node (> n 0))
-      (when (eq 'unmerged (git-fileinfo->state (ewoc-data node)))
-        (setq n (1- n))
-        (setq last node))
-      (setq node (ewoc-prev git-status node)))
-    (ewoc-goto-node git-status last)))
-
-(defun git-insert-file (file)
-  "Insert file(s) into the git-status buffer."
-  (interactive "fInsert file: ")
-  (git-update-status-files (list (file-relative-name file))))
-
-(defun git-add-file ()
-  "Add marked file(s) to the index cache."
-  (interactive)
-  (let ((files (git-get-filenames (git-marked-files-state 'unknown 'ignored 'unmerged))))
-    ;; FIXME: add support for directories
-    (unless files
-      (push (file-relative-name (read-file-name "File to add: " nil nil t)) files))
-    (when (apply 'git-call-process-display-error "update-index" "--add" "--" files)
-      (git-update-status-files files)
-      (git-success-message "Added" files))))
-
-(defun git-ignore-file ()
-  "Add marked file(s) to the ignore list."
-  (interactive)
-  (let ((files (git-get-filenames (git-marked-files-state 'unknown))))
-    (unless files
-      (push (file-relative-name (read-file-name "File to ignore: " nil nil t)) files))
-    (dolist (f files) (git-append-to-ignore f))
-    (git-update-status-files files)
-    (git-success-message "Ignored" files)))
-
-(defun git-remove-file ()
-  "Remove the marked file(s)."
-  (interactive)
-  (let ((files (git-get-filenames (git-marked-files-state 'added 'modified 'unknown 'uptodate 'ignored))))
-    (unless files
-      (push (file-relative-name (read-file-name "File to remove: " nil nil t)) files))
-    (if (yes-or-no-p
-         (if (cdr files)
-             (format "Remove %d files? " (length files))
-           (format "Remove %s? " (car files))))
-        (progn
-          (dolist (name files)
-            (ignore-errors
-              (if (file-directory-p name)
-                  (delete-directory name)
-                (delete-file name))))
-          (when (apply 'git-call-process-display-error "update-index" "--remove" "--" files)
-            (git-update-status-files files)
-            (git-success-message "Removed" files)))
-      (message "Aborting"))))
-
-(defun git-revert-file ()
-  "Revert changes to the marked file(s)."
-  (interactive)
-  (let ((files (git-marked-files-state 'added 'deleted 'modified 'unmerged))
-        added modified)
-    (when (and files
-               (yes-or-no-p
-                (if (cdr files)
-                    (format "Revert %d files? " (length files))
-                  (format "Revert %s? " (git-fileinfo->name (car files))))))
-      (dolist (info files)
-        (case (git-fileinfo->state info)
-          ('added (push (git-fileinfo->name info) added))
-          ('deleted (push (git-fileinfo->name info) modified))
-          ('unmerged (push (git-fileinfo->name info) modified))
-          ('modified (push (git-fileinfo->name info) modified))))
-      ;; check if a buffer contains one of the files and isn't saved
-      (dolist (file modified)
-        (let ((buffer (get-file-buffer file)))
-          (when (and buffer (buffer-modified-p buffer))
-            (error "Buffer %s is modified. Please kill or save modified buffers before reverting." (buffer-name buffer)))))
-      (let ((ok (and
-                 (or (not added)
-                     (apply 'git-call-process-display-error "update-index" "--force-remove" "--" added))
-                 (or (not modified)
-                     (apply 'git-call-process-display-error "checkout" "HEAD" modified))))
-            (names (git-get-filenames files)))
-        (git-update-status-files names)
-        (when ok
-          (dolist (file modified)
-            (let ((buffer (get-file-buffer file)))
-              (when buffer (with-current-buffer buffer (revert-buffer t t t)))))
-          (git-success-message "Reverted" names))))))
-
-(defun git-remove-handled ()
-  "Remove handled files from the status list."
-  (interactive)
-  (ewoc-filter git-status
-               (lambda (info)
-                 (case (git-fileinfo->state info)
-                   ('ignored git-show-ignored)
-                   ('uptodate git-show-uptodate)
-                   ('unknown git-show-unknown)
-                   (t t))))
-  (unless (ewoc-nth git-status 0)  ; refresh header if list is empty
-    (git-refresh-ewoc-hf git-status)))
-
-(defun git-toggle-show-uptodate ()
-  "Toogle the option for showing up-to-date files."
-  (interactive)
-  (if (setq git-show-uptodate (not git-show-uptodate))
-      (git-refresh-status)
-    (git-remove-handled)))
-
-(defun git-toggle-show-ignored ()
-  "Toogle the option for showing ignored files."
-  (interactive)
-  (if (setq git-show-ignored (not git-show-ignored))
-      (progn
-        (message "Inserting ignored files...")
-        (git-run-ls-files-with-excludes git-status nil 'ignored "-o" "-i")
-        (git-refresh-files)
-        (git-refresh-ewoc-hf git-status)
-        (message "Inserting ignored files...done"))
-    (git-remove-handled)))
-
-(defun git-toggle-show-unknown ()
-  "Toogle the option for showing unknown files."
-  (interactive)
-  (if (setq git-show-unknown (not git-show-unknown))
-      (progn
-        (message "Inserting unknown files...")
-        (git-run-ls-files-with-excludes git-status nil 'unknown "-o")
-        (git-refresh-files)
-        (git-refresh-ewoc-hf git-status)
-        (message "Inserting unknown files...done"))
-    (git-remove-handled)))
-
-(defun git-expand-directory (info)
-  "Expand the directory represented by INFO to list its files."
-  (when (eq (lsh (git-fileinfo->new-perm info) -9) ?\110)
-    (let ((dir (git-fileinfo->name info)))
-      (git-set-filenames-state git-status (list dir) nil)
-      (git-run-ls-files-with-excludes git-status (list (concat dir "/")) 'unknown "-o")
-      (git-refresh-files)
-      (git-refresh-ewoc-hf git-status)
-      t)))
-
-(defun git-setup-diff-buffer (buffer)
-  "Setup a buffer for displaying a diff."
-  (let ((dir default-directory))
-    (with-current-buffer buffer
-      (diff-mode)
-      (goto-char (point-min))
-      (setq default-directory dir)
-      (setq buffer-read-only t)))
-  (display-buffer buffer)
-  ; shrink window only if it displays the status buffer
-  (when (eq (window-buffer) (current-buffer))
-    (shrink-window-if-larger-than-buffer)))
-
-(defun git-diff-file ()
-  "Diff the marked file(s) against HEAD."
-  (interactive)
-  (let ((files (git-marked-files)))
-    (git-setup-diff-buffer
-     (apply #'git-run-command-buffer "*git-diff*" "diff-index" "-p" "-M" "HEAD" "--" (git-get-filenames files)))))
-
-(defun git-diff-file-merge-head (arg)
-  "Diff the marked file(s) against the first merge head (or the nth one with a numeric prefix)."
-  (interactive "p")
-  (let ((files (git-marked-files))
-        (merge-heads (git-get-merge-heads)))
-    (unless merge-heads (error "No merge in progress"))
-    (git-setup-diff-buffer
-     (apply #'git-run-command-buffer "*git-diff*" "diff-index" "-p" "-M"
-            (or (nth (1- arg) merge-heads) "HEAD") "--" (git-get-filenames files)))))
-
-(defun git-diff-unmerged-file (stage)
-  "Diff the marked unmerged file(s) against the specified stage."
-  (let ((files (git-marked-files)))
-    (git-setup-diff-buffer
-     (apply #'git-run-command-buffer "*git-diff*" "diff-files" "-p" stage "--" (git-get-filenames files)))))
-
-(defun git-diff-file-base ()
-  "Diff the marked unmerged file(s) against the common base file."
-  (interactive)
-  (git-diff-unmerged-file "-1"))
-
-(defun git-diff-file-mine ()
-  "Diff the marked unmerged file(s) against my pre-merge version."
-  (interactive)
-  (git-diff-unmerged-file "-2"))
-
-(defun git-diff-file-other ()
-  "Diff the marked unmerged file(s) against the other's pre-merge version."
-  (interactive)
-  (git-diff-unmerged-file "-3"))
-
-(defun git-diff-file-combined ()
-  "Do a combined diff of the marked unmerged file(s)."
-  (interactive)
-  (git-diff-unmerged-file "-c"))
-
-(defun git-diff-file-idiff ()
-  "Perform an interactive diff on the current file."
-  (interactive)
-  (let ((files (git-marked-files-state 'added 'deleted 'modified)))
-    (unless (eq 1 (length files))
-      (error "Cannot perform an interactive diff on multiple files."))
-    (let* ((filename (car (git-get-filenames files)))
-           (buff1 (find-file-noselect filename))
-           (buff2 (git-run-command-buffer (concat filename ".~HEAD~") "cat-file" "blob" (concat "HEAD:" filename))))
-      (ediff-buffers buff1 buff2))))
-
-(defun git-log-file ()
-  "Display a log of changes to the marked file(s)."
-  (interactive)
-  (let* ((files (git-marked-files))
-         (coding-system-for-read git-commits-coding-system)
-         (buffer (apply #'git-run-command-buffer "*git-log*" "rev-list" "--pretty" "HEAD" "--" (git-get-filenames files))))
-    (with-current-buffer buffer
-      ; (git-log-mode)  FIXME: implement log mode
-      (goto-char (point-min))
-      (setq buffer-read-only t))
-    (display-buffer buffer)))
-
-(defun git-log-edit-files ()
-  "Return a list of marked files for use in the log-edit buffer."
-  (with-current-buffer log-edit-parent-buffer
-    (git-get-filenames (git-marked-files-state 'added 'deleted 'modified))))
-
-(defun git-log-edit-diff ()
-  "Run a diff of the current files being committed from a log-edit buffer."
-  (with-current-buffer log-edit-parent-buffer
-    (git-diff-file)))
-
-(defun git-append-sign-off (name email)
-  "Append a Signed-off-by entry to the current buffer, avoiding duplicates."
-  (let ((sign-off (format "Signed-off-by: %s <%s>" name email))
-        (case-fold-search t))
-    (goto-char (point-min))
-    (unless (re-search-forward (concat "^" (regexp-quote sign-off)) nil t)
-      (goto-char (point-min))
-      (unless (re-search-forward "^Signed-off-by: " nil t)
-        (setq sign-off (concat "\n" sign-off)))
-      (goto-char (point-max))
-      (insert sign-off "\n"))))
-
-(defun git-setup-log-buffer (buffer &optional merge-heads author-name author-email subject date msg)
-  "Setup the log buffer for a commit."
-  (unless git-status (error "Not in git-status buffer."))
-  (let ((dir default-directory)
-        (committer-name (git-get-committer-name))
-        (committer-email (git-get-committer-email))
-        (sign-off git-append-signed-off-by))
-    (with-current-buffer buffer
-      (cd dir)
-      (erase-buffer)
-      (insert
-       (propertize
-        (format "Author: %s <%s>\n%s%s"
-                (or author-name committer-name)
-                (or author-email committer-email)
-                (if date (format "Date: %s\n" date) "")
-                (if merge-heads
-                    (format "Merge: %s\n"
-                            (mapconcat 'identity merge-heads " "))
-                  ""))
-        'face 'git-header-face)
-       (propertize git-log-msg-separator 'face 'git-separator-face)
-       "\n")
-      (when subject (insert subject "\n\n"))
-      (cond (msg (insert msg "\n"))
-            ((file-readable-p ".git/rebase-apply/msg")
-             (insert-file-contents ".git/rebase-apply/msg"))
-            ((file-readable-p ".git/MERGE_MSG")
-             (insert-file-contents ".git/MERGE_MSG")))
-      ; delete empty lines at end
-      (goto-char (point-min))
-      (when (re-search-forward "\n+\\'" nil t)
-        (replace-match "\n" t t))
-      (when sign-off (git-append-sign-off committer-name committer-email)))
-    buffer))
-
-(define-derived-mode git-log-edit-mode log-edit-mode "Git-Log-Edit"
-  "Major mode for editing git log messages.
-
-Set up git-specific `font-lock-keywords' for `log-edit-mode'."
-  (set (make-local-variable 'font-lock-defaults)
-       '(git-log-edit-font-lock-keywords t t)))
-
-(defun git-commit-file ()
-  "Commit the marked file(s), asking for a commit message."
-  (interactive)
-  (unless git-status (error "Not in git-status buffer."))
-  (when (git-run-pre-commit-hook)
-    (let ((buffer (get-buffer-create "*git-commit*"))
-          (coding-system (git-get-commits-coding-system))
-          author-name author-email subject date)
-      (when (eq 0 (buffer-size buffer))
-        (when (file-readable-p ".git/rebase-apply/info")
-          (with-temp-buffer
-            (insert-file-contents ".git/rebase-apply/info")
-            (goto-char (point-min))
-            (when (re-search-forward "^Author: \\(.*\\)\nEmail: \\(.*\\)$" nil t)
-              (setq author-name (match-string 1))
-              (setq author-email (match-string 2)))
-            (goto-char (point-min))
-            (when (re-search-forward "^Subject: \\(.*\\)$" nil t)
-              (setq subject (match-string 1)))
-            (goto-char (point-min))
-            (when (re-search-forward "^Date: \\(.*\\)$" nil t)
-              (setq date (match-string 1)))))
-        (git-setup-log-buffer buffer (git-get-merge-heads) author-name author-email subject date))
-      (if (boundp 'log-edit-diff-function)
-	  (log-edit 'git-do-commit nil '((log-edit-listfun . git-log-edit-files)
-					 (log-edit-diff-function . git-log-edit-diff)) buffer 'git-log-edit-mode)
-	(log-edit 'git-do-commit nil 'git-log-edit-files buffer
-                  'git-log-edit-mode))
-      (setq paragraph-separate (concat (regexp-quote git-log-msg-separator) "$\\|Author: \\|Date: \\|Merge: \\|Signed-off-by: \\|\f\\|[ 	]*$"))
-      (setq buffer-file-coding-system coding-system)
-      (re-search-forward (regexp-quote (concat git-log-msg-separator "\n")) nil t))))
-
-(defun git-setup-commit-buffer (commit)
-  "Setup the commit buffer with the contents of COMMIT."
-  (let (parents author-name author-email subject date msg)
-    (with-temp-buffer
-      (let ((coding-system (git-get-logoutput-coding-system)))
-        (git-call-process t "log" "-1" "--pretty=medium" "--abbrev=40" commit)
-        (goto-char (point-min))
-        (when (re-search-forward "^Merge: *\\(.*\\)$" nil t)
-          (setq parents (cdr (split-string (match-string 1) " +"))))
-        (when (re-search-forward "^Author: *\\(.*\\) <\\(.*\\)>$" nil t)
-          (setq author-name (match-string 1))
-          (setq author-email (match-string 2)))
-        (when (re-search-forward "^Date: *\\(.*\\)$" nil t)
-          (setq date (match-string 1)))
-        (while (re-search-forward "^    \\(.*\\)$" nil t)
-          (push (match-string 1) msg))
-        (setq msg (nreverse msg))
-        (setq subject (pop msg))
-        (while (and msg (zerop (length (car msg))) (pop msg)))))
-    (git-setup-log-buffer (get-buffer-create "*git-commit*")
-                          parents author-name author-email subject date
-                          (mapconcat #'identity msg "\n"))))
-
-(defun git-get-commit-files (commit)
-  "Retrieve a sorted list of files modified by COMMIT."
-  (let (files)
-    (with-temp-buffer
-      (git-call-process t "diff-tree" "-m" "-r" "-z" "--name-only" "--no-commit-id" "--root" commit)
-      (goto-char (point-min))
-      (while (re-search-forward "\\([^\0]*\\)\0" nil t 1)
-        (push (match-string 1) files)))
-    (sort files #'string-lessp)))
-
-(defun git-read-commit-name (prompt &optional default)
-  "Ask for a commit name, with completion for local branch, remote branch and tag."
-  (completing-read prompt
-                   (list* "HEAD" "ORIG_HEAD" "FETCH_HEAD" (mapcar #'car (git-for-each-ref)))
-		   nil nil nil nil default))
-
-(defun git-checkout (branch &optional merge)
-  "Checkout a branch, tag, or any commit.
-Use a prefix arg if git should merge while checking out."
-  (interactive
-   (list (git-read-commit-name "Checkout: ")
-         current-prefix-arg))
-  (unless git-status (error "Not in git-status buffer."))
-  (let ((args (list branch "--")))
-    (when merge (push "-m" args))
-    (when (apply #'git-call-process-display-error "checkout" args)
-      (git-update-status-files))))
-
-(defun git-branch (branch)
-  "Create a branch from the current HEAD and switch to it."
-  (interactive (list (git-read-commit-name "Branch: ")))
-  (unless git-status (error "Not in git-status buffer."))
-  (if (git-rev-parse (concat "refs/heads/" branch))
-      (if (yes-or-no-p (format "Branch %s already exists, replace it? " branch))
-          (and (git-call-process-display-error "branch" "-f" branch)
-               (git-call-process-display-error "checkout" branch))
-        (message "Canceled."))
-    (git-call-process-display-error "checkout" "-b" branch))
-    (git-refresh-ewoc-hf git-status))
-
-(defun git-amend-commit ()
-  "Undo the last commit on HEAD, and set things up to commit an
-amended version of it."
-  (interactive)
-  (unless git-status (error "Not in git-status buffer."))
-  (when (git-empty-db-p) (error "No commit to amend."))
-  (let* ((commit (git-rev-parse "HEAD"))
-         (files (git-get-commit-files commit)))
-    (when (if (git-rev-parse "HEAD^")
-              (git-call-process-display-error "reset" "--soft" "HEAD^")
-            (and (git-update-ref "ORIG_HEAD" commit)
-                 (git-update-ref "HEAD" nil commit)))
-      (git-update-status-files files t)
-      (git-setup-commit-buffer commit)
-      (git-commit-file))))
-
-(defun git-cherry-pick-commit (arg)
-  "Cherry-pick a commit."
-  (interactive (list (git-read-commit-name "Cherry-pick commit: ")))
-  (unless git-status (error "Not in git-status buffer."))
-  (let ((commit (git-rev-parse (concat arg "^0"))))
-    (unless commit (error "Not a valid commit '%s'." arg))
-    (when (git-rev-parse (concat commit "^2"))
-      (error "Cannot cherry-pick a merge commit."))
-    (let ((files (git-get-commit-files commit))
-          (ok (git-call-process-display-error "cherry-pick" "-n" commit)))
-      (git-update-status-files files ok)
-      (with-current-buffer (git-setup-commit-buffer commit)
-        (goto-char (point-min))
-        (if (re-search-forward "^\n*Signed-off-by:" nil t 1)
-            (goto-char (match-beginning 0))
-          (goto-char (point-max)))
-        (insert "(cherry picked from commit " commit ")\n"))
-      (when ok (git-commit-file)))))
-
-(defun git-revert-commit (arg)
-  "Revert a commit."
-  (interactive (list (git-read-commit-name "Revert commit: ")))
-  (unless git-status (error "Not in git-status buffer."))
-  (let ((commit (git-rev-parse (concat arg "^0"))))
-    (unless commit (error "Not a valid commit '%s'." arg))
-    (when (git-rev-parse (concat commit "^2"))
-      (error "Cannot revert a merge commit."))
-    (let ((files (git-get-commit-files commit))
-          (subject (git-get-commit-description commit))
-          (ok (git-call-process-display-error "revert" "-n" commit)))
-      (git-update-status-files files ok)
-      (when (string-match "^[0-9a-f]+ - \\(.*\\)$" subject)
-        (setq subject (match-string 1 subject)))
-      (git-setup-log-buffer (get-buffer-create "*git-commit*")
-                            (git-get-merge-heads) nil nil (format "Revert \"%s\"" subject) nil
-                            (format "This reverts commit %s.\n" commit))
-      (when ok (git-commit-file)))))
-
-(defun git-find-file ()
-  "Visit the current file in its own buffer."
-  (interactive)
-  (unless git-status (error "Not in git-status buffer."))
-  (let ((info (ewoc-data (ewoc-locate git-status))))
-    (unless (git-expand-directory info)
-      (find-file (git-fileinfo->name info))
-      (when (eq 'unmerged (git-fileinfo->state info))
-        (smerge-mode 1)))))
-
-(defun git-find-file-other-window ()
-  "Visit the current file in its own buffer in another window."
-  (interactive)
-  (unless git-status (error "Not in git-status buffer."))
-  (let ((info (ewoc-data (ewoc-locate git-status))))
-    (find-file-other-window (git-fileinfo->name info))
-    (when (eq 'unmerged (git-fileinfo->state info))
-      (smerge-mode))))
-
-(defun git-find-file-imerge ()
-  "Visit the current file in interactive merge mode."
-  (interactive)
-  (unless git-status (error "Not in git-status buffer."))
-  (let ((info (ewoc-data (ewoc-locate git-status))))
-    (find-file (git-fileinfo->name info))
-    (smerge-ediff)))
-
-(defun git-view-file ()
-  "View the current file in its own buffer."
-  (interactive)
-  (unless git-status (error "Not in git-status buffer."))
-  (let ((info (ewoc-data (ewoc-locate git-status))))
-    (view-file (git-fileinfo->name info))))
-
-(defun git-refresh-status ()
-  "Refresh the git status buffer."
-  (interactive)
-  (unless git-status (error "Not in git-status buffer."))
-  (message "Refreshing git status...")
-  (git-update-status-files)
-  (message "Refreshing git status...done"))
-
-(defun git-status-quit ()
-  "Quit git-status mode."
-  (interactive)
-  (bury-buffer))
-
-;;;; Major Mode
-;;;; ------------------------------------------------------------
-
-(defvar git-status-mode-hook nil
-  "Run after `git-status-mode' is setup.")
-
-(defvar git-status-mode-map nil
-  "Keymap for git major mode.")
-
-(defvar git-status nil
-  "List of all files managed by the git-status mode.")
-
-(unless git-status-mode-map
-  (let ((map (make-keymap))
-        (commit-map (make-sparse-keymap))
-        (diff-map (make-sparse-keymap))
-        (toggle-map (make-sparse-keymap)))
-    (suppress-keymap map)
-    (define-key map "?"   'git-help)
-    (define-key map "h"   'git-help)
-    (define-key map " "   'git-next-file)
-    (define-key map "a"   'git-add-file)
-    (define-key map "c"   'git-commit-file)
-    (define-key map "\C-c" commit-map)
-    (define-key map "d"    diff-map)
-    (define-key map "="   'git-diff-file)
-    (define-key map "f"   'git-find-file)
-    (define-key map "\r"  'git-find-file)
-    (define-key map "g"   'git-refresh-status)
-    (define-key map "i"   'git-ignore-file)
-    (define-key map "I"   'git-insert-file)
-    (define-key map "l"   'git-log-file)
-    (define-key map "m"   'git-mark-file)
-    (define-key map "M"   'git-mark-all)
-    (define-key map "n"   'git-next-file)
-    (define-key map "N"   'git-next-unmerged-file)
-    (define-key map "o"   'git-find-file-other-window)
-    (define-key map "p"   'git-prev-file)
-    (define-key map "P"   'git-prev-unmerged-file)
-    (define-key map "q"   'git-status-quit)
-    (define-key map "r"   'git-remove-file)
-    (define-key map "t"    toggle-map)
-    (define-key map "T"   'git-toggle-all-marks)
-    (define-key map "u"   'git-unmark-file)
-    (define-key map "U"   'git-revert-file)
-    (define-key map "v"   'git-view-file)
-    (define-key map "x"   'git-remove-handled)
-    (define-key map "\C-?" 'git-unmark-file-up)
-    (define-key map "\M-\C-?" 'git-unmark-all)
-    ; the commit submap
-    (define-key commit-map "\C-a" 'git-amend-commit)
-    (define-key commit-map "\C-b" 'git-branch)
-    (define-key commit-map "\C-o" 'git-checkout)
-    (define-key commit-map "\C-p" 'git-cherry-pick-commit)
-    (define-key commit-map "\C-v" 'git-revert-commit)
-    ; the diff submap
-    (define-key diff-map "b" 'git-diff-file-base)
-    (define-key diff-map "c" 'git-diff-file-combined)
-    (define-key diff-map "=" 'git-diff-file)
-    (define-key diff-map "e" 'git-diff-file-idiff)
-    (define-key diff-map "E" 'git-find-file-imerge)
-    (define-key diff-map "h" 'git-diff-file-merge-head)
-    (define-key diff-map "m" 'git-diff-file-mine)
-    (define-key diff-map "o" 'git-diff-file-other)
-    ; the toggle submap
-    (define-key toggle-map "u" 'git-toggle-show-uptodate)
-    (define-key toggle-map "i" 'git-toggle-show-ignored)
-    (define-key toggle-map "k" 'git-toggle-show-unknown)
-    (define-key toggle-map "m" 'git-toggle-all-marks)
-    (setq git-status-mode-map map))
-  (easy-menu-define git-menu git-status-mode-map
-    "Git Menu"
-    `("Git"
-      ["Refresh" git-refresh-status t]
-      ["Commit" git-commit-file t]
-      ["Checkout..." git-checkout t]
-      ["New Branch..." git-branch t]
-      ["Cherry-pick Commit..." git-cherry-pick-commit t]
-      ["Revert Commit..." git-revert-commit t]
-      ("Merge"
-	["Next Unmerged File" git-next-unmerged-file t]
-	["Prev Unmerged File" git-prev-unmerged-file t]
-	["Interactive Merge File" git-find-file-imerge t]
-	["Diff Against Common Base File" git-diff-file-base t]
-	["Diff Combined" git-diff-file-combined t]
-	["Diff Against Merge Head" git-diff-file-merge-head t]
-	["Diff Against Mine" git-diff-file-mine t]
-	["Diff Against Other" git-diff-file-other t])
-      "--------"
-      ["Add File" git-add-file t]
-      ["Revert File" git-revert-file t]
-      ["Ignore File" git-ignore-file t]
-      ["Remove File" git-remove-file t]
-      ["Insert File" git-insert-file t]
-      "--------"
-      ["Find File" git-find-file t]
-      ["View File" git-view-file t]
-      ["Diff File" git-diff-file t]
-      ["Interactive Diff File" git-diff-file-idiff t]
-      ["Log" git-log-file t]
-      "--------"
-      ["Mark" git-mark-file t]
-      ["Mark All" git-mark-all t]
-      ["Unmark" git-unmark-file t]
-      ["Unmark All" git-unmark-all t]
-      ["Toggle All Marks" git-toggle-all-marks t]
-      ["Hide Handled Files" git-remove-handled t]
-      "--------"
-      ["Show Uptodate Files" git-toggle-show-uptodate :style toggle :selected git-show-uptodate]
-      ["Show Ignored Files" git-toggle-show-ignored :style toggle :selected git-show-ignored]
-      ["Show Unknown Files" git-toggle-show-unknown :style toggle :selected git-show-unknown]
-      "--------"
-      ["Quit" git-status-quit t])))
-
-
-;; git mode should only run in the *git status* buffer
-(put 'git-status-mode 'mode-class 'special)
-
-(defun git-status-mode ()
-  "Major mode for interacting with Git.
-Commands:
-\\{git-status-mode-map}"
-  (kill-all-local-variables)
-  (buffer-disable-undo)
-  (setq mode-name "git status"
-        major-mode 'git-status-mode
-        goal-column 17
-        buffer-read-only t)
-  (use-local-map git-status-mode-map)
-  (let ((buffer-read-only nil))
-    (erase-buffer)
-  (let ((status (ewoc-create 'git-fileinfo-prettyprint "" "")))
-    (set (make-local-variable 'git-status) status))
-  (set (make-local-variable 'list-buffers-directory) default-directory)
-  (make-local-variable 'git-show-uptodate)
-  (make-local-variable 'git-show-ignored)
-  (make-local-variable 'git-show-unknown)
-  (run-hooks 'git-status-mode-hook)))
-
-(defun git-find-status-buffer (dir)
-  "Find the git status buffer handling a specified directory."
-  (let ((list (buffer-list))
-        (fulldir (expand-file-name dir))
-        found)
-    (while (and list (not found))
-      (let ((buffer (car list)))
-        (with-current-buffer buffer
-          (when (and list-buffers-directory
-                     (string-equal fulldir (expand-file-name list-buffers-directory))
-		     (eq major-mode 'git-status-mode))
-            (setq found buffer))))
-      (setq list (cdr list)))
-    found))
-
-(defun git-status (dir)
-  "Entry point into git-status mode."
-  (interactive "DSelect directory: ")
-  (setq dir (git-get-top-dir dir))
-  (if (file-exists-p (concat (file-name-as-directory dir) ".git"))
-      (let ((buffer (or (and git-reuse-status-buffer (git-find-status-buffer dir))
-                        (create-file-buffer (expand-file-name "*git-status*" dir)))))
-        (switch-to-buffer buffer)
-        (cd dir)
-        (git-status-mode)
-        (git-refresh-status)
-        (goto-char (point-min))
-        (add-hook 'after-save-hook 'git-update-saved-file))
-    (message "%s is not a git working tree." dir)))
-
-(defun git-update-saved-file ()
-  "Update the corresponding git-status buffer when a file is saved.
-Meant to be used in `after-save-hook'."
-  (let* ((file (expand-file-name buffer-file-name))
-         (dir (condition-case nil (git-get-top-dir (file-name-directory file)) (error nil)))
-         (buffer (and dir (git-find-status-buffer dir))))
-    (when buffer
-      (with-current-buffer buffer
-        (let ((filename (file-relative-name file dir)))
-          ; skip files located inside the .git directory
-          (unless (string-match "^\\.git/" filename)
-            (git-call-process nil "add" "--refresh" "--" filename)
-            (git-update-status-files (list filename))))))))
-
-(defun git-help ()
-  "Display help for Git mode."
-  (interactive)
-  (describe-function 'git-status-mode))
-
-(provide 'git)
-;;; git.el ends here
+(error "git.el no longer ships with git. It's recommended to
+replace its use with Magit, or simply delete references to git.el
+in your initialization file(s). See contrib/emacs/README in git's
+sources (https://github.com/git/git/blob/master/contrib/emacs/README)
+for suggested alternatives and for why this happened. Emacs's own
+VC mode and Magit are viable alternatives.")
diff --git a/contrib/mw-to-git/Makefile b/contrib/mw-to-git/Makefile
index a4b6f7a..4e60351 100644
--- a/contrib/mw-to-git/Makefile
+++ b/contrib/mw-to-git/Makefile
@@ -21,8 +21,9 @@
 INSTALL = install
 
 SCRIPT_PERL_FULL=$(patsubst %,$(HERE)/%,$(SCRIPT_PERL))
-INSTLIBDIR=$(shell $(MAKE) -C $(GIT_ROOT_DIR)/perl \
-                -s --no-print-directory instlibdir)
+INSTLIBDIR=$(shell $(MAKE) -C $(GIT_ROOT_DIR)/ \
+                -s --no-print-directory prefix=$(prefix) \
+                perllibdir=$(perllibdir) perllibdir)
 DESTDIR_SQ = $(subst ','\'',$(DESTDIR))
 INSTLIBDIR_SQ = $(subst ','\'',$(INSTLIBDIR))
 
diff --git a/contrib/update-unicode/README b/contrib/update-unicode/README
index b9e2fc8..151a197 100644
--- a/contrib/update-unicode/README
+++ b/contrib/update-unicode/README
@@ -1,10 +1,10 @@
 TL;DR: Run update_unicode.sh after the publication of a new Unicode
-standard and commit the resulting unicode_widths.h file.
+standard and commit the resulting unicode-widths.h file.
 
 The long version
 ================
 
-The Git source code ships the file unicode_widths.h which contains
+The Git source code ships the file unicode-widths.h which contains
 tables of zero and double width Unicode code points, respectively.
 These tables are generated using update_unicode.sh in this directory.
 update_unicode.sh itself uses a third-party tool, uniset, to query two
@@ -16,5 +16,5 @@
 
 On each run, update_unicode.sh checks whether more recent Unicode data
 files are available from the Unicode consortium, and rebuilds the header
-unicode_widths.h with the new data. The new header can then be
+unicode-widths.h with the new data. The new header can then be
 committed.
diff --git a/contrib/update-unicode/update_unicode.sh b/contrib/update-unicode/update_unicode.sh
index e05db92..aa90865 100755
--- a/contrib/update-unicode/update_unicode.sh
+++ b/contrib/update-unicode/update_unicode.sh
@@ -6,7 +6,7 @@
 #Cf Format          a format control character
 #
 cd "$(dirname "$0")"
-UNICODEWIDTH_H=$(git rev-parse --show-toplevel)/unicode_width.h
+UNICODEWIDTH_H=$(git rev-parse --show-toplevel)/unicode-width.h
 
 wget -N http://www.unicode.org/Public/UCD/latest/ucd/UnicodeData.txt \
 	http://www.unicode.org/Public/UCD/latest/ucd/EastAsianWidth.txt &&
diff --git a/convert.c b/convert.c
index c480097..64d0d30 100644
--- a/convert.c
+++ b/convert.c
@@ -7,6 +7,7 @@
 #include "sigchain.h"
 #include "pkt-line.h"
 #include "sub-process.h"
+#include "utf8.h"
 
 /*
  * convert.c - convert a file when checking it out and checking it in.
@@ -265,6 +266,241 @@
 
 }
 
+static int validate_encoding(const char *path, const char *enc,
+		      const char *data, size_t len, int die_on_error)
+{
+	/* We only check for UTF here as UTF?? can be an alias for UTF-?? */
+	if (istarts_with(enc, "UTF")) {
+		/*
+		 * Check for detectable errors in UTF encodings
+		 */
+		if (has_prohibited_utf_bom(enc, data, len)) {
+			const char *error_msg = _(
+				"BOM is prohibited in '%s' if encoded as %s");
+			/*
+			 * This advice is shown for UTF-??BE and UTF-??LE encodings.
+			 * We cut off the last two characters of the encoding name
+			 * to generate the encoding name suitable for BOMs.
+			 */
+			const char *advise_msg = _(
+				"The file '%s' contains a byte order "
+				"mark (BOM). Please use UTF-%s as "
+				"working-tree-encoding.");
+			const char *stripped = NULL;
+			char *upper = xstrdup_toupper(enc);
+			upper[strlen(upper)-2] = '\0';
+			if (!skip_prefix(upper, "UTF-", &stripped))
+				skip_prefix(stripped, "UTF", &stripped);
+			advise(advise_msg, path, stripped);
+			free(upper);
+			if (die_on_error)
+				die(error_msg, path, enc);
+			else {
+				return error(error_msg, path, enc);
+			}
+
+		} else if (is_missing_required_utf_bom(enc, data, len)) {
+			const char *error_msg = _(
+				"BOM is required in '%s' if encoded as %s");
+			const char *advise_msg = _(
+				"The file '%s' is missing a byte order "
+				"mark (BOM). Please use UTF-%sBE or UTF-%sLE "
+				"(depending on the byte order) as "
+				"working-tree-encoding.");
+			const char *stripped = NULL;
+			char *upper = xstrdup_toupper(enc);
+			if (!skip_prefix(upper, "UTF-", &stripped))
+				skip_prefix(stripped, "UTF", &stripped);
+			advise(advise_msg, path, stripped, stripped);
+			free(upper);
+			if (die_on_error)
+				die(error_msg, path, enc);
+			else {
+				return error(error_msg, path, enc);
+			}
+		}
+
+	}
+	return 0;
+}
+
+static void trace_encoding(const char *context, const char *path,
+			   const char *encoding, const char *buf, size_t len)
+{
+	static struct trace_key coe = TRACE_KEY_INIT(WORKING_TREE_ENCODING);
+	struct strbuf trace = STRBUF_INIT;
+	int i;
+
+	strbuf_addf(&trace, "%s (%s, considered %s):\n", context, path, encoding);
+	for (i = 0; i < len && buf; ++i) {
+		strbuf_addf(
+			&trace,"| \e[2m%2i:\e[0m %2x \e[2m%c\e[0m%c",
+			i,
+			(unsigned char) buf[i],
+			(buf[i] > 32 && buf[i] < 127 ? buf[i] : ' '),
+			((i+1) % 8 && (i+1) < len ? ' ' : '\n')
+		);
+	}
+	strbuf_addchars(&trace, '\n', 1);
+
+	trace_strbuf(&coe, &trace);
+	strbuf_release(&trace);
+}
+
+static int check_roundtrip(const char *enc_name)
+{
+	/*
+	 * check_roundtrip_encoding contains a string of comma and/or
+	 * space separated encodings (eg. "UTF-16, ASCII, CP1125").
+	 * Search for the given encoding in that string.
+	 */
+	const char *found = strcasestr(check_roundtrip_encoding, enc_name);
+	const char *next;
+	int len;
+	if (!found)
+		return 0;
+	next = found + strlen(enc_name);
+	len = strlen(check_roundtrip_encoding);
+	return (found && (
+			/*
+			 * check that the found encoding is at the
+			 * beginning of check_roundtrip_encoding or
+			 * that it is prefixed with a space or comma
+			 */
+			found == check_roundtrip_encoding || (
+				(isspace(found[-1]) || found[-1] == ',')
+			)
+		) && (
+			/*
+			 * check that the found encoding is at the
+			 * end of check_roundtrip_encoding or
+			 * that it is suffixed with a space or comma
+			 */
+			next == check_roundtrip_encoding + len || (
+				next < check_roundtrip_encoding + len &&
+				(isspace(next[0]) || next[0] == ',')
+			)
+		));
+}
+
+static const char *default_encoding = "UTF-8";
+
+static int encode_to_git(const char *path, const char *src, size_t src_len,
+			 struct strbuf *buf, const char *enc, int conv_flags)
+{
+	char *dst;
+	int dst_len;
+	int die_on_error = conv_flags & CONV_WRITE_OBJECT;
+
+	/*
+	 * No encoding is specified or there is nothing to encode.
+	 * Tell the caller that the content was not modified.
+	 */
+	if (!enc || (src && !src_len))
+		return 0;
+
+	/*
+	 * Looks like we got called from "would_convert_to_git()".
+	 * This means Git wants to know if it would encode (= modify!)
+	 * the content. Let's answer with "yes", since an encoding was
+	 * specified.
+	 */
+	if (!buf && !src)
+		return 1;
+
+	if (validate_encoding(path, enc, src, src_len, die_on_error))
+		return 0;
+
+	trace_encoding("source", path, enc, src, src_len);
+	dst = reencode_string_len(src, src_len, default_encoding, enc,
+				  &dst_len);
+	if (!dst) {
+		/*
+		 * We could add the blob "as-is" to Git. However, on checkout
+		 * we would try to reencode to the original encoding. This
+		 * would fail and we would leave the user with a messed-up
+		 * working tree. Let's try to avoid this by screaming loud.
+		 */
+		const char* msg = _("failed to encode '%s' from %s to %s");
+		if (die_on_error)
+			die(msg, path, enc, default_encoding);
+		else {
+			error(msg, path, enc, default_encoding);
+			return 0;
+		}
+	}
+	trace_encoding("destination", path, default_encoding, dst, dst_len);
+
+	/*
+	 * UTF supports lossless conversion round tripping [1] and conversions
+	 * between UTF and other encodings are mostly round trip safe as
+	 * Unicode aims to be a superset of all other character encodings.
+	 * However, certain encodings (e.g. SHIFT-JIS) are known to have round
+	 * trip issues [2]. Check the round trip conversion for all encodings
+	 * listed in core.checkRoundtripEncoding.
+	 *
+	 * The round trip check is only performed if content is written to Git.
+	 * This ensures that no information is lost during conversion to/from
+	 * the internal UTF-8 representation.
+	 *
+	 * Please note, the code below is not tested because I was not able to
+	 * generate a faulty round trip without an iconv error. Iconv errors
+	 * are already caught above.
+	 *
+	 * [1] http://unicode.org/faq/utf_bom.html#gen2
+	 * [2] https://support.microsoft.com/en-us/help/170559/prb-conversion-problem-between-shift-jis-and-unicode
+	 */
+	if (die_on_error && check_roundtrip(enc)) {
+		char *re_src;
+		int re_src_len;
+
+		re_src = reencode_string_len(dst, dst_len,
+					     enc, default_encoding,
+					     &re_src_len);
+
+		trace_printf("Checking roundtrip encoding for %s...\n", enc);
+		trace_encoding("reencoded source", path, enc,
+			       re_src, re_src_len);
+
+		if (!re_src || src_len != re_src_len ||
+		    memcmp(src, re_src, src_len)) {
+			const char* msg = _("encoding '%s' from %s to %s and "
+					    "back is not the same");
+			die(msg, path, enc, default_encoding);
+		}
+
+		free(re_src);
+	}
+
+	strbuf_attach(buf, dst, dst_len, dst_len + 1);
+	return 1;
+}
+
+static int encode_to_worktree(const char *path, const char *src, size_t src_len,
+			      struct strbuf *buf, const char *enc)
+{
+	char *dst;
+	int dst_len;
+
+	/*
+	 * No encoding is specified or there is nothing to encode.
+	 * Tell the caller that the content was not modified.
+	 */
+	if (!enc || (src && !src_len))
+		return 0;
+
+	dst = reencode_string_len(src, src_len, enc, default_encoding,
+				  &dst_len);
+	if (!dst) {
+		error("failed to encode '%s' from %s to %s",
+			path, default_encoding, enc);
+		return 0;
+	}
+
+	strbuf_attach(buf, dst, dst_len, dst_len + 1);
+	return 1;
+}
+
 static int crlf_to_git(const struct index_state *istate,
 		       const char *path, const char *src, size_t len,
 		       struct strbuf *buf,
@@ -978,6 +1214,24 @@
 	return 1;
 }
 
+static const char *git_path_check_encoding(struct attr_check_item *check)
+{
+	const char *value = check->value;
+
+	if (ATTR_UNSET(value) || !strlen(value))
+		return NULL;
+
+	if (ATTR_TRUE(value) || ATTR_FALSE(value)) {
+		die(_("true/false are no valid working-tree-encodings"));
+	}
+
+	/* Don't encode to the default encoding */
+	if (same_encoding(value, default_encoding))
+		return NULL;
+
+	return value;
+}
+
 static enum crlf_action git_path_check_crlf(struct attr_check_item *check)
 {
 	const char *value = check->value;
@@ -1033,6 +1287,7 @@
 	enum crlf_action attr_action; /* What attr says */
 	enum crlf_action crlf_action; /* When no attr is set, use core.autocrlf */
 	int ident;
+	const char *working_tree_encoding; /* Supported encoding or default encoding if NULL */
 };
 
 static void convert_attrs(struct conv_attrs *ca, const char *path)
@@ -1041,7 +1296,8 @@
 
 	if (!check) {
 		check = attr_check_initl("crlf", "ident", "filter",
-					 "eol", "text", NULL);
+					 "eol", "text", "working-tree-encoding",
+					 NULL);
 		user_convert_tail = &user_convert;
 		git_config(read_convert_config, NULL);
 	}
@@ -1064,6 +1320,7 @@
 			else if (eol_attr == EOL_CRLF)
 				ca->crlf_action = CRLF_TEXT_CRLF;
 		}
+		ca->working_tree_encoding = git_path_check_encoding(ccheck + 5);
 	} else {
 		ca->drv = NULL;
 		ca->crlf_action = CRLF_UNDEFINED;
@@ -1144,6 +1401,13 @@
 		src = dst->buf;
 		len = dst->len;
 	}
+
+	ret |= encode_to_git(path, src, len, dst, ca.working_tree_encoding, conv_flags);
+	if (ret && dst) {
+		src = dst->buf;
+		len = dst->len;
+	}
+
 	if (!(conv_flags & CONV_EOL_KEEP_CRLF)) {
 		ret |= crlf_to_git(istate, path, src, len, dst, ca.crlf_action, conv_flags);
 		if (ret && dst) {
@@ -1167,6 +1431,7 @@
 	if (!apply_filter(path, NULL, 0, fd, dst, ca.drv, CAP_CLEAN, NULL))
 		die("%s: clean filter '%s' failed", path, ca.drv->name);
 
+	encode_to_git(path, dst->buf, dst->len, dst, ca.working_tree_encoding, conv_flags);
 	crlf_to_git(istate, path, dst->buf, dst->len, dst, ca.crlf_action, conv_flags);
 	ident_to_git(path, dst->buf, dst->len, dst, ca.ident);
 }
@@ -1198,6 +1463,12 @@
 		}
 	}
 
+	ret |= encode_to_worktree(path, src, len, dst, ca.working_tree_encoding);
+	if (ret) {
+		src = dst->buf;
+		len = dst->len;
+	}
+
 	ret_filter = apply_filter(
 		path, src, len, -1, dst, ca.drv, CAP_SMUDGE, dco);
 	if (!ret_filter && ca.drv && ca.drv->required)
@@ -1664,6 +1935,9 @@
 	if (ca.drv && (ca.drv->process || ca.drv->smudge || ca.drv->clean))
 		return NULL;
 
+	if (ca.working_tree_encoding)
+		return NULL;
+
 	if (ca.crlf_action == CRLF_AUTO || ca.crlf_action == CRLF_AUTO_CRLF)
 		return NULL;
 
diff --git a/convert.h b/convert.h
index 2e9b4f4..01385d9 100644
--- a/convert.h
+++ b/convert.h
@@ -12,6 +12,7 @@
 #define CONV_EOL_RNDTRP_WARN  (1<<1) /* Warn if CRLF to LF to CRLF is different */
 #define CONV_EOL_RENORMALIZE  (1<<2) /* Convert CRLF to LF */
 #define CONV_EOL_KEEP_CRLF    (1<<3) /* Keep CRLF line endings as is */
+#define CONV_WRITE_OBJECT     (1<<4) /* Content is written to the index */
 
 extern int global_conv_flags_eol;
 
@@ -55,6 +56,7 @@
 };
 
 extern enum eol core_eol;
+extern char *check_roundtrip_encoding;
 extern const char *get_cached_convert_stats_ascii(const struct index_state *istate,
 						  const char *path);
 extern const char *get_wt_convert_stats_ascii(const char *path);
diff --git a/csum-file.c b/csum-file.c
index 5eda7fb..53ce37f 100644
--- a/csum-file.c
+++ b/csum-file.c
@@ -53,7 +53,7 @@
 	}
 }
 
-int hashclose(struct hashfile *f, unsigned char *result, unsigned int flags)
+int finalize_hashfile(struct hashfile *f, unsigned char *result, unsigned int flags)
 {
 	int fd;
 
@@ -61,11 +61,11 @@
 	the_hash_algo->final_fn(f->buffer, &f->ctx);
 	if (result)
 		hashcpy(result, f->buffer);
-	if (flags & (CSUM_CLOSE | CSUM_FSYNC)) {
-		/* write checksum and close fd */
+	if (flags & CSUM_HASH_IN_STREAM)
 		flush(f, f->buffer, the_hash_algo->rawsz);
-		if (flags & CSUM_FSYNC)
-			fsync_or_die(f->fd, f->name);
+	if (flags & CSUM_FSYNC)
+		fsync_or_die(f->fd, f->name);
+	if (flags & CSUM_CLOSE) {
 		if (close(f->fd))
 			die_errno("%s: sha1 file error on close", f->name);
 		fd = 0;
diff --git a/csum-file.h b/csum-file.h
index 992e5c0..c5a2e33 100644
--- a/csum-file.h
+++ b/csum-file.h
@@ -26,14 +26,15 @@
 extern void hashfile_checkpoint(struct hashfile *, struct hashfile_checkpoint *);
 extern int hashfile_truncate(struct hashfile *, struct hashfile_checkpoint *);
 
-/* hashclose flags */
-#define CSUM_CLOSE	1
-#define CSUM_FSYNC	2
+/* finalize_hashfile flags */
+#define CSUM_CLOSE		1
+#define CSUM_FSYNC		2
+#define CSUM_HASH_IN_STREAM	4
 
 extern struct hashfile *hashfd(int fd, const char *name);
 extern struct hashfile *hashfd_check(const char *name);
 extern struct hashfile *hashfd_throughput(int fd, const char *name, struct progress *tp);
-extern int hashclose(struct hashfile *, unsigned char *, unsigned int);
+extern int finalize_hashfile(struct hashfile *, unsigned char *, unsigned int);
 extern void hashwrite(struct hashfile *, const void *, unsigned int);
 extern void hashflush(struct hashfile *f);
 extern void crc32_begin(struct hashfile *);
diff --git a/daemon.c b/daemon.c
index fe833ea..9d2e0d2 100644
--- a/daemon.c
+++ b/daemon.c
@@ -1459,7 +1459,7 @@
 		die("base-path '%s' does not exist or is not a directory",
 		    base_path);
 
-	if (inetd_mode) {
+	if (log_destination != LOG_DESTINATION_STDERR) {
 		if (!freopen("/dev/null", "w", stderr))
 			die_errno("failed to redirect stderr to /dev/null");
 	}
diff --git a/detect-compiler b/detect-compiler
new file mode 100755
index 0000000..70b7544
--- /dev/null
+++ b/detect-compiler
@@ -0,0 +1,53 @@
+#!/bin/sh
+#
+# Probe the compiler for vintage, version, etc. This is used for setting
+# optional make knobs under the DEVELOPER knob.
+
+CC="$*"
+
+# we get something like (this is at least true for gcc and clang)
+#
+# FreeBSD clang version 3.4.1 (tags/RELEASE...)
+get_version_line() {
+	$CC -v 2>&1 | grep ' version '
+}
+
+get_family() {
+	get_version_line | sed 's/^\(.*\) version [0-9][^ ]* .*/\1/'
+}
+
+get_version() {
+	get_version_line | sed 's/^.* version \([0-9][^ ]*\) .*/\1/'
+}
+
+print_flags() {
+	family=$1
+	version=$(get_version | cut -f 1 -d .)
+
+	# Print a feature flag not only for the current version, but also
+	# for any prior versions we encompass. This avoids needing to do
+	# numeric comparisons in make, which are awkward.
+	while test "$version" -gt 0
+	do
+		echo $family$version
+		version=$((version - 1))
+	done
+}
+
+case "$(get_family)" in
+gcc)
+	print_flags gcc
+	;;
+clang)
+	print_flags clang
+	;;
+"FreeBSD clang")
+	print_flags clang
+	;;
+"Apple LLVM")
+	print_flags clang
+	;;
+*)
+	: unknown compiler family
+	;;
+esac
diff --git a/dir.c b/dir.c
index 63a917b..be08d3d 100644
--- a/dir.c
+++ b/dir.c
@@ -19,6 +19,7 @@
 #include "varint.h"
 #include "ewah/ewok.h"
 #include "fsmonitor.h"
+#include "submodule-config.h"
 
 /*
  * Tells read_directory_recursive how a file or directory should be treated.
@@ -3010,8 +3011,57 @@
 	untracked_cache_invalidate_path(istate, path, 1);
 }
 
-/* Update gitfile and core.worktree setting to connect work tree and git dir */
-void connect_work_tree_and_git_dir(const char *work_tree_, const char *git_dir_)
+static void connect_wt_gitdir_in_nested(const char *sub_worktree,
+					const char *sub_gitdir)
+{
+	int i;
+	struct repository subrepo;
+	struct strbuf sub_wt = STRBUF_INIT;
+	struct strbuf sub_gd = STRBUF_INIT;
+
+	const struct submodule *sub;
+
+	/* If the submodule has no working tree, we can ignore it. */
+	if (repo_init(&subrepo, sub_gitdir, sub_worktree))
+		return;
+
+	if (repo_read_index(&subrepo) < 0)
+		die("index file corrupt in repo %s", subrepo.gitdir);
+
+	for (i = 0; i < subrepo.index->cache_nr; i++) {
+		const struct cache_entry *ce = subrepo.index->cache[i];
+
+		if (!S_ISGITLINK(ce->ce_mode))
+			continue;
+
+		while (i + 1 < subrepo.index->cache_nr &&
+		       !strcmp(ce->name, subrepo.index->cache[i + 1]->name))
+			/*
+			 * Skip entries with the same name in different stages
+			 * to make sure an entry is returned only once.
+			 */
+			i++;
+
+		sub = submodule_from_path(&subrepo, &null_oid, ce->name);
+		if (!sub || !is_submodule_active(&subrepo, ce->name))
+			/* .gitmodules broken or inactive sub */
+			continue;
+
+		strbuf_reset(&sub_wt);
+		strbuf_reset(&sub_gd);
+		strbuf_addf(&sub_wt, "%s/%s", sub_worktree, sub->path);
+		strbuf_addf(&sub_gd, "%s/modules/%s", sub_gitdir, sub->name);
+
+		connect_work_tree_and_git_dir(sub_wt.buf, sub_gd.buf, 1);
+	}
+	strbuf_release(&sub_wt);
+	strbuf_release(&sub_gd);
+	repo_clear(&subrepo);
+}
+
+void connect_work_tree_and_git_dir(const char *work_tree_,
+				   const char *git_dir_,
+				   int recurse_into_nested)
 {
 	struct strbuf gitfile_sb = STRBUF_INIT;
 	struct strbuf cfg_sb = STRBUF_INIT;
@@ -3041,6 +3091,10 @@
 	strbuf_release(&gitfile_sb);
 	strbuf_release(&cfg_sb);
 	strbuf_release(&rel_path);
+
+	if (recurse_into_nested)
+		connect_wt_gitdir_in_nested(work_tree, git_dir);
+
 	free(work_tree);
 	free(git_dir);
 }
@@ -3054,5 +3108,5 @@
 		die_errno(_("could not migrate git directory from '%s' to '%s'"),
 			old_git_dir, new_git_dir);
 
-	connect_work_tree_and_git_dir(path, new_git_dir);
+	connect_work_tree_and_git_dir(path, new_git_dir, 0);
 }
diff --git a/dir.h b/dir.h
index b0758b8..3870193 100644
--- a/dir.h
+++ b/dir.h
@@ -359,7 +359,17 @@
 void write_untracked_extension(struct strbuf *out, struct untracked_cache *untracked);
 void add_untracked_cache(struct index_state *istate);
 void remove_untracked_cache(struct index_state *istate);
-extern void connect_work_tree_and_git_dir(const char *work_tree, const char *git_dir);
+
+/*
+ * Connect a worktree to a git directory by creating (or overwriting) a
+ * '.git' file containing the location of the git directory. In the git
+ * directory set the core.worktree setting to indicate where the worktree is.
+ * When `recurse_into_nested` is set, recurse into any nested submodules,
+ * connecting them as well.
+ */
+extern void connect_work_tree_and_git_dir(const char *work_tree,
+					  const char *git_dir,
+					  int recurse_into_nested);
 extern void relocate_gitdir(const char *path,
 			    const char *old_git_dir,
 			    const char *new_git_dir);
diff --git a/environment.c b/environment.c
index 39b3d90..2a6de23 100644
--- a/environment.c
+++ b/environment.c
@@ -15,6 +15,7 @@
 #include "commit.h"
 #include "argv-array.h"
 #include "object-store.h"
+#include "chdir-notify.h"
 
 int trust_executable_bit = 1;
 int trust_ctime = 1;
@@ -50,10 +51,11 @@
 const char *askpass_program;
 const char *excludes_file;
 enum auto_crlf auto_crlf = AUTO_CRLF_FALSE;
-int check_replace_refs = 1;
+int check_replace_refs = 1; /* NEEDSWORK: rename to read_replace_refs */
 char *git_replace_ref_base;
 enum eol core_eol = EOL_UNSET;
 int global_conv_flags_eol = CONV_EOL_RNDTRP_WARN;
+char *check_roundtrip_encoding = "SHIFT-JIS";
 unsigned whitespace_rule_cfg = WS_DEFAULT_RULE;
 enum branch_track git_branch_track = BRANCH_TRACK_REMOTE;
 enum rebase_setup_type autorebase = AUTOREBASE_NEVER;
@@ -64,6 +66,7 @@
 enum object_creation_mode object_creation_mode = OBJECT_CREATION_MODE;
 char *notes_ref_name;
 int grafts_replace_parents = 1;
+int core_commit_graph;
 int core_apply_sparse_checkout;
 int merge_log_config = -1;
 int precomposed_unicode = -1; /* see probe_utf8_pathname_composition() */
@@ -323,12 +326,31 @@
 	return the_repository->graft_file;
 }
 
-int set_git_dir(const char *path)
+static void set_git_dir_1(const char *path)
 {
 	if (setenv(GIT_DIR_ENVIRONMENT, path, 1))
-		return error("Could not set GIT_DIR to '%s'", path);
+		die("could not set GIT_DIR to '%s'", path);
 	setup_git_env(path);
-	return 0;
+}
+
+static void update_relative_gitdir(const char *name,
+				   const char *old_cwd,
+				   const char *new_cwd,
+				   void *data)
+{
+	char *path = reparent_relative_path(old_cwd, new_cwd, get_git_dir());
+	trace_printf_key(&trace_setup_key,
+			 "setup: move $GIT_DIR to '%s'",
+			 path);
+	set_git_dir_1(path);
+	free(path);
+}
+
+void set_git_dir(const char *path)
+{
+	set_git_dir_1(path);
+	if (!is_absolute_path(path))
+		chdir_notify_register(NULL, update_relative_gitdir, NULL);
 }
 
 const char *get_log_output_encoding(void)
diff --git a/exec_cmd.c b/exec-cmd.c
similarity index 99%
rename from exec_cmd.c
rename to exec-cmd.c
index ff5a297..02d31ee 100644
--- a/exec_cmd.c
+++ b/exec-cmd.c
@@ -1,5 +1,5 @@
 #include "cache.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "quote.h"
 #include "argv-array.h"
 
diff --git a/exec_cmd.h b/exec-cmd.h
similarity index 100%
rename from exec_cmd.h
rename to exec-cmd.h
diff --git a/fast-import.c b/fast-import.c
index 99f8f56..34edf3f 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -170,6 +170,7 @@
 #include "run-command.h"
 #include "packfile.h"
 #include "object-store.h"
+#include "mem-pool.h"
 
 #define PACK_ID_BITS 16
 #define MAX_PACK_ID ((1<<PACK_ID_BITS)-1)
@@ -211,13 +212,6 @@
 	unsigned no_swap : 1;
 };
 
-struct mem_pool {
-	struct mem_pool *next_pool;
-	char *next_free;
-	char *end;
-	uintmax_t space[FLEX_ARRAY]; /* more */
-};
-
 struct atom_str {
 	struct atom_str *next_atom;
 	unsigned short str_len;
@@ -306,9 +300,8 @@
 static const char **global_argv;
 
 /* Memory pools */
-static size_t mem_pool_alloc = 2*1024*1024 - sizeof(struct mem_pool);
-static size_t total_allocd;
-static struct mem_pool *mem_pool;
+static struct mem_pool fi_mem_pool =  {NULL, 2*1024*1024 -
+				       sizeof(struct mp_block), 0 };
 
 /* Atom management */
 static unsigned int atom_table_sz = 4451;
@@ -343,6 +336,7 @@
 static void *avail_tree_entry;
 static unsigned int avail_tree_table_sz = 100;
 static struct avail_tree_content **avail_tree_table;
+static size_t tree_entry_allocd;
 static struct strbuf old_tree = STRBUF_INIT;
 static struct strbuf new_tree = STRBUF_INIT;
 
@@ -636,49 +630,10 @@
 	return r;
 }
 
-static void *pool_alloc(size_t len)
-{
-	struct mem_pool *p;
-	void *r;
-
-	/* round up to a 'uintmax_t' alignment */
-	if (len & (sizeof(uintmax_t) - 1))
-		len += sizeof(uintmax_t) - (len & (sizeof(uintmax_t) - 1));
-
-	for (p = mem_pool; p; p = p->next_pool)
-		if ((p->end - p->next_free >= len))
-			break;
-
-	if (!p) {
-		if (len >= (mem_pool_alloc/2)) {
-			total_allocd += len;
-			return xmalloc(len);
-		}
-		total_allocd += sizeof(struct mem_pool) + mem_pool_alloc;
-		p = xmalloc(st_add(sizeof(struct mem_pool), mem_pool_alloc));
-		p->next_pool = mem_pool;
-		p->next_free = (char *) p->space;
-		p->end = p->next_free + mem_pool_alloc;
-		mem_pool = p;
-	}
-
-	r = p->next_free;
-	p->next_free += len;
-	return r;
-}
-
-static void *pool_calloc(size_t count, size_t size)
-{
-	size_t len = count * size;
-	void *r = pool_alloc(len);
-	memset(r, 0, len);
-	return r;
-}
-
 static char *pool_strdup(const char *s)
 {
 	size_t len = strlen(s) + 1;
-	char *r = pool_alloc(len);
+	char *r = mem_pool_alloc(&fi_mem_pool, len);
 	memcpy(r, s, len);
 	return r;
 }
@@ -687,7 +642,7 @@
 {
 	struct mark_set *s = marks;
 	while ((idnum >> s->shift) >= 1024) {
-		s = pool_calloc(1, sizeof(struct mark_set));
+		s = mem_pool_calloc(&fi_mem_pool, 1, sizeof(struct mark_set));
 		s->shift = marks->shift + 10;
 		s->data.sets[0] = marks;
 		marks = s;
@@ -696,7 +651,7 @@
 		uintmax_t i = idnum >> s->shift;
 		idnum -= i << s->shift;
 		if (!s->data.sets[i]) {
-			s->data.sets[i] = pool_calloc(1, sizeof(struct mark_set));
+			s->data.sets[i] = mem_pool_calloc(&fi_mem_pool, 1, sizeof(struct mark_set));
 			s->data.sets[i]->shift = s->shift - 10;
 		}
 		s = s->data.sets[i];
@@ -734,7 +689,7 @@
 		if (c->str_len == len && !strncmp(s, c->str_dat, len))
 			return c;
 
-	c = pool_alloc(sizeof(struct atom_str) + len + 1);
+	c = mem_pool_alloc(&fi_mem_pool, sizeof(struct atom_str) + len + 1);
 	c->str_len = len;
 	memcpy(c->str_dat, s, len);
 	c->str_dat[len] = 0;
@@ -765,7 +720,7 @@
 	if (check_refname_format(name, REFNAME_ALLOW_ONELEVEL))
 		die("Branch name doesn't conform to GIT standards: %s", name);
 
-	b = pool_calloc(1, sizeof(struct branch));
+	b = mem_pool_calloc(&fi_mem_pool, 1, sizeof(struct branch));
 	b->name = pool_strdup(name);
 	b->table_next_branch = branch_table[hc];
 	b->branch_tree.versions[0].mode = S_IFDIR;
@@ -801,7 +756,7 @@
 			avail_tree_table[hc] = f->next_avail;
 	} else {
 		cnt = cnt & 7 ? ((cnt / 8) + 1) * 8 : cnt;
-		f = pool_alloc(sizeof(*t) + sizeof(t->entries[0]) * cnt);
+		f = mem_pool_alloc(&fi_mem_pool, sizeof(*t) + sizeof(t->entries[0]) * cnt);
 		f->entry_capacity = cnt;
 	}
 
@@ -846,7 +801,7 @@
 
 	if (!avail_tree_entry) {
 		unsigned int n = tree_entry_alloc;
-		total_allocd += n * sizeof(struct tree_entry);
+		tree_entry_allocd += n * sizeof(struct tree_entry);
 		ALLOC_ARRAY(e, n);
 		avail_tree_entry = e;
 		while (n-- > 1) {
@@ -1018,7 +973,7 @@
 		struct tag *t;
 
 		close_pack_windows(pack_data);
-		hashclose(pack_file, cur_pack_oid.hash, 0);
+		finalize_hashfile(pack_file, cur_pack_oid.hash, 0);
 		fixup_pack_header_footer(pack_data->pack_fd, pack_data->sha1,
 				    pack_data->pack_name, object_count,
 				    cur_pack_oid.hash, pack_size);
@@ -2867,7 +2822,7 @@
 	enum object_type type;
 	const char *v;
 
-	t = pool_alloc(sizeof(struct tag));
+	t = mem_pool_alloc(&fi_mem_pool, sizeof(struct tag));
 	memset(t, 0, sizeof(struct tag));
 	t->name = pool_strdup(arg);
 	if (last_tag)
@@ -3466,12 +3421,12 @@
 	atom_table = xcalloc(atom_table_sz, sizeof(struct atom_str*));
 	branch_table = xcalloc(branch_table_sz, sizeof(struct branch*));
 	avail_tree_table = xcalloc(avail_tree_table_sz, sizeof(struct avail_tree_content*));
-	marks = pool_calloc(1, sizeof(struct mark_set));
+	marks = mem_pool_calloc(&fi_mem_pool, 1, sizeof(struct mark_set));
 
 	global_argc = argc;
 	global_argv = argv;
 
-	rc_free = pool_alloc(cmd_save * sizeof(*rc_free));
+	rc_free = mem_pool_alloc(&fi_mem_pool, cmd_save * sizeof(*rc_free));
 	for (i = 0; i < (cmd_save - 1); i++)
 		rc_free[i].next = &rc_free[i + 1];
 	rc_free[cmd_save - 1].next = NULL;
@@ -3545,8 +3500,8 @@
 		fprintf(stderr, "Total branches:  %10lu (%10lu loads     )\n", branch_count, branch_load_count);
 		fprintf(stderr, "      marks:     %10" PRIuMAX " (%10" PRIuMAX " unique    )\n", (((uintmax_t)1) << marks->shift) * 1024, marks_set_count);
 		fprintf(stderr, "      atoms:     %10u\n", atom_cnt);
-		fprintf(stderr, "Memory total:    %10" PRIuMAX " KiB\n", (total_allocd + alloc_count*sizeof(struct object_entry))/1024);
-		fprintf(stderr, "       pools:    %10lu KiB\n", (unsigned long)(total_allocd/1024));
+		fprintf(stderr, "Memory total:    %10" PRIuMAX " KiB\n", (tree_entry_allocd + fi_mem_pool.pool_alloc + alloc_count*sizeof(struct object_entry))/1024);
+		fprintf(stderr, "       pools:    %10lu KiB\n", (unsigned long)((tree_entry_allocd + fi_mem_pool.pool_alloc) /1024));
 		fprintf(stderr, "     objects:    %10" PRIuMAX " KiB\n", (alloc_count*sizeof(struct object_entry))/1024);
 		fprintf(stderr, "---------------------------------------------------------------------\n");
 		pack_report();
diff --git a/fetch-pack.c b/fetch-pack.c
index adc1b68..f93723f 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -6,7 +6,7 @@
 #include "pkt-line.h"
 #include "commit.h"
 #include "tag.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "pack.h"
 #include "sideband.h"
 #include "fetch-pack.h"
@@ -305,9 +305,9 @@
 #define PIPESAFE_FLUSH 32
 #define LARGE_FLUSH 16384
 
-static int next_flush(struct fetch_pack_args *args, int count)
+static int next_flush(int stateless_rpc, int count)
 {
-	if (args->stateless_rpc) {
+	if (stateless_rpc) {
 		if (count < LARGE_FLUSH)
 			count <<= 1;
 		else
@@ -470,7 +470,7 @@
 			send_request(args, fd[1], &req_buf);
 			strbuf_setlen(&req_buf, state_len);
 			flushes++;
-			flush_at = next_flush(args, count);
+			flush_at = next_flush(args->stateless_rpc, count);
 
 			/*
 			 * We keep one window "ahead" of the other side, and
@@ -1080,6 +1080,328 @@
 	return ref;
 }
 
+static void add_shallow_requests(struct strbuf *req_buf,
+				 const struct fetch_pack_args *args)
+{
+	if (is_repository_shallow())
+		write_shallow_commits(req_buf, 1, NULL);
+	if (args->depth > 0)
+		packet_buf_write(req_buf, "deepen %d", args->depth);
+	if (args->deepen_since) {
+		timestamp_t max_age = approxidate(args->deepen_since);
+		packet_buf_write(req_buf, "deepen-since %"PRItime, max_age);
+	}
+	if (args->deepen_not) {
+		int i;
+		for (i = 0; i < args->deepen_not->nr; i++) {
+			struct string_list_item *s = args->deepen_not->items + i;
+			packet_buf_write(req_buf, "deepen-not %s", s->string);
+		}
+	}
+}
+
+static void add_wants(const struct ref *wants, struct strbuf *req_buf)
+{
+	for ( ; wants ; wants = wants->next) {
+		const struct object_id *remote = &wants->old_oid;
+		const char *remote_hex;
+		struct object *o;
+
+		/*
+		 * If that object is complete (i.e. it is an ancestor of a
+		 * local ref), we tell them we have it but do not have to
+		 * tell them about its ancestors, which they already know
+		 * about.
+		 *
+		 * We use lookup_object here because we are only
+		 * interested in the case we *know* the object is
+		 * reachable and we have already scanned it.
+		 */
+		if (((o = lookup_object(remote->hash)) != NULL) &&
+		    (o->flags & COMPLETE)) {
+			continue;
+		}
+
+		remote_hex = oid_to_hex(remote);
+		packet_buf_write(req_buf, "want %s\n", remote_hex);
+	}
+}
+
+static void add_common(struct strbuf *req_buf, struct oidset *common)
+{
+	struct oidset_iter iter;
+	const struct object_id *oid;
+	oidset_iter_init(common, &iter);
+
+	while ((oid = oidset_iter_next(&iter))) {
+		packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
+	}
+}
+
+static int add_haves(struct strbuf *req_buf, int *haves_to_send, int *in_vain)
+{
+	int ret = 0;
+	int haves_added = 0;
+	const struct object_id *oid;
+
+	while ((oid = get_rev())) {
+		packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
+		if (++haves_added >= *haves_to_send)
+			break;
+	}
+
+	*in_vain += haves_added;
+	if (!haves_added || *in_vain >= MAX_IN_VAIN) {
+		/* Send Done */
+		packet_buf_write(req_buf, "done\n");
+		ret = 1;
+	}
+
+	/* Increase haves to send on next round */
+	*haves_to_send = next_flush(1, *haves_to_send);
+
+	return ret;
+}
+
+static int send_fetch_request(int fd_out, const struct fetch_pack_args *args,
+			      const struct ref *wants, struct oidset *common,
+			      int *haves_to_send, int *in_vain)
+{
+	int ret = 0;
+	struct strbuf req_buf = STRBUF_INIT;
+
+	if (server_supports_v2("fetch", 1))
+		packet_buf_write(&req_buf, "command=fetch");
+	if (server_supports_v2("agent", 0))
+		packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
+
+	packet_buf_delim(&req_buf);
+	if (args->use_thin_pack)
+		packet_buf_write(&req_buf, "thin-pack");
+	if (args->no_progress)
+		packet_buf_write(&req_buf, "no-progress");
+	if (args->include_tag)
+		packet_buf_write(&req_buf, "include-tag");
+	if (prefer_ofs_delta)
+		packet_buf_write(&req_buf, "ofs-delta");
+
+	/* Add shallow-info and deepen request */
+	if (server_supports_feature("fetch", "shallow", 0))
+		add_shallow_requests(&req_buf, args);
+	else if (is_repository_shallow() || args->deepen)
+		die(_("Server does not support shallow requests"));
+
+	/* add wants */
+	add_wants(wants, &req_buf);
+
+	/* Add all of the common commits we've found in previous rounds */
+	add_common(&req_buf, common);
+
+	/* Add initial haves */
+	ret = add_haves(&req_buf, haves_to_send, in_vain);
+
+	/* Send request */
+	packet_buf_flush(&req_buf);
+	write_or_die(fd_out, req_buf.buf, req_buf.len);
+
+	strbuf_release(&req_buf);
+	return ret;
+}
+
+/*
+ * Processes a section header in a server's response and checks if it matches
+ * `section`.  If the value of `peek` is 1, the header line will be peeked (and
+ * not consumed); if 0, the line will be consumed and the function will die if
+ * the section header doesn't match what was expected.
+ */
+static int process_section_header(struct packet_reader *reader,
+				  const char *section, int peek)
+{
+	int ret;
+
+	if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
+		die("error reading section header '%s'", section);
+
+	ret = !strcmp(reader->line, section);
+
+	if (!peek) {
+		if (!ret)
+			die("expected '%s', received '%s'",
+			    section, reader->line);
+		packet_reader_read(reader);
+	}
+
+	return ret;
+}
+
+static int process_acks(struct packet_reader *reader, struct oidset *common)
+{
+	/* received */
+	int received_ready = 0;
+	int received_ack = 0;
+
+	process_section_header(reader, "acknowledgments", 0);
+	while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
+		const char *arg;
+
+		if (!strcmp(reader->line, "NAK"))
+			continue;
+
+		if (skip_prefix(reader->line, "ACK ", &arg)) {
+			struct object_id oid;
+			if (!get_oid_hex(arg, &oid)) {
+				struct commit *commit;
+				oidset_insert(common, &oid);
+				commit = lookup_commit(&oid);
+				mark_common(commit, 0, 1);
+			}
+			continue;
+		}
+
+		if (!strcmp(reader->line, "ready")) {
+			clear_prio_queue(&rev_list);
+			received_ready = 1;
+			continue;
+		}
+
+		die("unexpected acknowledgment line: '%s'", reader->line);
+	}
+
+	if (reader->status != PACKET_READ_FLUSH &&
+	    reader->status != PACKET_READ_DELIM)
+		die("error processing acks: %d", reader->status);
+
+	/* return 0 if no common, 1 if there are common, or 2 if ready */
+	return received_ready ? 2 : (received_ack ? 1 : 0);
+}
+
+static void receive_shallow_info(struct fetch_pack_args *args,
+				 struct packet_reader *reader)
+{
+	process_section_header(reader, "shallow-info", 0);
+	while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
+		const char *arg;
+		struct object_id oid;
+
+		if (skip_prefix(reader->line, "shallow ", &arg)) {
+			if (get_oid_hex(arg, &oid))
+				die(_("invalid shallow line: %s"), reader->line);
+			register_shallow(&oid);
+			continue;
+		}
+		if (skip_prefix(reader->line, "unshallow ", &arg)) {
+			if (get_oid_hex(arg, &oid))
+				die(_("invalid unshallow line: %s"), reader->line);
+			if (!lookup_object(oid.hash))
+				die(_("object not found: %s"), reader->line);
+			/* make sure that it is parsed as shallow */
+			if (!parse_object(&oid))
+				die(_("error in object: %s"), reader->line);
+			if (unregister_shallow(&oid))
+				die(_("no shallow found: %s"), reader->line);
+			continue;
+		}
+		die(_("expected shallow/unshallow, got %s"), reader->line);
+	}
+
+	if (reader->status != PACKET_READ_FLUSH &&
+	    reader->status != PACKET_READ_DELIM)
+		die("error processing shallow info: %d", reader->status);
+
+	setup_alternate_shallow(&shallow_lock, &alternate_shallow_file, NULL);
+	args->deepen = 1;
+}
+
+enum fetch_state {
+	FETCH_CHECK_LOCAL = 0,
+	FETCH_SEND_REQUEST,
+	FETCH_PROCESS_ACKS,
+	FETCH_GET_PACK,
+	FETCH_DONE,
+};
+
+static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
+				    int fd[2],
+				    const struct ref *orig_ref,
+				    struct ref **sought, int nr_sought,
+				    char **pack_lockfile)
+{
+	struct ref *ref = copy_ref_list(orig_ref);
+	enum fetch_state state = FETCH_CHECK_LOCAL;
+	struct oidset common = OIDSET_INIT;
+	struct packet_reader reader;
+	int in_vain = 0;
+	int haves_to_send = INITIAL_FLUSH;
+	packet_reader_init(&reader, fd[0], NULL, 0,
+			   PACKET_READ_CHOMP_NEWLINE);
+
+	while (state != FETCH_DONE) {
+		switch (state) {
+		case FETCH_CHECK_LOCAL:
+			sort_ref_list(&ref, ref_compare_name);
+			QSORT(sought, nr_sought, cmp_ref_by_name);
+
+			/* v2 supports these by default */
+			allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
+			use_sideband = 2;
+			if (args->depth > 0 || args->deepen_since || args->deepen_not)
+				args->deepen = 1;
+
+			if (marked)
+				for_each_ref(clear_marks, NULL);
+			marked = 1;
+
+			for_each_ref(rev_list_insert_ref_oid, NULL);
+			for_each_cached_alternate(insert_one_alternate_object);
+
+			/* Filter 'ref' by 'sought' and those that aren't local */
+			if (everything_local(args, &ref, sought, nr_sought))
+				state = FETCH_DONE;
+			else
+				state = FETCH_SEND_REQUEST;
+			break;
+		case FETCH_SEND_REQUEST:
+			if (send_fetch_request(fd[1], args, ref, &common,
+					       &haves_to_send, &in_vain))
+				state = FETCH_GET_PACK;
+			else
+				state = FETCH_PROCESS_ACKS;
+			break;
+		case FETCH_PROCESS_ACKS:
+			/* Process ACKs/NAKs */
+			switch (process_acks(&reader, &common)) {
+			case 2:
+				state = FETCH_GET_PACK;
+				break;
+			case 1:
+				in_vain = 0;
+				/* fallthrough */
+			default:
+				state = FETCH_SEND_REQUEST;
+				break;
+			}
+			break;
+		case FETCH_GET_PACK:
+			/* Check for shallow-info section */
+			if (process_section_header(&reader, "shallow-info", 1))
+				receive_shallow_info(args, &reader);
+
+			/* get the pack */
+			process_section_header(&reader, "packfile", 0);
+			if (get_pack(args, fd, pack_lockfile))
+				die(_("git fetch-pack: fetch failed."));
+
+			state = FETCH_DONE;
+			break;
+		case FETCH_DONE:
+			continue;
+		}
+	}
+
+	oidset_clear(&common);
+	return ref;
+}
+
 static void fetch_pack_config(void)
 {
 	git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
@@ -1225,7 +1547,8 @@
 		       const char *dest,
 		       struct ref **sought, int nr_sought,
 		       struct oid_array *shallow,
-		       char **pack_lockfile)
+		       char **pack_lockfile,
+		       enum protocol_version version)
 {
 	struct ref *ref_cpy;
 	struct shallow_info si;
@@ -1239,8 +1562,12 @@
 		die(_("no matching remote head"));
 	}
 	prepare_shallow_info(&si, shallow);
-	ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
-				&si, pack_lockfile);
+	if (version == protocol_v2)
+		ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
+					   pack_lockfile);
+	else
+		ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
+					&si, pack_lockfile);
 	reprepare_packed_git(the_repository);
 	update_shallow(args, sought, nr_sought, &si);
 	clear_shallow_info(&si);
diff --git a/fetch-pack.h b/fetch-pack.h
index 3e224a1..6afa08b 100644
--- a/fetch-pack.h
+++ b/fetch-pack.h
@@ -3,6 +3,7 @@
 
 #include "string-list.h"
 #include "run-command.h"
+#include "protocol.h"
 #include "list-objects-filter-options.h"
 
 struct oid_array;
@@ -53,7 +54,8 @@
 		       struct ref **sought,
 		       int nr_sought,
 		       struct oid_array *shallow,
-		       char **pack_lockfile);
+		       char **pack_lockfile,
+		       enum protocol_version version);
 
 /*
  * Print an appropriate error message for each sought ref that wasn't
diff --git a/fsmonitor.c b/fsmonitor.c
index 6d7bcd5..ed3d1a0 100644
--- a/fsmonitor.c
+++ b/fsmonitor.c
@@ -104,7 +104,7 @@
 	if (!(argv[0] = core_fsmonitor))
 		return -1;
 
-	snprintf(ver, sizeof(version), "%d", version);
+	snprintf(ver, sizeof(ver), "%d", version);
 	snprintf(date, sizeof(date), "%" PRIuMAX, (uintmax_t)last_update);
 	argv[1] = ver;
 	argv[2] = date;
@@ -185,6 +185,9 @@
 		for (i = 0; i < istate->cache_nr; i++)
 			istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
 
+		/* If we're going to check every file, ensure we save the results */
+		istate->cache_changed |= FSMONITOR_CHANGED;
+
 		if (istate->untracked)
 			istate->untracked->use_fsmonitor = 0;
 	}
diff --git a/gettext.c b/gettext.c
index 4f59dfa..7272771 100644
--- a/gettext.c
+++ b/gettext.c
@@ -3,7 +3,7 @@
  */
 
 #include "cache.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "gettext.h"
 #include "strbuf.h"
 #include "utf8.h"
diff --git a/git-compat-util.h b/git-compat-util.h
index 07e3832..f1d7ada 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -455,6 +455,7 @@
 extern void set_die_is_recursing_routine(int (*routine)(void));
 
 extern int starts_with(const char *str, const char *prefix);
+extern int istarts_with(const char *str, const char *prefix);
 
 /*
  * If the string "str" begins with the string found in "prefix", return 1.
diff --git a/git-gui/git-gui.sh b/git-gui/git-gui.sh
index 91c00e6..6de74ce 100755
--- a/git-gui/git-gui.sh
+++ b/git-gui/git-gui.sh
@@ -3867,6 +3867,7 @@
 bind .   <$M1B-Key-plus> {show_more_context;break}
 bind .   <$M1B-Key-KP_Add> {show_more_context;break}
 bind .   <$M1B-Key-Return> do_commit
+bind .   <$M1B-Key-KP_Enter> do_commit
 foreach i [list $ui_index $ui_workdir] {
 	bind $i <Button-1>       { toggle_or_diff click %W %x %y; break }
 	bind $i <$M1B-Button-1>  { add_one_to_selection %W %x %y; break }
diff --git a/git-gui/lib/sshkey.tcl b/git-gui/lib/sshkey.tcl
index aa6457b..589ff8f 100644
--- a/git-gui/lib/sshkey.tcl
+++ b/git-gui/lib/sshkey.tcl
@@ -2,7 +2,10 @@
 # Copyright (C) 2006, 2007 Shawn Pearce
 
 proc find_ssh_key {} {
-	foreach name {~/.ssh/id_dsa.pub ~/.ssh/id_rsa.pub ~/.ssh/identity.pub} {
+	foreach name {
+		~/.ssh/id_dsa.pub ~/.ssh/id_ecdsa.pub ~/.ssh/id_ed25519.pub
+		~/.ssh/id_rsa.pub ~/.ssh/identity.pub
+	} {
 		if {[file exists $name]} {
 			set fh    [open $name r]
 			set cont  [read $fh]
diff --git a/git-gui/lib/themed.tcl b/git-gui/lib/themed.tcl
index 351a712..88b3119 100644
--- a/git-gui/lib/themed.tcl
+++ b/git-gui/lib/themed.tcl
@@ -1,6 +1,14 @@
 # Functions for supporting the use of themed Tk widgets in git-gui.
 # Copyright (C) 2009 Pat Thoyts <patthoyts@users.sourceforge.net>
 
+proc ttk_get_current_theme {} {
+	# Handle either current Tk or older versions of 8.5
+	if {[catch {set theme [ttk::style theme use]}]} {
+		set theme  $::ttk::currentTheme
+	}
+	return $theme
+}
+
 proc InitTheme {} {
 	# Create a color label style (bg can be overridden by widget option)
 	ttk::style layout Color.TLabel {
@@ -28,10 +36,7 @@
 		}
 	}
 
-	# Handle either current Tk or older versions of 8.5
-	if {[catch {set theme [ttk::style theme use]}]} {
-		set theme  $::ttk::currentTheme
-	}
+	set theme [ttk_get_current_theme]
 
 	if {[lsearch -exact {default alt classic clam} $theme] != -1} {
 		# Simple override of standard ttk::entry to change the field
@@ -248,7 +253,7 @@
 proc ttext {w args} {
 	global use_ttk
 	if {$use_ttk} {
-		switch -- [ttk::style theme use] {
+		switch -- [ttk_get_current_theme] {
 			"vista" - "xpnative" {
 				lappend args -highlightthickness 0 -borderwidth 0
 			}
diff --git a/git-rebase--am.sh b/git-rebase--am.sh
index e5fd610..99b8c17 100644
--- a/git-rebase--am.sh
+++ b/git-rebase--am.sh
@@ -32,61 +32,48 @@
 fi
 
 ret=0
-if test -n "$keep_empty"
+rm -f "$GIT_DIR/rebased-patches"
+
+git format-patch -k --stdout --full-index --cherry-pick --right-only \
+	--src-prefix=a/ --dst-prefix=b/ --no-renames --no-cover-letter \
+	--pretty=mboxrd \
+	$git_format_patch_opt \
+	"$revisions" ${restrict_revision+^$restrict_revision} \
+	>"$GIT_DIR/rebased-patches"
+ret=$?
+
+if test 0 != $ret
 then
-	# we have to do this the hard way.  git format-patch completely squashes
-	# empty commits and even if it didn't the format doesn't really lend
-	# itself well to recording empty patches.  fortunately, cherry-pick
-	# makes this easy
-	git cherry-pick ${gpg_sign_opt:+"$gpg_sign_opt"} --allow-empty \
-		$allow_rerere_autoupdate --right-only "$revisions" \
-		$allow_empty_message \
-		${restrict_revision+^$restrict_revision}
-	ret=$?
-else
 	rm -f "$GIT_DIR/rebased-patches"
+	case "$head_name" in
+	refs/heads/*)
+		git checkout -q "$head_name"
+		;;
+	*)
+		git checkout -q "$orig_head"
+		;;
+	esac
 
-	git format-patch -k --stdout --full-index --cherry-pick --right-only \
-		--src-prefix=a/ --dst-prefix=b/ --no-renames --no-cover-letter \
-		--pretty=mboxrd \
-		$git_format_patch_opt \
-		"$revisions" ${restrict_revision+^$restrict_revision} \
-		>"$GIT_DIR/rebased-patches"
-	ret=$?
+	cat >&2 <<-EOF
 
-	if test 0 != $ret
-	then
-		rm -f "$GIT_DIR/rebased-patches"
-		case "$head_name" in
-		refs/heads/*)
-			git checkout -q "$head_name"
-			;;
-		*)
-			git checkout -q "$orig_head"
-			;;
-		esac
+	git encountered an error while preparing the patches to replay
+	these revisions:
 
-		cat >&2 <<-EOF
+	    $revisions
 
-		git encountered an error while preparing the patches to replay
-		these revisions:
-
-		    $revisions
-
-		As a result, git cannot rebase them.
-		EOF
-		return $ret
-	fi
-
-	git am $git_am_opt --rebasing --resolvemsg="$resolvemsg" \
-		--patch-format=mboxrd \
-		$allow_rerere_autoupdate \
-		${gpg_sign_opt:+"$gpg_sign_opt"} <"$GIT_DIR/rebased-patches"
-	ret=$?
-
-	rm -f "$GIT_DIR/rebased-patches"
+	As a result, git cannot rebase them.
+	EOF
+	return $ret
 fi
 
+git am $git_am_opt --rebasing --resolvemsg="$resolvemsg" \
+	--patch-format=mboxrd \
+	$allow_rerere_autoupdate \
+	${gpg_sign_opt:+"$gpg_sign_opt"} <"$GIT_DIR/rebased-patches"
+ret=$?
+
+rm -f "$GIT_DIR/rebased-patches"
+
 if test 0 != $ret
 then
 	test -d "$state_dir" && write_basic_state
diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 50323fc..9947e62 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -285,7 +285,7 @@
 		pick_one_preserving_merges "$@" && return
 	output eval git cherry-pick $allow_rerere_autoupdate $allow_empty_message \
 			${gpg_sign_opt:+$(git rev-parse --sq-quote "$gpg_sign_opt")} \
-			"$strategy_args" $empty_args $ff "$@"
+			$signoff "$strategy_args" $empty_args $ff "$@"
 
 	# If cherry-pick dies it leaves the to-be-picked commit unrecorded. Reschedule
 	# previous task so this commit is not lost.
@@ -524,10 +524,10 @@
 		# resolve before manually running git commit --amend then git
 		# rebase --continue.
 		git commit --allow-empty --allow-empty-message --amend \
-			   --no-post-rewrite -n -q -C $sha1 &&
+			   --no-post-rewrite -n -q -C $sha1 $signoff &&
 			pick_one -n $sha1 &&
 			git commit --allow-empty --allow-empty-message \
-				   --amend --no-post-rewrite -n -q -C $sha1 \
+				   --amend --no-post-rewrite -n -q -C $sha1 $signoff \
 				   ${gpg_sign_opt:+"$gpg_sign_opt"} ||
 				   die_with_patch $sha1 "$(eval_gettext "Could not apply \$sha1... \$rest")"
 	else
diff --git a/git-rebase--merge.sh b/git-rebase--merge.sh
index 685f48c..cf4c042 100644
--- a/git-rebase--merge.sh
+++ b/git-rebase--merge.sh
@@ -27,7 +27,7 @@
 	cmt=$(cat "$state_dir/current")
 	if ! git diff-index --quiet --ignore-submodules HEAD --
 	then
-		if ! git commit ${gpg_sign_opt:+"$gpg_sign_opt"} $allow_empty_message \
+		if ! git commit ${gpg_sign_opt:+"$gpg_sign_opt"} $signoff $allow_empty_message \
 			--no-verify -C "$cmt"
 		then
 			echo "Commit failed, please do not call \"git commit\""
diff --git a/git-rebase.sh b/git-rebase.sh
index fb64ee1..ded5de0 100755
--- a/git-rebase.sh
+++ b/git-rebase.sh
@@ -62,6 +62,7 @@
 You can instead skip this commit: run "git rebase --skip".
 To abort and get back to the state before "git rebase", run "git rebase --abort".')
 "
+squash_onto=
 unset onto
 unset restrict_revision
 cmd=
@@ -92,6 +93,7 @@
 autosquash=
 keep_empty=
 allow_empty_message=
+signoff=
 test "$(git config --bool rebase.autosquash)" = "true" && autosquash=t
 case "$(git config --bool commit.gpgsign)" in
 true)	gpg_sign_opt=-S ;;
@@ -121,6 +123,10 @@
 		allow_rerere_autoupdate="$(cat "$state_dir"/allow_rerere_autoupdate)"
 	test -f "$state_dir"/gpg_sign_opt &&
 		gpg_sign_opt="$(cat "$state_dir"/gpg_sign_opt)"
+	test -f "$state_dir"/signoff && {
+		signoff="$(cat "$state_dir"/signoff)"
+		force_rebase=t
+	}
 }
 
 write_basic_state () {
@@ -135,6 +141,7 @@
 	test -n "$allow_rerere_autoupdate" && echo "$allow_rerere_autoupdate" > \
 		"$state_dir"/allow_rerere_autoupdate
 	test -n "$gpg_sign_opt" && echo "$gpg_sign_opt" > "$state_dir"/gpg_sign_opt
+	test -n "$signoff" && echo "$signoff" >"$state_dir"/signoff
 }
 
 output () {
@@ -270,6 +277,9 @@
 	--allow-empty-message)
 		allow_empty_message=--allow-empty-message
 		;;
+	--no-keep-empty)
+		keep_empty=
+		;;
 	--preserve-merges)
 		preserve_merges=t
 		test -z "$interactive_rebase" && interactive_rebase=implied
@@ -332,7 +342,13 @@
 	--ignore-whitespace)
 		git_am_opt="$git_am_opt $1"
 		;;
-	--committer-date-is-author-date|--ignore-date|--signoff|--no-signoff)
+	--signoff)
+		signoff=--signoff
+		;;
+	--no-signoff)
+		signoff=
+		;;
+	--committer-date-is-author-date|--ignore-date)
 		git_am_opt="$git_am_opt $1"
 		force_rebase=t
 		;;
@@ -448,6 +464,11 @@
 	test -z "$interactive_rebase" && interactive_rebase=implied
 fi
 
+if test -n "$keep_empty"
+then
+	test -z "$interactive_rebase" && interactive_rebase=implied
+fi
+
 if test -n "$interactive_rebase"
 then
 	type=interactive
@@ -466,6 +487,14 @@
 	git_format_patch_opt="$git_format_patch_opt --progress"
 fi
 
+if test -n "$signoff"
+then
+	test -n "$preserve_merges" &&
+		die "$(gettext "error: cannot combine '--signoff' with '--preserve-merges'")"
+	git_am_opt="$git_am_opt $signoff"
+	force_rebase=t
+fi
+
 if test -z "$rebase_root"
 then
 	case "$#" in
diff --git a/git-send-email.perl b/git-send-email.perl
index 2fa7818..7157397 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -1642,10 +1642,15 @@
 			elsif (/^Content-Transfer-Encoding: (.*)/i) {
 				$xfer_encoding = $1 if not defined $xfer_encoding;
 			}
+			elsif (/^In-Reply-To: (.*)/i) {
+				$in_reply_to = $1;
+			}
+			elsif (/^References: (.*)/i) {
+				$references = $1;
+			}
 			elsif (!/^Date:\s/i && /^[-A-Za-z]+:\s+\S/) {
 				push @xh, $_;
 			}
-
 		} else {
 			# In the traditional
 			# "send lots of email" format,
diff --git a/git-svn.perl b/git-svn.perl
index a6b6c3e..050f2a3 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -374,7 +374,8 @@
 usage(1) unless defined $cmd;
 load_authors() if $_authors;
 if (defined $_authors_prog) {
-	$_authors_prog = "'" . File::Spec->rel2abs($_authors_prog) . "'";
+	my $abs_file = File::Spec->rel2abs($_authors_prog);
+	$_authors_prog = "'" . $abs_file . "'" if -x $abs_file;
 }
 
 unless ($cmd =~ /^(?:clone|init|multi-init|commit-diff)$/) {
diff --git a/git.c b/git.c
index 48432f9..bab6bbf 100644
--- a/git.c
+++ b/git.c
@@ -1,6 +1,6 @@
 #include "builtin.h"
 #include "config.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "help.h"
 #include "run-command.h"
 
@@ -392,6 +392,7 @@
 	{ "clone", cmd_clone },
 	{ "column", cmd_column, RUN_SETUP_GENTLY },
 	{ "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
+	{ "commit-graph", cmd_commit_graph, RUN_SETUP },
 	{ "commit-tree", cmd_commit_tree, RUN_SETUP | NO_PARSEOPT },
 	{ "config", cmd_config, RUN_SETUP_GENTLY | DELAY_PAGER_CONFIG },
 	{ "count-objects", cmd_count_objects, RUN_SETUP },
@@ -465,6 +466,7 @@
 	{ "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 	{ "rm", cmd_rm, RUN_SETUP },
 	{ "send-pack", cmd_send_pack, RUN_SETUP },
+	{ "serve", cmd_serve, RUN_SETUP },
 	{ "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 	{ "show", cmd_show, RUN_SETUP },
 	{ "show-branch", cmd_show_branch, RUN_SETUP },
@@ -482,6 +484,7 @@
 	{ "update-server-info", cmd_update_server_info, RUN_SETUP },
 	{ "upload-archive", cmd_upload_archive, NO_PARSEOPT },
 	{ "upload-archive--writer", cmd_upload_archive_writer, NO_PARSEOPT },
+	{ "upload-pack", cmd_upload_pack },
 	{ "var", cmd_var, RUN_SETUP_GENTLY | NO_PARSEOPT },
 	{ "verify-commit", cmd_verify_commit, RUN_SETUP },
 	{ "verify-pack", cmd_verify_pack },
diff --git a/gpg-interface.c b/gpg-interface.c
index 4feacf1..0647bd6 100644
--- a/gpg-interface.c
+++ b/gpg-interface.c
@@ -101,22 +101,26 @@
 		fputs(output, stderr);
 }
 
-/*
- * Look at GPG signed content (e.g. a signed tag object), whose
- * payload is followed by a detached signature on it.  Return the
- * offset where the embedded detached signature begins, or the end of
- * the data when there is no such signature.
- */
-size_t parse_signature(const char *buf, unsigned long size)
+static int is_gpg_start(const char *line)
 {
-	char *eol;
+	return starts_with(line, PGP_SIGNATURE) ||
+		starts_with(line, PGP_MESSAGE);
+}
+
+size_t parse_signature(const char *buf, size_t size)
+{
 	size_t len = 0;
-	while (len < size && !starts_with(buf + len, PGP_SIGNATURE) &&
-			!starts_with(buf + len, PGP_MESSAGE)) {
+	size_t match = size;
+	while (len < size) {
+		const char *eol;
+
+		if (is_gpg_start(buf + len))
+			match = len;
+
 		eol = memchr(buf + len, '\n', size - len);
 		len += eol ? eol - (buf + len) + 1 : size - len;
 	}
-	return len;
+	return match;
 }
 
 void set_signing_key(const char *key)
@@ -128,13 +132,19 @@
 int git_gpg_config(const char *var, const char *value, void *cb)
 {
 	if (!strcmp(var, "user.signingkey")) {
+		if (!value)
+			return config_error_nonbool(var);
 		set_signing_key(value);
+		return 0;
 	}
+
 	if (!strcmp(var, "gpg.program")) {
 		if (!value)
 			return config_error_nonbool(var);
 		gpg_program = xstrdup(value);
+		return 0;
 	}
+
 	return 0;
 }
 
@@ -145,12 +155,6 @@
 	return git_committer_info(IDENT_STRICT|IDENT_NO_DATE);
 }
 
-/*
- * Create a detached signature for the contents of "buffer" and append
- * it after "signature"; "buffer" and "signature" can be the same
- * strbuf instance, which would cause the detached signature appended
- * at the end.
- */
 int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key)
 {
 	struct child_process gpg = CHILD_PROCESS_INIT;
@@ -192,11 +196,6 @@
 	return 0;
 }
 
-/*
- * Run "gpg" to see if the payload matches the detached signature.
- * gpg_output, when set, receives the diagnostic output from GPG.
- * gpg_status, when set, receives the status output from GPG.
- */
 int verify_signed_buffer(const char *payload, size_t payload_size,
 			 const char *signature, size_t signature_size,
 			 struct strbuf *gpg_output, struct strbuf *gpg_status)
diff --git a/gpg-interface.h b/gpg-interface.h
index d2d4fd3..a5e6517 100644
--- a/gpg-interface.h
+++ b/gpg-interface.h
@@ -23,16 +23,43 @@
 	char *key;
 };
 
-extern void signature_check_clear(struct signature_check *sigc);
-extern size_t parse_signature(const char *buf, unsigned long size);
-extern void parse_gpg_output(struct signature_check *);
-extern int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key);
-extern int verify_signed_buffer(const char *payload, size_t payload_size, const char *signature, size_t signature_size, struct strbuf *gpg_output, struct strbuf *gpg_status);
-extern int git_gpg_config(const char *, const char *, void *);
-extern void set_signing_key(const char *);
-extern const char *get_signing_key(void);
-extern int check_signature(const char *payload, size_t plen,
-	const char *signature, size_t slen, struct signature_check *sigc);
-void print_signature_buffer(const struct signature_check *sigc, unsigned flags);
+void signature_check_clear(struct signature_check *sigc);
+
+/*
+ * Look at GPG signed content (e.g. a signed tag object), whose
+ * payload is followed by a detached signature on it.  Return the
+ * offset where the embedded detached signature begins, or the end of
+ * the data when there is no such signature.
+ */
+size_t parse_signature(const char *buf, size_t size);
+
+void parse_gpg_output(struct signature_check *);
+
+/*
+ * Create a detached signature for the contents of "buffer" and append
+ * it after "signature"; "buffer" and "signature" can be the same
+ * strbuf instance, which would cause the detached signature appended
+ * at the end.
+ */
+int sign_buffer(struct strbuf *buffer, struct strbuf *signature,
+		const char *signing_key);
+
+/*
+ * Run "gpg" to see if the payload matches the detached signature.
+ * gpg_output, when set, receives the diagnostic output from GPG.
+ * gpg_status, when set, receives the status output from GPG.
+ */
+int verify_signed_buffer(const char *payload, size_t payload_size,
+			 const char *signature, size_t signature_size,
+			 struct strbuf *gpg_output, struct strbuf *gpg_status);
+
+int git_gpg_config(const char *, const char *, void *);
+void set_signing_key(const char *);
+const char *get_signing_key(void);
+int check_signature(const char *payload, size_t plen,
+		    const char *signature, size_t slen,
+		    struct signature_check *sigc);
+void print_signature_buffer(const struct signature_check *sigc,
+			    unsigned flags);
 
 #endif
diff --git a/help.c b/help.c
index 60071a9..a4feef2 100644
--- a/help.c
+++ b/help.c
@@ -1,7 +1,7 @@
 #include "cache.h"
 #include "config.h"
 #include "builtin.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "run-command.h"
 #include "levenshtein.h"
 #include "help.h"
diff --git a/http-backend.c b/http-backend.c
index 88d2a9b..adaef16 100644
--- a/http-backend.c
+++ b/http-backend.c
@@ -5,13 +5,14 @@
 #include "pkt-line.h"
 #include "object.h"
 #include "tag.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "run-command.h"
 #include "string-list.h"
 #include "url.h"
 #include "argv-array.h"
 #include "packfile.h"
 #include "object-store.h"
+#include "protocol.h"
 
 static const char content_type[] = "Content-Type";
 static const char content_length[] = "Content-Length";
@@ -468,8 +469,11 @@
 		hdr_str(hdr, content_type, buf.buf);
 		end_headers(hdr);
 
-		packet_write_fmt(1, "# service=git-%s\n", svc->name);
-		packet_flush(1);
+
+		if (determine_protocol_version_server() != protocol_v2) {
+			packet_write_fmt(1, "# service=git-%s\n", svc->name);
+			packet_flush(1);
+		}
 
 		argv[0] = svc->name;
 		run_service(argv, 0);
diff --git a/http-fetch.c b/http-fetch.c
index 8af3800..885e471 100644
--- a/http-fetch.c
+++ b/http-fetch.c
@@ -1,6 +1,6 @@
 #include "cache.h"
 #include "config.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "http.h"
 #include "walker.h"
 
diff --git a/http-push.c b/http-push.c
index c0998fd..f308ce0 100644
--- a/http-push.c
+++ b/http-push.c
@@ -6,7 +6,7 @@
 #include "refs.h"
 #include "diff.h"
 #include "revision.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "remote.h"
 #include "list-objects.h"
 #include "sigchain.h"
diff --git a/http.c b/http.c
index 3034d10..fed13b2 100644
--- a/http.c
+++ b/http.c
@@ -976,21 +976,6 @@
 		*var = val;
 }
 
-static void protocol_http_header(void)
-{
-	if (get_protocol_version_config() > 0) {
-		struct strbuf protocol_header = STRBUF_INIT;
-
-		strbuf_addf(&protocol_header, GIT_PROTOCOL_HEADER ": version=%d",
-			    get_protocol_version_config());
-
-
-		extra_http_headers = curl_slist_append(extra_http_headers,
-						       protocol_header.buf);
-		strbuf_release(&protocol_header);
-	}
-}
-
 void http_init(struct remote *remote, const char *url, int proactive_auth)
 {
 	char *low_speed_limit;
@@ -1021,8 +1006,6 @@
 	if (remote)
 		var_override(&http_proxy_authmethod, remote->http_proxy_authmethod);
 
-	protocol_http_header();
-
 	pragma_header = curl_slist_append(http_copy_default_headers(),
 		"Pragma: no-cache");
 	no_pragma_header = curl_slist_append(http_copy_default_headers(),
@@ -1795,6 +1778,14 @@
 
 	headers = curl_slist_append(headers, buf.buf);
 
+	/* Add additional headers here */
+	if (options && options->extra_headers) {
+		const struct string_list_item *item;
+		for_each_string_list_item(item, options->extra_headers) {
+			headers = curl_slist_append(headers, item->string);
+		}
+	}
+
 	curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
 	curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
diff --git a/http.h b/http.h
index f7bd3b2..4df4a25 100644
--- a/http.h
+++ b/http.h
@@ -172,6 +172,13 @@
 	 * for details.
 	 */
 	struct strbuf *base_url;
+
+	/*
+	 * If not NULL, contains additional HTTP headers to be sent with the
+	 * request. The strings in the list must not be freed until after the
+	 * request has completed.
+	 */
+	struct string_list *extra_headers;
 };
 
 /* Return values for http_get_*() */
diff --git a/imap-send.c b/imap-send.c
index ffb0a6e..3573cbf 100644
--- a/imap-send.c
+++ b/imap-send.c
@@ -24,7 +24,7 @@
 #include "cache.h"
 #include "config.h"
 #include "credential.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "run-command.h"
 #include "parse-options.h"
 #ifdef NO_OPENSSL
diff --git a/list-objects-filter.c b/list-objects-filter.c
index 0ec83aa..2477175 100644
--- a/list-objects-filter.c
+++ b/list-objects-filter.c
@@ -19,7 +19,7 @@
  * in the traversal (until we mark it SEEN).  This is a way to
  * let us silently de-dup calls to show() in the caller.  This
  * is subtly different from the "revision.h:SHOWN" and the
- * "sha1_name.c:ONELINE_SEEN" bits.  And also different from
+ * "sha1-name.c:ONELINE_SEEN" bits.  And also different from
  * the non-de-dup usage in pack-bitmap.c
  */
 #define FILTER_SHOWN_BUT_REVISIT (1<<21)
diff --git a/ls-refs.c b/ls-refs.c
new file mode 100644
index 0000000..a06f12e
--- /dev/null
+++ b/ls-refs.c
@@ -0,0 +1,96 @@
+#include "cache.h"
+#include "repository.h"
+#include "refs.h"
+#include "remote.h"
+#include "argv-array.h"
+#include "ls-refs.h"
+#include "pkt-line.h"
+
+/*
+ * Check if one of the prefixes is a prefix of the ref.
+ * If no prefixes were provided, all refs match.
+ */
+static int ref_match(const struct argv_array *prefixes, const char *refname)
+{
+	int i;
+
+	if (!prefixes->argc)
+		return 1; /* no restriction */
+
+	for (i = 0; i < prefixes->argc; i++) {
+		const char *prefix = prefixes->argv[i];
+
+		if (starts_with(refname, prefix))
+			return 1;
+	}
+
+	return 0;
+}
+
+struct ls_refs_data {
+	unsigned peel;
+	unsigned symrefs;
+	struct argv_array prefixes;
+};
+
+static int send_ref(const char *refname, const struct object_id *oid,
+		    int flag, void *cb_data)
+{
+	struct ls_refs_data *data = cb_data;
+	const char *refname_nons = strip_namespace(refname);
+	struct strbuf refline = STRBUF_INIT;
+
+	if (!ref_match(&data->prefixes, refname))
+		return 0;
+
+	strbuf_addf(&refline, "%s %s", oid_to_hex(oid), refname_nons);
+	if (data->symrefs && flag & REF_ISSYMREF) {
+		struct object_id unused;
+		const char *symref_target = resolve_ref_unsafe(refname, 0,
+							       &unused,
+							       &flag);
+
+		if (!symref_target)
+			die("'%s' is a symref but it is not?", refname);
+
+		strbuf_addf(&refline, " symref-target:%s", symref_target);
+	}
+
+	if (data->peel) {
+		struct object_id peeled;
+		if (!peel_ref(refname, &peeled))
+			strbuf_addf(&refline, " peeled:%s", oid_to_hex(&peeled));
+	}
+
+	strbuf_addch(&refline, '\n');
+	packet_write(1, refline.buf, refline.len);
+
+	strbuf_release(&refline);
+	return 0;
+}
+
+int ls_refs(struct repository *r, struct argv_array *keys,
+	    struct packet_reader *request)
+{
+	struct ls_refs_data data;
+
+	memset(&data, 0, sizeof(data));
+
+	while (packet_reader_read(request) != PACKET_READ_FLUSH) {
+		const char *arg = request->line;
+		const char *out;
+
+		if (!strcmp("peel", arg))
+			data.peel = 1;
+		else if (!strcmp("symrefs", arg))
+			data.symrefs = 1;
+		else if (skip_prefix(arg, "ref-prefix ", &out))
+			argv_array_push(&data.prefixes, out);
+	}
+
+	head_ref_namespaced(send_ref, &data);
+	for_each_namespaced_ref(send_ref, &data);
+	packet_flush(1);
+	argv_array_clear(&data.prefixes);
+	return 0;
+}
diff --git a/ls-refs.h b/ls-refs.h
new file mode 100644
index 0000000..b62877e
--- /dev/null
+++ b/ls-refs.h
@@ -0,0 +1,10 @@
+#ifndef LS_REFS_H
+#define LS_REFS_H
+
+struct repository;
+struct argv_array;
+struct packet_reader;
+extern int ls_refs(struct repository *r, struct argv_array *keys,
+		   struct packet_reader *request);
+
+#endif /* LS_REFS_H */
diff --git a/mem-pool.c b/mem-pool.c
new file mode 100644
index 0000000..389d7af
--- /dev/null
+++ b/mem-pool.c
@@ -0,0 +1,55 @@
+/*
+ * Memory Pool implementation logic.
+ */
+
+#include "cache.h"
+#include "mem-pool.h"
+
+static struct mp_block *mem_pool_alloc_block(struct mem_pool *mem_pool, size_t block_alloc)
+{
+	struct mp_block *p;
+
+	mem_pool->pool_alloc += sizeof(struct mp_block) + block_alloc;
+	p = xmalloc(st_add(sizeof(struct mp_block), block_alloc));
+	p->next_block = mem_pool->mp_block;
+	p->next_free = (char *)p->space;
+	p->end = p->next_free + block_alloc;
+	mem_pool->mp_block = p;
+
+	return p;
+}
+
+void *mem_pool_alloc(struct mem_pool *mem_pool, size_t len)
+{
+	struct mp_block *p;
+	void *r;
+
+	/* round up to a 'uintmax_t' alignment */
+	if (len & (sizeof(uintmax_t) - 1))
+		len += sizeof(uintmax_t) - (len & (sizeof(uintmax_t) - 1));
+
+	for (p = mem_pool->mp_block; p; p = p->next_block)
+		if (p->end - p->next_free >= len)
+			break;
+
+	if (!p) {
+		if (len >= (mem_pool->block_alloc / 2)) {
+			mem_pool->pool_alloc += len;
+			return xmalloc(len);
+		}
+
+		p = mem_pool_alloc_block(mem_pool, mem_pool->block_alloc);
+	}
+
+	r = p->next_free;
+	p->next_free += len;
+	return r;
+}
+
+void *mem_pool_calloc(struct mem_pool *mem_pool, size_t count, size_t size)
+{
+	size_t len = st_mult(count, size);
+	void *r = mem_pool_alloc(mem_pool, len);
+	memset(r, 0, len);
+	return r;
+}
diff --git a/mem-pool.h b/mem-pool.h
new file mode 100644
index 0000000..829ad58
--- /dev/null
+++ b/mem-pool.h
@@ -0,0 +1,34 @@
+#ifndef MEM_POOL_H
+#define MEM_POOL_H
+
+struct mp_block {
+	struct mp_block *next_block;
+	char *next_free;
+	char *end;
+	uintmax_t space[FLEX_ARRAY]; /* more */
+};
+
+struct mem_pool {
+	struct mp_block *mp_block;
+
+	/*
+	 * The amount of available memory to grow the pool by.
+	 * This size does not include the overhead for the mp_block.
+	 */
+	size_t block_alloc;
+
+	/* The total amount of memory allocated by the pool. */
+	size_t pool_alloc;
+};
+
+/*
+ * Alloc memory from the mem_pool.
+ */
+void *mem_pool_alloc(struct mem_pool *pool, size_t len);
+
+/*
+ * Allocate and zero memory from the memory pool.
+ */
+void *mem_pool_calloc(struct mem_pool *pool, size_t count, size_t size);
+
+#endif
diff --git a/mergetools/guiffy b/mergetools/guiffy
new file mode 100644
index 0000000..8b23a13
--- /dev/null
+++ b/mergetools/guiffy
@@ -0,0 +1,18 @@
+diff_cmd () {
+	"$merge_tool_path" "$LOCAL" "$REMOTE"
+}
+
+merge_cmd () {
+	if $base_present
+	then
+		"$merge_tool_path" -s "$LOCAL" \
+		"$REMOTE" "$BASE" "$MERGED"
+	else
+		"$merge_tool_path" -m "$LOCAL" \
+		"$REMOTE" "$MERGED"
+	fi
+}
+
+exit_code_trustable () {
+	true
+}
diff --git a/object-store.h b/object-store.h
index fef33f3..1ff862c 100644
--- a/object-store.h
+++ b/object-store.h
@@ -1,6 +1,8 @@
 #ifndef OBJECT_STORE_H
 #define OBJECT_STORE_H
 
+#include "oidmap.h"
+
 struct alternate_object_database {
 	struct alternate_object_database *next;
 
@@ -94,6 +96,12 @@
 	struct alternate_object_database **alt_odb_tail;
 
 	/*
+	 * Objects that should be substituted by other objects
+	 * (see git-replace(1)).
+	 */
+	struct oidmap *replace_map;
+
+	/*
 	 * private data
 	 *
 	 * should only be accessed directly by packfile.c
diff --git a/object.c b/object.c
index a0a756f..66cffaf 100644
--- a/object.c
+++ b/object.c
@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "object.h"
+#include "replace-object.h"
 #include "blob.h"
 #include "tree.h"
 #include "commit.h"
@@ -246,7 +247,7 @@
 	unsigned long size;
 	enum object_type type;
 	int eaten;
-	const struct object_id *repl = lookup_replace_object(oid);
+	const struct object_id *repl = lookup_replace_object(the_repository, oid);
 	void *buffer;
 	struct object *obj;
 
diff --git a/object.h b/object.h
index f13f85b..b8e70e5 100644
--- a/object.h
+++ b/object.h
@@ -37,7 +37,7 @@
  * bundle.c:                                        16
  * http-push.c:                                     16-----19
  * commit.c:                                        16-----19
- * sha1_name.c:                                              20
+ * sha1-name.c:                                              20
  * list-objects-filter.c:                                      21
  * builtin/fsck.c:           0--3
  * builtin/index-pack.c:                                     2021
diff --git a/pack-bitmap-write.c b/pack-bitmap-write.c
index 41ae27f..9d1bb05 100644
--- a/pack-bitmap-write.c
+++ b/pack-bitmap-write.c
@@ -534,7 +534,7 @@
 	if (options & BITMAP_OPT_HASH_CACHE)
 		write_hash_cache(f, index, index_nr);
 
-	hashclose(f, NULL, CSUM_FSYNC);
+	finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE);
 
 	if (adjust_shared_perm(tmp_file.buf))
 		die_errno("unable to make temporary bitmap file readable");
diff --git a/pack-write.c b/pack-write.c
index d775c74..a9d46bc 100644
--- a/pack-write.c
+++ b/pack-write.c
@@ -170,8 +170,9 @@
 	}
 
 	hashwrite(f, sha1, the_hash_algo->rawsz);
-	hashclose(f, NULL, ((opts->flags & WRITE_IDX_VERIFY)
-			    ? CSUM_CLOSE : CSUM_FSYNC));
+	finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_CLOSE |
+				    ((opts->flags & WRITE_IDX_VERIFY)
+				    ? 0 : CSUM_FSYNC));
 	return index_name;
 }
 
diff --git a/packfile.c b/packfile.c
index 0bc67d0..6c3ddc3 100644
--- a/packfile.c
+++ b/packfile.c
@@ -304,7 +304,7 @@
 	}
 }
 
-static void close_pack(struct packed_git *p)
+void close_pack(struct packed_git *p)
 {
 	close_pack_windows(p);
 	close_pack_fd(p);
@@ -1869,7 +1869,7 @@
 	return 1;
 }
 
-static int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn cb, void *data)
+int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn cb, void *data)
 {
 	uint32_t i;
 	int r = 0;
diff --git a/packfile.h b/packfile.h
index a92c0b2..9c2f885 100644
--- a/packfile.h
+++ b/packfile.h
@@ -65,6 +65,7 @@
 
 extern unsigned char *use_pack(struct packed_git *, struct pack_window **, off_t, unsigned long *);
 extern void close_pack_windows(struct packed_git *);
+extern void close_pack(struct packed_git *);
 extern void close_all_packs(struct raw_object_store *o);
 extern void unuse_pack(struct pack_window **);
 extern void clear_delta_base_cache(void);
@@ -154,6 +155,7 @@
 				  struct packed_git *pack,
 				  uint32_t pos,
 				  void *data);
+extern int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn, void *data);
 extern int for_each_packed_object(each_packed_object_fn, void *, unsigned flags);
 
 /*
diff --git a/parse-options-cb.c b/parse-options-cb.c
index c6679cb..0f9f311 100644
--- a/parse-options-cb.c
+++ b/parse-options-cb.c
@@ -38,7 +38,11 @@
 int parse_opt_expiry_date_cb(const struct option *opt, const char *arg,
 			     int unset)
 {
-	return parse_expiry_date(arg, (timestamp_t *)opt->value);
+	if (unset)
+		arg = "never";
+	if (parse_expiry_date(arg, (timestamp_t *)opt->value))
+		die(_("malformed expiration date '%s'"), arg);
+	return 0;
 }
 
 int parse_opt_color_flag_cb(const struct option *opt, const char *arg,
diff --git a/perl/Git.pm b/perl/Git.pm
index 16ebcc6..d856930 100644
--- a/perl/Git.pm
+++ b/perl/Git.pm
@@ -554,7 +554,7 @@
 	my ($fh, $rs) = @_;
 	local $/ = $rs;
 	my $rec = <$fh>;
-	chomp $rec if defined $rs;
+	chomp $rec if defined $rec;
 	$rec;
 }
 
diff --git a/perl/Git/SVN.pm b/perl/Git/SVN.pm
index 991a588..76b2965 100644
--- a/perl/Git/SVN.pm
+++ b/perl/Git/SVN.pm
@@ -1482,7 +1482,6 @@
 	}
 	if ($author =~ /^\s*(.+?)\s*<(.*)>\s*$/) {
 		my ($name, $email) = ($1, $2);
-		$email = undef if length $2 == 0;
 		return [$name, $email];
 	} else {
 		die "Author: $orig_author: $::_authors_prog returned "
@@ -2020,8 +2019,8 @@
 		remove_username($full_url);
 		$log_entry{metadata} = "$full_url\@$r $uuid";
 		$log_entry{svm_revision} = $r;
-		$email ||= "$author\@$uuid";
-		$commit_email ||= "$author\@$uuid";
+		$email = "$author\@$uuid" unless defined $email;
+		$commit_email = "$author\@$uuid" unless defined $commit_email;
 	} elsif ($self->use_svnsync_props) {
 		my $full_url = canonicalize_url(
 			add_path_to_url( $self->svnsync->{url}, $self->path )
@@ -2029,15 +2028,15 @@
 		remove_username($full_url);
 		my $uuid = $self->svnsync->{uuid};
 		$log_entry{metadata} = "$full_url\@$rev $uuid";
-		$email ||= "$author\@$uuid";
-		$commit_email ||= "$author\@$uuid";
+		$email = "$author\@$uuid" unless defined $email;
+		$commit_email = "$author\@$uuid" unless defined $commit_email;
 	} else {
 		my $url = $self->metadata_url;
 		remove_username($url);
 		my $uuid = $self->rewrite_uuid || $self->ra->get_uuid;
 		$log_entry{metadata} = "$url\@$rev " . $uuid;
-		$email ||= "$author\@" . $uuid;
-		$commit_email ||= "$author\@" . $uuid;
+		$email = "$author\@$uuid" unless defined $email;
+		$commit_email = "$author\@$uuid" unless defined $commit_email;
 	}
 	$log_entry{name} = $name;
 	$log_entry{email} = $email;
diff --git a/pkt-line.c b/pkt-line.c
index 2827ca7..555eb2a 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -91,6 +91,12 @@
 	write_or_die(fd, "0000", 4);
 }
 
+void packet_delim(int fd)
+{
+	packet_trace("0001", 4, 1);
+	write_or_die(fd, "0001", 4);
+}
+
 int packet_flush_gently(int fd)
 {
 	packet_trace("0000", 4, 1);
@@ -105,6 +111,12 @@
 	strbuf_add(buf, "0000", 4);
 }
 
+void packet_buf_delim(struct strbuf *buf)
+{
+	packet_trace("0001", 4, 1);
+	strbuf_add(buf, "0001", 4);
+}
+
 static void set_packet_header(char *buf, const int size)
 {
 	static char hexchar[] = "0123456789abcdef";
@@ -203,6 +215,22 @@
 	va_end(args);
 }
 
+void packet_buf_write_len(struct strbuf *buf, const char *data, size_t len)
+{
+	size_t orig_len, n;
+
+	orig_len = buf->len;
+	strbuf_addstr(buf, "0000");
+	strbuf_add(buf, data, len);
+	n = buf->len - orig_len;
+
+	if (n > LARGE_PACKET_MAX)
+		die("protocol error: impossibly long line");
+
+	set_packet_header(&buf->buf[orig_len], n);
+	packet_trace(data, len, 1);
+}
+
 int write_packetized_from_fd(int fd_in, int fd_out)
 {
 	static char buf[LARGE_PACKET_DATA_MAX];
@@ -280,28 +308,43 @@
 	return (val < 0) ? val : (val << 8) | hex2chr(linelen + 2);
 }
 
-int packet_read(int fd, char **src_buf, size_t *src_len,
-		char *buffer, unsigned size, int options)
+enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
+						size_t *src_len, char *buffer,
+						unsigned size, int *pktlen,
+						int options)
 {
-	int len, ret;
+	int len;
 	char linelen[4];
 
-	ret = get_packet_data(fd, src_buf, src_len, linelen, 4, options);
-	if (ret < 0)
-		return ret;
-	len = packet_length(linelen);
-	if (len < 0)
-		die("protocol error: bad line length character: %.4s", linelen);
-	if (!len) {
-		packet_trace("0000", 4, 0);
-		return 0;
+	if (get_packet_data(fd, src_buffer, src_len, linelen, 4, options) < 0) {
+		*pktlen = -1;
+		return PACKET_READ_EOF;
 	}
-	len -= 4;
-	if (len >= size)
+
+	len = packet_length(linelen);
+
+	if (len < 0) {
+		die("protocol error: bad line length character: %.4s", linelen);
+	} else if (!len) {
+		packet_trace("0000", 4, 0);
+		*pktlen = 0;
+		return PACKET_READ_FLUSH;
+	} else if (len == 1) {
+		packet_trace("0001", 4, 0);
+		*pktlen = 0;
+		return PACKET_READ_DELIM;
+	} else if (len < 4) {
 		die("protocol error: bad line length %d", len);
-	ret = get_packet_data(fd, src_buf, src_len, buffer, len, options);
-	if (ret < 0)
-		return ret;
+	}
+
+	len -= 4;
+	if ((unsigned)len >= size)
+		die("protocol error: bad line length %d", len);
+
+	if (get_packet_data(fd, src_buffer, src_len, buffer, len, options) < 0) {
+		*pktlen = -1;
+		return PACKET_READ_EOF;
+	}
 
 	if ((options & PACKET_READ_CHOMP_NEWLINE) &&
 	    len && buffer[len-1] == '\n')
@@ -309,7 +352,19 @@
 
 	buffer[len] = 0;
 	packet_trace(buffer, len, 0);
-	return len;
+	*pktlen = len;
+	return PACKET_READ_NORMAL;
+}
+
+int packet_read(int fd, char **src_buffer, size_t *src_len,
+		char *buffer, unsigned size, int options)
+{
+	int pktlen = -1;
+
+	packet_read_with_status(fd, src_buffer, src_len, buffer, size,
+				&pktlen, options);
+
+	return pktlen;
 }
 
 static char *packet_read_line_generic(int fd,
@@ -377,3 +432,53 @@
 	}
 	return sb_out->len - orig_len;
 }
+
+/* Packet Reader Functions */
+void packet_reader_init(struct packet_reader *reader, int fd,
+			char *src_buffer, size_t src_len,
+			int options)
+{
+	memset(reader, 0, sizeof(*reader));
+
+	reader->fd = fd;
+	reader->src_buffer = src_buffer;
+	reader->src_len = src_len;
+	reader->buffer = packet_buffer;
+	reader->buffer_size = sizeof(packet_buffer);
+	reader->options = options;
+}
+
+enum packet_read_status packet_reader_read(struct packet_reader *reader)
+{
+	if (reader->line_peeked) {
+		reader->line_peeked = 0;
+		return reader->status;
+	}
+
+	reader->status = packet_read_with_status(reader->fd,
+						 &reader->src_buffer,
+						 &reader->src_len,
+						 reader->buffer,
+						 reader->buffer_size,
+						 &reader->pktlen,
+						 reader->options);
+
+	if (reader->status == PACKET_READ_NORMAL)
+		reader->line = reader->buffer;
+	else
+		reader->line = NULL;
+
+	return reader->status;
+}
+
+enum packet_read_status packet_reader_peek(struct packet_reader *reader)
+{
+	/* Only allow peeking a single line */
+	if (reader->line_peeked)
+		return reader->status;
+
+	/* Peek a line by reading it and setting peeked flag */
+	packet_reader_read(reader);
+	reader->line_peeked = 1;
+	return reader->status;
+}
diff --git a/pkt-line.h b/pkt-line.h
index 3dad583..5b28d43 100644
--- a/pkt-line.h
+++ b/pkt-line.h
@@ -20,10 +20,13 @@
  * side can't, we stay with pure read/write interfaces.
  */
 void packet_flush(int fd);
+void packet_delim(int fd);
 void packet_write_fmt(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
 void packet_buf_flush(struct strbuf *buf);
+void packet_buf_delim(struct strbuf *buf);
 void packet_write(int fd_out, const char *buf, size_t size);
 void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
+void packet_buf_write_len(struct strbuf *buf, const char *data, size_t len);
 int packet_flush_gently(int fd);
 int packet_write_fmt_gently(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
 int write_packetized_from_fd(int fd_in, int fd_out);
@@ -66,6 +69,23 @@
 		*buffer, unsigned size, int options);
 
 /*
+ * Read a packetized line into a buffer like the 'packet_read()' function but
+ * returns an 'enum packet_read_status' which indicates the status of the read.
+ * The number of bytes read will be assigined to *pktlen if the status of the
+ * read was 'PACKET_READ_NORMAL'.
+ */
+enum packet_read_status {
+	PACKET_READ_EOF,
+	PACKET_READ_NORMAL,
+	PACKET_READ_FLUSH,
+	PACKET_READ_DELIM,
+};
+enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
+						size_t *src_len, char *buffer,
+						unsigned size, int *pktlen,
+						int options);
+
+/*
  * Convenience wrapper for packet_read that is not gentle, and sets the
  * CHOMP_NEWLINE option. The return value is NULL for a flush packet,
  * and otherwise points to a static buffer (that may be overwritten by
@@ -96,6 +116,64 @@
  */
 ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out);
 
+struct packet_reader {
+	/* source file descriptor */
+	int fd;
+
+	/* source buffer and its size */
+	char *src_buffer;
+	size_t src_len;
+
+	/* buffer that pkt-lines are read into and its size */
+	char *buffer;
+	unsigned buffer_size;
+
+	/* options to be used during reads */
+	int options;
+
+	/* status of the last read */
+	enum packet_read_status status;
+
+	/* length of data read during the last read */
+	int pktlen;
+
+	/* the last line read */
+	const char *line;
+
+	/* indicates if a line has been peeked */
+	int line_peeked;
+};
+
+/*
+ * Initialize a 'struct packet_reader' object which is an
+ * abstraction around the 'packet_read_with_status()' function.
+ */
+extern void packet_reader_init(struct packet_reader *reader, int fd,
+			       char *src_buffer, size_t src_len,
+			       int options);
+
+/*
+ * Perform a packet read and return the status of the read.
+ * The values of 'pktlen' and 'line' are updated based on the status of the
+ * read as follows:
+ *
+ * PACKET_READ_ERROR: 'pktlen' is set to '-1' and 'line' is set to NULL
+ * PACKET_READ_NORMAL: 'pktlen' is set to the number of bytes read
+ *		       'line' is set to point at the read line
+ * PACKET_READ_FLUSH: 'pktlen' is set to '0' and 'line' is set to NULL
+ */
+extern enum packet_read_status packet_reader_read(struct packet_reader *reader);
+
+/*
+ * Peek the next packet line without consuming it and return the status.
+ * The next call to 'packet_reader_read()' will perform a read of the same line
+ * that was peeked, consuming the line.
+ *
+ * Peeking multiple times without calling 'packet_reader_read()' will return
+ * the same result.
+ */
+extern enum packet_read_status packet_reader_peek(struct packet_reader *reader);
+
 #define DEFAULT_PACKET_MAX 1000
 #define LARGE_PACKET_MAX 65520
 #define LARGE_PACKET_DATA_MAX (LARGE_PACKET_MAX - 4)
diff --git a/protocol.c b/protocol.c
index 43012b7..5e63678 100644
--- a/protocol.c
+++ b/protocol.c
@@ -8,6 +8,8 @@
 		return protocol_v0;
 	else if (!strcmp(value, "1"))
 		return protocol_v1;
+	else if (!strcmp(value, "2"))
+		return protocol_v2;
 	else
 		return protocol_unknown_version;
 }
diff --git a/protocol.h b/protocol.h
index 1b2bc94..2ad35e4 100644
--- a/protocol.h
+++ b/protocol.h
@@ -5,6 +5,7 @@
 	protocol_unknown_version = -1,
 	protocol_v0 = 0,
 	protocol_v1 = 1,
+	protocol_v2 = 2,
 };
 
 /*
diff --git a/ref-filter.c b/ref-filter.c
index 9a333e2..39e2744 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -101,22 +101,38 @@
 } *used_atom;
 static int used_atom_cnt, need_tagged, need_symref;
 
-static void color_atom_parser(const struct ref_format *format, struct used_atom *atom, const char *color_value)
+/*
+ * Expand string, append it to strbuf *sb, then return error code ret.
+ * Allow to save few lines of code.
+ */
+static int strbuf_addf_ret(struct strbuf *sb, int ret, const char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+	strbuf_vaddf(sb, fmt, ap);
+	va_end(ap);
+	return ret;
+}
+
+static int color_atom_parser(const struct ref_format *format, struct used_atom *atom,
+			     const char *color_value, struct strbuf *err)
 {
 	if (!color_value)
-		die(_("expected format: %%(color:<color>)"));
+		return strbuf_addf_ret(err, -1, _("expected format: %%(color:<color>)"));
 	if (color_parse(color_value, atom->u.color) < 0)
-		die(_("unrecognized color: %%(color:%s)"), color_value);
+		return strbuf_addf_ret(err, -1, _("unrecognized color: %%(color:%s)"),
+				       color_value);
 	/*
 	 * We check this after we've parsed the color, which lets us complain
 	 * about syntactically bogus color names even if they won't be used.
 	 */
 	if (!want_color(format->use_color))
 		color_parse("", atom->u.color);
+	return 0;
 }
 
-static void refname_atom_parser_internal(struct refname_atom *atom,
-					 const char *arg, const char *name)
+static int refname_atom_parser_internal(struct refname_atom *atom, const char *arg,
+					 const char *name, struct strbuf *err)
 {
 	if (!arg)
 		atom->option = R_NORMAL;
@@ -126,16 +142,18 @@
 		 skip_prefix(arg, "strip=", &arg)) {
 		atom->option = R_LSTRIP;
 		if (strtol_i(arg, 10, &atom->lstrip))
-			die(_("Integer value expected refname:lstrip=%s"), arg);
+			return strbuf_addf_ret(err, -1, _("Integer value expected refname:lstrip=%s"), arg);
 	} else if (skip_prefix(arg, "rstrip=", &arg)) {
 		atom->option = R_RSTRIP;
 		if (strtol_i(arg, 10, &atom->rstrip))
-			die(_("Integer value expected refname:rstrip=%s"), arg);
+			return strbuf_addf_ret(err, -1, _("Integer value expected refname:rstrip=%s"), arg);
 	} else
-		die(_("unrecognized %%(%s) argument: %s"), name, arg);
+		return strbuf_addf_ret(err, -1, _("unrecognized %%(%s) argument: %s"), name, arg);
+	return 0;
 }
 
-static void remote_ref_atom_parser(const struct ref_format *format, struct used_atom *atom, const char *arg)
+static int remote_ref_atom_parser(const struct ref_format *format, struct used_atom *atom,
+				  const char *arg, struct strbuf *err)
 {
 	struct string_list params = STRING_LIST_INIT_DUP;
 	int i;
@@ -145,9 +163,8 @@
 
 	if (!arg) {
 		atom->u.remote_ref.option = RR_REF;
-		refname_atom_parser_internal(&atom->u.remote_ref.refname,
-					     arg, atom->name);
-		return;
+		return refname_atom_parser_internal(&atom->u.remote_ref.refname,
+						    arg, atom->name, err);
 	}
 
 	atom->u.remote_ref.nobracket = 0;
@@ -170,29 +187,38 @@
 			atom->u.remote_ref.push_remote = 1;
 		} else {
 			atom->u.remote_ref.option = RR_REF;
-			refname_atom_parser_internal(&atom->u.remote_ref.refname,
-						     arg, atom->name);
+			if (refname_atom_parser_internal(&atom->u.remote_ref.refname,
+							 arg, atom->name, err)) {
+				string_list_clear(&params, 0);
+				return -1;
+			}
 		}
 	}
 
 	string_list_clear(&params, 0);
+	return 0;
 }
 
-static void body_atom_parser(const struct ref_format *format, struct used_atom *atom, const char *arg)
+static int body_atom_parser(const struct ref_format *format, struct used_atom *atom,
+			    const char *arg, struct strbuf *err)
 {
 	if (arg)
-		die(_("%%(body) does not take arguments"));
+		return strbuf_addf_ret(err, -1, _("%%(body) does not take arguments"));
 	atom->u.contents.option = C_BODY_DEP;
+	return 0;
 }
 
-static void subject_atom_parser(const struct ref_format *format, struct used_atom *atom, const char *arg)
+static int subject_atom_parser(const struct ref_format *format, struct used_atom *atom,
+			       const char *arg, struct strbuf *err)
 {
 	if (arg)
-		die(_("%%(subject) does not take arguments"));
+		return strbuf_addf_ret(err, -1, _("%%(subject) does not take arguments"));
 	atom->u.contents.option = C_SUB;
+	return 0;
 }
 
-static void trailers_atom_parser(const struct ref_format *format, struct used_atom *atom, const char *arg)
+static int trailers_atom_parser(const struct ref_format *format, struct used_atom *atom,
+				const char *arg, struct strbuf *err)
 {
 	struct string_list params = STRING_LIST_INIT_DUP;
 	int i;
@@ -205,15 +231,20 @@
 				atom->u.contents.trailer_opts.unfold = 1;
 			else if (!strcmp(s, "only"))
 				atom->u.contents.trailer_opts.only_trailers = 1;
-			else
-				die(_("unknown %%(trailers) argument: %s"), s);
+			else {
+				strbuf_addf(err, _("unknown %%(trailers) argument: %s"), s);
+				string_list_clear(&params, 0);
+				return -1;
+			}
 		}
 	}
 	atom->u.contents.option = C_TRAILERS;
 	string_list_clear(&params, 0);
+	return 0;
 }
 
-static void contents_atom_parser(const struct ref_format *format, struct used_atom *atom, const char *arg)
+static int contents_atom_parser(const struct ref_format *format, struct used_atom *atom,
+				const char *arg, struct strbuf *err)
 {
 	if (!arg)
 		atom->u.contents.option = C_BARE;
@@ -225,16 +256,19 @@
 		atom->u.contents.option = C_SUB;
 	else if (skip_prefix(arg, "trailers", &arg)) {
 		skip_prefix(arg, ":", &arg);
-		trailers_atom_parser(format, atom, *arg ? arg : NULL);
+		if (trailers_atom_parser(format, atom, *arg ? arg : NULL, err))
+			return -1;
 	} else if (skip_prefix(arg, "lines=", &arg)) {
 		atom->u.contents.option = C_LINES;
 		if (strtoul_ui(arg, 10, &atom->u.contents.nlines))
-			die(_("positive value expected contents:lines=%s"), arg);
+			return strbuf_addf_ret(err, -1, _("positive value expected contents:lines=%s"), arg);
 	} else
-		die(_("unrecognized %%(contents) argument: %s"), arg);
+		return strbuf_addf_ret(err, -1, _("unrecognized %%(contents) argument: %s"), arg);
+	return 0;
 }
 
-static void objectname_atom_parser(const struct ref_format *format, struct used_atom *atom, const char *arg)
+static int objectname_atom_parser(const struct ref_format *format, struct used_atom *atom,
+				  const char *arg, struct strbuf *err)
 {
 	if (!arg)
 		atom->u.objectname.option = O_FULL;
@@ -244,16 +278,18 @@
 		atom->u.objectname.option = O_LENGTH;
 		if (strtoul_ui(arg, 10, &atom->u.objectname.length) ||
 		    atom->u.objectname.length == 0)
-			die(_("positive value expected objectname:short=%s"), arg);
+			return strbuf_addf_ret(err, -1, _("positive value expected objectname:short=%s"), arg);
 		if (atom->u.objectname.length < MINIMUM_ABBREV)
 			atom->u.objectname.length = MINIMUM_ABBREV;
 	} else
-		die(_("unrecognized %%(objectname) argument: %s"), arg);
+		return strbuf_addf_ret(err, -1, _("unrecognized %%(objectname) argument: %s"), arg);
+	return 0;
 }
 
-static void refname_atom_parser(const struct ref_format *format, struct used_atom *atom, const char *arg)
+static int refname_atom_parser(const struct ref_format *format, struct used_atom *atom,
+			       const char *arg, struct strbuf *err)
 {
-	refname_atom_parser_internal(&atom->u.refname, arg, atom->name);
+	return refname_atom_parser_internal(&atom->u.refname, arg, atom->name, err);
 }
 
 static align_type parse_align_position(const char *s)
@@ -267,7 +303,8 @@
 	return -1;
 }
 
-static void align_atom_parser(const struct ref_format *format, struct used_atom *atom, const char *arg)
+static int align_atom_parser(const struct ref_format *format, struct used_atom *atom,
+			     const char *arg, struct strbuf *err)
 {
 	struct align *align = &atom->u.align;
 	struct string_list params = STRING_LIST_INIT_DUP;
@@ -275,7 +312,7 @@
 	unsigned int width = ~0U;
 
 	if (!arg)
-		die(_("expected format: %%(align:<width>,<position>)"));
+		return strbuf_addf_ret(err, -1, _("expected format: %%(align:<width>,<position>)"));
 
 	align->position = ALIGN_LEFT;
 
@@ -286,49 +323,65 @@
 
 		if (skip_prefix(s, "position=", &s)) {
 			position = parse_align_position(s);
-			if (position < 0)
-				die(_("unrecognized position:%s"), s);
+			if (position < 0) {
+				strbuf_addf(err, _("unrecognized position:%s"), s);
+				string_list_clear(&params, 0);
+				return -1;
+			}
 			align->position = position;
 		} else if (skip_prefix(s, "width=", &s)) {
-			if (strtoul_ui(s, 10, &width))
-				die(_("unrecognized width:%s"), s);
+			if (strtoul_ui(s, 10, &width)) {
+				strbuf_addf(err, _("unrecognized width:%s"), s);
+				string_list_clear(&params, 0);
+				return -1;
+			}
 		} else if (!strtoul_ui(s, 10, &width))
 			;
 		else if ((position = parse_align_position(s)) >= 0)
 			align->position = position;
-		else
-			die(_("unrecognized %%(align) argument: %s"), s);
+		else {
+			strbuf_addf(err, _("unrecognized %%(align) argument: %s"), s);
+			string_list_clear(&params, 0);
+			return -1;
+		}
 	}
 
-	if (width == ~0U)
-		die(_("positive width expected with the %%(align) atom"));
+	if (width == ~0U) {
+		string_list_clear(&params, 0);
+		return strbuf_addf_ret(err, -1, _("positive width expected with the %%(align) atom"));
+	}
 	align->width = width;
 	string_list_clear(&params, 0);
+	return 0;
 }
 
-static void if_atom_parser(const struct ref_format *format, struct used_atom *atom, const char *arg)
+static int if_atom_parser(const struct ref_format *format, struct used_atom *atom,
+			  const char *arg, struct strbuf *err)
 {
 	if (!arg) {
 		atom->u.if_then_else.cmp_status = COMPARE_NONE;
-		return;
+		return 0;
 	} else if (skip_prefix(arg, "equals=", &atom->u.if_then_else.str)) {
 		atom->u.if_then_else.cmp_status = COMPARE_EQUAL;
 	} else if (skip_prefix(arg, "notequals=", &atom->u.if_then_else.str)) {
 		atom->u.if_then_else.cmp_status = COMPARE_UNEQUAL;
-	} else {
-		die(_("unrecognized %%(if) argument: %s"), arg);
-	}
+	} else
+		return strbuf_addf_ret(err, -1, _("unrecognized %%(if) argument: %s"), arg);
+	return 0;
 }
 
-static void head_atom_parser(const struct ref_format *format, struct used_atom *atom, const char *arg)
+static int head_atom_parser(const struct ref_format *format, struct used_atom *atom,
+			    const char *arg, struct strbuf *unused_err)
 {
 	atom->u.head = resolve_refdup("HEAD", RESOLVE_REF_READING, NULL, NULL);
+	return 0;
 }
 
 static struct {
 	const char *name;
 	cmp_type cmp_type;
-	void (*parser)(const struct ref_format *format, struct used_atom *atom, const char *arg);
+	int (*parser)(const struct ref_format *format, struct used_atom *atom,
+		      const char *arg, struct strbuf *err);
 } valid_atom[] = {
 	{ "refname" , FIELD_STR, refname_atom_parser },
 	{ "objecttype" },
@@ -387,7 +440,8 @@
 
 struct atom_value {
 	const char *s;
-	void (*handler)(struct atom_value *atomv, struct ref_formatting_state *state);
+	int (*handler)(struct atom_value *atomv, struct ref_formatting_state *state,
+		       struct strbuf *err);
 	uintmax_t value; /* used for sorting when not FIELD_STR */
 	struct used_atom *atom;
 };
@@ -396,7 +450,8 @@
  * Used to parse format string and sort specifiers
  */
 static int parse_ref_filter_atom(const struct ref_format *format,
-				 const char *atom, const char *ep)
+				 const char *atom, const char *ep,
+				 struct strbuf *err)
 {
 	const char *sp;
 	const char *arg;
@@ -406,7 +461,8 @@
 	if (*sp == '*' && sp < ep)
 		sp++; /* deref */
 	if (ep <= sp)
-		die(_("malformed field name: %.*s"), (int)(ep-atom), atom);
+		return strbuf_addf_ret(err, -1, _("malformed field name: %.*s"),
+				       (int)(ep-atom), atom);
 
 	/* Do we have the atom already used elsewhere? */
 	for (i = 0; i < used_atom_cnt; i++) {
@@ -432,7 +488,8 @@
 	}
 
 	if (ARRAY_SIZE(valid_atom) <= i)
-		die(_("unknown field name: %.*s"), (int)(ep-atom), atom);
+		return strbuf_addf_ret(err, -1, _("unknown field name: %.*s"),
+				       (int)(ep-atom), atom);
 
 	/* Add it in, including the deref prefix */
 	at = used_atom_cnt;
@@ -451,8 +508,8 @@
 		}
 	}
 	memset(&used_atom[at].u, 0, sizeof(used_atom[at].u));
-	if (valid_atom[i].parser)
-		valid_atom[i].parser(format, &used_atom[at], arg);
+	if (valid_atom[i].parser && valid_atom[i].parser(format, &used_atom[at], arg, err))
+		return -1;
 	if (*atom == '*')
 		need_tagged = 1;
 	if (!strcmp(valid_atom[i].name, "symref"))
@@ -481,7 +538,8 @@
 	}
 }
 
-static void append_atom(struct atom_value *v, struct ref_formatting_state *state)
+static int append_atom(struct atom_value *v, struct ref_formatting_state *state,
+		       struct strbuf *unused_err)
 {
 	/*
 	 * Quote formatting is only done when the stack has a single
@@ -493,6 +551,7 @@
 		quote_formatting(&state->stack->output, v->s, state->quote_style);
 	else
 		strbuf_addstr(&state->stack->output, v->s);
+	return 0;
 }
 
 static void push_stack_element(struct ref_formatting_stack **stack)
@@ -527,7 +586,8 @@
 	strbuf_release(&s);
 }
 
-static void align_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+static int align_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state,
+			      struct strbuf *unused_err)
 {
 	struct ref_formatting_stack *new_stack;
 
@@ -535,6 +595,7 @@
 	new_stack = state->stack;
 	new_stack->at_end = end_align_handler;
 	new_stack->at_end_data = &atomv->atom->u.align;
+	return 0;
 }
 
 static void if_then_else_handler(struct ref_formatting_stack **stack)
@@ -572,7 +633,8 @@
 	free(if_then_else);
 }
 
-static void if_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+static int if_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state,
+			   struct strbuf *unused_err)
 {
 	struct ref_formatting_stack *new_stack;
 	struct if_then_else *if_then_else = xcalloc(sizeof(struct if_then_else), 1);
@@ -584,6 +646,7 @@
 	new_stack = state->stack;
 	new_stack->at_end = if_then_else_handler;
 	new_stack->at_end_data = if_then_else;
+	return 0;
 }
 
 static int is_empty(const char *s)
@@ -596,7 +659,8 @@
 	return 1;
 }
 
-static void then_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+static int then_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state,
+			     struct strbuf *err)
 {
 	struct ref_formatting_stack *cur = state->stack;
 	struct if_then_else *if_then_else = NULL;
@@ -604,11 +668,11 @@
 	if (cur->at_end == if_then_else_handler)
 		if_then_else = (struct if_then_else *)cur->at_end_data;
 	if (!if_then_else)
-		die(_("format: %%(then) atom used without an %%(if) atom"));
+		return strbuf_addf_ret(err, -1, _("format: %%(then) atom used without an %%(if) atom"));
 	if (if_then_else->then_atom_seen)
-		die(_("format: %%(then) atom used more than once"));
+		return strbuf_addf_ret(err, -1, _("format: %%(then) atom used more than once"));
 	if (if_then_else->else_atom_seen)
-		die(_("format: %%(then) atom used after %%(else)"));
+		return strbuf_addf_ret(err, -1, _("format: %%(then) atom used after %%(else)"));
 	if_then_else->then_atom_seen = 1;
 	/*
 	 * If the 'equals' or 'notequals' attribute is used then
@@ -624,9 +688,11 @@
 	} else if (cur->output.len && !is_empty(cur->output.buf))
 		if_then_else->condition_satisfied = 1;
 	strbuf_reset(&cur->output);
+	return 0;
 }
 
-static void else_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+static int else_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state,
+			     struct strbuf *err)
 {
 	struct ref_formatting_stack *prev = state->stack;
 	struct if_then_else *if_then_else = NULL;
@@ -634,24 +700,26 @@
 	if (prev->at_end == if_then_else_handler)
 		if_then_else = (struct if_then_else *)prev->at_end_data;
 	if (!if_then_else)
-		die(_("format: %%(else) atom used without an %%(if) atom"));
+		return strbuf_addf_ret(err, -1, _("format: %%(else) atom used without an %%(if) atom"));
 	if (!if_then_else->then_atom_seen)
-		die(_("format: %%(else) atom used without a %%(then) atom"));
+		return strbuf_addf_ret(err, -1, _("format: %%(else) atom used without a %%(then) atom"));
 	if (if_then_else->else_atom_seen)
-		die(_("format: %%(else) atom used more than once"));
+		return strbuf_addf_ret(err, -1, _("format: %%(else) atom used more than once"));
 	if_then_else->else_atom_seen = 1;
 	push_stack_element(&state->stack);
 	state->stack->at_end_data = prev->at_end_data;
 	state->stack->at_end = prev->at_end;
+	return 0;
 }
 
-static void end_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+static int end_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state,
+			    struct strbuf *err)
 {
 	struct ref_formatting_stack *current = state->stack;
 	struct strbuf s = STRBUF_INIT;
 
 	if (!current->at_end)
-		die(_("format: %%(end) atom used without corresponding atom"));
+		return strbuf_addf_ret(err, -1, _("format: %%(end) atom used without corresponding atom"));
 	current->at_end(&state->stack);
 
 	/*  Stack may have been popped within at_end(), hence reset the current pointer */
@@ -668,6 +736,7 @@
 	}
 	strbuf_release(&s);
 	pop_stack_element(&state->stack);
+	return 0;
 }
 
 /*
@@ -702,17 +771,21 @@
 
 	format->need_color_reset_at_eol = 0;
 	for (cp = format->format; *cp && (sp = find_next(cp)); ) {
+		struct strbuf err = STRBUF_INIT;
 		const char *color, *ep = strchr(sp, ')');
 		int at;
 
 		if (!ep)
 			return error(_("malformed format string %s"), sp);
 		/* sp points at "%(" and ep points at the closing ")" */
-		at = parse_ref_filter_atom(format, sp + 2, ep);
+		at = parse_ref_filter_atom(format, sp + 2, ep, &err);
+		if (at < 0)
+			die("%s", err.buf);
 		cp = ep + 1;
 
 		if (skip_prefix(used_atom[at].name, "color:", &color))
 			format->need_color_reset_at_eol = !!strcmp(color, "reset");
+		strbuf_release(&err);
 	}
 	if (format->need_color_reset_at_eol && !want_color(format->use_color))
 		format->need_color_reset_at_eol = 0;
@@ -1309,10 +1382,14 @@
 	memset(&state, 0, sizeof(state));
 	wt_status_get_state(&state, 1);
 	if (state.rebase_in_progress ||
-	    state.rebase_interactive_in_progress)
-		strbuf_addf(&desc, _("(no branch, rebasing %s)"),
-			    state.branch);
-	else if (state.bisect_in_progress)
+	    state.rebase_interactive_in_progress) {
+		if (state.branch)
+			strbuf_addf(&desc, _("(no branch, rebasing %s)"),
+				    state.branch);
+		else
+			strbuf_addf(&desc, _("(no branch, rebasing detached HEAD %s)"),
+				    state.detached_from);
+	} else if (state.bisect_in_progress)
 		strbuf_addf(&desc, _("(no branch, bisect started on %s)"),
 			    state.branch);
 	else if (state.detached_from) {
@@ -1354,28 +1431,30 @@
 	return show_ref(&atom->u.refname, ref->refname);
 }
 
-static void get_object(struct ref_array_item *ref, const struct object_id *oid,
-		       int deref, struct object **obj)
+static int get_object(struct ref_array_item *ref, const struct object_id *oid,
+		       int deref, struct object **obj, struct strbuf *err)
 {
 	int eaten;
+	int ret = 0;
 	unsigned long size;
 	void *buf = get_obj(oid, obj, &size, &eaten);
 	if (!buf)
-		die(_("missing object %s for %s"),
-		    oid_to_hex(oid), ref->refname);
-	if (!*obj)
-		die(_("parse_object_buffer failed on %s for %s"),
-		    oid_to_hex(oid), ref->refname);
-
-	grab_values(ref->value, deref, *obj, buf, size);
+		ret = strbuf_addf_ret(err, -1, _("missing object %s for %s"),
+				      oid_to_hex(oid), ref->refname);
+	else if (!*obj)
+		ret = strbuf_addf_ret(err, -1, _("parse_object_buffer failed on %s for %s"),
+				      oid_to_hex(oid), ref->refname);
+	else
+		grab_values(ref->value, deref, *obj, buf, size);
 	if (!eaten)
 		free(buf);
+	return ret;
 }
 
 /*
  * Parse the object referred by ref, and grab needed value.
  */
-static void populate_value(struct ref_array_item *ref)
+static int populate_value(struct ref_array_item *ref, struct strbuf *err)
 {
 	struct object *obj;
 	int i;
@@ -1497,16 +1576,17 @@
 			break;
 	}
 	if (used_atom_cnt <= i)
-		return;
+		return 0;
 
-	get_object(ref, &ref->objectname, 0, &obj);
+	if (get_object(ref, &ref->objectname, 0, &obj, err))
+		return -1;
 
 	/*
 	 * If there is no atom that wants to know about tagged
 	 * object, we are done.
 	 */
 	if (!need_tagged || (obj->type != OBJ_TAG))
-		return;
+		return 0;
 
 	/*
 	 * If it is a tag object, see if we use a value that derefs
@@ -1520,20 +1600,23 @@
 	 * is not consistent with what deref_tag() does
 	 * which peels the onion to the core.
 	 */
-	get_object(ref, tagged, 1, &obj);
+	return get_object(ref, tagged, 1, &obj, err);
 }
 
 /*
  * Given a ref, return the value for the atom.  This lazily gets value
  * out of the object by calling populate value.
  */
-static void get_ref_atom_value(struct ref_array_item *ref, int atom, struct atom_value **v)
+static int get_ref_atom_value(struct ref_array_item *ref, int atom,
+			      struct atom_value **v, struct strbuf *err)
 {
 	if (!ref->value) {
-		populate_value(ref);
+		if (populate_value(ref, err))
+			return -1;
 		fill_missing_values(ref->value);
 	}
 	*v = &ref->value[atom];
+	return 0;
 }
 
 /*
@@ -1824,15 +1907,30 @@
 	return NULL;
 }
 
-/* Allocate space for a new ref_array_item and copy the objectname and flag to it */
+/*
+ * Allocate space for a new ref_array_item and copy the name and oid to it.
+ *
+ * Callers can then fill in other struct members at their leisure.
+ */
 static struct ref_array_item *new_ref_array_item(const char *refname,
-						 const unsigned char *objectname,
-						 int flag)
+						 const struct object_id *oid)
 {
 	struct ref_array_item *ref;
+
 	FLEX_ALLOC_STR(ref, refname, refname);
-	hashcpy(ref->objectname.hash, objectname);
-	ref->flag = flag;
+	oidcpy(&ref->objectname, oid);
+
+	return ref;
+}
+
+struct ref_array_item *ref_array_push(struct ref_array *array,
+				      const char *refname,
+				      const struct object_id *oid)
+{
+	struct ref_array_item *ref = new_ref_array_item(refname, oid);
+
+	ALLOC_GROW(array->items, array->nr + 1, array->alloc);
+	array->items[array->nr++] = ref;
 
 	return ref;
 }
@@ -1927,12 +2025,11 @@
 	 * to do its job and the resulting list may yet to be pruned
 	 * by maxcount logic.
 	 */
-	ref = new_ref_array_item(refname, oid->hash, flag);
+	ref = ref_array_push(ref_cbdata->array, refname, oid);
 	ref->commit = commit;
-
-	REALLOC_ARRAY(ref_cbdata->array->items, ref_cbdata->array->nr + 1);
-	ref_cbdata->array->items[ref_cbdata->array->nr++] = ref;
+	ref->flag = flag;
 	ref->kind = kind;
+
 	return 0;
 }
 
@@ -2057,9 +2154,13 @@
 	int cmp;
 	cmp_type cmp_type = used_atom[s->atom].type;
 	int (*cmp_fn)(const char *, const char *);
+	struct strbuf err = STRBUF_INIT;
 
-	get_ref_atom_value(a, s->atom, &va);
-	get_ref_atom_value(b, s->atom, &vb);
+	if (get_ref_atom_value(a, s->atom, &va, &err))
+		die("%s", err.buf);
+	if (get_ref_atom_value(b, s->atom, &vb, &err))
+		die("%s", err.buf);
+	strbuf_release(&err);
 	cmp_fn = s->ignore_case ? strcasecmp : strcmp;
 	if (s->version)
 		cmp = versioncmp(va->s, vb->s);
@@ -2118,9 +2219,10 @@
 	}
 }
 
-void format_ref_array_item(struct ref_array_item *info,
+int format_ref_array_item(struct ref_array_item *info,
 			   const struct ref_format *format,
-			   struct strbuf *final_buf)
+			   struct strbuf *final_buf,
+			   struct strbuf *error_buf)
 {
 	const char *cp, *sp, *ep;
 	struct ref_formatting_state state = REF_FORMATTING_STATE_INIT;
@@ -2130,14 +2232,17 @@
 
 	for (cp = format->format; *cp && (sp = find_next(cp)); cp = ep + 1) {
 		struct atom_value *atomv;
+		int pos;
 
 		ep = strchr(sp, ')');
 		if (cp < sp)
 			append_literal(cp, sp, &state);
-		get_ref_atom_value(info,
-				   parse_ref_filter_atom(format, sp + 2, ep),
-				   &atomv);
-		atomv->handler(atomv, &state);
+		pos = parse_ref_filter_atom(format, sp + 2, ep, error_buf);
+		if (pos < 0 || get_ref_atom_value(info, pos, &atomv, error_buf) ||
+		    atomv->handler(atomv, &state, error_buf)) {
+			pop_stack_element(&state.stack);
+			return -1;
+		}
 	}
 	if (*cp) {
 		sp = cp + strlen(cp);
@@ -2146,30 +2251,39 @@
 	if (format->need_color_reset_at_eol) {
 		struct atom_value resetv;
 		resetv.s = GIT_COLOR_RESET;
-		append_atom(&resetv, &state);
+		if (append_atom(&resetv, &state, error_buf)) {
+			pop_stack_element(&state.stack);
+			return -1;
+		}
 	}
-	if (state.stack->prev)
-		die(_("format: %%(end) atom missing"));
+	if (state.stack->prev) {
+		pop_stack_element(&state.stack);
+		return strbuf_addf_ret(error_buf, -1, _("format: %%(end) atom missing"));
+	}
 	strbuf_addbuf(final_buf, &state.stack->output);
 	pop_stack_element(&state.stack);
+	return 0;
 }
 
 void show_ref_array_item(struct ref_array_item *info,
 			 const struct ref_format *format)
 {
 	struct strbuf final_buf = STRBUF_INIT;
+	struct strbuf error_buf = STRBUF_INIT;
 
-	format_ref_array_item(info, format, &final_buf);
+	if (format_ref_array_item(info, format, &final_buf, &error_buf))
+		die("%s", error_buf.buf);
 	fwrite(final_buf.buf, 1, final_buf.len, stdout);
+	strbuf_release(&error_buf);
 	strbuf_release(&final_buf);
 	putchar('\n');
 }
 
-void pretty_print_ref(const char *name, const unsigned char *sha1,
+void pretty_print_ref(const char *name, const struct object_id *oid,
 		      const struct ref_format *format)
 {
 	struct ref_array_item *ref_item;
-	ref_item = new_ref_array_item(name, sha1, 0);
+	ref_item = new_ref_array_item(name, oid);
 	ref_item->kind = ref_kind_from_refname(name);
 	show_ref_array_item(ref_item, format);
 	free_array_item(ref_item);
@@ -2183,7 +2297,12 @@
 	 */
 	struct ref_format dummy = REF_FORMAT_INIT;
 	const char *end = atom + strlen(atom);
-	return parse_ref_filter_atom(&dummy, atom, end);
+	struct strbuf err = STRBUF_INIT;
+	int res = parse_ref_filter_atom(&dummy, atom, end, &err);
+	if (res < 0)
+		die("%s", err.buf);
+	strbuf_release(&err);
+	return res;
 }
 
 /*  If no sorting option is given, use refname to sort as default */
diff --git a/ref-filter.h b/ref-filter.h
index 0d98342..85c8ebc 100644
--- a/ref-filter.h
+++ b/ref-filter.h
@@ -110,9 +110,10 @@
 /*  Sort the given ref_array as per the ref_sorting provided */
 void ref_array_sort(struct ref_sorting *sort, struct ref_array *array);
 /*  Based on the given format and quote_style, fill the strbuf */
-void format_ref_array_item(struct ref_array_item *info,
-			   const struct ref_format *format,
-			   struct strbuf *final_buf);
+int format_ref_array_item(struct ref_array_item *info,
+			  const struct ref_format *format,
+			  struct strbuf *final_buf,
+			  struct strbuf *error_buf);
 /*  Print the ref using the given format and quote_style */
 void show_ref_array_item(struct ref_array_item *info, const struct ref_format *format);
 /*  Parse a single sort specifier and add it to the list */
@@ -132,7 +133,15 @@
  * Print a single ref, outside of any ref-filter. Note that the
  * name must be a fully qualified refname.
  */
-void pretty_print_ref(const char *name, const unsigned char *sha1,
+void pretty_print_ref(const char *name, const struct object_id *oid,
 		      const struct ref_format *format);
 
+/*
+ * Push a single ref onto the array; this can be used to construct your own
+ * ref_array without using filter_refs().
+ */
+struct ref_array_item *ref_array_push(struct ref_array *array,
+				      const char *refname,
+				      const struct object_id *oid);
+
 #endif /*  REF_FILTER_H  */
diff --git a/refs.c b/refs.c
index 8b7a77f..64aadd1 100644
--- a/refs.c
+++ b/refs.c
@@ -13,6 +13,8 @@
 #include "tag.h"
 #include "submodule.h"
 #include "worktree.h"
+#include "argv-array.h"
+#include "repository.h"
 
 /*
  * List of all available backends
@@ -206,7 +208,7 @@
 char *resolve_refdup(const char *refname, int resolve_flags,
 		     struct object_id *oid, int *flags)
 {
-	return refs_resolve_refdup(get_main_ref_store(),
+	return refs_resolve_refdup(get_main_ref_store(the_repository),
 				   refname, resolve_flags,
 				   oid, flags);
 }
@@ -228,7 +230,7 @@
 
 int read_ref_full(const char *refname, int resolve_flags, struct object_id *oid, int *flags)
 {
-	return refs_read_ref_full(get_main_ref_store(), refname,
+	return refs_read_ref_full(get_main_ref_store(the_repository), refname,
 				  resolve_flags, oid, flags);
 }
 
@@ -375,7 +377,7 @@
 
 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
 {
-	return refs_for_each_tag_ref(get_main_ref_store(), fn, cb_data);
+	return refs_for_each_tag_ref(get_main_ref_store(the_repository), fn, cb_data);
 }
 
 int refs_for_each_branch_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
@@ -385,7 +387,7 @@
 
 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
 {
-	return refs_for_each_branch_ref(get_main_ref_store(), fn, cb_data);
+	return refs_for_each_branch_ref(get_main_ref_store(the_repository), fn, cb_data);
 }
 
 int refs_for_each_remote_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
@@ -395,7 +397,7 @@
 
 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
 {
-	return refs_for_each_remote_ref(get_main_ref_store(), fn, cb_data);
+	return refs_for_each_remote_ref(get_main_ref_store(the_repository), fn, cb_data);
 }
 
 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
@@ -502,6 +504,19 @@
 }
 
 /*
+ * Given a 'prefix' expand it by the rules in 'ref_rev_parse_rules' and add
+ * the results to 'prefixes'
+ */
+void expand_ref_prefix(struct argv_array *prefixes, const char *prefix)
+{
+	const char **p;
+	int len = strlen(prefix);
+
+	for (p = ref_rev_parse_rules; *p; p++)
+		argv_array_pushf(prefixes, *p, len, prefix);
+}
+
+/*
  * *string and *len will only be substituted, and *string returned (for
  * later free()ing) if the string passed in is a magic short-hand form
  * to name a branch.
@@ -730,7 +745,7 @@
 	struct strbuf err = STRBUF_INIT;
 
 	if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
-		assert(refs == get_main_ref_store());
+		assert(refs == get_main_ref_store(the_repository));
 		return delete_pseudoref(refname, old_oid);
 	}
 
@@ -752,7 +767,7 @@
 int delete_ref(const char *msg, const char *refname,
 	       const struct object_id *old_oid, unsigned int flags)
 {
-	return refs_delete_ref(get_main_ref_store(), msg, refname,
+	return refs_delete_ref(get_main_ref_store(the_repository), msg, refname,
 			       old_oid, flags);
 }
 
@@ -928,7 +943,7 @@
 
 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
 {
-	return ref_store_transaction_begin(get_main_ref_store(), err);
+	return ref_store_transaction_begin(get_main_ref_store(the_repository), err);
 }
 
 void ref_transaction_free(struct ref_transaction *transaction)
@@ -1060,7 +1075,7 @@
 	int ret = 0;
 
 	if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
-		assert(refs == get_main_ref_store());
+		assert(refs == get_main_ref_store(the_repository));
 		ret = write_pseudoref(refname, new_oid, old_oid, &err);
 	} else {
 		t = ref_store_transaction_begin(refs, &err);
@@ -1099,7 +1114,7 @@
 	       const struct object_id *old_oid,
 	       unsigned int flags, enum action_on_err onerr)
 {
-	return refs_update_ref(get_main_ref_store(), msg, refname, new_oid,
+	return refs_update_ref(get_main_ref_store(the_repository), msg, refname, new_oid,
 			       old_oid, flags, onerr);
 }
 
@@ -1320,7 +1335,7 @@
 
 int head_ref(each_ref_fn fn, void *cb_data)
 {
-	return refs_head_ref(get_main_ref_store(), fn, cb_data);
+	return refs_head_ref(get_main_ref_store(the_repository), fn, cb_data);
 }
 
 struct ref_iterator *refs_ref_iterator_begin(
@@ -1379,7 +1394,7 @@
 
 int for_each_ref(each_ref_fn fn, void *cb_data)
 {
-	return refs_for_each_ref(get_main_ref_store(), fn, cb_data);
+	return refs_for_each_ref(get_main_ref_store(the_repository), fn, cb_data);
 }
 
 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
@@ -1390,7 +1405,7 @@
 
 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
 {
-	return refs_for_each_ref_in(get_main_ref_store(), prefix, fn, cb_data);
+	return refs_for_each_ref_in(get_main_ref_store(the_repository), prefix, fn, cb_data);
 }
 
 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
@@ -1399,7 +1414,7 @@
 
 	if (broken)
 		flag = DO_FOR_EACH_INCLUDE_BROKEN;
-	return do_for_each_ref(get_main_ref_store(),
+	return do_for_each_ref(get_main_ref_store(the_repository),
 			       prefix, fn, 0, flag, cb_data);
 }
 
@@ -1414,9 +1429,9 @@
 	return do_for_each_ref(refs, prefix, fn, 0, flag, cb_data);
 }
 
-int for_each_replace_ref(each_ref_fn fn, void *cb_data)
+int for_each_replace_ref(struct repository *r, each_ref_fn fn, void *cb_data)
 {
-	return do_for_each_ref(get_main_ref_store(),
+	return do_for_each_ref(get_main_ref_store(r),
 			       git_replace_ref_base, fn,
 			       strlen(git_replace_ref_base),
 			       DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
@@ -1427,7 +1442,7 @@
 	struct strbuf buf = STRBUF_INIT;
 	int ret;
 	strbuf_addf(&buf, "%srefs/", get_git_namespace());
-	ret = do_for_each_ref(get_main_ref_store(),
+	ret = do_for_each_ref(get_main_ref_store(the_repository),
 			      buf.buf, fn, 0, 0, cb_data);
 	strbuf_release(&buf);
 	return ret;
@@ -1441,7 +1456,7 @@
 
 int for_each_rawref(each_ref_fn fn, void *cb_data)
 {
-	return refs_for_each_rawref(get_main_ref_store(), fn, cb_data);
+	return refs_for_each_rawref(get_main_ref_store(the_repository), fn, cb_data);
 }
 
 int refs_read_raw_ref(struct ref_store *ref_store,
@@ -1547,7 +1562,7 @@
 /* backend functions */
 int refs_init_db(struct strbuf *err)
 {
-	struct ref_store *refs = get_main_ref_store();
+	struct ref_store *refs = get_main_ref_store(the_repository);
 
 	return refs->be->init_db(refs, err);
 }
@@ -1555,7 +1570,7 @@
 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
 			       struct object_id *oid, int *flags)
 {
-	return refs_resolve_ref_unsafe(get_main_ref_store(), refname,
+	return refs_resolve_ref_unsafe(get_main_ref_store(the_repository), refname,
 				       resolve_flags, oid, flags);
 }
 
@@ -1607,9 +1622,6 @@
 	return entry;
 }
 
-/* A pointer to the ref_store for the main repository: */
-static struct ref_store *main_ref_store;
-
 /* A hashmap of ref_stores, stored by submodule name: */
 static struct hashmap submodule_ref_stores;
 
@@ -1651,13 +1663,13 @@
 	return refs;
 }
 
-struct ref_store *get_main_ref_store(void)
+struct ref_store *get_main_ref_store(struct repository *r)
 {
-	if (main_ref_store)
-		return main_ref_store;
+	if (r->refs)
+		return r->refs;
 
-	main_ref_store = ref_store_init(get_git_dir(), REF_STORE_ALL_CAPS);
-	return main_ref_store;
+	r->refs = ref_store_init(r->gitdir, REF_STORE_ALL_CAPS);
+	return r->refs;
 }
 
 /*
@@ -1726,7 +1738,7 @@
 	const char *id;
 
 	if (wt->is_current)
-		return get_main_ref_store();
+		return get_main_ref_store(the_repository);
 
 	id = wt->id ? wt->id : "/";
 	refs = lookup_ref_store_map(&worktree_ref_stores, id);
@@ -1782,7 +1794,7 @@
 
 int peel_ref(const char *refname, struct object_id *oid)
 {
-	return refs_peel_ref(get_main_ref_store(), refname, oid);
+	return refs_peel_ref(get_main_ref_store(the_repository), refname, oid);
 }
 
 int refs_create_symref(struct ref_store *refs,
@@ -1798,7 +1810,7 @@
 int create_symref(const char *ref_target, const char *refs_heads_master,
 		  const char *logmsg)
 {
-	return refs_create_symref(get_main_ref_store(), ref_target,
+	return refs_create_symref(get_main_ref_store(the_repository), ref_target,
 				  refs_heads_master, logmsg);
 }
 
@@ -2006,7 +2018,7 @@
 
 int for_each_reflog(each_ref_fn fn, void *cb_data)
 {
-	return refs_for_each_reflog(get_main_ref_store(), fn, cb_data);
+	return refs_for_each_reflog(get_main_ref_store(the_repository), fn, cb_data);
 }
 
 int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
@@ -2021,7 +2033,7 @@
 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn,
 				void *cb_data)
 {
-	return refs_for_each_reflog_ent_reverse(get_main_ref_store(),
+	return refs_for_each_reflog_ent_reverse(get_main_ref_store(the_repository),
 						refname, fn, cb_data);
 }
 
@@ -2034,7 +2046,7 @@
 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn,
 			void *cb_data)
 {
-	return refs_for_each_reflog_ent(get_main_ref_store(), refname,
+	return refs_for_each_reflog_ent(get_main_ref_store(the_repository), refname,
 					fn, cb_data);
 }
 
@@ -2045,7 +2057,7 @@
 
 int reflog_exists(const char *refname)
 {
-	return refs_reflog_exists(get_main_ref_store(), refname);
+	return refs_reflog_exists(get_main_ref_store(the_repository), refname);
 }
 
 int refs_create_reflog(struct ref_store *refs, const char *refname,
@@ -2057,7 +2069,7 @@
 int safe_create_reflog(const char *refname, int force_create,
 		       struct strbuf *err)
 {
-	return refs_create_reflog(get_main_ref_store(), refname,
+	return refs_create_reflog(get_main_ref_store(the_repository), refname,
 				  force_create, err);
 }
 
@@ -2068,7 +2080,7 @@
 
 int delete_reflog(const char *refname)
 {
-	return refs_delete_reflog(get_main_ref_store(), refname);
+	return refs_delete_reflog(get_main_ref_store(the_repository), refname);
 }
 
 int refs_reflog_expire(struct ref_store *refs,
@@ -2091,7 +2103,7 @@
 		  reflog_expiry_cleanup_fn cleanup_fn,
 		  void *policy_cb_data)
 {
-	return refs_reflog_expire(get_main_ref_store(),
+	return refs_reflog_expire(get_main_ref_store(the_repository),
 				  refname, oid, flags,
 				  prepare_fn, should_prune_fn,
 				  cleanup_fn, policy_cb_data);
@@ -2114,7 +2126,7 @@
 int delete_refs(const char *msg, struct string_list *refnames,
 		unsigned int flags)
 {
-	return refs_delete_refs(get_main_ref_store(), msg, refnames, flags);
+	return refs_delete_refs(get_main_ref_store(the_repository), msg, refnames, flags);
 }
 
 int refs_rename_ref(struct ref_store *refs, const char *oldref,
@@ -2125,7 +2137,7 @@
 
 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
 {
-	return refs_rename_ref(get_main_ref_store(), oldref, newref, logmsg);
+	return refs_rename_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
 }
 
 int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
@@ -2136,5 +2148,5 @@
 
 int copy_existing_ref(const char *oldref, const char *newref, const char *logmsg)
 {
-	return refs_copy_existing_ref(get_main_ref_store(), oldref, newref, logmsg);
+	return refs_copy_existing_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
 }
diff --git a/refs.h b/refs.h
index 01be5ae..cc2fb4c 100644
--- a/refs.h
+++ b/refs.h
@@ -139,6 +139,13 @@
  */
 int refname_match(const char *abbrev_name, const char *full_name);
 
+/*
+ * Given a 'prefix' expand it by the rules in 'ref_rev_parse_rules' and add
+ * the results to 'prefixes'
+ */
+struct argv_array;
+void expand_ref_prefix(struct argv_array *prefixes, const char *prefix);
+
 int expand_ref(const char *str, int len, struct object_id *oid, char **ref);
 int dwim_ref(const char *str, int len, struct object_id *oid, char **ref);
 int dwim_log(const char *str, int len, struct object_id *oid, char **ref);
@@ -300,7 +307,7 @@
 int for_each_tag_ref(each_ref_fn fn, void *cb_data);
 int for_each_branch_ref(each_ref_fn fn, void *cb_data);
 int for_each_remote_ref(each_ref_fn fn, void *cb_data);
-int for_each_replace_ref(each_ref_fn fn, void *cb_data);
+int for_each_replace_ref(struct repository *r, each_ref_fn fn, void *cb_data);
 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data);
 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
 			 const char *prefix, void *cb_data);
@@ -758,7 +765,7 @@
 
 int ref_storage_backend_exists(const char *name);
 
-struct ref_store *get_main_ref_store(void);
+struct ref_store *get_main_ref_store(struct repository *r);
 /*
  * Return the ref_store instance for the specified submodule. For the
  * main repository, use submodule==NULL; such a call cannot fail. For
diff --git a/refs/files-backend.c b/refs/files-backend.c
index bec8e30..49d8f67 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -9,6 +9,7 @@
 #include "../lockfile.h"
 #include "../object.h"
 #include "../dir.h"
+#include "../chdir-notify.h"
 
 /*
  * This backend uses the following flags in `ref_update::flags` for
@@ -61,10 +62,6 @@
 	struct object_id old_oid;
 };
 
-/*
- * Future: need to be in "struct repository"
- * when doing a full libification.
- */
 struct files_ref_store {
 	struct ref_store base;
 	unsigned int store_flags;
@@ -106,6 +103,11 @@
 	refs->packed_ref_store = packed_ref_store_create(sb.buf, flags);
 	strbuf_release(&sb);
 
+	chdir_notify_reparent("files-backend $GIT_DIR",
+			      &refs->gitdir);
+	chdir_notify_reparent("files-backend $GIT_COMMONDIR",
+			      &refs->gitcommondir);
+
 	return ref_store;
 }
 
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index 65288c6..369c34f 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -5,6 +5,7 @@
 #include "packed-backend.h"
 #include "../iterator.h"
 #include "../lockfile.h"
+#include "../chdir-notify.h"
 
 enum mmap_strategy {
 	/*
@@ -202,6 +203,8 @@
 	refs->store_flags = store_flags;
 
 	refs->path = xstrdup(path);
+	chdir_notify_reparent("packed-refs", &refs->path);
+
 	return ref_store;
 }
 
diff --git a/remote-curl.c b/remote-curl.c
index a7c4c9b..68e7b1c 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -1,10 +1,11 @@
 #include "cache.h"
 #include "config.h"
 #include "remote.h"
+#include "connect.h"
 #include "strbuf.h"
 #include "walker.h"
 #include "http.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "run-command.h"
 #include "pkt-line.h"
 #include "string-list.h"
@@ -13,6 +14,7 @@
 #include "credential.h"
 #include "sha1-array.h"
 #include "send-pack.h"
+#include "protocol.h"
 #include "quote.h"
 
 static struct remote *remote;
@@ -184,12 +186,13 @@
 }
 
 struct discovery {
-	const char *service;
+	char *service;
 	char *buf_alloc;
 	char *buf;
 	size_t len;
 	struct ref *refs;
 	struct oid_array shallow;
+	enum protocol_version version;
 	unsigned proto_git : 1;
 };
 static struct discovery *last_discovery;
@@ -197,8 +200,31 @@
 static struct ref *parse_git_refs(struct discovery *heads, int for_push)
 {
 	struct ref *list = NULL;
-	get_remote_heads(-1, heads->buf, heads->len, &list,
-			 for_push ? REF_NORMAL : 0, NULL, &heads->shallow);
+	struct packet_reader reader;
+
+	packet_reader_init(&reader, -1, heads->buf, heads->len,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_GENTLE_ON_EOF);
+
+	heads->version = discover_version(&reader);
+	switch (heads->version) {
+	case protocol_v2:
+		/*
+		 * Do nothing.  This isn't a list of refs but rather a
+		 * capability advertisement.  Client would have run
+		 * 'stateless-connect' so we'll dump this capability listing
+		 * and let them request the refs themselves.
+		 */
+		break;
+	case protocol_v1:
+	case protocol_v0:
+		get_remote_heads(&reader, &list, for_push ? REF_NORMAL : 0,
+				 NULL, &heads->shallow);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
+
 	return list;
 }
 
@@ -259,6 +285,7 @@
 		free(d->shallow.oid);
 		free(d->buf_alloc);
 		free_refs(d->refs);
+		free(d->service);
 		free(d);
 	}
 }
@@ -290,6 +317,19 @@
 	return 0;
 }
 
+static int get_protocol_http_header(enum protocol_version version,
+				    struct strbuf *header)
+{
+	if (version > 0) {
+		strbuf_addf(header, GIT_PROTOCOL_HEADER ": version=%d",
+			    version);
+
+		return 1;
+	}
+
+	return 0;
+}
+
 static struct discovery *discover_refs(const char *service, int for_push)
 {
 	struct strbuf exp = STRBUF_INIT;
@@ -298,9 +338,12 @@
 	struct strbuf buffer = STRBUF_INIT;
 	struct strbuf refs_url = STRBUF_INIT;
 	struct strbuf effective_url = STRBUF_INIT;
+	struct strbuf protocol_header = STRBUF_INIT;
+	struct string_list extra_headers = STRING_LIST_INIT_DUP;
 	struct discovery *last = last_discovery;
 	int http_ret, maybe_smart = 0;
 	struct http_get_options http_options;
+	enum protocol_version version = get_protocol_version_config();
 
 	if (last && !strcmp(service, last->service))
 		return last;
@@ -317,11 +360,24 @@
 		strbuf_addf(&refs_url, "service=%s", service);
 	}
 
+	/*
+	 * NEEDSWORK: If we are trying to use protocol v2 and we are planning
+	 * to perform a push, then fallback to v0 since the client doesn't know
+	 * how to push yet using v2.
+	 */
+	if (version == protocol_v2 && !strcmp("git-receive-pack", service))
+		version = protocol_v0;
+
+	/* Add the extra Git-Protocol header */
+	if (get_protocol_http_header(version, &protocol_header))
+		string_list_append(&extra_headers, protocol_header.buf);
+
 	memset(&http_options, 0, sizeof(http_options));
 	http_options.content_type = &type;
 	http_options.charset = &charset;
 	http_options.effective_url = &effective_url;
 	http_options.base_url = &url;
+	http_options.extra_headers = &extra_headers;
 	http_options.initial_request = 1;
 	http_options.no_cache = 1;
 	http_options.keep_error = 1;
@@ -345,7 +401,7 @@
 		warning(_("redirecting to %s"), url.buf);
 
 	last= xcalloc(1, sizeof(*last_discovery));
-	last->service = service;
+	last->service = xstrdup(service);
 	last->buf_alloc = strbuf_detach(&buffer, &last->len);
 	last->buf = last->buf_alloc;
 
@@ -377,6 +433,9 @@
 			;
 
 		last->proto_git = 1;
+	} else if (maybe_smart &&
+		   last->len > 5 && starts_with(last->buf + 4, "version 2")) {
+		last->proto_git = 1;
 	}
 
 	if (last->proto_git)
@@ -390,6 +449,8 @@
 	strbuf_release(&charset);
 	strbuf_release(&effective_url);
 	strbuf_release(&buffer);
+	strbuf_release(&protocol_header);
+	string_list_clear(&extra_headers, 0);
 	last_discovery = last;
 	return last;
 }
@@ -426,6 +487,7 @@
 	char *service_url;
 	char *hdr_content_type;
 	char *hdr_accept;
+	char *protocol_header;
 	char *buf;
 	size_t alloc;
 	size_t len;
@@ -612,6 +674,10 @@
 	headers = curl_slist_append(headers, needs_100_continue ?
 		"Expect: 100-continue" : "Expect:");
 
+	/* Add the extra Git-Protocol header */
+	if (rpc->protocol_header)
+		headers = curl_slist_append(headers, rpc->protocol_header);
+
 retry:
 	slot = get_active_slot();
 
@@ -752,6 +818,11 @@
 	strbuf_addf(&buf, "Accept: application/x-%s-result", svc);
 	rpc->hdr_accept = strbuf_detach(&buf, NULL);
 
+	if (get_protocol_http_header(heads->version, &buf))
+		rpc->protocol_header = strbuf_detach(&buf, NULL);
+	else
+		rpc->protocol_header = NULL;
+
 	while (!err) {
 		int n = packet_read(rpc->out, NULL, NULL, rpc->buf, rpc->alloc, 0);
 		if (!n)
@@ -779,6 +850,7 @@
 	free(rpc->service_url);
 	free(rpc->hdr_content_type);
 	free(rpc->hdr_accept);
+	free(rpc->protocol_header);
 	free(rpc->buf);
 	strbuf_release(&buf);
 	return err;
@@ -1056,6 +1128,202 @@
 	free(specs);
 }
 
+/*
+ * Used to represent the state of a connection to an HTTP server when
+ * communicating using git's wire-protocol version 2.
+ */
+struct proxy_state {
+	char *service_name;
+	char *service_url;
+	struct curl_slist *headers;
+	struct strbuf request_buffer;
+	int in;
+	int out;
+	struct packet_reader reader;
+	size_t pos;
+	int seen_flush;
+};
+
+static void proxy_state_init(struct proxy_state *p, const char *service_name,
+			     enum protocol_version version)
+{
+	struct strbuf buf = STRBUF_INIT;
+
+	memset(p, 0, sizeof(*p));
+	p->service_name = xstrdup(service_name);
+
+	p->in = 0;
+	p->out = 1;
+	strbuf_init(&p->request_buffer, 0);
+
+	strbuf_addf(&buf, "%s%s", url.buf, p->service_name);
+	p->service_url = strbuf_detach(&buf, NULL);
+
+	p->headers = http_copy_default_headers();
+
+	strbuf_addf(&buf, "Content-Type: application/x-%s-request", p->service_name);
+	p->headers = curl_slist_append(p->headers, buf.buf);
+	strbuf_reset(&buf);
+
+	strbuf_addf(&buf, "Accept: application/x-%s-result", p->service_name);
+	p->headers = curl_slist_append(p->headers, buf.buf);
+	strbuf_reset(&buf);
+
+	p->headers = curl_slist_append(p->headers, "Transfer-Encoding: chunked");
+
+	/* Add the Git-Protocol header */
+	if (get_protocol_http_header(version, &buf))
+		p->headers = curl_slist_append(p->headers, buf.buf);
+
+	packet_reader_init(&p->reader, p->in, NULL, 0,
+			   PACKET_READ_GENTLE_ON_EOF);
+
+	strbuf_release(&buf);
+}
+
+static void proxy_state_clear(struct proxy_state *p)
+{
+	free(p->service_name);
+	free(p->service_url);
+	curl_slist_free_all(p->headers);
+	strbuf_release(&p->request_buffer);
+}
+
+/*
+ * CURLOPT_READFUNCTION callback function.
+ * Attempts to copy over a single packet-line at a time into the
+ * curl provided buffer.
+ */
+static size_t proxy_in(char *buffer, size_t eltsize,
+		       size_t nmemb, void *userdata)
+{
+	size_t max;
+	struct proxy_state *p = userdata;
+	size_t avail = p->request_buffer.len - p->pos;
+
+
+	if (eltsize != 1)
+		BUG("curl read callback called with size = %"PRIuMAX" != 1",
+		    (uintmax_t)eltsize);
+	max = nmemb;
+
+	if (!avail) {
+		if (p->seen_flush) {
+			p->seen_flush = 0;
+			return 0;
+		}
+
+		strbuf_reset(&p->request_buffer);
+		switch (packet_reader_read(&p->reader)) {
+		case PACKET_READ_EOF:
+			die("unexpected EOF when reading from parent process");
+		case PACKET_READ_NORMAL:
+			packet_buf_write_len(&p->request_buffer, p->reader.line,
+					     p->reader.pktlen);
+			break;
+		case PACKET_READ_DELIM:
+			packet_buf_delim(&p->request_buffer);
+			break;
+		case PACKET_READ_FLUSH:
+			packet_buf_flush(&p->request_buffer);
+			p->seen_flush = 1;
+			break;
+		}
+		p->pos = 0;
+		avail = p->request_buffer.len;
+	}
+
+	if (max < avail)
+		avail = max;
+	memcpy(buffer, p->request_buffer.buf + p->pos, avail);
+	p->pos += avail;
+	return avail;
+}
+
+static size_t proxy_out(char *buffer, size_t eltsize,
+			size_t nmemb, void *userdata)
+{
+	size_t size;
+	struct proxy_state *p = userdata;
+
+	if (eltsize != 1)
+		BUG("curl read callback called with size = %"PRIuMAX" != 1",
+		    (uintmax_t)eltsize);
+	size = nmemb;
+
+	write_or_die(p->out, buffer, size);
+	return size;
+}
+
+/* Issues a request to the HTTP server configured in `p` */
+static int proxy_request(struct proxy_state *p)
+{
+	struct active_request_slot *slot;
+
+	slot = get_active_slot();
+
+	curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
+	curl_easy_setopt(slot->curl, CURLOPT_POST, 1);
+	curl_easy_setopt(slot->curl, CURLOPT_URL, p->service_url);
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, p->headers);
+
+	/* Setup function to read request from client */
+	curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, proxy_in);
+	curl_easy_setopt(slot->curl, CURLOPT_READDATA, p);
+
+	/* Setup function to write server response to client */
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, proxy_out);
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEDATA, p);
+
+	if (run_slot(slot, NULL) != HTTP_OK)
+		return -1;
+
+	return 0;
+}
+
+static int stateless_connect(const char *service_name)
+{
+	struct discovery *discover;
+	struct proxy_state p;
+
+	/*
+	 * Run the info/refs request and see if the server supports protocol
+	 * v2.  If and only if the server supports v2 can we successfully
+	 * establish a stateless connection, otherwise we need to tell the
+	 * client to fallback to using other transport helper functions to
+	 * complete their request.
+	 */
+	discover = discover_refs(service_name, 0);
+	if (discover->version != protocol_v2) {
+		printf("fallback\n");
+		fflush(stdout);
+		return -1;
+	} else {
+		/* Stateless Connection established */
+		printf("\n");
+		fflush(stdout);
+	}
+
+	proxy_state_init(&p, service_name, discover->version);
+
+	/*
+	 * Dump the capability listing that we got from the server earlier
+	 * during the info/refs request.
+	 */
+	write_or_die(p.out, discover->buf, discover->len);
+
+	/* Peek the next packet line.  Until we see EOF keep sending POSTs */
+	while (packet_reader_peek(&p.reader) != PACKET_READ_EOF) {
+		if (proxy_request(&p)) {
+			/* We would have an err here */
+			break;
+		}
+	}
+
+	proxy_state_clear(&p);
+	return 0;
+}
+
 int cmd_main(int argc, const char **argv)
 {
 	struct strbuf buf = STRBUF_INIT;
@@ -1124,12 +1392,16 @@
 			fflush(stdout);
 
 		} else if (!strcmp(buf.buf, "capabilities")) {
+			printf("stateless-connect\n");
 			printf("fetch\n");
 			printf("option\n");
 			printf("push\n");
 			printf("check-connectivity\n");
 			printf("\n");
 			fflush(stdout);
+		} else if (skip_prefix(buf.buf, "stateless-connect ", &arg)) {
+			if (!stateless_connect(arg))
+				break;
 		} else {
 			error("remote-curl: unknown command '%s' from git", buf.buf);
 			return 1;
diff --git a/remote-testsvn.c b/remote-testsvn.c
index c4bb9a8..444d980 100644
--- a/remote-testsvn.c
+++ b/remote-testsvn.c
@@ -3,7 +3,7 @@
 #include "remote.h"
 #include "strbuf.h"
 #include "url.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "run-command.h"
 #include "vcs-svn/svndump.h"
 #include "notes.h"
diff --git a/remote.h b/remote.h
index f09c019..2b3180f 100644
--- a/remote.h
+++ b/remote.h
@@ -151,10 +151,17 @@
 void free_refs(struct ref *ref);
 
 struct oid_array;
-extern struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
+struct packet_reader;
+struct argv_array;
+extern struct ref **get_remote_heads(struct packet_reader *reader,
 				     struct ref **list, unsigned int flags,
 				     struct oid_array *extra_have,
-				     struct oid_array *shallow);
+				     struct oid_array *shallow_points);
+
+/* Used for protocol v2 in order to retrieve refs from a remote */
+extern struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
+				    struct ref **list, int for_push,
+				    const struct argv_array *ref_prefixes);
 
 int resolve_remote_symref(struct ref *ref, struct ref *list);
 int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid);
diff --git a/replace-object.c b/replace-object.c
new file mode 100644
index 0000000..246b98c
--- /dev/null
+++ b/replace-object.c
@@ -0,0 +1,73 @@
+#include "cache.h"
+#include "oidmap.h"
+#include "object-store.h"
+#include "replace-object.h"
+#include "refs.h"
+#include "repository.h"
+#include "commit.h"
+
+static int register_replace_ref(const char *refname,
+				const struct object_id *oid,
+				int flag, void *cb_data)
+{
+	/* Get sha1 from refname */
+	const char *slash = strrchr(refname, '/');
+	const char *hash = slash ? slash + 1 : refname;
+	struct replace_object *repl_obj = xmalloc(sizeof(*repl_obj));
+
+	if (get_oid_hex(hash, &repl_obj->original.oid)) {
+		free(repl_obj);
+		warning("bad replace ref name: %s", refname);
+		return 0;
+	}
+
+	/* Copy sha1 from the read ref */
+	oidcpy(&repl_obj->replacement, oid);
+
+	/* Register new object */
+	if (oidmap_put(the_repository->objects->replace_map, repl_obj))
+		die("duplicate replace ref: %s", refname);
+
+	return 0;
+}
+
+static void prepare_replace_object(struct repository *r)
+{
+	if (r->objects->replace_map)
+		return;
+
+	r->objects->replace_map =
+		xmalloc(sizeof(*the_repository->objects->replace_map));
+	oidmap_init(r->objects->replace_map, 0);
+
+	for_each_replace_ref(r, register_replace_ref, NULL);
+}
+
+/* We allow "recursive" replacement. Only within reason, though */
+#define MAXREPLACEDEPTH 5
+
+/*
+ * If a replacement for object oid has been set up, return the
+ * replacement object's name (replaced recursively, if necessary).
+ * The return value is either oid or a pointer to a
+ * permanently-allocated value.  This function always respects replace
+ * references, regardless of the value of check_replace_refs.
+ */
+const struct object_id *do_lookup_replace_object(struct repository *r,
+						 const struct object_id *oid)
+{
+	int depth = MAXREPLACEDEPTH;
+	const struct object_id *cur = oid;
+
+	prepare_replace_object(r);
+
+	/* Try to recursively replace the object */
+	while (depth-- > 0) {
+		struct replace_object *repl_obj =
+			oidmap_get(r->objects->replace_map, cur);
+		if (!repl_obj)
+			return cur;
+		cur = &repl_obj->replacement;
+	}
+	die("replace depth too high for object %s", oid_to_hex(oid));
+}
diff --git a/replace-object.h b/replace-object.h
new file mode 100644
index 0000000..f996de3
--- /dev/null
+++ b/replace-object.h
@@ -0,0 +1,36 @@
+#ifndef REPLACE_OBJECT_H
+#define REPLACE_OBJECT_H
+
+#include "oidmap.h"
+#include "repository.h"
+#include "object-store.h"
+
+struct replace_object {
+	struct oidmap_entry original;
+	struct object_id replacement;
+};
+
+/*
+ * This internal function is only declared here for the benefit of
+ * lookup_replace_object().  Please do not call it directly.
+ */
+extern const struct object_id *do_lookup_replace_object(struct repository *r,
+							const struct object_id *oid);
+
+/*
+ * If object sha1 should be replaced, return the replacement object's
+ * name (replaced recursively, if necessary).  The return value is
+ * either sha1 or a pointer to a permanently-allocated value.  When
+ * object replacement is suppressed, always return sha1.
+ */
+static inline const struct object_id *lookup_replace_object(struct repository *r,
+							    const struct object_id *oid)
+{
+	if (!check_replace_refs ||
+	    (r->objects->replace_map &&
+	     r->objects->replace_map->map.tablesize == 0))
+		return oid;
+	return do_lookup_replace_object(r, oid);
+}
+
+#endif /* REPLACE_OBJECT_H */
diff --git a/replace_object.c b/replace_object.c
deleted file mode 100644
index 3363573..0000000
--- a/replace_object.c
+++ /dev/null
@@ -1,120 +0,0 @@
-#include "cache.h"
-#include "sha1-lookup.h"
-#include "refs.h"
-#include "commit.h"
-
-/*
- * An array of replacements.  The array is kept sorted by the original
- * sha1.
- */
-static struct replace_object {
-	struct object_id original;
-	struct object_id replacement;
-} **replace_object;
-
-static int replace_object_alloc, replace_object_nr;
-
-static const unsigned char *replace_sha1_access(size_t index, void *table)
-{
-	struct replace_object **replace = table;
-	return replace[index]->original.hash;
-}
-
-static int replace_object_pos(const unsigned char *sha1)
-{
-	return sha1_pos(sha1, replace_object, replace_object_nr,
-			replace_sha1_access);
-}
-
-static int register_replace_object(struct replace_object *replace,
-				   int ignore_dups)
-{
-	int pos = replace_object_pos(replace->original.hash);
-
-	if (0 <= pos) {
-		if (ignore_dups)
-			free(replace);
-		else {
-			free(replace_object[pos]);
-			replace_object[pos] = replace;
-		}
-		return 1;
-	}
-	pos = -pos - 1;
-	ALLOC_GROW(replace_object, replace_object_nr + 1, replace_object_alloc);
-	replace_object_nr++;
-	if (pos < replace_object_nr)
-		MOVE_ARRAY(replace_object + pos + 1, replace_object + pos,
-			   replace_object_nr - pos - 1);
-	replace_object[pos] = replace;
-	return 0;
-}
-
-static int register_replace_ref(const char *refname,
-				const struct object_id *oid,
-				int flag, void *cb_data)
-{
-	/* Get sha1 from refname */
-	const char *slash = strrchr(refname, '/');
-	const char *hash = slash ? slash + 1 : refname;
-	struct replace_object *repl_obj = xmalloc(sizeof(*repl_obj));
-
-	if (get_oid_hex(hash, &repl_obj->original)) {
-		free(repl_obj);
-		warning("bad replace ref name: %s", refname);
-		return 0;
-	}
-
-	/* Copy sha1 from the read ref */
-	oidcpy(&repl_obj->replacement, oid);
-
-	/* Register new object */
-	if (register_replace_object(repl_obj, 1))
-		die("duplicate replace ref: %s", refname);
-
-	return 0;
-}
-
-static void prepare_replace_object(void)
-{
-	static int replace_object_prepared;
-
-	if (replace_object_prepared)
-		return;
-
-	for_each_replace_ref(register_replace_ref, NULL);
-	replace_object_prepared = 1;
-	if (!replace_object_nr)
-		check_replace_refs = 0;
-}
-
-/* We allow "recursive" replacement. Only within reason, though */
-#define MAXREPLACEDEPTH 5
-
-/*
- * If a replacement for object oid has been set up, return the
- * replacement object's name (replaced recursively, if necessary).
- * The return value is either oid or a pointer to a
- * permanently-allocated value.  This function always respects replace
- * references, regardless of the value of check_replace_refs.
- */
-const struct object_id *do_lookup_replace_object(const struct object_id *oid)
-{
-	int pos, depth = MAXREPLACEDEPTH;
-	const struct object_id *cur = oid;
-
-	prepare_replace_object();
-
-	/* Try to recursively replace the object */
-	do {
-		if (--depth < 0)
-			die("replace depth too high for object %s",
-			    oid_to_hex(oid));
-
-		pos = replace_object_pos(cur->hash);
-		if (0 <= pos)
-			cur = &replace_object[pos]->replacement;
-	} while (0 <= pos);
-
-	return cur;
-}
diff --git a/repository.c b/repository.c
index a4848c1..beff3ca 100644
--- a/repository.c
+++ b/repository.c
@@ -135,9 +135,9 @@
  * Initialize 'repo' based on the provided 'gitdir'.
  * Return 0 upon success and a non-zero value upon failure.
  */
-static int repo_init(struct repository *repo,
-		     const char *gitdir,
-		     const char *worktree)
+int repo_init(struct repository *repo,
+	      const char *gitdir,
+	      const char *worktree)
 {
 	struct repository_format format;
 	memset(repo, 0, sizeof(*repo));
@@ -176,7 +176,7 @@
 	struct strbuf worktree = STRBUF_INIT;
 	int ret = 0;
 
-	sub = submodule_from_cache(superproject, &null_oid, path);
+	sub = submodule_from_path(superproject, &null_oid, path);
 	if (!sub) {
 		ret = -1;
 		goto out;
diff --git a/repository.h b/repository.h
index 09df94a..f2646f0 100644
--- a/repository.h
+++ b/repository.h
@@ -26,6 +26,9 @@
 	 */
 	struct raw_object_store *objects;
 
+	/* The store in which the refs are held. */
+	struct ref_store *refs;
+
 	/*
 	 * Path to the repository's graft file.
 	 * Cannot be NULL after initialization.
@@ -97,6 +100,9 @@
 extern void repo_set_worktree(struct repository *repo, const char *path);
 extern void repo_set_hash_algo(struct repository *repo, int algo);
 extern void initialize_the_repository(void);
+extern int repo_init(struct repository *r,
+		     const char *gitdir,
+		     const char *worktree);
 extern int repo_submodule_init(struct repository *submodule,
 			       struct repository *superproject,
 			       const char *path);
diff --git a/revision.c b/revision.c
index b42c836..1cff118 100644
--- a/revision.c
+++ b/revision.c
@@ -6,6 +6,7 @@
 #include "diff.h"
 #include "refs.h"
 #include "revision.h"
+#include "repository.h"
 #include "graph.h"
 #include "grep.h"
 #include "reflog-walk.h"
@@ -1285,7 +1286,7 @@
 
 	cb.all_revs = revs;
 	cb.all_flags = flags;
-	cb.refs = get_main_ref_store();
+	cb.refs = get_main_ref_store(the_repository);
 	for_each_reflog(handle_one_reflog, &cb);
 
 	if (!revs->single_worktree)
@@ -2176,7 +2177,7 @@
 			die("BUG: --single-worktree cannot be used together with submodule");
 		refs = get_submodule_ref_store(submodule);
 	} else
-		refs = get_main_ref_store();
+		refs = get_main_ref_store(the_repository);
 
 	/*
 	 * NOTE!
diff --git a/run-command.c b/run-command.c
index 84899e4..12c94c1 100644
--- a/run-command.c
+++ b/run-command.c
@@ -1,6 +1,6 @@
 #include "cache.h"
 #include "run-command.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "sigchain.h"
 #include "argv-array.h"
 #include "thread-utils.h"
diff --git a/sequencer.c b/sequencer.c
index 667f35e..4ce5120 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -7,7 +7,7 @@
 #include "sequencer.h"
 #include "tag.h"
 #include "run-command.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "utf8.h"
 #include "cache-tree.h"
 #include "diff.h"
@@ -127,6 +127,7 @@
 static GIT_PATH_FUNC(rebase_path_gpg_sign_opt, "rebase-merge/gpg_sign_opt")
 static GIT_PATH_FUNC(rebase_path_orig_head, "rebase-merge/orig-head")
 static GIT_PATH_FUNC(rebase_path_verbose, "rebase-merge/verbose")
+static GIT_PATH_FUNC(rebase_path_signoff, "rebase-merge/signoff")
 static GIT_PATH_FUNC(rebase_path_head_name, "rebase-merge/head-name")
 static GIT_PATH_FUNC(rebase_path_onto, "rebase-merge/onto")
 static GIT_PATH_FUNC(rebase_path_autostash, "rebase-merge/autostash")
@@ -1148,6 +1149,8 @@
 		goto out;
 	}
 
+	reset_ident_date();
+
 	if (commit_tree_extended(msg->buf, msg->len, &tree, parents,
 				 oid, author, opts->gpg_sign, extra)) {
 		res = error(_("failed to write commit object"));
@@ -1604,7 +1607,7 @@
 		}
 	}
 
-	if (opts->signoff)
+	if (opts->signoff && !is_fixup(command))
 		append_signoff(&msgbuf, 0, 0);
 
 	if (is_rebase_i(opts) && write_author_script(msg.message) < 0)
@@ -2043,6 +2046,11 @@
 		if (file_exists(rebase_path_verbose()))
 			opts->verbose = 1;
 
+		if (file_exists(rebase_path_signoff())) {
+			opts->allow_ff = 0;
+			opts->signoff = 1;
+		}
+
 		read_strategy_opts(opts, &buf);
 		strbuf_release(&buf);
 
@@ -3001,7 +3009,7 @@
 	init_revisions(&revs, NULL);
 	revs.verbose_header = 1;
 	revs.max_parents = 1;
-	revs.cherry_pick = 1;
+	revs.cherry_mark = 1;
 	revs.limited = 1;
 	revs.reverse = 1;
 	revs.right_only = 1;
@@ -3026,8 +3034,12 @@
 		return error(_("make_script: error preparing revisions"));
 
 	while ((commit = get_revision(&revs))) {
+		int is_empty  = is_original_commit_empty(commit);
+
+		if (!is_empty && (commit->object.flags & PATCHSAME))
+			continue;
 		strbuf_reset(&buf);
-		if (!keep_empty && is_original_commit_empty(commit))
+		if (!keep_empty && is_empty)
 			strbuf_addf(&buf, "%c ", comment_line_char);
 		strbuf_addf(&buf, "%s %s ", insn,
 			    oid_to_hex(&commit->object.oid));
diff --git a/serve.c b/serve.c
new file mode 100644
index 0000000..a5a7b2f
--- /dev/null
+++ b/serve.c
@@ -0,0 +1,257 @@
+#include "cache.h"
+#include "repository.h"
+#include "config.h"
+#include "pkt-line.h"
+#include "version.h"
+#include "argv-array.h"
+#include "ls-refs.h"
+#include "serve.h"
+#include "upload-pack.h"
+
+static int always_advertise(struct repository *r,
+			    struct strbuf *value)
+{
+	return 1;
+}
+
+static int agent_advertise(struct repository *r,
+			   struct strbuf *value)
+{
+	if (value)
+		strbuf_addstr(value, git_user_agent_sanitized());
+	return 1;
+}
+
+struct protocol_capability {
+	/*
+	 * The name of the capability.  The server uses this name when
+	 * advertising this capability, and the client uses this name to
+	 * specify this capability.
+	 */
+	const char *name;
+
+	/*
+	 * Function queried to see if a capability should be advertised.
+	 * Optionally a value can be specified by adding it to 'value'.
+	 * If a value is added to 'value', the server will advertise this
+	 * capability as "<name>=<value>" instead of "<name>".
+	 */
+	int (*advertise)(struct repository *r, struct strbuf *value);
+
+	/*
+	 * Function called when a client requests the capability as a command.
+	 * The function will be provided the capabilities requested via 'keys'
+	 * as well as a struct packet_reader 'request' which the command should
+	 * use to read the command specific part of the request.  Every command
+	 * MUST read until a flush packet is seen before sending a response.
+	 *
+	 * This field should be NULL for capabilities which are not commands.
+	 */
+	int (*command)(struct repository *r,
+		       struct argv_array *keys,
+		       struct packet_reader *request);
+};
+
+static struct protocol_capability capabilities[] = {
+	{ "agent", agent_advertise, NULL },
+	{ "ls-refs", always_advertise, ls_refs },
+	{ "fetch", upload_pack_advertise, upload_pack_v2 },
+};
+
+static void advertise_capabilities(void)
+{
+	struct strbuf capability = STRBUF_INIT;
+	struct strbuf value = STRBUF_INIT;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(capabilities); i++) {
+		struct protocol_capability *c = &capabilities[i];
+
+		if (c->advertise(the_repository, &value)) {
+			strbuf_addstr(&capability, c->name);
+
+			if (value.len) {
+				strbuf_addch(&capability, '=');
+				strbuf_addbuf(&capability, &value);
+			}
+
+			strbuf_addch(&capability, '\n');
+			packet_write(1, capability.buf, capability.len);
+		}
+
+		strbuf_reset(&capability);
+		strbuf_reset(&value);
+	}
+
+	packet_flush(1);
+	strbuf_release(&capability);
+	strbuf_release(&value);
+}
+
+static struct protocol_capability *get_capability(const char *key)
+{
+	int i;
+
+	if (!key)
+		return NULL;
+
+	for (i = 0; i < ARRAY_SIZE(capabilities); i++) {
+		struct protocol_capability *c = &capabilities[i];
+		const char *out;
+		if (skip_prefix(key, c->name, &out) && (!*out || *out == '='))
+			return c;
+	}
+
+	return NULL;
+}
+
+static int is_valid_capability(const char *key)
+{
+	const struct protocol_capability *c = get_capability(key);
+
+	return c && c->advertise(the_repository, NULL);
+}
+
+static int is_command(const char *key, struct protocol_capability **command)
+{
+	const char *out;
+
+	if (skip_prefix(key, "command=", &out)) {
+		struct protocol_capability *cmd = get_capability(out);
+
+		if (*command)
+			die("command '%s' requested after already requesting command '%s'",
+			    out, (*command)->name);
+		if (!cmd || !cmd->advertise(the_repository, NULL) || !cmd->command)
+			die("invalid command '%s'", out);
+
+		*command = cmd;
+		return 1;
+	}
+
+	return 0;
+}
+
+int has_capability(const struct argv_array *keys, const char *capability,
+		   const char **value)
+{
+	int i;
+	for (i = 0; i < keys->argc; i++) {
+		const char *out;
+		if (skip_prefix(keys->argv[i], capability, &out) &&
+		    (!*out || *out == '=')) {
+			if (value) {
+				if (*out == '=')
+					out++;
+				*value = out;
+			}
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+enum request_state {
+	PROCESS_REQUEST_KEYS,
+	PROCESS_REQUEST_DONE,
+};
+
+static int process_request(void)
+{
+	enum request_state state = PROCESS_REQUEST_KEYS;
+	struct packet_reader reader;
+	struct argv_array keys = ARGV_ARRAY_INIT;
+	struct protocol_capability *command = NULL;
+
+	packet_reader_init(&reader, 0, NULL, 0,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_GENTLE_ON_EOF);
+
+	/*
+	 * Check to see if the client closed their end before sending another
+	 * request.  If so we can terminate the connection.
+	 */
+	if (packet_reader_peek(&reader) == PACKET_READ_EOF)
+		return 1;
+	reader.options = PACKET_READ_CHOMP_NEWLINE;
+
+	while (state != PROCESS_REQUEST_DONE) {
+		switch (packet_reader_peek(&reader)) {
+		case PACKET_READ_EOF:
+			BUG("Should have already died when seeing EOF");
+		case PACKET_READ_NORMAL:
+			/* collect request; a sequence of keys and values */
+			if (is_command(reader.line, &command) ||
+			    is_valid_capability(reader.line))
+				argv_array_push(&keys, reader.line);
+			else
+				die("unknown capability '%s'", reader.line);
+
+			/* Consume the peeked line */
+			packet_reader_read(&reader);
+			break;
+		case PACKET_READ_FLUSH:
+			/*
+			 * If no command and no keys were given then the client
+			 * wanted to terminate the connection.
+			 */
+			if (!keys.argc)
+				return 1;
+
+			/*
+			 * The flush packet isn't consume here like it is in
+			 * the other parts of this switch statement.  This is
+			 * so that the command can read the flush packet and
+			 * see the end of the request in the same way it would
+			 * if command specific arguments were provided after a
+			 * delim packet.
+			 */
+			state = PROCESS_REQUEST_DONE;
+			break;
+		case PACKET_READ_DELIM:
+			/* Consume the peeked line */
+			packet_reader_read(&reader);
+
+			state = PROCESS_REQUEST_DONE;
+			break;
+		}
+	}
+
+	if (!command)
+		die("no command requested");
+
+	command->command(the_repository, &keys, &reader);
+
+	argv_array_clear(&keys);
+	return 0;
+}
+
+/* Main serve loop for protocol version 2 */
+void serve(struct serve_options *options)
+{
+	if (options->advertise_capabilities || !options->stateless_rpc) {
+		/* serve by default supports v2 */
+		packet_write_fmt(1, "version 2\n");
+
+		advertise_capabilities();
+		/*
+		 * If only the list of capabilities was requested exit
+		 * immediately after advertising capabilities
+		 */
+		if (options->advertise_capabilities)
+			return;
+	}
+
+	/*
+	 * If stateless-rpc was requested then exit after
+	 * a single request/response exchange
+	 */
+	if (options->stateless_rpc) {
+		process_request();
+	} else {
+		for (;;)
+			if (process_request())
+				break;
+	}
+}
diff --git a/serve.h b/serve.h
new file mode 100644
index 0000000..fe65ba9
--- /dev/null
+++ b/serve.h
@@ -0,0 +1,15 @@
+#ifndef SERVE_H
+#define SERVE_H
+
+struct argv_array;
+extern int has_capability(const struct argv_array *keys, const char *capability,
+			  const char **value);
+
+struct serve_options {
+	unsigned advertise_capabilities;
+	unsigned stateless_rpc;
+};
+#define SERVE_OPTIONS_INIT { 0 }
+extern void serve(struct serve_options *options);
+
+#endif /* SERVE_H */
diff --git a/setup.c b/setup.c
index 664453f..3e03d44 100644
--- a/setup.c
+++ b/setup.c
@@ -3,6 +3,7 @@
 #include "config.h"
 #include "dir.h"
 #include "string-list.h"
+#include "chdir-notify.h"
 
 static int inside_git_dir = -1;
 static int inside_work_tree = -1;
@@ -378,7 +379,7 @@
 
 void setup_work_tree(void)
 {
-	const char *work_tree, *git_dir;
+	const char *work_tree;
 	static int initialized = 0;
 
 	if (initialized)
@@ -388,10 +389,7 @@
 		die(_("unable to set up work tree using invalid config"));
 
 	work_tree = get_git_work_tree();
-	git_dir = get_git_dir();
-	if (!is_absolute_path(git_dir))
-		git_dir = real_path(get_git_dir());
-	if (!work_tree || chdir(work_tree))
+	if (!work_tree || chdir_notify(work_tree))
 		die(_("this operation must be run in a work tree"));
 
 	/*
@@ -401,7 +399,6 @@
 	if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 		setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 
-	set_git_dir(remove_leading_path(git_dir, work_tree));
 	initialized = 1;
 }
 
diff --git a/sha1_file.c b/sha1-file.c
similarity index 99%
rename from sha1_file.c
rename to sha1-file.c
index 77ccaab..4607260 100644
--- a/sha1_file.c
+++ b/sha1-file.c
@@ -23,6 +23,7 @@
 #include "sha1-lookup.h"
 #include "bulk-checkin.h"
 #include "repository.h"
+#include "replace-object.h"
 #include "streaming.h"
 #include "dir.h"
 #include "list.h"
@@ -141,7 +142,7 @@
 	if (flags & HASH_RENORMALIZE)
 		return CONV_EOL_RENORMALIZE;
 	else if (flags & HASH_WRITE_OBJECT)
-	  return global_conv_flags_eol;
+		return global_conv_flags_eol | CONV_WRITE_OBJECT;
 	else
 		return 0;
 }
@@ -1239,7 +1240,7 @@
 	int already_retried = 0;
 
 	if (flags & OBJECT_INFO_LOOKUP_REPLACE)
-		real = lookup_replace_object(oid);
+		real = lookup_replace_object(the_repository, oid);
 
 	if (is_null_oid(real))
 		return -1;
@@ -1383,8 +1384,8 @@
 	const struct packed_git *p;
 	const char *path;
 	struct stat st;
-	const struct object_id *repl = lookup_replace ? lookup_replace_object(oid)
-						      : oid;
+	const struct object_id *repl = lookup_replace ?
+		lookup_replace_object(the_repository, oid) : oid;
 
 	errno = 0;
 	data = read_object(repl->hash, type, size);
diff --git a/sha1_name.c b/sha1-name.c
similarity index 100%
rename from sha1_name.c
rename to sha1-name.c
diff --git a/shell.c b/shell.c
index 234b2d4..0200d10 100644
--- a/shell.c
+++ b/shell.c
@@ -1,6 +1,6 @@
 #include "cache.h"
 #include "quote.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "strbuf.h"
 #include "run-command.h"
 
diff --git a/strbuf.c b/strbuf.c
index 43a840c..622c462 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -11,6 +11,15 @@
 			return 0;
 }
 
+int istarts_with(const char *str, const char *prefix)
+{
+	for (; ; str++, prefix++)
+		if (!*prefix)
+			return 1;
+		else if (tolower(*str) != tolower(*prefix))
+			return 0;
+}
+
 int skip_to_optional_arg_default(const char *str, const char *prefix,
 				 const char **arg, const char *def)
 {
@@ -793,7 +802,18 @@
 	result = xmallocz(len);
 	for (i = 0; i < len; i++)
 		result[i] = tolower(string[i]);
-	result[i] = '\0';
+	return result;
+}
+
+char *xstrdup_toupper(const char *string)
+{
+	char *result;
+	size_t len, i;
+
+	len = strlen(string);
+	result = xmallocz(len);
+	for (i = 0; i < len; i++)
+		result[i] = toupper(string[i]);
 	return result;
 }
 
diff --git a/strbuf.h b/strbuf.h
index 4efa80c..8c25e4b 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -616,6 +616,7 @@
 extern int fprintf_ln(FILE *fp, const char *fmt, ...);
 
 char *xstrdup_tolower(const char *);
+char *xstrdup_toupper(const char *);
 
 /**
  * Create a newly allocated string using printf format. You can do this easily
diff --git a/streaming.c b/streaming.c
index 7d55ba6..cce7b17 100644
--- a/streaming.c
+++ b/streaming.c
@@ -5,6 +5,7 @@
 #include "streaming.h"
 #include "repository.h"
 #include "object-store.h"
+#include "replace-object.h"
 #include "packfile.h"
 
 enum input_source {
@@ -139,7 +140,7 @@
 {
 	struct git_istream *st;
 	struct object_info oi = OBJECT_INFO_INIT;
-	const struct object_id *real = lookup_replace_object(oid);
+	const struct object_id *real = lookup_replace_object(the_repository, oid);
 	enum input_source src = istream_source(real, type, &oi);
 
 	if (src < 0)
diff --git a/submodule-config.c b/submodule-config.c
index 3f20757..d87c3ff 100644
--- a/submodule-config.c
+++ b/submodule-config.c
@@ -619,31 +619,24 @@
 		repo_read_gitmodules(repo);
 }
 
-const struct submodule *submodule_from_name(const struct object_id *treeish_name,
+const struct submodule *submodule_from_name(struct repository *r,
+					    const struct object_id *treeish_name,
 		const char *name)
 {
-	gitmodules_read_check(the_repository);
-	return config_from(the_repository->submodule_cache, treeish_name, name, lookup_name);
+	gitmodules_read_check(r);
+	return config_from(r->submodule_cache, treeish_name, name, lookup_name);
 }
 
-const struct submodule *submodule_from_path(const struct object_id *treeish_name,
+const struct submodule *submodule_from_path(struct repository *r,
+					    const struct object_id *treeish_name,
 		const char *path)
 {
-	gitmodules_read_check(the_repository);
-	return config_from(the_repository->submodule_cache, treeish_name, path, lookup_path);
+	gitmodules_read_check(r);
+	return config_from(r->submodule_cache, treeish_name, path, lookup_path);
 }
 
-const struct submodule *submodule_from_cache(struct repository *repo,
-					     const struct object_id *treeish_name,
-					     const char *key)
+void submodule_free(struct repository *r)
 {
-	gitmodules_read_check(repo);
-	return config_from(repo->submodule_cache, treeish_name,
-			   key, lookup_path);
-}
-
-void submodule_free(void)
-{
-	if (the_repository->submodule_cache)
-		submodule_cache_clear(the_repository->submodule_cache);
+	if (r->submodule_cache)
+		submodule_cache_clear(r->submodule_cache);
 }
diff --git a/submodule-config.h b/submodule-config.h
index a5503a5..6f68618 100644
--- a/submodule-config.h
+++ b/submodule-config.h
@@ -39,13 +39,12 @@
 extern int parse_push_recurse_submodules_arg(const char *opt, const char *arg);
 extern void repo_read_gitmodules(struct repository *repo);
 extern void gitmodules_config_oid(const struct object_id *commit_oid);
-extern const struct submodule *submodule_from_name(
-		const struct object_id *commit_or_tree, const char *name);
-extern const struct submodule *submodule_from_path(
-		const struct object_id *commit_or_tree, const char *path);
-extern const struct submodule *submodule_from_cache(struct repository *repo,
-						    const struct object_id *treeish_name,
-						    const char *key);
-extern void submodule_free(void);
+const struct submodule *submodule_from_name(struct repository *r,
+					    const struct object_id *commit_or_tree,
+					    const char *name);
+const struct submodule *submodule_from_path(struct repository *r,
+					    const struct object_id *commit_or_tree,
+					    const char *path);
+void submodule_free(struct repository *r);
 
 #endif /* SUBMODULE_CONFIG_H */
diff --git a/submodule.c b/submodule.c
index 9a50168..74d35b2 100644
--- a/submodule.c
+++ b/submodule.c
@@ -96,7 +96,7 @@
 	if (is_gitmodules_unmerged(&the_index))
 		die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
 
-	submodule = submodule_from_path(&null_oid, oldpath);
+	submodule = submodule_from_path(the_repository, &null_oid, oldpath);
 	if (!submodule || !submodule->name) {
 		warning(_("Could not find section in .gitmodules where path=%s"), oldpath);
 		return -1;
@@ -130,7 +130,7 @@
 	if (is_gitmodules_unmerged(&the_index))
 		die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
 
-	submodule = submodule_from_path(&null_oid, path);
+	submodule = submodule_from_path(the_repository, &null_oid, path);
 	if (!submodule || !submodule->name) {
 		warning(_("Could not find section in .gitmodules where path=%s"), path);
 		return -1;
@@ -174,7 +174,8 @@
 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 					     const char *path)
 {
-	const struct submodule *submodule = submodule_from_path(&null_oid, path);
+	const struct submodule *submodule = submodule_from_path(the_repository,
+								&null_oid, path);
 	if (submodule) {
 		const char *ignore;
 		char *key;
@@ -230,7 +231,7 @@
 	const struct string_list *sl;
 	const struct submodule *module;
 
-	module = submodule_from_cache(repo, &null_oid, path);
+	module = submodule_from_path(repo, &null_oid, path);
 
 	/* early return if there isn't a path->module mapping */
 	if (!module)
@@ -674,7 +675,7 @@
 	if (!should_update_submodules())
 		return NULL;
 
-	return submodule_from_path(&null_oid, ce->name);
+	return submodule_from_path(the_repository, &null_oid, ce->name);
 }
 
 static struct oid_array *submodule_commits(struct string_list *submodules,
@@ -731,13 +732,14 @@
 		if (!S_ISGITLINK(p->two->mode))
 			continue;
 
-		submodule = submodule_from_path(commit_oid, p->two->path);
+		submodule = submodule_from_path(the_repository,
+						commit_oid, p->two->path);
 		if (submodule)
 			name = submodule->name;
 		else {
 			name = default_name_or_path(p->two->path);
 			/* make sure name does not collide with existing one */
-			submodule = submodule_from_name(commit_oid, name);
+			submodule = submodule_from_name(the_repository, commit_oid, name);
 			if (submodule) {
 				warning("Submodule in commit %s at path: "
 					"'%s' collides with a submodule named "
@@ -945,7 +947,7 @@
 		const struct submodule *submodule;
 		const char *path = NULL;
 
-		submodule = submodule_from_name(&null_oid, name->string);
+		submodule = submodule_from_name(the_repository, &null_oid, name->string);
 		if (submodule)
 			path = submodule->path;
 		else
@@ -1113,7 +1115,7 @@
 	const struct string_list_item *name;
 
 	/* No need to check if there are no submodules configured */
-	if (!submodule_from_path(NULL, NULL))
+	if (!submodule_from_path(the_repository, NULL, NULL))
 		return;
 
 	argv_array_push(&argv, "--"); /* argv[0] program name */
@@ -1134,7 +1136,7 @@
 		const struct submodule *submodule;
 		const char *path = NULL;
 
-		submodule = submodule_from_name(&null_oid, name->string);
+		submodule = submodule_from_name(the_repository, &null_oid, name->string);
 		if (submodule)
 			path = submodule->path;
 		else
@@ -1162,7 +1164,7 @@
 	int ret;
 
 	/* No need to check if there are no submodules configured */
-	if (!submodule_from_path(NULL, NULL))
+	if (!submodule_from_path(the_repository, NULL, NULL))
 		return 0;
 
 	argv_array_push(&args, "--"); /* args[0] program name */
@@ -1234,7 +1236,7 @@
 		if (!S_ISGITLINK(ce->ce_mode))
 			continue;
 
-		submodule = submodule_from_cache(spf->r, &null_oid, ce->name);
+		submodule = submodule_from_path(spf->r, &null_oid, ce->name);
 		if (!submodule) {
 			const char *name = default_name_or_path(ce->name);
 			if (name) {
@@ -1604,7 +1606,7 @@
 	if (old_head && !is_submodule_populated_gently(path, error_code_ptr))
 		return 0;
 
-	sub = submodule_from_path(&null_oid, path);
+	sub = submodule_from_path(the_repository, &null_oid, path);
 
 	if (!sub)
 		die("BUG: could not get submodule information for '%s'", path);
@@ -1623,7 +1625,7 @@
 		} else {
 			char *gitdir = xstrfmt("%s/modules/%s",
 				    get_git_common_dir(), sub->name);
-			connect_work_tree_and_git_dir(path, gitdir);
+			connect_work_tree_and_git_dir(path, gitdir, 0);
 			free(gitdir);
 
 			/* make sure the index is clean as well */
@@ -1633,7 +1635,7 @@
 		if (old_head && (flags & SUBMODULE_MOVE_HEAD_FORCE)) {
 			char *gitdir = xstrfmt("%s/modules/%s",
 				    get_git_common_dir(), sub->name);
-			connect_work_tree_and_git_dir(path, gitdir);
+			connect_work_tree_and_git_dir(path, gitdir, 1);
 			free(gitdir);
 		}
 	}
@@ -1886,7 +1888,7 @@
 
 	real_old_git_dir = real_pathdup(old_git_dir, 1);
 
-	sub = submodule_from_path(&null_oid, path);
+	sub = submodule_from_path(the_repository, &null_oid, path);
 	if (!sub)
 		die(_("could not lookup name for submodule '%s'"), path);
 
@@ -1942,11 +1944,11 @@
 		* superproject did not rewrite the git file links yet,
 		* fix it now.
 		*/
-		sub = submodule_from_path(&null_oid, path);
+		sub = submodule_from_path(the_repository, &null_oid, path);
 		if (!sub)
 			die(_("could not lookup name for submodule '%s'"), path);
 		connect_work_tree_and_git_dir(path,
-			git_path("modules/%s", sub->name));
+			git_path("modules/%s", sub->name), 0);
 	} else {
 		/* Is it already absorbed into the superprojects git dir? */
 		char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
@@ -2088,7 +2090,7 @@
 		strbuf_addstr(buf, git_dir);
 	}
 	if (!is_git_directory(buf->buf)) {
-		sub = submodule_from_path(&null_oid, submodule);
+		sub = submodule_from_path(the_repository, &null_oid, submodule);
 		if (!sub) {
 			ret = -1;
 			goto cleanup;
diff --git a/submodule.h b/submodule.h
index 9589f13..e5526f6 100644
--- a/submodule.h
+++ b/submodule.h
@@ -105,7 +105,6 @@
 				    const char **refspec, int refspec_nr,
 				    const struct string_list *push_options,
 				    int dry_run);
-extern void connect_work_tree_and_git_dir(const char *work_tree, const char *git_dir);
 /*
  * Given a submodule path (as in the index), return the repository
  * path of that submodule in 'buf'. Return -1 on error or when the
diff --git a/t/helper/test-chmtime.c b/t/helper/test-chmtime.c
index 1790cea..aa22af4 100644
--- a/t/helper/test-chmtime.c
+++ b/t/helper/test-chmtime.c
@@ -18,20 +18,30 @@
  *
  * Examples:
  *
- * To just print the mtime use --verbose and set the file mtime offset to 0:
+ * To print the mtime and the file name use --verbose and set
+ * the file mtime offset to 0:
  *
  *	test-tool chmtime -v +0 file
  *
+ * To print only the mtime use --get:
+ *
+ *	test-tool chmtime --get file
+ *
  * To set the mtime to current time:
  *
  *	test-tool chmtime =+0 file
  *
+ * To set the file mtime offset to +1 and print the new value:
+ *
+ *	test-tool chmtime --get +1 file
+ *
  */
 #include "test-tool.h"
 #include "git-compat-util.h"
 #include <utime.h>
 
-static const char usage_str[] = "-v|--verbose (+|=|=+|=-|-)<seconds> <file>...";
+static const char usage_str[] =
+	"(-v|--verbose|-g|--get) (+|=|=+|=-|-)<seconds> <file>...";
 
 static int timespec_arg(const char *arg, long int *set_time, int *set_eq)
 {
@@ -47,7 +57,6 @@
 	}
 	*set_time = strtol(timespec, &test, 10);
 	if (*test) {
-		fprintf(stderr, "Not a base-10 integer: %s\n", arg + 1);
 		return 0;
 	}
 	if ((*set_eq && *set_time < 0) || *set_eq == 2) {
@@ -60,6 +69,7 @@
 int cmd__chmtime(int argc, const char **argv)
 {
 	static int verbose;
+	static int get;
 
 	int i = 1;
 	/* no mtime change by default */
@@ -69,18 +79,34 @@
 	if (argc < 3)
 		goto usage;
 
-	if (strcmp(argv[i], "--verbose") == 0 || strcmp(argv[i], "-v") == 0) {
+	if (strcmp(argv[i], "--get") == 0 || strcmp(argv[i], "-g") == 0) {
+		get = 1;
+		++i;
+	} else if (strcmp(argv[i], "--verbose") == 0 || strcmp(argv[i], "-v") == 0) {
 		verbose = 1;
 		++i;
 	}
-	if (timespec_arg(argv[i], &set_time, &set_eq))
+
+	if (i == argc) {
+		goto usage;
+	}
+
+	if (timespec_arg(argv[i], &set_time, &set_eq)) {
 		++i;
-	else
+	} else {
+		if (get == 0) {
+			fprintf(stderr, "Not a base-10 integer: %s\n", argv[i] + 1);
+			goto usage;
+		}
+	}
+
+	if (i == argc)
 		goto usage;
 
 	for (; i < argc; i++) {
 		struct stat sb;
 		struct utimbuf utb;
+		uintmax_t mtime;
 
 		if (stat(argv[i], &sb) < 0) {
 			fprintf(stderr, "Failed to stat %s: %s\n",
@@ -100,8 +126,10 @@
 		utb.actime = sb.st_atime;
 		utb.modtime = set_eq ? set_time : sb.st_mtime + set_time;
 
-		if (verbose) {
-			uintmax_t mtime = utb.modtime < 0 ? 0: utb.modtime;
+		mtime = utb.modtime < 0 ? 0: utb.modtime;
+		if (get) {
+			printf("%"PRIuMAX"\n", mtime);
+		} else if (verbose) {
 			printf("%"PRIuMAX"\t%s\n", mtime, argv[i]);
 		}
 
diff --git a/t/helper/test-pkt-line.c b/t/helper/test-pkt-line.c
new file mode 100644
index 0000000..0f19e53
--- /dev/null
+++ b/t/helper/test-pkt-line.c
@@ -0,0 +1,64 @@
+#include "pkt-line.h"
+
+static void pack_line(const char *line)
+{
+	if (!strcmp(line, "0000") || !strcmp(line, "0000\n"))
+		packet_flush(1);
+	else if (!strcmp(line, "0001") || !strcmp(line, "0001\n"))
+		packet_delim(1);
+	else
+		packet_write_fmt(1, "%s", line);
+}
+
+static void pack(int argc, const char **argv)
+{
+	if (argc) { /* read from argv */
+		int i;
+		for (i = 0; i < argc; i++)
+			pack_line(argv[i]);
+	} else { /* read from stdin */
+		char line[LARGE_PACKET_MAX];
+		while (fgets(line, sizeof(line), stdin)) {
+			pack_line(line);
+		}
+	}
+}
+
+static void unpack(void)
+{
+	struct packet_reader reader;
+	packet_reader_init(&reader, 0, NULL, 0,
+			   PACKET_READ_GENTLE_ON_EOF |
+			   PACKET_READ_CHOMP_NEWLINE);
+
+	while (packet_reader_read(&reader) != PACKET_READ_EOF) {
+		switch (reader.status) {
+		case PACKET_READ_EOF:
+			break;
+		case PACKET_READ_NORMAL:
+			printf("%s\n", reader.line);
+			break;
+		case PACKET_READ_FLUSH:
+			printf("0000\n");
+			break;
+		case PACKET_READ_DELIM:
+			printf("0001\n");
+			break;
+		}
+	}
+}
+
+int cmd_main(int argc, const char **argv)
+{
+	if (argc < 2)
+		die("too few arguments");
+
+	if (!strcmp(argv[1], "pack"))
+		pack(argc - 2, argv + 2);
+	else if (!strcmp(argv[1], "unpack"))
+		unpack();
+	else
+		die("invalid argument '%s'", argv[1]);
+
+	return 0;
+}
diff --git a/t/helper/test-ref-store.c b/t/helper/test-ref-store.c
index 7c4f437..e9e0541 100644
--- a/t/helper/test-ref-store.c
+++ b/t/helper/test-ref-store.c
@@ -3,6 +3,7 @@
 #include "refs.h"
 #include "worktree.h"
 #include "object-store.h"
+#include "repository.h"
 
 static const char *notnull(const char *arg, const char *name)
 {
@@ -23,7 +24,7 @@
 	if (!argv[0]) {
 		die("ref store required");
 	} else if (!strcmp(argv[0], "main")) {
-		*refs = get_main_ref_store();
+		*refs = get_main_ref_store(the_repository);
 	} else if (skip_prefix(argv[0], "submodule:", &gitdir)) {
 		struct strbuf sb = STRBUF_INIT;
 		int ret;
diff --git a/t/helper/test-submodule-config.c b/t/helper/test-submodule-config.c
index 5c6e4b0..e269274 100644
--- a/t/helper/test-submodule-config.c
+++ b/t/helper/test-submodule-config.c
@@ -49,9 +49,11 @@
 			die_usage(argc, argv, "Commit not found.");
 
 		if (lookup_name) {
-			submodule = submodule_from_name(&commit_oid, path_or_name);
+			submodule = submodule_from_name(the_repository,
+							&commit_oid, path_or_name);
 		} else
-			submodule = submodule_from_path(&commit_oid, path_or_name);
+			submodule = submodule_from_path(the_repository,
+							&commit_oid, path_or_name);
 		if (!submodule)
 			die_usage(argc, argv, "Submodule not found.");
 
@@ -65,7 +67,7 @@
 		arg += 2;
 	}
 
-	submodule_free();
+	submodule_free(the_repository);
 
 	return 0;
 }
diff --git a/t/perf/bisect_regression b/t/perf/bisect_regression
new file mode 100755
index 0000000..a94d995
--- /dev/null
+++ b/t/perf/bisect_regression
@@ -0,0 +1,73 @@
+#!/bin/sh
+
+# Read a line coming from `./aggregate.perl --sort-by regression ...`
+# and automatically bisect to find the commit responsible for the
+# performance regression.
+#
+# Lines from `./aggregate.perl --sort-by regression ...` look like:
+#
+# +100.0% p7821-grep-engines-fixed.1 0.04(0.10+0.03) 0.08(0.11+0.08) v2.14.3 v2.15.1
+# +33.3% p7820-grep-engines.1 0.03(0.08+0.02) 0.04(0.08+0.02) v2.14.3 v2.15.1
+#
+
+die () {
+	echo >&2 "error: $*"
+	exit 1
+}
+
+while [ $# -gt 0 ]; do
+	arg="$1"
+	case "$arg" in
+	--help)
+		echo "usage: $0 [--config file] [--subsection subsection]"
+		exit 0
+		;;
+	--config)
+		shift
+		GIT_PERF_CONFIG_FILE=$(cd "$(dirname "$1")"; pwd)/$(basename "$1")
+		export GIT_PERF_CONFIG_FILE
+		shift ;;
+	--subsection)
+		shift
+		GIT_PERF_SUBSECTION="$1"
+		export GIT_PERF_SUBSECTION
+		shift ;;
+	--*)
+		die "unrecognised option: '$arg'" ;;
+	*)
+		die "unknown argument '$arg'"
+		;;
+	esac
+done
+
+read -r regression subtest oldtime newtime oldrev newrev
+
+test_script=$(echo "$subtest" | sed -e 's/\(.*\)\.[0-9]*$/\1.sh/')
+test_number=$(echo "$subtest" | sed -e 's/.*\.\([0-9]*\)$/\1/')
+
+# oldtime and newtime are decimal number, not integers
+
+oldtime=$(echo "$oldtime" | sed -e 's/^\([0-9]\+\.[0-9]\+\).*$/\1/')
+newtime=$(echo "$newtime" | sed -e 's/^\([0-9]\+\.[0-9]\+\).*$/\1/')
+
+test $(echo "$newtime" "$oldtime" | awk '{ print ($1 > $2) }') = 1 ||
+	die "New time '$newtime' shoud be greater than old time '$oldtime'"
+
+tmpdir=$(mktemp -d -t bisect_regression_XXXXXX) || die "Failed to create temp directory"
+echo "$oldtime" >"$tmpdir/oldtime" || die "Failed to write to '$tmpdir/oldtime'"
+echo "$newtime" >"$tmpdir/newtime" || die "Failed to write to '$tmpdir/newtime'"
+
+# Bisecting must be performed from the top level directory (even with --no-checkout)
+(
+	toplevel_dir=$(git rev-parse --show-toplevel) || die "Failed to find top level directory"
+	cd "$toplevel_dir" || die "Failed to cd into top level directory '$toplevel_dir'"
+
+	git bisect start --no-checkout "$newrev" "$oldrev" || die "Failed to start bisecting"
+
+	git bisect run t/perf/bisect_run_script "$test_script" "$test_number" "$tmpdir"
+	res="$?"
+
+	git bisect reset
+
+	exit "$res"
+)
diff --git a/t/perf/bisect_run_script b/t/perf/bisect_run_script
new file mode 100755
index 0000000..038255d
--- /dev/null
+++ b/t/perf/bisect_run_script
@@ -0,0 +1,47 @@
+#!/bin/sh
+
+script="$1"
+test_number="$2"
+info_dir="$3"
+
+# This aborts the bisection immediately
+die () {
+	echo >&2 "error: $*"
+	exit 255
+}
+
+bisect_head=$(git rev-parse --verify BISECT_HEAD) || die "Failed to find BISECT_HEAD ref"
+
+script_number=$(echo "$script" | sed -e "s/^p\([0-9]*\).*\$/\1/") || die "Failed to get script number for '$script'"
+
+oldtime=$(cat "$info_dir/oldtime") || die "Failed to access '$info_dir/oldtime'"
+newtime=$(cat "$info_dir/newtime") || die "Failed to access '$info_dir/newtime'"
+
+cd t/perf || die "Failed to cd into 't/perf'"
+
+result_file="$info_dir/perf_${script_number}_${bisect_head}_results.txt"
+
+GIT_PERF_DIRS_OR_REVS="$bisect_head"
+export GIT_PERF_DIRS_OR_REVS
+
+./run "$script" >"$result_file" 2>&1 || die "Failed to run perf test '$script'"
+
+rtime=$(sed -n "s/^$script_number\.$test_number:.*\([0-9]\+\.[0-9]\+\)(.*).*\$/\1/p" "$result_file")
+
+echo "newtime: $newtime"
+echo "rtime: $rtime"
+echo "oldtime: $oldtime"
+
+# Compare ($newtime - $rtime) with ($rtime - $oldtime)
+# Times are decimal number, not integers
+
+if test $(echo "$newtime" "$rtime" "$oldtime" | awk '{ print ($1 - $2 > $2 - $3) }') = 1
+then
+	# Current commit is considered "good/old"
+	echo "$rtime" >"$info_dir/oldtime"
+	exit 0
+else
+	# Current commit is considered "bad/new"
+	echo "$rtime" >"$info_dir/newtime"
+	exit 1
+fi
diff --git a/t/perf/run b/t/perf/run
index 213da5d..9aaa733 100755
--- a/t/perf/run
+++ b/t/perf/run
@@ -1,21 +1,34 @@
 #!/bin/sh
 
-case "$1" in
+die () {
+	echo >&2 "error: $*"
+	exit 1
+}
+
+while [ $# -gt 0 ]; do
+	arg="$1"
+	case "$arg" in
+	--)
+		break ;;
 	--help)
-		echo "usage: $0 [--config file] [other_git_tree...] [--] [test_scripts]"
-		exit 0
-		;;
+		echo "usage: $0 [--config file] [--subsection subsec] [other_git_tree...] [--] [test_scripts]"
+		exit 0 ;;
 	--config)
 		shift
 		GIT_PERF_CONFIG_FILE=$(cd "$(dirname "$1")"; pwd)/$(basename "$1")
 		export GIT_PERF_CONFIG_FILE
 		shift ;;
-esac
-
-die () {
-	echo >&2 "error: $*"
-	exit 1
-}
+	--subsection)
+		shift
+		GIT_PERF_SUBSECTION="$1"
+		export GIT_PERF_SUBSECTION
+		shift ;;
+	--*)
+		die "unrecognised option: '$arg'" ;;
+	*)
+		break ;;
+	esac
+done
 
 run_one_dir () {
 	if test $# -eq 0; then
@@ -172,9 +185,32 @@
 
 if test $(wc -l <test-results/run_subsections.names) -eq 0
 then
+	if test -n "$GIT_PERF_SUBSECTION"
+	then
+		if test -n "$GIT_PERF_CONFIG_FILE"
+		then
+			die "no subsections are defined in config file '$GIT_PERF_CONFIG_FILE'"
+		else
+			die "subsection '$GIT_PERF_SUBSECTION' defined without a config file"
+		fi
+	fi
 	(
 		run_subsection "$@"
 	)
+elif test -n "$GIT_PERF_SUBSECTION"
+then
+	egrep "^$GIT_PERF_SUBSECTION\$" test-results/run_subsections.names >/dev/null ||
+		die "subsection '$GIT_PERF_SUBSECTION' not found in '$GIT_PERF_CONFIG_FILE'"
+
+	egrep "^$GIT_PERF_SUBSECTION\$" test-results/run_subsections.names | while read -r subsec
+	do
+		(
+			GIT_PERF_SUBSECTION="$subsec"
+			export GIT_PERF_SUBSECTION
+			echo "======== Run for subsection '$GIT_PERF_SUBSECTION' ========"
+			run_subsection "$@"
+		)
+	done
 else
 	while read -r subsec
 	do
diff --git a/t/t0028-working-tree-encoding.sh b/t/t0028-working-tree-encoding.sh
new file mode 100755
index 0000000..12b8eb9
--- /dev/null
+++ b/t/t0028-working-tree-encoding.sh
@@ -0,0 +1,245 @@
+#!/bin/sh
+
+test_description='working-tree-encoding conversion via gitattributes'
+
+. ./test-lib.sh
+
+GIT_TRACE_WORKING_TREE_ENCODING=1 && export GIT_TRACE_WORKING_TREE_ENCODING
+
+test_expect_success 'setup test files' '
+	git config core.eol lf &&
+
+	text="hallo there!\ncan you read me?" &&
+	echo "*.utf16 text working-tree-encoding=utf-16" >.gitattributes &&
+	printf "$text" >test.utf8.raw &&
+	printf "$text" | iconv -f UTF-8 -t UTF-16 >test.utf16.raw &&
+	printf "$text" | iconv -f UTF-8 -t UTF-32 >test.utf32.raw &&
+
+	# Line ending tests
+	printf "one\ntwo\nthree\n" >lf.utf8.raw &&
+	printf "one\r\ntwo\r\nthree\r\n" >crlf.utf8.raw &&
+
+	# BOM tests
+	printf "\0a\0b\0c"                         >nobom.utf16be.raw &&
+	printf "a\0b\0c\0"                         >nobom.utf16le.raw &&
+	printf "\376\777\0a\0b\0c"                 >bebom.utf16be.raw &&
+	printf "\777\376a\0b\0c\0"                 >lebom.utf16le.raw &&
+	printf "\0\0\0a\0\0\0b\0\0\0c"             >nobom.utf32be.raw &&
+	printf "a\0\0\0b\0\0\0c\0\0\0"             >nobom.utf32le.raw &&
+	printf "\0\0\376\777\0\0\0a\0\0\0b\0\0\0c" >bebom.utf32be.raw &&
+	printf "\777\376\0\0a\0\0\0b\0\0\0c\0\0\0" >lebom.utf32le.raw &&
+
+	# Add only UTF-16 file, we will add the UTF-32 file later
+	cp test.utf16.raw test.utf16 &&
+	cp test.utf32.raw test.utf32 &&
+	git add .gitattributes test.utf16 &&
+	git commit -m initial
+'
+
+test_expect_success 'ensure UTF-8 is stored in Git' '
+	test_when_finished "rm -f test.utf16.git" &&
+
+	git cat-file -p :test.utf16 >test.utf16.git &&
+	test_cmp_bin test.utf8.raw test.utf16.git
+'
+
+test_expect_success 're-encode to UTF-16 on checkout' '
+	test_when_finished "rm -f test.utf16.raw" &&
+
+	rm test.utf16 &&
+	git checkout test.utf16 &&
+	test_cmp_bin test.utf16.raw test.utf16
+'
+
+test_expect_success 'check $GIT_DIR/info/attributes support' '
+	test_when_finished "rm -f test.utf32.git" &&
+	test_when_finished "git reset --hard HEAD" &&
+
+	echo "*.utf32 text working-tree-encoding=utf-32" >.git/info/attributes &&
+	git add test.utf32 &&
+
+	git cat-file -p :test.utf32 >test.utf32.git &&
+	test_cmp_bin test.utf8.raw test.utf32.git
+'
+
+for i in 16 32
+do
+	test_expect_success "check prohibited UTF-${i} BOM" '
+		test_when_finished "git reset --hard HEAD" &&
+
+		echo "*.utf${i}be text working-tree-encoding=utf-${i}be" >>.gitattributes &&
+		echo "*.utf${i}le text working-tree-encoding=utf-${i}LE" >>.gitattributes &&
+
+		# Here we add a UTF-16 (resp. UTF-32) files with BOM (big/little-endian)
+		# but we tell Git to treat it as UTF-16BE/UTF-16LE (resp. UTF-32).
+		# In these cases the BOM is prohibited.
+		cp bebom.utf${i}be.raw bebom.utf${i}be &&
+		test_must_fail git add bebom.utf${i}be 2>err.out &&
+		test_i18ngrep "fatal: BOM is prohibited .* utf-${i}be" err.out &&
+		test_i18ngrep "use UTF-${i} as working-tree-encoding" err.out &&
+
+		cp lebom.utf${i}le.raw lebom.utf${i}be &&
+		test_must_fail git add lebom.utf${i}be 2>err.out &&
+		test_i18ngrep "fatal: BOM is prohibited .* utf-${i}be" err.out &&
+		test_i18ngrep "use UTF-${i} as working-tree-encoding" err.out &&
+
+		cp bebom.utf${i}be.raw bebom.utf${i}le &&
+		test_must_fail git add bebom.utf${i}le 2>err.out &&
+		test_i18ngrep "fatal: BOM is prohibited .* utf-${i}LE" err.out &&
+		test_i18ngrep "use UTF-${i} as working-tree-encoding" err.out &&
+
+		cp lebom.utf${i}le.raw lebom.utf${i}le &&
+		test_must_fail git add lebom.utf${i}le 2>err.out &&
+		test_i18ngrep "fatal: BOM is prohibited .* utf-${i}LE" err.out &&
+		test_i18ngrep "use UTF-${i} as working-tree-encoding" err.out
+	'
+
+	test_expect_success "check required UTF-${i} BOM" '
+		test_when_finished "git reset --hard HEAD" &&
+
+		echo "*.utf${i} text working-tree-encoding=utf-${i}" >>.gitattributes &&
+
+		cp nobom.utf${i}be.raw nobom.utf${i} &&
+		test_must_fail git add nobom.utf${i} 2>err.out &&
+		test_i18ngrep "fatal: BOM is required .* utf-${i}" err.out &&
+		test_i18ngrep "use UTF-${i}BE or UTF-${i}LE" err.out &&
+
+		cp nobom.utf${i}le.raw nobom.utf${i} &&
+		test_must_fail git add nobom.utf${i} 2>err.out &&
+		test_i18ngrep "fatal: BOM is required .* utf-${i}" err.out &&
+		test_i18ngrep "use UTF-${i}BE or UTF-${i}LE" err.out
+	'
+
+	test_expect_success "eol conversion for UTF-${i} encoded files on checkout" '
+		test_when_finished "rm -f crlf.utf${i}.raw lf.utf${i}.raw" &&
+		test_when_finished "git reset --hard HEAD^" &&
+
+		cat lf.utf8.raw | iconv -f UTF-8 -t UTF-${i} >lf.utf${i}.raw &&
+		cat crlf.utf8.raw | iconv -f UTF-8 -t UTF-${i} >crlf.utf${i}.raw &&
+		cp crlf.utf${i}.raw eol.utf${i} &&
+
+		cat >expectIndexLF <<-EOF &&
+			i/lf    w/-text attr/text             	eol.utf${i}
+		EOF
+
+		git add eol.utf${i} &&
+		git commit -m eol &&
+
+		# UTF-${i} with CRLF (Windows line endings)
+		rm eol.utf${i} &&
+		git -c core.eol=crlf checkout eol.utf${i} &&
+		test_cmp_bin crlf.utf${i}.raw eol.utf${i} &&
+
+		# Although the file has CRLF in the working tree,
+		# ensure LF in the index
+		git ls-files --eol eol.utf${i} >actual &&
+		test_cmp expectIndexLF actual &&
+
+		# UTF-${i} with LF (Unix line endings)
+		rm eol.utf${i} &&
+		git -c core.eol=lf checkout eol.utf${i} &&
+		test_cmp_bin lf.utf${i}.raw eol.utf${i} &&
+
+		# The file LF in the working tree, ensure LF in the index
+		git ls-files --eol eol.utf${i} >actual &&
+		test_cmp expectIndexLF actual
+	'
+done
+
+test_expect_success 'check unsupported encodings' '
+	test_when_finished "git reset --hard HEAD" &&
+
+	echo "*.set text working-tree-encoding" >.gitattributes &&
+	printf "set" >t.set &&
+	test_must_fail git add t.set 2>err.out &&
+	test_i18ngrep "true/false are no valid working-tree-encodings" err.out &&
+
+	echo "*.unset text -working-tree-encoding" >.gitattributes &&
+	printf "unset" >t.unset &&
+	git add t.unset &&
+
+	echo "*.empty text working-tree-encoding=" >.gitattributes &&
+	printf "empty" >t.empty &&
+	git add t.empty &&
+
+	echo "*.garbage text working-tree-encoding=garbage" >.gitattributes &&
+	printf "garbage" >t.garbage &&
+	test_must_fail git add t.garbage 2>err.out &&
+	test_i18ngrep "failed to encode" err.out
+'
+
+test_expect_success 'error if encoding round trip is not the same during refresh' '
+	BEFORE_STATE=$(git rev-parse HEAD) &&
+	test_when_finished "git reset --hard $BEFORE_STATE" &&
+
+	# Add and commit a UTF-16 file but skip the "working-tree-encoding"
+	# filter. Consequently, the in-repo representation is UTF-16 and not
+	# UTF-8. This simulates a Git version that has no working tree encoding
+	# support.
+	echo "*.utf16le text working-tree-encoding=utf-16le" >.gitattributes &&
+	echo "hallo" >nonsense.utf16le &&
+	TEST_HASH=$(git hash-object --no-filters -w nonsense.utf16le) &&
+	git update-index --add --cacheinfo 100644 $TEST_HASH nonsense.utf16le &&
+	COMMIT=$(git commit-tree -p $(git rev-parse HEAD) -m "plain commit" $(git write-tree)) &&
+	git update-ref refs/heads/master $COMMIT &&
+
+	test_must_fail git checkout HEAD^ 2>err.out &&
+	test_i18ngrep "error: .* overwritten by checkout:" err.out
+'
+
+test_expect_success 'error if encoding garbage is already in Git' '
+	BEFORE_STATE=$(git rev-parse HEAD) &&
+	test_when_finished "git reset --hard $BEFORE_STATE" &&
+
+	# Skip the UTF-16 filter for the added file
+	# This simulates a Git version that has no checkoutEncoding support
+	cp nobom.utf16be.raw nonsense.utf16 &&
+	TEST_HASH=$(git hash-object --no-filters -w nonsense.utf16) &&
+	git update-index --add --cacheinfo 100644 $TEST_HASH nonsense.utf16 &&
+	COMMIT=$(git commit-tree -p $(git rev-parse HEAD) -m "plain commit" $(git write-tree)) &&
+	git update-ref refs/heads/master $COMMIT &&
+
+	git diff 2>err.out &&
+	test_i18ngrep "error: BOM is required" err.out
+'
+
+test_expect_success 'check roundtrip encoding' '
+	test_when_finished "rm -f roundtrip.shift roundtrip.utf16" &&
+	test_when_finished "git reset --hard HEAD" &&
+
+	text="hallo there!\nroundtrip test here!" &&
+	printf "$text" | iconv -f UTF-8 -t SHIFT-JIS >roundtrip.shift &&
+	printf "$text" | iconv -f UTF-8 -t UTF-16 >roundtrip.utf16 &&
+	echo "*.shift text working-tree-encoding=SHIFT-JIS" >>.gitattributes &&
+
+	# SHIFT-JIS encoded files are round-trip checked by default...
+	GIT_TRACE=1 git add .gitattributes roundtrip.shift 2>&1 |
+		grep "Checking roundtrip encoding for SHIFT-JIS" &&
+	git reset &&
+
+	# ... unless we overwrite the Git config!
+	! GIT_TRACE=1 git -c core.checkRoundtripEncoding=garbage \
+		add .gitattributes roundtrip.shift 2>&1 |
+		grep "Checking roundtrip encoding for SHIFT-JIS" &&
+	git reset &&
+
+	# UTF-16 encoded files should not be round-trip checked by default...
+	! GIT_TRACE=1 git add roundtrip.utf16 2>&1 |
+		grep "Checking roundtrip encoding for UTF-16" &&
+	git reset &&
+
+	# ... unless we tell Git to check it!
+	GIT_TRACE=1 git -c core.checkRoundtripEncoding="UTF-16, UTF-32" \
+		add roundtrip.utf16 2>&1 |
+		grep "Checking roundtrip encoding for utf-16" &&
+	git reset &&
+
+	# ... unless we tell Git to check it!
+	# (here we also check that the casing of the encoding is irrelevant)
+	GIT_TRACE=1 git -c core.checkRoundtripEncoding="UTF-32, utf-16" \
+		add roundtrip.utf16 2>&1 |
+		grep "Checking roundtrip encoding for utf-16" &&
+	git reset
+'
+
+test_done
diff --git a/t/t1300-repo-config.sh b/t/t1300-config.sh
similarity index 89%
rename from t/t1300-repo-config.sh
rename to t/t1300-config.sh
index e95b1e6..03c2237 100755
--- a/t/t1300-repo-config.sh
+++ b/t/t1300-config.sh
@@ -108,6 +108,7 @@
 [beta]
 baz = multiple \
 lines
+foo = bar
 EOF
 
 test_expect_success 'unset with cont. lines' '
@@ -118,6 +119,7 @@
 [alpha]
 bar = foo
 [beta]
+foo = bar
 EOF
 
 test_expect_success 'unset with cont. lines is correct' 'test_cmp expect .git/config'
@@ -740,7 +742,7 @@
 	do
 	    git config --bool --get bool.true$i >>result
 	    git config --bool --get bool.false$i >>result
-        done &&
+	done &&
 	test_cmp expect result'
 
 test_expect_success 'invalid bool (--get)' '
@@ -931,6 +933,36 @@
 	test_must_fail git config --expiry-date date.invalid1
 '
 
+test_expect_success 'get --type=color' '
+	rm .git/config &&
+	git config foo.color "red" &&
+	git config --get --type=color foo.color >actual.raw &&
+	test_decode_color <actual.raw >actual &&
+	echo "<RED>" >expect &&
+	test_cmp expect actual
+'
+
+cat >expect << EOF
+[foo]
+	color = red
+EOF
+
+test_expect_success 'set --type=color' '
+	rm .git/config &&
+	git config --type=color foo.color "red" &&
+	test_cmp expect .git/config
+'
+
+test_expect_success 'get --type=color barfs on non-color' '
+	echo "[foo]bar=not-a-color" >.git/config &&
+	test_must_fail git config --get --type=color foo.bar
+'
+
+test_expect_success 'set --type=color barfs on non-color' '
+	test_must_fail git config --type=color foo.color "not-a-color" 2>error &&
+	test_i18ngrep "cannot parse color" error
+'
+
 cat > expect << EOF
 [quote]
 	leading = " test"
@@ -1411,7 +1443,7 @@
 '
 
 # good section hygiene
-test_expect_failure 'unsetting the last key in a section removes header' '
+test_expect_success '--unset last key removes section (except if commented)' '
 	cat >.git/config <<-\EOF &&
 	# some generic comment on the configuration file itself
 	# a comment specific to this "section" section.
@@ -1425,13 +1457,86 @@
 
 	cat >expect <<-\EOF &&
 	# some generic comment on the configuration file itself
+	# a comment specific to this "section" section.
+	[section]
+	# some intervening lines
+	# that should also be dropped
+
+	# please be careful when you update the above variable
 	EOF
 
 	git config --unset section.key &&
-	test_cmp expect .git/config
+	test_cmp expect .git/config &&
+
+	cat >.git/config <<-\EOF &&
+	[section]
+	key = value
+	[next-section]
+	EOF
+
+	cat >expect <<-\EOF &&
+	[next-section]
+	EOF
+
+	git config --unset section.key &&
+	test_cmp expect .git/config &&
+
+	q_to_tab >.git/config <<-\EOF &&
+	[one]
+	Qkey = "multiline \
+	QQ# with comment"
+	[two]
+	key = true
+	EOF
+	git config --unset two.key &&
+	! grep two .git/config &&
+
+	q_to_tab >.git/config <<-\EOF &&
+	[one]
+	Qkey = "multiline \
+	QQ# with comment"
+	[one]
+	key = true
+	EOF
+	git config --unset-all one.key &&
+	test_line_count = 0 .git/config &&
+
+	q_to_tab >.git/config <<-\EOF &&
+	[one]
+	Qkey = true
+	Q# a comment not at the start
+	[two]
+	Qkey = true
+	EOF
+	git config --unset two.key &&
+	grep two .git/config &&
+
+	q_to_tab >.git/config <<-\EOF &&
+	[one]
+	Qkey = not [two "subsection"]
+	[two "subsection"]
+	[two "subsection"]
+	Qkey = true
+	[TWO "subsection"]
+	[one]
+	EOF
+	git config --unset two.subsection.key &&
+	test "not [two subsection]" = "$(git config one.key)" &&
+	test_line_count = 3 .git/config
 '
 
-test_expect_failure 'adding a key into an empty section reuses header' '
+test_expect_success '--unset-all removes section if empty & uncommented' '
+	cat >.git/config <<-\EOF &&
+	[section]
+	key = value1
+	key = value2
+	EOF
+
+	git config --unset-all section.key &&
+	test_line_count = 0 .git/config
+'
+
+test_expect_success 'adding a key into an empty section reuses header' '
 	cat >.git/config <<-\EOF &&
 	[section]
 	EOF
@@ -1611,4 +1716,88 @@
 	test_expect_code 128 nongit git config --local foo.bar
 '
 
+cat >.git/config <<-\EOF &&
+[core]
+foo = true
+number = 10
+big = 1M
+EOF
+
+test_expect_success 'identical modern --type specifiers are allowed' '
+	git config --type=int --type=int core.big >actual &&
+	echo 1048576 >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'identical legacy --type specifiers are allowed' '
+	git config --int --int core.big >actual &&
+	echo 1048576 >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'identical mixed --type specifiers are allowed' '
+	git config --int --type=int core.big >actual &&
+	echo 1048576 >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'non-identical modern --type specifiers are not allowed' '
+	test_must_fail git config --type=int --type=bool core.big 2>error &&
+	test_i18ngrep "only one type at a time" error
+'
+
+test_expect_success 'non-identical legacy --type specifiers are not allowed' '
+	test_must_fail git config --int --bool core.big 2>error &&
+	test_i18ngrep "only one type at a time" error
+'
+
+test_expect_success 'non-identical mixed --type specifiers are not allowed' '
+	test_must_fail git config --type=int --bool core.big 2>error &&
+	test_i18ngrep "only one type at a time" error
+'
+
+test_expect_success '--type allows valid type specifiers' '
+	echo "true" >expect &&
+	git config --type=bool core.foo >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--no-type unsets type specifiers' '
+	echo "10" >expect &&
+	git config --type=bool --no-type core.number >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'unset type specifiers may be reset to conflicting ones' '
+	echo 1048576 >expect &&
+	git config --type=bool --no-type --type=int core.big >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--type rejects unknown specifiers' '
+	test_must_fail git config --type=nonsense core.foo 2>error &&
+	test_i18ngrep "unrecognized --type argument" error
+'
+
+test_expect_success '--replace-all does not invent newlines' '
+	q_to_tab >.git/config <<-\EOF &&
+	[abc]key
+	QkeepSection
+	[xyz]
+	Qkey = 1
+	[abc]
+	Qkey = a
+	EOF
+	q_to_tab >expect <<-\EOF &&
+	[abc]
+	QkeepSection
+	[xyz]
+	Qkey = 1
+	[abc]
+	Qkey = b
+	EOF
+	git config --replace-all abc.key b &&
+	test_cmp .git/config expect
+'
+
 test_done
diff --git a/t/t1310-config-default.sh b/t/t1310-config-default.sh
new file mode 100755
index 0000000..6049d91
--- /dev/null
+++ b/t/t1310-config-default.sh
@@ -0,0 +1,36 @@
+#!/bin/sh
+
+test_description='Test git config in different settings (with --default)'
+
+. ./test-lib.sh
+
+test_expect_success 'uses --default when entry missing' '
+	echo quux >expect &&
+	git config -f config --default=quux core.foo >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'does not use --default when entry present' '
+	echo bar >expect &&
+	git -c core.foo=bar config --default=baz core.foo >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'canonicalizes --default with appropriate type' '
+	echo true >expect &&
+	git config -f config --default=yes --bool core.foo >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'dies when --default cannot be parsed' '
+	test_must_fail git config -f config --type=expiry-date --default=x --get \
+		not.a.section 2>error &&
+	test_i18ngrep "failed to format default config value" error
+'
+
+test_expect_success 'does not allow --default without --get' '
+	test_must_fail git config --default=quux --unset a.section >output 2>&1 &&
+	test_i18ngrep "\-\-default is only applicable to" output
+'
+
+test_done
diff --git a/t/t1501-work-tree.sh b/t/t1501-work-tree.sh
index 02cf201..9c0bc65 100755
--- a/t/t1501-work-tree.sh
+++ b/t/t1501-work-tree.sh
@@ -431,4 +431,16 @@
 	)
 '
 
+test_expect_success 'refs work with relative gitdir and work tree' '
+	git init relative &&
+	git -C relative commit --allow-empty -m one &&
+	git -C relative commit --allow-empty -m two &&
+
+	GIT_DIR=relative/.git GIT_WORK_TREE=relative git reset HEAD^ &&
+
+	git -C relative log -1 --format=%s >actual &&
+	echo one >expect &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t1510-repo-setup.sh b/t/t1510-repo-setup.sh
index e6854b8..972bd9c 100755
--- a/t/t1510-repo-setup.sh
+++ b/t/t1510-repo-setup.sh
@@ -238,7 +238,6 @@
 '
 
 test_expect_success '#1: GIT_WORK_TREE without explicit GIT_DIR is accepted' '
-	mkdir -p wt &&
 	try_repo 1 "$here" unset unset "" unset \
 		"$here/1/.git" "$here" "$here" 1/ \
 		"$here/1/.git" "$here" "$here" 1/sub/ 2>message &&
diff --git a/t/t2022-checkout-paths.sh b/t/t2022-checkout-paths.sh
index e74d58b..fc3eb43 100755
--- a/t/t2022-checkout-paths.sh
+++ b/t/t2022-checkout-paths.sh
@@ -73,8 +73,8 @@
 	git checkout HEAD -- file1 file2 &&
 	echo one >expect &&
 	test_cmp expect file1 &&
-	echo "1000000000	file2" >expect &&
-	test-tool chmtime -v +0 file2 >actual &&
+	echo "1000000000" >expect &&
+	test-tool chmtime --get file2 >actual &&
 	test_cmp expect actual
 '
 
diff --git a/t/t2028-worktree-move.sh b/t/t2028-worktree-move.sh
index 5d5b363..5f7d45b 100755
--- a/t/t2028-worktree-move.sh
+++ b/t/t2028-worktree-move.sh
@@ -72,12 +72,11 @@
 '
 
 test_expect_success 'move worktree' '
-	toplevel="$(pwd)" &&
 	git worktree move source destination &&
 	test_path_is_missing source &&
 	git worktree list --porcelain >out &&
-	grep "^worktree.*/destination" out &&
-	! grep "^worktree.*/source" out &&
+	grep "^worktree.*/destination$" out &&
+	! grep "^worktree.*/source$" out &&
 	git -C destination log --format=%s >actual2 &&
 	echo init >expected2 &&
 	test_cmp expected2 actual2
@@ -93,7 +92,7 @@
 	test_when_finished "git worktree move some-dir/destination destination" &&
 	test_path_is_missing destination &&
 	git worktree list --porcelain >out &&
-	grep "^worktree.*/some-dir/destination" out &&
+	grep "^worktree.*/some-dir/destination$" out &&
 	git -C some-dir/destination log --format=%s >actual2 &&
 	echo init >expected2 &&
 	test_cmp expected2 actual2
diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
index 6c0b7ea..c0ef946 100755
--- a/t/t3200-branch.sh
+++ b/t/t3200-branch.sh
@@ -6,6 +6,7 @@
 test_description='git branch assorted tests'
 
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-rebase.sh
 
 test_expect_success 'prepare a trivial repository' '
 	echo Hello >A &&
@@ -1246,6 +1247,29 @@
 	test_must_fail git branch --merged HEAD --no-merged HEAD
 '
 
+test_expect_success '--list during rebase' '
+	test_when_finished "reset_rebase" &&
+	git checkout master &&
+	FAKE_LINES="1 edit 2" &&
+	export FAKE_LINES &&
+	set_fake_editor &&
+	git rebase -i HEAD~2 &&
+	git branch --list >actual &&
+	test_i18ngrep "rebasing master" actual
+'
+
+test_expect_success '--list during rebase from detached HEAD' '
+	test_when_finished "reset_rebase && git checkout master" &&
+	git checkout master^0 &&
+	oid=$(git rev-parse --short HEAD) &&
+	FAKE_LINES="1 edit 2" &&
+	export FAKE_LINES &&
+	set_fake_editor &&
+	git rebase -i HEAD~2 &&
+	git branch --list >actual &&
+	test_i18ngrep "rebasing detached HEAD $oid" actual
+'
+
 test_expect_success 'tracking with unexpected .fetch refspec' '
 	rm -rf a b c d &&
 	git init a &&
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 756de26..59c7665 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -717,7 +717,7 @@
 	set_fake_editor &&
 	git rebase -i HEAD~4 &&
 	test $HEAD = $(git rev-parse HEAD) &&
-	MTIME=$(test-tool chmtime -v +0 file3 | sed 's/[^0-9].*$//') &&
+	MTIME=$(test-tool chmtime --get file3) &&
 	test 123456789 = $MTIME
 '
 
diff --git a/t/t3421-rebase-topology-linear.sh b/t/t3421-rebase-topology-linear.sh
index 68fe200..b078f93 100755
--- a/t/t3421-rebase-topology-linear.sh
+++ b/t/t3421-rebase-topology-linear.sh
@@ -199,7 +199,7 @@
 	"
 }
 test_run_rebase success ''
-test_run_rebase failure -m
+test_run_rebase success -m
 test_run_rebase success -i
 test_run_rebase failure -p
 
@@ -214,8 +214,8 @@
 	"
 }
 test_run_rebase success ''
-test_run_rebase failure -m
-test_run_rebase failure -i
+test_run_rebase success -m
+test_run_rebase success -i
 test_run_rebase failure -p
 
 #       m
diff --git a/t/t3428-rebase-signoff.sh b/t/t3428-rebase-signoff.sh
index 2afb564..f6993b7 100755
--- a/t/t3428-rebase-signoff.sh
+++ b/t/t3428-rebase-signoff.sh
@@ -12,6 +12,13 @@
 a
 EOF
 
+# Expected commit message for initial commit after rebase --signoff
+cat >expected-initial-signed <<EOF
+Initial empty commit
+
+Signed-off-by: $(git var GIT_COMMITTER_IDENT | sed -e "s/>.*/>/")
+EOF
+
 # Expected commit message after rebase --signoff
 cat >expected-signed <<EOF
 first
@@ -43,4 +50,35 @@
 	test_cmp expected-unsigned actual
 '
 
+test_expect_success 'rebase --exec --signoff adds a sign-off line' '
+	test_when_finished "rm exec" &&
+	git commit --amend -m "first" &&
+	git rebase --exec "touch exec" --signoff HEAD^ &&
+	test_path_is_file exec &&
+	git cat-file commit HEAD | sed -e "1,/^\$/d" >actual &&
+	test_cmp expected-signed actual
+'
+
+test_expect_success 'rebase --root --signoff adds a sign-off line' '
+	git commit --amend -m "first" &&
+	git rebase --root --keep-empty --signoff &&
+	git cat-file commit HEAD^ | sed -e "1,/^\$/d" >actual &&
+	test_cmp expected-initial-signed actual &&
+	git cat-file commit HEAD | sed -e "1,/^\$/d" >actual &&
+	test_cmp expected-signed actual
+'
+
+test_expect_success 'rebase -i --signoff fails' '
+	git commit --amend -m "first" &&
+	git rebase -i --signoff HEAD^ &&
+	git cat-file commit HEAD | sed -e "1,/^\$/d" >actual &&
+	test_cmp expected-signed actual
+'
+
+test_expect_success 'rebase -m --signoff fails' '
+	git commit --amend -m "first" &&
+	git rebase -m --signoff HEAD^ &&
+	git cat-file commit HEAD | sed -e "1,/^\$/d" >actual &&
+	test_cmp expected-signed actual
+'
 test_done
diff --git a/t/t3510-cherry-pick-sequence.sh b/t/t3510-cherry-pick-sequence.sh
index 9f93445..21b4f19 100755
--- a/t/t3510-cherry-pick-sequence.sh
+++ b/t/t3510-cherry-pick-sequence.sh
@@ -247,9 +247,9 @@
 test_expect_success 'cherry-pick does not implicitly stomp an existing operation' '
 	pristine_detach initial &&
 	test_expect_code 1 git cherry-pick base..anotherpick &&
-	test-tool chmtime -v +0 .git/sequencer >expect &&
+	test-tool chmtime --get .git/sequencer >expect &&
 	test_expect_code 128 git cherry-pick unrelatedpick &&
-	test-tool chmtime -v +0 .git/sequencer >actual &&
+	test-tool chmtime --get .git/sequencer >actual &&
 	test_cmp expect actual
 '
 
diff --git a/t/t4200-rerere.sh b/t/t4200-rerere.sh
index deafaa3..eaf18c8 100755
--- a/t/t4200-rerere.sh
+++ b/t/t4200-rerere.sh
@@ -166,7 +166,7 @@
 	git commit -q -a -m "prefer first over second" &&
 	test -f $rr/postimage &&
 
-	oldmtimepost=$(test-tool chmtime -v -60 $rr/postimage | cut -f 1) &&
+	oldmtimepost=$(test-tool chmtime --get -60 $rr/postimage) &&
 
 	git checkout -b third master &&
 	git show second^:a1 | sed "s/To die: t/To die! T/" >a1 &&
@@ -179,7 +179,7 @@
 '
 
 test_expect_success 'rerere updates postimage timestamp' '
-	newmtimepost=$(test-tool chmtime -v +0 $rr/postimage | cut -f 1) &&
+	newmtimepost=$(test-tool chmtime --get $rr/postimage) &&
 	test $oldmtimepost -lt $newmtimepost
 '
 
@@ -512,7 +512,7 @@
 	count_pre_post 2 0 &&
 
 	# Pretend that the conflicts were made quite some time ago
-	find .git/rr-cache/ -type f | xargs test-tool chmtime -172800 &&
+	test-tool chmtime -172800 $(find .git/rr-cache/ -type f) &&
 
 	# Unresolved entries have not expired yet
 	git -c gc.rerereresolved=5 -c gc.rerereunresolved=5 rerere gc &&
@@ -568,7 +568,7 @@
 	git rerere &&
 
 	# Pretend that the resolutions are old again
-	find .git/rr-cache/ -type f | xargs test-tool chmtime -172800 &&
+	test-tool chmtime -172800 $(find .git/rr-cache/ -type f) &&
 
 	# Resolved entries have not expired yet
 	git -c gc.rerereresolved=5 -c gc.rerereunresolved=5 rerere gc &&
diff --git a/t/t5000-tar-tree.sh b/t/t5000-tar-tree.sh
index af4d9b8..2a97b27 100755
--- a/t/t5000-tar-tree.sh
+++ b/t/t5000-tar-tree.sh
@@ -192,7 +192,7 @@
     'validate file modification time' \
     'mkdir extract &&
      "$TAR" xf b.tar -C extract a/a &&
-     test-tool chmtime -v +0 extract/a/a |cut -f 1 >b.mtime &&
+     test-tool chmtime --get extract/a/a >b.mtime &&
      echo "1117231200" >expected.mtime &&
      test_cmp expected.mtime b.mtime'
 
diff --git a/t/t5304-prune.sh b/t/t5304-prune.sh
index f0f6e2a..f20f03c 100755
--- a/t/t5304-prune.sh
+++ b/t/t5304-prune.sh
@@ -320,4 +320,14 @@
 	test_cmp expected actual
 '
 
+test_expect_success 'prune: handle expire option correctly' '
+	test_must_fail git prune --expire 2>error &&
+	test_i18ngrep "requires a value" error &&
+
+	test_must_fail git prune --expire=nyah 2>error &&
+	test_i18ngrep "malformed expiration" error &&
+
+	git prune --no-expire
+'
+
 test_done
diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
new file mode 100755
index 0000000..a380419
--- /dev/null
+++ b/t/t5318-commit-graph.sh
@@ -0,0 +1,224 @@
+#!/bin/sh
+
+test_description='commit graph'
+. ./test-lib.sh
+
+test_expect_success 'setup full repo' '
+	mkdir full &&
+	cd "$TRASH_DIRECTORY/full" &&
+	git init &&
+	git config core.commitGraph true &&
+	objdir=".git/objects"
+'
+
+test_expect_success 'write graph with no packs' '
+	cd "$TRASH_DIRECTORY/full" &&
+	git commit-graph write --object-dir . &&
+	test_path_is_file info/commit-graph
+'
+
+test_expect_success 'create commits and repack' '
+	cd "$TRASH_DIRECTORY/full" &&
+	for i in $(test_seq 3)
+	do
+		test_commit $i &&
+		git branch commits/$i
+	done &&
+	git repack
+'
+
+graph_git_two_modes() {
+	git -c core.graph=true $1 >output
+	git -c core.graph=false $1 >expect
+	test_cmp output expect
+}
+
+graph_git_behavior() {
+	MSG=$1
+	DIR=$2
+	BRANCH=$3
+	COMPARE=$4
+	test_expect_success "check normal git operations: $MSG" '
+		cd "$TRASH_DIRECTORY/$DIR" &&
+		graph_git_two_modes "log --oneline $BRANCH" &&
+		graph_git_two_modes "log --topo-order $BRANCH" &&
+		graph_git_two_modes "log --graph $COMPARE..$BRANCH" &&
+		graph_git_two_modes "branch -vv" &&
+		graph_git_two_modes "merge-base -a $BRANCH $COMPARE"
+	'
+}
+
+graph_git_behavior 'no graph' full commits/3 commits/1
+
+graph_read_expect() {
+	OPTIONAL=""
+	NUM_CHUNKS=3
+	if test ! -z $2
+	then
+		OPTIONAL=" $2"
+		NUM_CHUNKS=$((3 + $(echo "$2" | wc -w)))
+	fi
+	cat >expect <<- EOF
+	header: 43475048 1 1 $NUM_CHUNKS 0
+	num_commits: $1
+	chunks: oid_fanout oid_lookup commit_metadata$OPTIONAL
+	EOF
+	git commit-graph read >output &&
+	test_cmp expect output
+}
+
+test_expect_success 'write graph' '
+	cd "$TRASH_DIRECTORY/full" &&
+	graph1=$(git commit-graph write) &&
+	test_path_is_file $objdir/info/commit-graph &&
+	graph_read_expect "3"
+'
+
+graph_git_behavior 'graph exists' full commits/3 commits/1
+
+test_expect_success 'Add more commits' '
+	cd "$TRASH_DIRECTORY/full" &&
+	git reset --hard commits/1 &&
+	for i in $(test_seq 4 5)
+	do
+		test_commit $i &&
+		git branch commits/$i
+	done &&
+	git reset --hard commits/2 &&
+	for i in $(test_seq 6 7)
+	do
+		test_commit $i &&
+		git branch commits/$i
+	done &&
+	git reset --hard commits/2 &&
+	git merge commits/4 &&
+	git branch merge/1 &&
+	git reset --hard commits/4 &&
+	git merge commits/6 &&
+	git branch merge/2 &&
+	git reset --hard commits/3 &&
+	git merge commits/5 commits/7 &&
+	git branch merge/3 &&
+	git repack
+'
+
+# Current graph structure:
+#
+#   __M3___
+#  /   |   \
+# 3 M1 5 M2 7
+# |/  \|/  \|
+# 2    4    6
+# |___/____/
+# 1
+
+test_expect_success 'write graph with merges' '
+	cd "$TRASH_DIRECTORY/full" &&
+	git commit-graph write &&
+	test_path_is_file $objdir/info/commit-graph &&
+	graph_read_expect "10" "large_edges"
+'
+
+graph_git_behavior 'merge 1 vs 2' full merge/1 merge/2
+graph_git_behavior 'merge 1 vs 3' full merge/1 merge/3
+graph_git_behavior 'merge 2 vs 3' full merge/2 merge/3
+
+test_expect_success 'Add one more commit' '
+	cd "$TRASH_DIRECTORY/full" &&
+	test_commit 8 &&
+	git branch commits/8 &&
+	ls $objdir/pack | grep idx >existing-idx &&
+	git repack &&
+	ls $objdir/pack| grep idx | grep -v --file=existing-idx >new-idx
+'
+
+# Current graph structure:
+#
+#      8
+#      |
+#   __M3___
+#  /   |   \
+# 3 M1 5 M2 7
+# |/  \|/  \|
+# 2    4    6
+# |___/____/
+# 1
+
+graph_git_behavior 'mixed mode, commit 8 vs merge 1' full commits/8 merge/1
+graph_git_behavior 'mixed mode, commit 8 vs merge 2' full commits/8 merge/2
+
+test_expect_success 'write graph with new commit' '
+	cd "$TRASH_DIRECTORY/full" &&
+	git commit-graph write &&
+	test_path_is_file $objdir/info/commit-graph &&
+	graph_read_expect "11" "large_edges"
+'
+
+graph_git_behavior 'full graph, commit 8 vs merge 1' full commits/8 merge/1
+graph_git_behavior 'full graph, commit 8 vs merge 2' full commits/8 merge/2
+
+test_expect_success 'write graph with nothing new' '
+	cd "$TRASH_DIRECTORY/full" &&
+	git commit-graph write &&
+	test_path_is_file $objdir/info/commit-graph &&
+	graph_read_expect "11" "large_edges"
+'
+
+graph_git_behavior 'cleared graph, commit 8 vs merge 1' full commits/8 merge/1
+graph_git_behavior 'cleared graph, commit 8 vs merge 2' full commits/8 merge/2
+
+test_expect_success 'build graph from latest pack with closure' '
+	cd "$TRASH_DIRECTORY/full" &&
+	cat new-idx | git commit-graph write --stdin-packs &&
+	test_path_is_file $objdir/info/commit-graph &&
+	graph_read_expect "9" "large_edges"
+'
+
+graph_git_behavior 'graph from pack, commit 8 vs merge 1' full commits/8 merge/1
+graph_git_behavior 'graph from pack, commit 8 vs merge 2' full commits/8 merge/2
+
+test_expect_success 'build graph from commits with closure' '
+	cd "$TRASH_DIRECTORY/full" &&
+	git tag -a -m "merge" tag/merge merge/2 &&
+	git rev-parse tag/merge >commits-in &&
+	git rev-parse merge/1 >>commits-in &&
+	cat commits-in | git commit-graph write --stdin-commits &&
+	test_path_is_file $objdir/info/commit-graph &&
+	graph_read_expect "6"
+'
+
+graph_git_behavior 'graph from commits, commit 8 vs merge 1' full commits/8 merge/1
+graph_git_behavior 'graph from commits, commit 8 vs merge 2' full commits/8 merge/2
+
+test_expect_success 'build graph from commits with append' '
+	cd "$TRASH_DIRECTORY/full" &&
+	git rev-parse merge/3 | git commit-graph write --stdin-commits --append &&
+	test_path_is_file $objdir/info/commit-graph &&
+	graph_read_expect "10" "large_edges"
+'
+
+graph_git_behavior 'append graph, commit 8 vs merge 1' full commits/8 merge/1
+graph_git_behavior 'append graph, commit 8 vs merge 2' full commits/8 merge/2
+
+test_expect_success 'setup bare repo' '
+	cd "$TRASH_DIRECTORY" &&
+	git clone --bare --no-local full bare &&
+	cd bare &&
+	git config core.commitGraph true &&
+	baredir="./objects"
+'
+
+graph_git_behavior 'bare repo, commit 8 vs merge 1' bare commits/8 merge/1
+graph_git_behavior 'bare repo, commit 8 vs merge 2' bare commits/8 merge/2
+
+test_expect_success 'write graph in bare repo' '
+	cd "$TRASH_DIRECTORY/bare" &&
+	git commit-graph write &&
+	test_path_is_file $baredir/info/commit-graph &&
+	graph_read_expect "11" "large_edges"
+'
+
+graph_git_behavior 'bare repo with graph, commit 8 vs merge 1' bare commits/8 merge/1
+graph_git_behavior 'bare repo with graph, commit 8 vs merge 2' bare commits/8 merge/2
+
+test_done
diff --git a/t/t5404-tracking-branches.sh b/t/t5404-tracking-branches.sh
index 2b8c0ba..2762f42 100755
--- a/t/t5404-tracking-branches.sh
+++ b/t/t5404-tracking-branches.sh
@@ -56,7 +56,7 @@
 test_expect_success 'already deleted tracking branches ignored' '
 	git branch -d -r origin/b3 &&
 	git push origin :b3 >output 2>&1 &&
-	! grep error output
+	! grep "^error: " output
 '
 
 test_done
diff --git a/t/t5512-ls-remote.sh b/t/t5512-ls-remote.sh
index 02106c9..83cd35c 100755
--- a/t/t5512-ls-remote.sh
+++ b/t/t5512-ls-remote.sh
@@ -10,6 +10,9 @@
 	test_tick &&
 	git commit -m initial &&
 	git tag mark &&
+	git tag mark1.1 &&
+	git tag mark1.2 &&
+	git tag mark1.10 &&
 	git show-ref --tags -d | sed -e "s/ /	/" >expected.tag &&
 	(
 		echo "$(git rev-parse HEAD)	HEAD"
@@ -39,6 +42,39 @@
 	test_cmp expected.all actual
 '
 
+test_expect_success 'ls-remote --sort="version:refname" --tags self' '
+	cat >expect <<-EOF &&
+	$(git rev-parse mark)	refs/tags/mark
+	$(git rev-parse mark1.1)	refs/tags/mark1.1
+	$(git rev-parse mark1.2)	refs/tags/mark1.2
+	$(git rev-parse mark1.10)	refs/tags/mark1.10
+	EOF
+	git ls-remote --sort="version:refname" --tags self >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'ls-remote --sort="-version:refname" --tags self' '
+	cat >expect <<-EOF &&
+	$(git rev-parse mark1.10)	refs/tags/mark1.10
+	$(git rev-parse mark1.2)	refs/tags/mark1.2
+	$(git rev-parse mark1.1)	refs/tags/mark1.1
+	$(git rev-parse mark)	refs/tags/mark
+	EOF
+	git ls-remote --sort="-version:refname" --tags self >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'ls-remote --sort="-refname" --tags self' '
+	cat >expect <<-EOF &&
+	$(git rev-parse mark1.2)	refs/tags/mark1.2
+	$(git rev-parse mark1.10)	refs/tags/mark1.10
+	$(git rev-parse mark1.1)	refs/tags/mark1.1
+	$(git rev-parse mark)	refs/tags/mark
+	EOF
+	git ls-remote --sort="-refname" --tags self >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'dies when no remote specified and no default remotes found' '
 	test_must_fail git ls-remote
 '
@@ -131,7 +167,7 @@
 
 test_expect_success 'Report match with --exit-code' '
 	git ls-remote --exit-code other.git "refs/tags/*" >actual &&
-	git ls-remote . tags/mark >expect &&
+	git ls-remote . tags/mark* >expect &&
 	test_cmp expect actual
 '
 
@@ -170,14 +206,18 @@
 	grep refs/tags/magic actual
 '
 
+git fetch origin
 test_expect_success 'ls-remote --symref' '
-	cat >expect <<-\EOF &&
+	cat >expect <<-EOF &&
 	ref: refs/heads/master	HEAD
-	1bd44cb9d13204b0fe1958db0082f5028a16eb3a	HEAD
-	1bd44cb9d13204b0fe1958db0082f5028a16eb3a	refs/heads/master
-	1bd44cb9d13204b0fe1958db0082f5028a16eb3a	refs/remotes/origin/HEAD
-	1bd44cb9d13204b0fe1958db0082f5028a16eb3a	refs/remotes/origin/master
-	1bd44cb9d13204b0fe1958db0082f5028a16eb3a	refs/tags/mark
+	$(git rev-parse HEAD)	HEAD
+	$(git rev-parse refs/heads/master)	refs/heads/master
+	$(git rev-parse HEAD)	refs/remotes/origin/HEAD
+	$(git rev-parse refs/remotes/origin/master)	refs/remotes/origin/master
+	$(git rev-parse refs/tags/mark)	refs/tags/mark
+	$(git rev-parse refs/tags/mark1.1)	refs/tags/mark1.1
+	$(git rev-parse refs/tags/mark1.10)	refs/tags/mark1.10
+	$(git rev-parse refs/tags/mark1.2)	refs/tags/mark1.2
 	EOF
 	git ls-remote --symref >actual &&
 	test_cmp expect actual
diff --git a/t/t5541-http-push-smart.sh b/t/t5541-http-push-smart.sh
index 21340e8..a2af693 100755
--- a/t/t5541-http-push-smart.sh
+++ b/t/t5541-http-push-smart.sh
@@ -377,5 +377,17 @@
 	grep "^To $HTTPD_URL/smart/test_repo.git" status
 '
 
+test_expect_success 'colorize errors/hints' '
+	cd "$ROOT_PATH"/test_repo_clone &&
+	test_must_fail git -c color.transport=always -c color.advice=always \
+		-c color.push=always \
+		push origin origin/master^:master 2>act &&
+	test_decode_color <act >decoded &&
+	test_i18ngrep "<RED>.*rejected.*<RESET>" decoded &&
+	test_i18ngrep "<RED>error: failed to push some refs" decoded &&
+	test_i18ngrep "<YELLOW>hint: " decoded &&
+	test_i18ngrep ! "^hint: " decoded
+'
+
 stop_httpd
 test_done
diff --git a/t/t5561-http-backend.sh b/t/t5561-http-backend.sh
index 90e0d6f..84a9557 100755
--- a/t/t5561-http-backend.sh
+++ b/t/t5561-http-backend.sh
@@ -3,10 +3,16 @@
 test_description='test git-http-backend'
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-httpd.sh
+
+if ! test_have_prereq CURL; then
+	skip_all='skipping raw http-backend tests, curl not available'
+	test_done
+fi
+
 start_httpd
 
 GET() {
-	curl --include "$HTTPD_URL/$SMART/repo.git/$1" >out 2>/dev/null &&
+	curl --include "$HTTPD_URL/$SMART/repo.git/$1" >out &&
 	tr '\015' Q <out |
 	sed '
 		s/Q$//
@@ -19,7 +25,7 @@
 POST() {
 	curl --include --data "$2" \
 	--header "Content-Type: application/x-$1-request" \
-	"$HTTPD_URL/smart/repo.git/$1" >out 2>/dev/null &&
+	"$HTTPD_URL/smart/repo.git/$1" >out &&
 	tr '\015' Q <out |
 	sed '
 		s/Q$//
diff --git a/t/t5701-git-serve.sh b/t/t5701-git-serve.sh
new file mode 100755
index 0000000..72d7bc5
--- /dev/null
+++ b/t/t5701-git-serve.sh
@@ -0,0 +1,176 @@
+#!/bin/sh
+
+test_description='test git-serve and server commands'
+
+. ./test-lib.sh
+
+test_expect_success 'test capability advertisement' '
+	cat >expect <<-EOF &&
+	version 2
+	agent=git/$(git version | cut -d" " -f3)
+	ls-refs
+	fetch=shallow
+	0000
+	EOF
+
+	git serve --advertise-capabilities >out &&
+	test-pkt-line unpack <out >actual &&
+	test_cmp actual expect
+'
+
+test_expect_success 'stateless-rpc flag does not list capabilities' '
+	# Empty request
+	test-pkt-line pack >in <<-EOF &&
+	0000
+	EOF
+	git serve --stateless-rpc >out <in &&
+	test_must_be_empty out &&
+
+	# EOF
+	git serve --stateless-rpc >out &&
+	test_must_be_empty out
+'
+
+test_expect_success 'request invalid capability' '
+	test-pkt-line pack >in <<-EOF &&
+	foobar
+	0000
+	EOF
+	test_must_fail git serve --stateless-rpc 2>err <in &&
+	test_i18ngrep "unknown capability" err
+'
+
+test_expect_success 'request with no command' '
+	test-pkt-line pack >in <<-EOF &&
+	agent=git/test
+	0000
+	EOF
+	test_must_fail git serve --stateless-rpc 2>err <in &&
+	test_i18ngrep "no command requested" err
+'
+
+test_expect_success 'request invalid command' '
+	test-pkt-line pack >in <<-EOF &&
+	command=foo
+	agent=git/test
+	0000
+	EOF
+	test_must_fail git serve --stateless-rpc 2>err <in &&
+	test_i18ngrep "invalid command" err
+'
+
+# Test the basics of ls-refs
+#
+test_expect_success 'setup some refs and tags' '
+	test_commit one &&
+	git branch dev master &&
+	test_commit two &&
+	git symbolic-ref refs/heads/release refs/heads/master &&
+	git tag -a -m "annotated tag" annotated-tag
+'
+
+test_expect_success 'basics of ls-refs' '
+	test-pkt-line pack >in <<-EOF &&
+	command=ls-refs
+	0000
+	EOF
+
+	cat >expect <<-EOF &&
+	$(git rev-parse HEAD) HEAD
+	$(git rev-parse refs/heads/dev) refs/heads/dev
+	$(git rev-parse refs/heads/master) refs/heads/master
+	$(git rev-parse refs/heads/release) refs/heads/release
+	$(git rev-parse refs/tags/annotated-tag) refs/tags/annotated-tag
+	$(git rev-parse refs/tags/one) refs/tags/one
+	$(git rev-parse refs/tags/two) refs/tags/two
+	0000
+	EOF
+
+	git serve --stateless-rpc <in >out &&
+	test-pkt-line unpack <out >actual &&
+	test_cmp actual expect
+'
+
+test_expect_success 'basic ref-prefixes' '
+	test-pkt-line pack >in <<-EOF &&
+	command=ls-refs
+	0001
+	ref-prefix refs/heads/master
+	ref-prefix refs/tags/one
+	0000
+	EOF
+
+	cat >expect <<-EOF &&
+	$(git rev-parse refs/heads/master) refs/heads/master
+	$(git rev-parse refs/tags/one) refs/tags/one
+	0000
+	EOF
+
+	git serve --stateless-rpc <in >out &&
+	test-pkt-line unpack <out >actual &&
+	test_cmp actual expect
+'
+
+test_expect_success 'refs/heads prefix' '
+	test-pkt-line pack >in <<-EOF &&
+	command=ls-refs
+	0001
+	ref-prefix refs/heads/
+	0000
+	EOF
+
+	cat >expect <<-EOF &&
+	$(git rev-parse refs/heads/dev) refs/heads/dev
+	$(git rev-parse refs/heads/master) refs/heads/master
+	$(git rev-parse refs/heads/release) refs/heads/release
+	0000
+	EOF
+
+	git serve --stateless-rpc <in >out &&
+	test-pkt-line unpack <out >actual &&
+	test_cmp actual expect
+'
+
+test_expect_success 'peel parameter' '
+	test-pkt-line pack >in <<-EOF &&
+	command=ls-refs
+	0001
+	peel
+	ref-prefix refs/tags/
+	0000
+	EOF
+
+	cat >expect <<-EOF &&
+	$(git rev-parse refs/tags/annotated-tag) refs/tags/annotated-tag peeled:$(git rev-parse refs/tags/annotated-tag^{})
+	$(git rev-parse refs/tags/one) refs/tags/one
+	$(git rev-parse refs/tags/two) refs/tags/two
+	0000
+	EOF
+
+	git serve --stateless-rpc <in >out &&
+	test-pkt-line unpack <out >actual &&
+	test_cmp actual expect
+'
+
+test_expect_success 'symrefs parameter' '
+	test-pkt-line pack >in <<-EOF &&
+	command=ls-refs
+	0001
+	symrefs
+	ref-prefix refs/heads/
+	0000
+	EOF
+
+	cat >expect <<-EOF &&
+	$(git rev-parse refs/heads/dev) refs/heads/dev
+	$(git rev-parse refs/heads/master) refs/heads/master
+	$(git rev-parse refs/heads/release) refs/heads/release symref-target:refs/heads/master
+	0000
+	EOF
+
+	git serve --stateless-rpc <in >out &&
+	test-pkt-line unpack <out >actual &&
+	test_cmp actual expect
+'
+
+test_done
diff --git a/t/t5702-protocol-v2.sh b/t/t5702-protocol-v2.sh
new file mode 100755
index 0000000..56f7c3c
--- /dev/null
+++ b/t/t5702-protocol-v2.sh
@@ -0,0 +1,273 @@
+#!/bin/sh
+
+test_description='test git wire-protocol version 2'
+
+TEST_NO_CREATE_REPO=1
+
+. ./test-lib.sh
+
+# Test protocol v2 with 'git://' transport
+#
+. "$TEST_DIRECTORY"/lib-git-daemon.sh
+start_git_daemon --export-all --enable=receive-pack
+daemon_parent=$GIT_DAEMON_DOCUMENT_ROOT_PATH/parent
+
+test_expect_success 'create repo to be served by git-daemon' '
+	git init "$daemon_parent" &&
+	test_commit -C "$daemon_parent" one
+'
+
+test_expect_success 'list refs with git:// using protocol v2' '
+	test_when_finished "rm -f log" &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -c protocol.version=2 \
+		ls-remote --symref "$GIT_DAEMON_URL/parent" >actual &&
+
+	# Client requested to use protocol v2
+	grep "git> .*\\\0\\\0version=2\\\0$" log &&
+	# Server responded using protocol v2
+	grep "git< version 2" log &&
+
+	git ls-remote --symref "$GIT_DAEMON_URL/parent" >expect &&
+	test_cmp actual expect
+'
+
+test_expect_success 'ref advertisment is filtered with ls-remote using protocol v2' '
+	test_when_finished "rm -f log" &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -c protocol.version=2 \
+		ls-remote "$GIT_DAEMON_URL/parent" master >actual &&
+
+	cat >expect <<-EOF &&
+	$(git -C "$daemon_parent" rev-parse refs/heads/master)$(printf "\t")refs/heads/master
+	EOF
+
+	test_cmp actual expect
+'
+
+test_expect_success 'clone with git:// using protocol v2' '
+	test_when_finished "rm -f log" &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -c protocol.version=2 \
+		clone "$GIT_DAEMON_URL/parent" daemon_child &&
+
+	git -C daemon_child log -1 --format=%s >actual &&
+	git -C "$daemon_parent" log -1 --format=%s >expect &&
+	test_cmp expect actual &&
+
+	# Client requested to use protocol v2
+	grep "clone> .*\\\0\\\0version=2\\\0$" log &&
+	# Server responded using protocol v2
+	grep "clone< version 2" log
+'
+
+test_expect_success 'fetch with git:// using protocol v2' '
+	test_when_finished "rm -f log" &&
+
+	test_commit -C "$daemon_parent" two &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -C daemon_child -c protocol.version=2 \
+		fetch &&
+
+	git -C daemon_child log -1 --format=%s origin/master >actual &&
+	git -C "$daemon_parent" log -1 --format=%s >expect &&
+	test_cmp expect actual &&
+
+	# Client requested to use protocol v2
+	grep "fetch> .*\\\0\\\0version=2\\\0$" log &&
+	# Server responded using protocol v2
+	grep "fetch< version 2" log
+'
+
+test_expect_success 'pull with git:// using protocol v2' '
+	test_when_finished "rm -f log" &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -C daemon_child -c protocol.version=2 \
+		pull &&
+
+	git -C daemon_child log -1 --format=%s >actual &&
+	git -C "$daemon_parent" log -1 --format=%s >expect &&
+	test_cmp expect actual &&
+
+	# Client requested to use protocol v2
+	grep "fetch> .*\\\0\\\0version=2\\\0$" log &&
+	# Server responded using protocol v2
+	grep "fetch< version 2" log
+'
+
+test_expect_success 'push with git:// and a config of v2 does not request v2' '
+	test_when_finished "rm -f log" &&
+
+	# Till v2 for push is designed, make sure that if a client has
+	# protocol.version configured to use v2, that the client instead falls
+	# back and uses v0.
+
+	test_commit -C daemon_child three &&
+
+	# Push to another branch, as the target repository has the
+	# master branch checked out and we cannot push into it.
+	GIT_TRACE_PACKET="$(pwd)/log" git -C daemon_child -c protocol.version=2 \
+		push origin HEAD:client_branch &&
+
+	git -C daemon_child log -1 --format=%s >actual &&
+	git -C "$daemon_parent" log -1 --format=%s client_branch >expect &&
+	test_cmp expect actual &&
+
+	# Client requested to use protocol v2
+	! grep "push> .*\\\0\\\0version=2\\\0$" log &&
+	# Server responded using protocol v2
+	! grep "push< version 2" log
+'
+
+stop_git_daemon
+
+# Test protocol v2 with 'file://' transport
+#
+test_expect_success 'create repo to be served by file:// transport' '
+	git init file_parent &&
+	test_commit -C file_parent one
+'
+
+test_expect_success 'list refs with file:// using protocol v2' '
+	test_when_finished "rm -f log" &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -c protocol.version=2 \
+		ls-remote --symref "file://$(pwd)/file_parent" >actual &&
+
+	# Server responded using protocol v2
+	grep "git< version 2" log &&
+
+	git ls-remote --symref "file://$(pwd)/file_parent" >expect &&
+	test_cmp actual expect
+'
+
+test_expect_success 'ref advertisment is filtered with ls-remote using protocol v2' '
+	test_when_finished "rm -f log" &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -c protocol.version=2 \
+		ls-remote "file://$(pwd)/file_parent" master >actual &&
+
+	cat >expect <<-EOF &&
+	$(git -C file_parent rev-parse refs/heads/master)$(printf "\t")refs/heads/master
+	EOF
+
+	test_cmp actual expect
+'
+
+test_expect_success 'clone with file:// using protocol v2' '
+	test_when_finished "rm -f log" &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -c protocol.version=2 \
+		clone "file://$(pwd)/file_parent" file_child &&
+
+	git -C file_child log -1 --format=%s >actual &&
+	git -C file_parent log -1 --format=%s >expect &&
+	test_cmp expect actual &&
+
+	# Server responded using protocol v2
+	grep "clone< version 2" log
+'
+
+test_expect_success 'fetch with file:// using protocol v2' '
+	test_when_finished "rm -f log" &&
+
+	test_commit -C file_parent two &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -C file_child -c protocol.version=2 \
+		fetch origin &&
+
+	git -C file_child log -1 --format=%s origin/master >actual &&
+	git -C file_parent log -1 --format=%s >expect &&
+	test_cmp expect actual &&
+
+	# Server responded using protocol v2
+	grep "fetch< version 2" log
+'
+
+test_expect_success 'ref advertisment is filtered during fetch using protocol v2' '
+	test_when_finished "rm -f log" &&
+
+	test_commit -C file_parent three &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -C file_child -c protocol.version=2 \
+		fetch origin master &&
+
+	git -C file_child log -1 --format=%s origin/master >actual &&
+	git -C file_parent log -1 --format=%s >expect &&
+	test_cmp expect actual &&
+
+	! grep "refs/tags/one" log &&
+	! grep "refs/tags/two" log &&
+	! grep "refs/tags/three" log
+'
+
+# Test protocol v2 with 'http://' transport
+#
+. "$TEST_DIRECTORY"/lib-httpd.sh
+start_httpd
+
+test_expect_success 'create repo to be served by http:// transport' '
+	git init "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" &&
+	git -C "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" config http.receivepack true &&
+	test_commit -C "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" one
+'
+
+test_expect_success 'clone with http:// using protocol v2' '
+	test_when_finished "rm -f log" &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" GIT_TRACE_CURL="$(pwd)/log" git -c protocol.version=2 \
+		clone "$HTTPD_URL/smart/http_parent" http_child &&
+
+	git -C http_child log -1 --format=%s >actual &&
+	git -C "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" log -1 --format=%s >expect &&
+	test_cmp expect actual &&
+
+	# Client requested to use protocol v2
+	grep "Git-Protocol: version=2" log &&
+	# Server responded using protocol v2
+	grep "git< version 2" log
+'
+
+test_expect_success 'fetch with http:// using protocol v2' '
+	test_when_finished "rm -f log" &&
+
+	test_commit -C "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" two &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -C http_child -c protocol.version=2 \
+		fetch &&
+
+	git -C http_child log -1 --format=%s origin/master >actual &&
+	git -C "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" log -1 --format=%s >expect &&
+	test_cmp expect actual &&
+
+	# Server responded using protocol v2
+	grep "git< version 2" log
+'
+
+test_expect_success 'push with http:// and a config of v2 does not request v2' '
+	test_when_finished "rm -f log" &&
+	# Till v2 for push is designed, make sure that if a client has
+	# protocol.version configured to use v2, that the client instead falls
+	# back and uses v0.
+
+	test_commit -C http_child three &&
+
+	# Push to another branch, as the target repository has the
+	# master branch checked out and we cannot push into it.
+	GIT_TRACE_PACKET="$(pwd)/log" git -C http_child -c protocol.version=2 \
+		push origin HEAD:client_branch &&
+
+	git -C http_child log -1 --format=%s >actual &&
+	git -C "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" log -1 --format=%s client_branch >expect &&
+	test_cmp expect actual &&
+
+	# Client didnt request to use protocol v2
+	! grep "Git-Protocol: version=2" log &&
+	# Server didnt respond using protocol v2
+	! grep "git< version 2" log
+'
+
+
+stop_httpd
+
+test_done
diff --git a/t/t6022-merge-rename.sh b/t/t6022-merge-rename.sh
index a1fad69..48747e7 100755
--- a/t/t6022-merge-rename.sh
+++ b/t/t6022-merge-rename.sh
@@ -635,10 +635,9 @@
 
 test_expect_success 'avoid unnecessary update, normal rename' '
 	git checkout -q avoid-unnecessary-update-1^0 &&
-	test-tool chmtime =1000000000 rename &&
-	test-tool chmtime -v +0 rename >expect &&
+	test-tool chmtime --get =1000000000 rename >expect &&
 	git merge merge-branch-1 &&
-	test-tool chmtime -v +0 rename >actual &&
+	test-tool chmtime --get rename >actual &&
 	test_cmp expect actual # "rename" should have stayed intact
 '
 
@@ -668,10 +667,9 @@
 
 test_expect_success 'avoid unnecessary update, with D/F conflict' '
 	git checkout -q avoid-unnecessary-update-2^0 &&
-	test-tool chmtime =1000000000 df &&
-	test-tool chmtime -v +0 df >expect &&
+	test-tool chmtime --get =1000000000 df >expect &&
 	git merge merge-branch-2 &&
-	test-tool chmtime -v +0 df >actual &&
+	test-tool chmtime --get df >actual &&
 	test_cmp expect actual # "df" should have stayed intact
 '
 
@@ -700,10 +698,9 @@
 
 test_expect_success 'avoid unnecessary update, dir->(file,nothing)' '
 	git checkout -q master^0 &&
-	test-tool chmtime =1000000000 df &&
-	test-tool chmtime -v +0 df >expect &&
+	test-tool chmtime --get =1000000000 df >expect &&
 	git merge side &&
-	test-tool chmtime -v +0 df >actual &&
+	test-tool chmtime --get df >actual &&
 	test_cmp expect actual # "df" should have stayed intact
 '
 
@@ -730,10 +727,9 @@
 
 test_expect_success 'avoid unnecessary update, modify/delete' '
 	git checkout -q master^0 &&
-	test-tool chmtime =1000000000 file &&
-	test-tool chmtime -v +0 file >expect &&
+	test-tool chmtime --get =1000000000 file >expect &&
 	test_must_fail git merge side &&
-	test-tool chmtime -v +0 file >actual &&
+	test-tool chmtime --get file >actual &&
 	test_cmp expect actual # "file" should have stayed intact
 '
 
@@ -759,10 +755,9 @@
 
 test_expect_success 'avoid unnecessary update, rename/add-dest' '
 	git checkout -q master^0 &&
-	test-tool chmtime =1000000000 newfile &&
-	test-tool chmtime -v +0 newfile >expect &&
+	test-tool chmtime --get =1000000000 newfile >expect &&
 	git merge side &&
-	test-tool chmtime -v +0 newfile >actual &&
+	test-tool chmtime --get newfile >actual &&
 	test_cmp expect actual # "file" should have stayed intact
 '
 
diff --git a/t/t6501-freshen-objects.sh b/t/t6501-freshen-objects.sh
index 765cced..033871e 100755
--- a/t/t6501-freshen-objects.sh
+++ b/t/t6501-freshen-objects.sh
@@ -72,8 +72,7 @@
 	'
 
 	test_expect_success "simulate time passing ($title)" '
-		find .git/objects -type f |
-		xargs test-tool chmtime -v -86400
+		test-tool chmtime --get -86400 $(find .git/objects -type f)
 	'
 
 	test_expect_success "start writing new commit with old blob ($title)" '
@@ -103,8 +102,7 @@
 
 	test_expect_success "abandon objects again ($title)" '
 		git reset --hard HEAD^ &&
-		find .git/objects -type f |
-		xargs test-tool chmtime -v -86400
+		test-tool chmtime --get -86400 $(find .git/objects -type f)
 	'
 
 	test_expect_success "start writing new commit with same tree ($title)" '
diff --git a/t/t7001-mv.sh b/t/t7001-mv.sh
index e96cbdb..cc3fd2b 100755
--- a/t/t7001-mv.sh
+++ b/t/t7001-mv.sh
@@ -495,7 +495,7 @@
 	test_cmp expect actual
 '
 
-test_expect_failure 'moving nested submodules' '
+test_expect_success 'moving nested submodules' '
 	git commit -am "cleanup commit" &&
 	mkdir sub_nested_nested &&
 	(cd sub_nested_nested &&
diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
index 2aac77a..e3f1e01 100755
--- a/t/t7004-tag.sh
+++ b/t/t7004-tag.sh
@@ -1056,7 +1056,18 @@
 	git tag -s -F sigblanknonlfile blanknonlfile-signed-tag &&
 	get_tag_msg blanknonlfile-signed-tag >actual &&
 	test_cmp expect actual &&
-	git tag -v signed-tag
+	git tag -v blanknonlfile-signed-tag
+'
+
+test_expect_success GPG 'signed tag with embedded PGP message' '
+	cat >msg <<-\EOF &&
+	-----BEGIN PGP MESSAGE-----
+
+	this is not a real PGP message
+	-----END PGP MESSAGE-----
+	EOF
+	git tag -s -F msg confusing-pgp-message &&
+	git tag -v confusing-pgp-message
 '
 
 # messages with commented lines for signed tags:
diff --git a/t/t7501-commit.sh b/t/t7501-commit.sh
index fa61b1a..9dbbd01 100755
--- a/t/t7501-commit.sh
+++ b/t/t7501-commit.sh
@@ -52,6 +52,18 @@
 	git reset --hard HEAD^
 '
 
+test_expect_success 'removed files and relative paths' '
+	test_when_finished "rm -rf foo" &&
+	git init foo &&
+	>foo/foo.txt &&
+	git -C foo add foo.txt &&
+	git -C foo commit -m first &&
+	git -C foo rm foo.txt &&
+
+	mkdir -p foo/bar &&
+	git -C foo/bar commit -m second ../foo.txt
+'
+
 test_expect_success 'using invalid commit with -C' '
 	test_must_fail git commit --allow-empty -C bogus
 '
diff --git a/t/t7508-status.sh b/t/t7508-status.sh
index 7afadb1..18a4025 100755
--- a/t/t7508-status.sh
+++ b/t/t7508-status.sh
@@ -1674,10 +1674,10 @@
 test_expect_success '--no-optional-locks prevents index update' '
 	test-tool chmtime =1234567890 .git/index &&
 	git --no-optional-locks status &&
-	test-tool chmtime -v +0 .git/index >out &&
+	test-tool chmtime --get .git/index >out &&
 	grep ^1234567890 out &&
 	git status &&
-	test-tool chmtime -v +0 .git/index >out &&
+	test-tool chmtime --get .git/index >out &&
 	! grep ^1234567890 out
 '
 
diff --git a/t/t7701-repack-unpack-unreachable.sh b/t/t7701-repack-unpack-unreachable.sh
index 8a586ab..48261ba 100755
--- a/t/t7701-repack-unpack-unreachable.sh
+++ b/t/t7701-repack-unpack-unreachable.sh
@@ -55,8 +55,8 @@
 
 compare_mtimes ()
 {
-	read tref rest &&
-	while read t rest; do
+	read tref &&
+	while read t; do
 		test "$tref" = "$t" || return 1
 	done
 }
@@ -90,7 +90,7 @@
 	tmppack=".git/objects/pack/tmp_pack" &&
 	ln "$packfile" "$tmppack" &&
 	git repack -A -l -d &&
-	test-tool chmtime -v +0 "$tmppack" "$fsha1path" "$csha1path" "$tsha1path" \
+	test-tool chmtime --get "$tmppack" "$fsha1path" "$csha1path" "$tsha1path" \
 		> mtimes &&
 	compare_mtimes < mtimes
 '
diff --git a/t/t9130-git-svn-authors-file.sh b/t/t9130-git-svn-authors-file.sh
index 7752a1f..d826285 100755
--- a/t/t9130-git-svn-authors-file.sh
+++ b/t/t9130-git-svn-authors-file.sh
@@ -112,6 +112,20 @@
 	)
 '
 
+cat >> svn-authors <<EOF
+ff = FFFFFFF FFFFFFF <>
+EOF
+
+test_expect_success 'authors-file imported user without email' '
+	svn_cmd mkdir -m aa/branches/ff --username ff "$svnrepo/aa/branches/ff" &&
+	(
+		cd aa-work &&
+		git svn fetch --authors-file=../svn-authors &&
+		git rev-list -1 --pretty=raw refs/remotes/origin/ff | \
+		  grep "^author FFFFFFF FFFFFFF <> "
+	)
+	'
+
 test_debug 'GIT_DIR=gitconfig.clone/.git git log'
 
 test_done
diff --git a/t/t9138-git-svn-authors-prog.sh b/t/t9138-git-svn-authors-prog.sh
index 48109f9..93ef44f 100755
--- a/t/t9138-git-svn-authors-prog.sh
+++ b/t/t9138-git-svn-authors-prog.sh
@@ -9,7 +9,9 @@
 
 write_script svn-authors-prog "$PERL_PATH" <<-\EOF
 	$_ = shift;
-	if (s/-sub$//)  {
+	if (s/-hermit//) {
+		print "$_ <>\n";
+	} elsif (s/-sub$//)  {
 		print "$_ <$_\@sub.example.com>\n";
 	} else {
 		print "$_ <$_\@example.com>\n";
@@ -69,6 +71,28 @@
 git --git-dir=x/.git config --unset svn.authorsfile
 git --git-dir=x/.git config --unset svn.authorsprog
 
+test_expect_success 'authors-prog imported user without email' '
+	svn mkdir -m gg --username gg-hermit "$svnrepo"/gg &&
+	(
+		cd x &&
+		git svn fetch --authors-prog=../svn-authors-prog &&
+		git rev-list -1 --pretty=raw refs/remotes/git-svn | \
+		  grep "^author gg <> "
+	)
+'
+
+test_expect_success 'imported without authors-prog and authors-file' '
+	svn mkdir -m hh --username hh "$svnrepo"/hh &&
+	(
+		uuid=$(svn info "$svnrepo" |
+			sed -n "s/^Repository UUID: //p") &&
+		cd x &&
+		git svn fetch &&
+		git rev-list -1 --pretty=raw refs/remotes/git-svn | \
+		  grep "^author hh <hh@$uuid> "
+	)
+'
+
 test_expect_success 'authors-prog handled special characters in username' '
 	svn mkdir -m bad --username "xyz; touch evil" "$svnrepo"/bad &&
 	(
diff --git a/t/t9350-fast-export.sh b/t/t9350-fast-export.sh
index d5679ff..6a392e8 100755
--- a/t/t9350-fast-export.sh
+++ b/t/t9350-fast-export.sh
@@ -538,4 +538,22 @@
 	test_cmp expected actual
 '
 
+test_expect_success 'merge commit gets exported with --import-marks' '
+	test_create_repo merging &&
+	(
+		cd merging &&
+		test_commit initial &&
+		git checkout -b topic &&
+		test_commit on-topic &&
+		git checkout master &&
+		test_commit on-master &&
+		test_tick &&
+		git merge --no-ff -m Yeah topic &&
+
+		echo ":1 $(git rev-parse HEAD^^)" >marks &&
+		git fast-export --import-marks=marks master >out &&
+		grep Yeah out
+	)
+'
+
 test_done
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 483c8d6..ea2bbaa 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1208,3 +1208,7 @@
 
 test_lazy_prereq TIME_IS_64BIT 'test-tool date is64bit'
 test_lazy_prereq TIME_T_IS_64BIT 'test-tool date time_t-is64bit'
+
+test_lazy_prereq CURL '
+	curl --version
+'
diff --git a/trace.c b/trace.c
index 7f3b08e..fc623e9 100644
--- a/trace.c
+++ b/trace.c
@@ -26,6 +26,7 @@
 
 struct trace_key trace_default_key = { "GIT_TRACE", 0, 0, 0 };
 struct trace_key trace_perf_key = TRACE_KEY_INIT(PERFORMANCE);
+struct trace_key trace_setup_key = TRACE_KEY_INIT(SETUP);
 
 /* Get a trace file descriptor from "key" env variable. */
 static int get_trace_fd(struct trace_key *key)
@@ -300,11 +301,10 @@
 /* FIXME: move prefix to startup_info struct and get rid of this arg */
 void trace_repo_setup(const char *prefix)
 {
-	static struct trace_key key = TRACE_KEY_INIT(SETUP);
 	const char *git_work_tree;
 	char *cwd;
 
-	if (!trace_want(&key))
+	if (!trace_want(&trace_setup_key))
 		return;
 
 	cwd = xgetcwd();
@@ -315,11 +315,11 @@
 	if (!prefix)
 		prefix = "(null)";
 
-	trace_printf_key(&key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
-	trace_printf_key(&key, "setup: git_common_dir: %s\n", quote_crnl(get_git_common_dir()));
-	trace_printf_key(&key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
-	trace_printf_key(&key, "setup: cwd: %s\n", quote_crnl(cwd));
-	trace_printf_key(&key, "setup: prefix: %s\n", quote_crnl(prefix));
+	trace_printf_key(&trace_setup_key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
+	trace_printf_key(&trace_setup_key, "setup: git_common_dir: %s\n", quote_crnl(get_git_common_dir()));
+	trace_printf_key(&trace_setup_key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
+	trace_printf_key(&trace_setup_key, "setup: cwd: %s\n", quote_crnl(cwd));
+	trace_printf_key(&trace_setup_key, "setup: prefix: %s\n", quote_crnl(prefix));
 
 	free(cwd);
 }
diff --git a/trace.h b/trace.h
index 88055ab..2b6a1bc 100644
--- a/trace.h
+++ b/trace.h
@@ -15,6 +15,7 @@
 
 #define TRACE_KEY_INIT(name) { "GIT_TRACE_" #name, 0, 0, 0 }
 extern struct trace_key trace_perf_key;
+extern struct trace_key trace_setup_key;
 
 extern void trace_repo_setup(const char *prefix);
 extern int trace_want(struct trace_key *key);
diff --git a/transport-helper.c b/transport-helper.c
index 3f380d8..11f1055 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -12,6 +12,7 @@
 #include "argv-array.h"
 #include "refs.h"
 #include "transport-internal.h"
+#include "protocol.h"
 
 static int debug;
 
@@ -26,6 +27,7 @@
 		option : 1,
 		push : 1,
 		connect : 1,
+		stateless_connect : 1,
 		signed_tags : 1,
 		check_connectivity : 1,
 		no_disconnect_req : 1,
@@ -49,7 +51,7 @@
 		die_errno("Full write to remote helper failed");
 }
 
-static int recvline_fh(FILE *helper, struct strbuf *buffer, const char *name)
+static int recvline_fh(FILE *helper, struct strbuf *buffer)
 {
 	strbuf_reset(buffer);
 	if (debug)
@@ -67,7 +69,7 @@
 
 static int recvline(struct helper_data *helper, struct strbuf *buffer)
 {
-	return recvline_fh(helper->out, buffer, helper->name);
+	return recvline_fh(helper->out, buffer);
 }
 
 static void write_constant(int fd, const char *str)
@@ -188,6 +190,8 @@
 			refspecs[refspec_nr++] = xstrdup(arg);
 		} else if (!strcmp(capname, "connect")) {
 			data->connect = 1;
+		} else if (!strcmp(capname, "stateless-connect")) {
+			data->stateless_connect = 1;
 		} else if (!strcmp(capname, "signed-tags")) {
 			data->signed_tags = 1;
 		} else if (skip_prefix(capname, "export-marks ", &arg)) {
@@ -545,14 +549,13 @@
 	return 0;
 }
 
-static int process_connect_service(struct transport *transport,
-				   const char *name, const char *exec)
+static int run_connect(struct transport *transport, struct strbuf *cmdbuf)
 {
 	struct helper_data *data = transport->data;
-	struct strbuf cmdbuf = STRBUF_INIT;
-	struct child_process *helper;
-	int r, duped, ret = 0;
+	int ret = 0;
+	int duped;
 	FILE *input;
+	struct child_process *helper;
 
 	helper = get_helper(transport);
 
@@ -568,44 +571,61 @@
 	input = xfdopen(duped, "r");
 	setvbuf(input, NULL, _IONBF, 0);
 
+	sendline(data, cmdbuf);
+	if (recvline_fh(input, cmdbuf))
+		exit(128);
+
+	if (!strcmp(cmdbuf->buf, "")) {
+		data->no_disconnect_req = 1;
+		if (debug)
+			fprintf(stderr, "Debug: Smart transport connection "
+				"ready.\n");
+		ret = 1;
+	} else if (!strcmp(cmdbuf->buf, "fallback")) {
+		if (debug)
+			fprintf(stderr, "Debug: Falling back to dumb "
+				"transport.\n");
+	} else {
+		die("Unknown response to connect: %s",
+			cmdbuf->buf);
+	}
+
+	fclose(input);
+	return ret;
+}
+
+static int process_connect_service(struct transport *transport,
+				   const char *name, const char *exec)
+{
+	struct helper_data *data = transport->data;
+	struct strbuf cmdbuf = STRBUF_INIT;
+	int ret = 0;
+
 	/*
 	 * Handle --upload-pack and friends. This is fire and forget...
 	 * just warn if it fails.
 	 */
 	if (strcmp(name, exec)) {
-		r = set_helper_option(transport, "servpath", exec);
+		int r = set_helper_option(transport, "servpath", exec);
 		if (r > 0)
 			warning("Setting remote service path not supported by protocol.");
 		else if (r < 0)
 			warning("Invalid remote service path.");
 	}
 
-	if (data->connect)
+	if (data->connect) {
 		strbuf_addf(&cmdbuf, "connect %s\n", name);
-	else
-		goto exit;
+		ret = run_connect(transport, &cmdbuf);
+	} else if (data->stateless_connect &&
+		   (get_protocol_version_config() == protocol_v2) &&
+		   !strcmp("git-upload-pack", name)) {
+		strbuf_addf(&cmdbuf, "stateless-connect %s\n", name);
+		ret = run_connect(transport, &cmdbuf);
+		if (ret)
+			transport->stateless_rpc = 1;
+	}
 
-	sendline(data, &cmdbuf);
-	if (recvline_fh(input, &cmdbuf, name))
-		exit(128);
-
-	if (!strcmp(cmdbuf.buf, "")) {
-		data->no_disconnect_req = 1;
-		if (debug)
-			fprintf(stderr, "Debug: Smart transport connection "
-				"ready.\n");
-		ret = 1;
-	} else if (!strcmp(cmdbuf.buf, "fallback")) {
-		if (debug)
-			fprintf(stderr, "Debug: Falling back to dumb "
-				"transport.\n");
-	} else
-		die("Unknown response to connect: %s",
-			cmdbuf.buf);
-
-exit:
 	strbuf_release(&cmdbuf);
-	fclose(input);
 	return ret;
 }
 
@@ -1031,7 +1051,8 @@
 	}
 }
 
-static struct ref *get_refs_list(struct transport *transport, int for_push)
+static struct ref *get_refs_list(struct transport *transport, int for_push,
+				 const struct argv_array *ref_prefixes)
 {
 	struct helper_data *data = transport->data;
 	struct child_process *helper;
@@ -1044,7 +1065,7 @@
 
 	if (process_connect(transport, for_push)) {
 		do_take_over(transport);
-		return transport->vtable->get_refs_list(transport, for_push);
+		return transport->vtable->get_refs_list(transport, for_push, ref_prefixes);
 	}
 
 	if (data->push && for_push)
diff --git a/transport-internal.h b/transport-internal.h
index 3c1a29d..1cde625 100644
--- a/transport-internal.h
+++ b/transport-internal.h
@@ -3,6 +3,7 @@
 
 struct ref;
 struct transport;
+struct argv_array;
 
 struct transport_vtable {
 	/**
@@ -17,11 +18,19 @@
 	 * the transport to try to share connections, for_push is a
 	 * hint as to whether the ultimate operation is a push or a fetch.
 	 *
+	 * If communicating using protocol v2 a list of prefixes can be
+	 * provided to be sent to the server to enable it to limit the ref
+	 * advertisement.  Since ref filtering is done on the server's end, and
+	 * only when using protocol v2, this list will be ignored when not
+	 * using protocol v2 meaning this function can return refs which don't
+	 * match the provided ref_prefixes.
+	 *
 	 * If the transport is able to determine the remote hash for
 	 * the ref without a huge amount of effort, it should store it
 	 * in the ref's old_sha1 field; otherwise it should be all 0.
 	 **/
-	struct ref *(*get_refs_list)(struct transport *transport, int for_push);
+	struct ref *(*get_refs_list)(struct transport *transport, int for_push,
+				     const struct argv_array *ref_prefixes);
 
 	/**
 	 * Fetch the objects for the given refs. Note that this gets
diff --git a/transport.c b/transport.c
index 94eccf2..37410d8 100644
--- a/transport.c
+++ b/transport.c
@@ -18,7 +18,58 @@
 #include "sha1-array.h"
 #include "sigchain.h"
 #include "transport-internal.h"
+#include "protocol.h"
 #include "object-store.h"
+#include "color.h"
+
+static int transport_use_color = -1;
+static char transport_colors[][COLOR_MAXLEN] = {
+	GIT_COLOR_RESET,
+	GIT_COLOR_RED		/* REJECTED */
+};
+
+enum color_transport {
+	TRANSPORT_COLOR_RESET = 0,
+	TRANSPORT_COLOR_REJECTED = 1
+};
+
+static int transport_color_config(void)
+{
+	const char *keys[] = {
+		"color.transport.reset",
+		"color.transport.rejected"
+	}, *key = "color.transport";
+	char *value;
+	int i;
+	static int initialized;
+
+	if (initialized)
+		return 0;
+	initialized = 1;
+
+	if (!git_config_get_string(key, &value))
+		transport_use_color = git_config_colorbool(key, value);
+
+	if (!want_color_stderr(transport_use_color))
+		return 0;
+
+	for (i = 0; i < ARRAY_SIZE(keys); i++)
+		if (!git_config_get_string(keys[i], &value)) {
+			if (!value)
+				return config_error_nonbool(keys[i]);
+			if (color_parse(value, transport_colors[i]) < 0)
+				return -1;
+		}
+
+	return 0;
+}
+
+static const char *transport_get_color(enum color_transport ix)
+{
+	if (want_color_stderr(transport_use_color))
+		return transport_colors[ix];
+	return "";
+}
 
 static void set_upstreams(struct transport *transport, struct ref *refs,
 	int pretend)
@@ -72,7 +123,9 @@
 	struct bundle_header header;
 };
 
-static struct ref *get_refs_from_bundle(struct transport *transport, int for_push)
+static struct ref *get_refs_from_bundle(struct transport *transport,
+					int for_push,
+					const struct argv_array *ref_prefixes)
 {
 	struct bundle_transport_data *data = transport->data;
 	struct ref *result = NULL;
@@ -118,6 +171,7 @@
 	struct child_process *conn;
 	int fd[2];
 	unsigned got_remote_heads : 1;
+	enum protocol_version version;
 	struct oid_array extra_have;
 	struct oid_array shallow;
 };
@@ -197,16 +251,35 @@
 	return 0;
 }
 
-static struct ref *get_refs_via_connect(struct transport *transport, int for_push)
+static struct ref *get_refs_via_connect(struct transport *transport, int for_push,
+					const struct argv_array *ref_prefixes)
 {
 	struct git_transport_data *data = transport->data;
-	struct ref *refs;
+	struct ref *refs = NULL;
+	struct packet_reader reader;
 
 	connect_setup(transport, for_push);
-	get_remote_heads(data->fd[0], NULL, 0, &refs,
-			 for_push ? REF_NORMAL : 0,
-			 &data->extra_have,
-			 &data->shallow);
+
+	packet_reader_init(&reader, data->fd[0], NULL, 0,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_GENTLE_ON_EOF);
+
+	data->version = discover_version(&reader);
+	switch (data->version) {
+	case protocol_v2:
+		get_remote_refs(data->fd[1], &reader, &refs, for_push,
+				ref_prefixes);
+		break;
+	case protocol_v1:
+	case protocol_v0:
+		get_remote_heads(&reader, &refs,
+				 for_push ? REF_NORMAL : 0,
+				 &data->extra_have,
+				 &data->shallow);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
 	data->got_remote_heads = 1;
 
 	return refs;
@@ -217,7 +290,7 @@
 {
 	int ret = 0;
 	struct git_transport_data *data = transport->data;
-	struct ref *refs;
+	struct ref *refs = NULL;
 	char *dest = xstrdup(transport->url);
 	struct fetch_pack_args args;
 	struct ref *refs_tmp = NULL;
@@ -242,18 +315,29 @@
 	args.from_promisor = data->options.from_promisor;
 	args.no_dependents = data->options.no_dependents;
 	args.filter_options = data->options.filter_options;
+	args.stateless_rpc = transport->stateless_rpc;
 
-	if (!data->got_remote_heads) {
-		connect_setup(transport, 0);
-		get_remote_heads(data->fd[0], NULL, 0, &refs_tmp, 0,
-				 NULL, &data->shallow);
-		data->got_remote_heads = 1;
+	if (!data->got_remote_heads)
+		refs_tmp = get_refs_via_connect(transport, 0, NULL);
+
+	switch (data->version) {
+	case protocol_v2:
+		refs = fetch_pack(&args, data->fd, data->conn,
+				  refs_tmp ? refs_tmp : transport->remote_refs,
+				  dest, to_fetch, nr_heads, &data->shallow,
+				  &transport->pack_lockfile, data->version);
+		break;
+	case protocol_v1:
+	case protocol_v0:
+		refs = fetch_pack(&args, data->fd, data->conn,
+				  refs_tmp ? refs_tmp : transport->remote_refs,
+				  dest, to_fetch, nr_heads, &data->shallow,
+				  &transport->pack_lockfile, data->version);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
 	}
 
-	refs = fetch_pack(&args, data->fd, data->conn,
-			  refs_tmp ? refs_tmp : transport->remote_refs,
-			  dest, to_fetch, nr_heads, &data->shallow,
-			  &transport->pack_lockfile);
 	close(data->fd[0]);
 	close(data->fd[1]);
 	if (finish_connect(data->conn))
@@ -339,7 +423,13 @@
 		else
 			fprintf(stdout, "%s\n", summary);
 	} else {
-		fprintf(stderr, " %c %-*s ", flag, summary_width, summary);
+		const char *red = "", *reset = "";
+		if (push_had_errors(to)) {
+			red = transport_get_color(TRANSPORT_COLOR_REJECTED);
+			reset = transport_get_color(TRANSPORT_COLOR_RESET);
+		}
+		fprintf(stderr, " %s%c %-*s%s ", red, flag, summary_width,
+			summary, reset);
 		if (from)
 			fprintf(stderr, "%s -> %s", prettify_refname(from->name), prettify_refname(to->name));
 		else
@@ -488,6 +578,9 @@
 	char *head;
 	int summary_width = transport_summary_width(refs);
 
+	if (transport_color_config() < 0)
+		warning(_("could not parse transport.color.* config"));
+
 	head = resolve_refdup("HEAD", RESOLVE_REF_READING, NULL, NULL);
 
 	if (verbose) {
@@ -552,16 +645,13 @@
 {
 	struct git_transport_data *data = transport->data;
 	struct send_pack_args args;
-	int ret;
+	int ret = 0;
 
-	if (!data->got_remote_heads) {
-		struct ref *tmp_refs;
-		connect_setup(transport, 1);
+	if (transport_color_config() < 0)
+		return -1;
 
-		get_remote_heads(data->fd[0], NULL, 0, &tmp_refs, REF_NORMAL,
-				 NULL, &data->shallow);
-		data->got_remote_heads = 1;
-	}
+	if (!data->got_remote_heads)
+		get_refs_via_connect(transport, 1, NULL);
 
 	memset(&args, 0, sizeof(args));
 	args.send_mirror = !!(flags & TRANSPORT_PUSH_MIRROR);
@@ -583,8 +673,18 @@
 	else
 		args.push_cert = SEND_PACK_PUSH_CERT_NEVER;
 
-	ret = send_pack(&args, data->fd, data->conn, remote_refs,
-			&data->extra_have);
+	switch (data->version) {
+	case protocol_v2:
+		die("support for protocol v2 not implemented yet");
+		break;
+	case protocol_v1:
+	case protocol_v0:
+		ret = send_pack(&args, data->fd, data->conn, remote_refs,
+				&data->extra_have);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
 
 	close(data->fd[1]);
 	close(data->fd[0]);
@@ -998,6 +1098,9 @@
 	*reject_reasons = 0;
 	transport_verify_remote_names(refspec_nr, refspec);
 
+	if (transport_color_config() < 0)
+		return -1;
+
 	if (transport->vtable->push_refs) {
 		struct ref *remote_refs;
 		struct ref *local_refs = get_local_heads();
@@ -1007,11 +1110,38 @@
 		int porcelain = flags & TRANSPORT_PUSH_PORCELAIN;
 		int pretend = flags & TRANSPORT_PUSH_DRY_RUN;
 		int push_ret, ret, err;
+		struct refspec *tmp_rs;
+		struct argv_array ref_prefixes = ARGV_ARRAY_INIT;
+		int i;
 
 		if (check_push_refs(local_refs, refspec_nr, refspec) < 0)
 			return -1;
 
-		remote_refs = transport->vtable->get_refs_list(transport, 1);
+		tmp_rs = parse_push_refspec(refspec_nr, refspec);
+		for (i = 0; i < refspec_nr; i++) {
+			const char *prefix = NULL;
+
+			if (tmp_rs[i].dst)
+				prefix = tmp_rs[i].dst;
+			else if (tmp_rs[i].src && !tmp_rs[i].exact_sha1)
+				prefix = tmp_rs[i].src;
+
+			if (prefix) {
+				const char *glob = strchr(prefix, '*');
+				if (glob)
+					argv_array_pushf(&ref_prefixes, "%.*s",
+							 (int)(glob - prefix),
+							 prefix);
+				else
+					expand_ref_prefix(&ref_prefixes, prefix);
+			}
+		}
+
+		remote_refs = transport->vtable->get_refs_list(transport, 1,
+							       &ref_prefixes);
+
+		argv_array_clear(&ref_prefixes);
+		free_refspec(refspec_nr, tmp_rs);
 
 		if (flags & TRANSPORT_PUSH_ALL)
 			match_flags |= MATCH_REFS_ALL;
@@ -1117,10 +1247,13 @@
 	return 1;
 }
 
-const struct ref *transport_get_remote_refs(struct transport *transport)
+const struct ref *transport_get_remote_refs(struct transport *transport,
+					    const struct argv_array *ref_prefixes)
 {
 	if (!transport->got_remote_refs) {
-		transport->remote_refs = transport->vtable->get_refs_list(transport, 0);
+		transport->remote_refs =
+			transport->vtable->get_refs_list(transport, 0,
+							 ref_prefixes);
 		transport->got_remote_refs = 1;
 	}
 
diff --git a/transport.h b/transport.h
index 3c68d73..e783cfa 100644
--- a/transport.h
+++ b/transport.h
@@ -60,6 +60,12 @@
 	unsigned cloning : 1;
 
 	/*
+	 * Indicates that the transport is connected via a half-duplex
+	 * connection and should operate in stateless-rpc mode.
+	 */
+	unsigned stateless_rpc : 1;
+
+	/*
 	 * These strings will be passed to the {pre, post}-receive hook,
 	 * on the remote side, if both sides support the push options capability.
 	 */
@@ -194,7 +200,17 @@
 		   int refspec_nr, const char **refspec, int flags,
 		   unsigned int * reject_reasons);
 
-const struct ref *transport_get_remote_refs(struct transport *transport);
+/*
+ * Retrieve refs from a remote.
+ *
+ * Optionally a list of ref prefixes can be provided which can be sent to the
+ * server (when communicating using protocol v2) to enable it to limit the ref
+ * advertisement.  Since ref filtering is done on the server's end (and only
+ * when using protocol v2), this can return refs which don't match the provided
+ * ref_prefixes.
+ */
+const struct ref *transport_get_remote_refs(struct transport *transport,
+					    const struct argv_array *ref_prefixes);
 
 int transport_fetch_refs(struct transport *transport, struct ref *refs);
 void transport_unlock_pack(struct transport *transport);
diff --git a/unicode_width.h b/unicode-width.h
similarity index 100%
rename from unicode_width.h
rename to unicode-width.h
diff --git a/unpack-trees.c b/unpack-trees.c
index e737450..dec37ad 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -290,7 +290,7 @@
 		if (!state && ce->ce_flags & CE_WT_REMOVE) {
 			repo_read_gitmodules(the_repository);
 		} else if (state && (ce->ce_flags & CE_UPDATE)) {
-			submodule_free();
+			submodule_free(the_repository);
 			checkout_entry(ce, state, NULL);
 			repo_read_gitmodules(the_repository);
 		}
diff --git a/upload-pack.c b/upload-pack.c
index 4a82602..87b4d32 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -6,7 +6,6 @@
 #include "tag.h"
 #include "object.h"
 #include "commit.h"
-#include "exec_cmd.h"
 #include "diff.h"
 #include "revision.h"
 #include "list-objects.h"
@@ -17,16 +16,12 @@
 #include "sigchain.h"
 #include "version.h"
 #include "string-list.h"
-#include "parse-options.h"
 #include "argv-array.h"
 #include "prio-queue.h"
 #include "protocol.h"
 #include "quote.h"
-
-static const char * const upload_pack_usage[] = {
-	N_("git upload-pack [<options>] <dir>"),
-	NULL
-};
+#include "upload-pack.h"
+#include "serve.h"
 
 /* Remember to update object flag allocation in object.h */
 #define THEY_HAVE	(1u << 11)
@@ -64,7 +59,6 @@
  * otherwise maximum packet size (up to 65520 bytes).
  */
 static int use_sideband;
-static int advertise_refs;
 static int stateless_rpc;
 static const char *pack_objects_hook;
 
@@ -734,7 +728,6 @@
 	}
 
 	send_unshallow(shallows);
-	packet_flush(1);
 }
 
 static void deepen_by_rev_list(int ac, const char **av,
@@ -746,7 +739,122 @@
 	send_shallow(result);
 	free_commit_list(result);
 	send_unshallow(shallows);
-	packet_flush(1);
+}
+
+/* Returns 1 if a shallow list is sent or 0 otherwise */
+static int send_shallow_list(int depth, int deepen_rev_list,
+			     timestamp_t deepen_since,
+			     struct string_list *deepen_not,
+			     struct object_array *shallows)
+{
+	int ret = 0;
+
+	if (depth > 0 && deepen_rev_list)
+		die("git upload-pack: deepen and deepen-since (or deepen-not) cannot be used together");
+	if (depth > 0) {
+		deepen(depth, deepen_relative, shallows);
+		ret = 1;
+	} else if (deepen_rev_list) {
+		struct argv_array av = ARGV_ARRAY_INIT;
+		int i;
+
+		argv_array_push(&av, "rev-list");
+		if (deepen_since)
+			argv_array_pushf(&av, "--max-age=%"PRItime, deepen_since);
+		if (deepen_not->nr) {
+			argv_array_push(&av, "--not");
+			for (i = 0; i < deepen_not->nr; i++) {
+				struct string_list_item *s = deepen_not->items + i;
+				argv_array_push(&av, s->string);
+			}
+			argv_array_push(&av, "--not");
+		}
+		for (i = 0; i < want_obj.nr; i++) {
+			struct object *o = want_obj.objects[i].item;
+			argv_array_push(&av, oid_to_hex(&o->oid));
+		}
+		deepen_by_rev_list(av.argc, av.argv, shallows);
+		argv_array_clear(&av);
+		ret = 1;
+	} else {
+		if (shallows->nr > 0) {
+			int i;
+			for (i = 0; i < shallows->nr; i++)
+				register_shallow(&shallows->objects[i].item->oid);
+		}
+	}
+
+	shallow_nr += shallows->nr;
+	return ret;
+}
+
+static int process_shallow(const char *line, struct object_array *shallows)
+{
+	const char *arg;
+	if (skip_prefix(line, "shallow ", &arg)) {
+		struct object_id oid;
+		struct object *object;
+		if (get_oid_hex(arg, &oid))
+			die("invalid shallow line: %s", line);
+		object = parse_object(&oid);
+		if (!object)
+			return 1;
+		if (object->type != OBJ_COMMIT)
+			die("invalid shallow object %s", oid_to_hex(&oid));
+		if (!(object->flags & CLIENT_SHALLOW)) {
+			object->flags |= CLIENT_SHALLOW;
+			add_object_array(object, NULL, shallows);
+		}
+		return 1;
+	}
+
+	return 0;
+}
+
+static int process_deepen(const char *line, int *depth)
+{
+	const char *arg;
+	if (skip_prefix(line, "deepen ", &arg)) {
+		char *end = NULL;
+		*depth = (int)strtol(arg, &end, 0);
+		if (!end || *end || *depth <= 0)
+			die("Invalid deepen: %s", line);
+		return 1;
+	}
+
+	return 0;
+}
+
+static int process_deepen_since(const char *line, timestamp_t *deepen_since, int *deepen_rev_list)
+{
+	const char *arg;
+	if (skip_prefix(line, "deepen-since ", &arg)) {
+		char *end = NULL;
+		*deepen_since = parse_timestamp(arg, &end, 0);
+		if (!end || *end || !deepen_since ||
+		    /* revisions.c's max_age -1 is special */
+		    *deepen_since == -1)
+			die("Invalid deepen-since: %s", line);
+		*deepen_rev_list = 1;
+		return 1;
+	}
+	return 0;
+}
+
+static int process_deepen_not(const char *line, struct string_list *deepen_not, int *deepen_rev_list)
+{
+	const char *arg;
+	if (skip_prefix(line, "deepen-not ", &arg)) {
+		char *ref = NULL;
+		struct object_id oid;
+		if (expand_ref(arg, strlen(arg), &oid, &ref) != 1)
+			die("git upload-pack: ambiguous deepen-not: %s", line);
+		string_list_append(deepen_not, ref);
+		free(ref);
+		*deepen_rev_list = 1;
+		return 1;
+	}
+	return 0;
 }
 
 static void receive_needs(void)
@@ -770,55 +878,22 @@
 		if (!line)
 			break;
 
-		if (skip_prefix(line, "shallow ", &arg)) {
-			struct object_id oid;
-			struct object *object;
-			if (get_oid_hex(arg, &oid))
-				die("invalid shallow line: %s", line);
-			object = parse_object(&oid);
-			if (!object)
-				continue;
-			if (object->type != OBJ_COMMIT)
-				die("invalid shallow object %s", oid_to_hex(&oid));
-			if (!(object->flags & CLIENT_SHALLOW)) {
-				object->flags |= CLIENT_SHALLOW;
-				add_object_array(object, NULL, &shallows);
-			}
+		if (process_shallow(line, &shallows))
 			continue;
-		}
-		if (skip_prefix(line, "deepen ", &arg)) {
-			char *end = NULL;
-			depth = strtol(arg, &end, 0);
-			if (!end || *end || depth <= 0)
-				die("Invalid deepen: %s", line);
+		if (process_deepen(line, &depth))
 			continue;
-		}
-		if (skip_prefix(line, "deepen-since ", &arg)) {
-			char *end = NULL;
-			deepen_since = parse_timestamp(arg, &end, 0);
-			if (!end || *end || !deepen_since ||
-			    /* revisions.c's max_age -1 is special */
-			    deepen_since == -1)
-				die("Invalid deepen-since: %s", line);
-			deepen_rev_list = 1;
+		if (process_deepen_since(line, &deepen_since, &deepen_rev_list))
 			continue;
-		}
-		if (skip_prefix(line, "deepen-not ", &arg)) {
-			char *ref = NULL;
-			struct object_id oid;
-			if (expand_ref(arg, strlen(arg), &oid, &ref) != 1)
-				die("git upload-pack: ambiguous deepen-not: %s", line);
-			string_list_append(&deepen_not, ref);
-			free(ref);
-			deepen_rev_list = 1;
+		if (process_deepen_not(line, &deepen_not, &deepen_rev_list))
 			continue;
-		}
+
 		if (skip_prefix(line, "filter ", &arg)) {
 			if (!filter_capability_requested)
 				die("git upload-pack: filtering capability not negotiated");
 			parse_list_objects_filter(&filter_options, arg);
 			continue;
 		}
+
 		if (!skip_prefix(line, "want ", &arg) ||
 		    get_oid_hex(arg, &oid_buf))
 			die("git upload-pack: protocol error, "
@@ -881,40 +956,10 @@
 
 	if (depth == 0 && !deepen_rev_list && shallows.nr == 0)
 		return;
-	if (depth > 0 && deepen_rev_list)
-		die("git upload-pack: deepen and deepen-since (or deepen-not) cannot be used together");
-	if (depth > 0)
-		deepen(depth, deepen_relative, &shallows);
-	else if (deepen_rev_list) {
-		struct argv_array av = ARGV_ARRAY_INIT;
-		int i;
 
-		argv_array_push(&av, "rev-list");
-		if (deepen_since)
-			argv_array_pushf(&av, "--max-age=%"PRItime, deepen_since);
-		if (deepen_not.nr) {
-			argv_array_push(&av, "--not");
-			for (i = 0; i < deepen_not.nr; i++) {
-				struct string_list_item *s = deepen_not.items + i;
-				argv_array_push(&av, s->string);
-			}
-			argv_array_push(&av, "--not");
-		}
-		for (i = 0; i < want_obj.nr; i++) {
-			struct object *o = want_obj.objects[i].item;
-			argv_array_push(&av, oid_to_hex(&o->oid));
-		}
-		deepen_by_rev_list(av.argc, av.argv, &shallows);
-		argv_array_clear(&av);
-	}
-	else
-		if (shallows.nr > 0) {
-			int i;
-			for (i = 0; i < shallows.nr; i++)
-				register_shallow(&shallows.objects[i].item->oid);
-		}
-
-	shallow_nr += shallows.nr;
+	if (send_shallow_list(depth, deepen_rev_list, deepen_since,
+			      &deepen_not, &shallows))
+		packet_flush(1);
 	object_array_clear(&shallows);
 }
 
@@ -1004,33 +1049,6 @@
 	return 0;
 }
 
-static void upload_pack(void)
-{
-	struct string_list symref = STRING_LIST_INIT_DUP;
-
-	head_ref_namespaced(find_symref, &symref);
-
-	if (advertise_refs || !stateless_rpc) {
-		reset_timeout();
-		head_ref_namespaced(send_ref, &symref);
-		for_each_namespaced_ref(send_ref, &symref);
-		advertise_shallow_grafts(1);
-		packet_flush(1);
-	} else {
-		head_ref_namespaced(check_ref, NULL);
-		for_each_namespaced_ref(check_ref, NULL);
-	}
-	string_list_clear(&symref, 1);
-	if (advertise_refs)
-		return;
-
-	receive_needs();
-	if (want_obj.nr) {
-		get_common_commits();
-		create_pack_file();
-	}
-}
-
 static int upload_pack_config(const char *var, const char *value, void *unused)
 {
 	if (!strcmp("uploadpack.allowtipsha1inwant", var)) {
@@ -1061,58 +1079,356 @@
 	return parse_hide_refs_config(var, value, "uploadpack");
 }
 
-int cmd_main(int argc, const char **argv)
+void upload_pack(struct upload_pack_options *options)
 {
-	const char *dir;
-	int strict = 0;
-	struct option options[] = {
-		OPT_BOOL(0, "stateless-rpc", &stateless_rpc,
-			 N_("quit after a single request/response exchange")),
-		OPT_BOOL(0, "advertise-refs", &advertise_refs,
-			 N_("exit immediately after initial ref advertisement")),
-		OPT_BOOL(0, "strict", &strict,
-			 N_("do not try <directory>/.git/ if <directory> is no Git directory")),
-		OPT_INTEGER(0, "timeout", &timeout,
-			    N_("interrupt transfer after <n> seconds of inactivity")),
-		OPT_END()
-	};
+	struct string_list symref = STRING_LIST_INIT_DUP;
 
-	packet_trace_identity("upload-pack");
-	check_replace_refs = 0;
-
-	argc = parse_options(argc, argv, NULL, options, upload_pack_usage, 0);
-
-	if (argc != 1)
-		usage_with_options(upload_pack_usage, options);
-
-	if (timeout)
-		daemon_mode = 1;
-
-	setup_path();
-
-	dir = argv[0];
-
-	if (!enter_repo(dir, strict))
-		die("'%s' does not appear to be a git repository", dir);
+	stateless_rpc = options->stateless_rpc;
+	timeout = options->timeout;
+	daemon_mode = options->daemon_mode;
 
 	git_config(upload_pack_config, NULL);
 
-	switch (determine_protocol_version_server()) {
-	case protocol_v1:
-		/*
-		 * v1 is just the original protocol with a version string,
-		 * so just fall through after writing the version string.
-		 */
-		if (advertise_refs || !stateless_rpc)
-			packet_write_fmt(1, "version 1\n");
+	head_ref_namespaced(find_symref, &symref);
 
-		/* fallthrough */
-	case protocol_v0:
-		upload_pack();
-		break;
-	case protocol_unknown_version:
-		BUG("unknown protocol version");
+	if (options->advertise_refs || !stateless_rpc) {
+		reset_timeout();
+		head_ref_namespaced(send_ref, &symref);
+		for_each_namespaced_ref(send_ref, &symref);
+		advertise_shallow_grafts(1);
+		packet_flush(1);
+	} else {
+		head_ref_namespaced(check_ref, NULL);
+		for_each_namespaced_ref(check_ref, NULL);
+	}
+	string_list_clear(&symref, 1);
+	if (options->advertise_refs)
+		return;
+
+	receive_needs();
+	if (want_obj.nr) {
+		get_common_commits();
+		create_pack_file();
+	}
+}
+
+struct upload_pack_data {
+	struct object_array wants;
+	struct oid_array haves;
+
+	struct object_array shallows;
+	struct string_list deepen_not;
+	int depth;
+	timestamp_t deepen_since;
+	int deepen_rev_list;
+	int deepen_relative;
+
+	unsigned stateless_rpc : 1;
+
+	unsigned use_thin_pack : 1;
+	unsigned use_ofs_delta : 1;
+	unsigned no_progress : 1;
+	unsigned use_include_tag : 1;
+	unsigned done : 1;
+};
+
+static void upload_pack_data_init(struct upload_pack_data *data)
+{
+	struct object_array wants = OBJECT_ARRAY_INIT;
+	struct oid_array haves = OID_ARRAY_INIT;
+	struct object_array shallows = OBJECT_ARRAY_INIT;
+	struct string_list deepen_not = STRING_LIST_INIT_DUP;
+
+	memset(data, 0, sizeof(*data));
+	data->wants = wants;
+	data->haves = haves;
+	data->shallows = shallows;
+	data->deepen_not = deepen_not;
+}
+
+static void upload_pack_data_clear(struct upload_pack_data *data)
+{
+	object_array_clear(&data->wants);
+	oid_array_clear(&data->haves);
+	object_array_clear(&data->shallows);
+	string_list_clear(&data->deepen_not, 0);
+}
+
+static int parse_want(const char *line)
+{
+	const char *arg;
+	if (skip_prefix(line, "want ", &arg)) {
+		struct object_id oid;
+		struct object *o;
+
+		if (get_oid_hex(arg, &oid))
+			die("git upload-pack: protocol error, "
+			    "expected to get oid, not '%s'", line);
+
+		o = parse_object(&oid);
+		if (!o) {
+			packet_write_fmt(1,
+					 "ERR upload-pack: not our ref %s",
+					 oid_to_hex(&oid));
+			die("git upload-pack: not our ref %s",
+			    oid_to_hex(&oid));
+		}
+
+		if (!(o->flags & WANTED)) {
+			o->flags |= WANTED;
+			add_object_array(o, NULL, &want_obj);
+		}
+
+		return 1;
 	}
 
 	return 0;
 }
+
+static int parse_have(const char *line, struct oid_array *haves)
+{
+	const char *arg;
+	if (skip_prefix(line, "have ", &arg)) {
+		struct object_id oid;
+
+		if (get_oid_hex(arg, &oid))
+			die("git upload-pack: expected SHA1 object, got '%s'", arg);
+		oid_array_append(haves, &oid);
+		return 1;
+	}
+
+	return 0;
+}
+
+static void process_args(struct packet_reader *request,
+			 struct upload_pack_data *data)
+{
+	while (packet_reader_read(request) != PACKET_READ_FLUSH) {
+		const char *arg = request->line;
+
+		/* process want */
+		if (parse_want(arg))
+			continue;
+		/* process have line */
+		if (parse_have(arg, &data->haves))
+			continue;
+
+		/* process args like thin-pack */
+		if (!strcmp(arg, "thin-pack")) {
+			use_thin_pack = 1;
+			continue;
+		}
+		if (!strcmp(arg, "ofs-delta")) {
+			use_ofs_delta = 1;
+			continue;
+		}
+		if (!strcmp(arg, "no-progress")) {
+			no_progress = 1;
+			continue;
+		}
+		if (!strcmp(arg, "include-tag")) {
+			use_include_tag = 1;
+			continue;
+		}
+		if (!strcmp(arg, "done")) {
+			data->done = 1;
+			continue;
+		}
+
+		/* Shallow related arguments */
+		if (process_shallow(arg, &data->shallows))
+			continue;
+		if (process_deepen(arg, &data->depth))
+			continue;
+		if (process_deepen_since(arg, &data->deepen_since,
+					 &data->deepen_rev_list))
+			continue;
+		if (process_deepen_not(arg, &data->deepen_not,
+				       &data->deepen_rev_list))
+			continue;
+		if (!strcmp(arg, "deepen-relative")) {
+			data->deepen_relative = 1;
+			continue;
+		}
+
+		/* ignore unknown lines maybe? */
+		die("unexpect line: '%s'", arg);
+	}
+}
+
+static int process_haves(struct oid_array *haves, struct oid_array *common)
+{
+	int i;
+
+	/* Process haves */
+	for (i = 0; i < haves->nr; i++) {
+		const struct object_id *oid = &haves->oid[i];
+		struct object *o;
+		int we_knew_they_have = 0;
+
+		if (!has_object_file(oid))
+			continue;
+
+		oid_array_append(common, oid);
+
+		o = parse_object(oid);
+		if (!o)
+			die("oops (%s)", oid_to_hex(oid));
+		if (o->type == OBJ_COMMIT) {
+			struct commit_list *parents;
+			struct commit *commit = (struct commit *)o;
+			if (o->flags & THEY_HAVE)
+				we_knew_they_have = 1;
+			else
+				o->flags |= THEY_HAVE;
+			if (!oldest_have || (commit->date < oldest_have))
+				oldest_have = commit->date;
+			for (parents = commit->parents;
+			     parents;
+			     parents = parents->next)
+				parents->item->object.flags |= THEY_HAVE;
+		}
+		if (!we_knew_they_have)
+			add_object_array(o, NULL, &have_obj);
+	}
+
+	return 0;
+}
+
+static int send_acks(struct oid_array *acks, struct strbuf *response)
+{
+	int i;
+
+	packet_buf_write(response, "acknowledgments\n");
+
+	/* Send Acks */
+	if (!acks->nr)
+		packet_buf_write(response, "NAK\n");
+
+	for (i = 0; i < acks->nr; i++) {
+		packet_buf_write(response, "ACK %s\n",
+				 oid_to_hex(&acks->oid[i]));
+	}
+
+	if (ok_to_give_up()) {
+		/* Send Ready */
+		packet_buf_write(response, "ready\n");
+		return 1;
+	}
+
+	return 0;
+}
+
+static int process_haves_and_send_acks(struct upload_pack_data *data)
+{
+	struct oid_array common = OID_ARRAY_INIT;
+	struct strbuf response = STRBUF_INIT;
+	int ret = 0;
+
+	process_haves(&data->haves, &common);
+	if (data->done) {
+		ret = 1;
+	} else if (send_acks(&common, &response)) {
+		packet_buf_delim(&response);
+		ret = 1;
+	} else {
+		/* Add Flush */
+		packet_buf_flush(&response);
+		ret = 0;
+	}
+
+	/* Send response */
+	write_or_die(1, response.buf, response.len);
+	strbuf_release(&response);
+
+	oid_array_clear(&data->haves);
+	oid_array_clear(&common);
+	return ret;
+}
+
+static void send_shallow_info(struct upload_pack_data *data)
+{
+	/* No shallow info needs to be sent */
+	if (!data->depth && !data->deepen_rev_list && !data->shallows.nr &&
+	    !is_repository_shallow())
+		return;
+
+	packet_write_fmt(1, "shallow-info\n");
+
+	if (!send_shallow_list(data->depth, data->deepen_rev_list,
+			       data->deepen_since, &data->deepen_not,
+			       &data->shallows) && is_repository_shallow())
+		deepen(INFINITE_DEPTH, data->deepen_relative, &data->shallows);
+
+	packet_delim(1);
+}
+
+enum fetch_state {
+	FETCH_PROCESS_ARGS = 0,
+	FETCH_SEND_ACKS,
+	FETCH_SEND_PACK,
+	FETCH_DONE,
+};
+
+int upload_pack_v2(struct repository *r, struct argv_array *keys,
+		   struct packet_reader *request)
+{
+	enum fetch_state state = FETCH_PROCESS_ARGS;
+	struct upload_pack_data data;
+
+	upload_pack_data_init(&data);
+	use_sideband = LARGE_PACKET_MAX;
+
+	while (state != FETCH_DONE) {
+		switch (state) {
+		case FETCH_PROCESS_ARGS:
+			process_args(request, &data);
+
+			if (!want_obj.nr) {
+				/*
+				 * Request didn't contain any 'want' lines,
+				 * guess they didn't want anything.
+				 */
+				state = FETCH_DONE;
+			} else if (data.haves.nr) {
+				/*
+				 * Request had 'have' lines, so lets ACK them.
+				 */
+				state = FETCH_SEND_ACKS;
+			} else {
+				/*
+				 * Request had 'want's but no 'have's so we can
+				 * immedietly go to construct and send a pack.
+				 */
+				state = FETCH_SEND_PACK;
+			}
+			break;
+		case FETCH_SEND_ACKS:
+			if (process_haves_and_send_acks(&data))
+				state = FETCH_SEND_PACK;
+			else
+				state = FETCH_DONE;
+			break;
+		case FETCH_SEND_PACK:
+			send_shallow_info(&data);
+
+			packet_write_fmt(1, "packfile\n");
+			create_pack_file();
+			state = FETCH_DONE;
+			break;
+		case FETCH_DONE:
+			continue;
+		}
+	}
+
+	upload_pack_data_clear(&data);
+	return 0;
+}
+
+int upload_pack_advertise(struct repository *r,
+			  struct strbuf *value)
+{
+	if (value)
+		strbuf_addstr(value, "shallow");
+	return 1;
+}
diff --git a/upload-pack.h b/upload-pack.h
new file mode 100644
index 0000000..cab2178
--- /dev/null
+++ b/upload-pack.h
@@ -0,0 +1,23 @@
+#ifndef UPLOAD_PACK_H
+#define UPLOAD_PACK_H
+
+struct upload_pack_options {
+	int stateless_rpc;
+	int advertise_refs;
+	unsigned int timeout;
+	int daemon_mode;
+};
+
+void upload_pack(struct upload_pack_options *options);
+
+struct repository;
+struct argv_array;
+struct packet_reader;
+extern int upload_pack_v2(struct repository *r, struct argv_array *keys,
+			  struct packet_reader *request);
+
+struct strbuf;
+extern int upload_pack_advertise(struct repository *r,
+				 struct strbuf *value);
+
+#endif /* UPLOAD_PACK_H */
diff --git a/utf8.c b/utf8.c
index 2c27ce0..0fcc648 100644
--- a/utf8.c
+++ b/utf8.c
@@ -81,7 +81,7 @@
 	/*
 	 * Sorted list of non-overlapping intervals of non-spacing characters,
 	 */
-#include "unicode_width.h"
+#include "unicode-width.h"
 
 	/* test for 8-bit control characters */
 	if (ch == 0)
@@ -401,18 +401,40 @@
 	strbuf_release(&sb_dst);
 }
 
+/*
+ * Returns true (1) if the src encoding name matches the dst encoding
+ * name directly or one of its alternative names. E.g. UTF-16BE is the
+ * same as UTF16BE.
+ */
+static int same_utf_encoding(const char *src, const char *dst)
+{
+	if (istarts_with(src, "utf") && istarts_with(dst, "utf")) {
+		/* src[3] or dst[3] might be '\0' */
+		int i = (src[3] == '-' ? 4 : 3);
+		int j = (dst[3] == '-' ? 4 : 3);
+		return !strcasecmp(src+i, dst+j);
+	}
+	return 0;
+}
+
 int is_encoding_utf8(const char *name)
 {
 	if (!name)
 		return 1;
-	if (!strcasecmp(name, "utf-8") || !strcasecmp(name, "utf8"))
+	if (same_utf_encoding("utf-8", name))
 		return 1;
 	return 0;
 }
 
 int same_encoding(const char *src, const char *dst)
 {
-	if (is_encoding_utf8(src) && is_encoding_utf8(dst))
+	static const char utf8[] = "UTF-8";
+
+	if (!src)
+		src = utf8;
+	if (!dst)
+		dst = utf8;
+	if (same_utf_encoding(src, dst))
 		return 1;
 	return !strcasecmp(src, dst);
 }
@@ -538,6 +560,45 @@
 }
 #endif
 
+static int has_bom_prefix(const char *data, size_t len,
+			  const char *bom, size_t bom_len)
+{
+	return data && bom && (len >= bom_len) && !memcmp(data, bom, bom_len);
+}
+
+static const char utf16_be_bom[] = {0xFE, 0xFF};
+static const char utf16_le_bom[] = {0xFF, 0xFE};
+static const char utf32_be_bom[] = {0x00, 0x00, 0xFE, 0xFF};
+static const char utf32_le_bom[] = {0xFF, 0xFE, 0x00, 0x00};
+
+int has_prohibited_utf_bom(const char *enc, const char *data, size_t len)
+{
+	return (
+	  (same_utf_encoding("UTF-16BE", enc) ||
+	   same_utf_encoding("UTF-16LE", enc)) &&
+	  (has_bom_prefix(data, len, utf16_be_bom, sizeof(utf16_be_bom)) ||
+	   has_bom_prefix(data, len, utf16_le_bom, sizeof(utf16_le_bom)))
+	) || (
+	  (same_utf_encoding("UTF-32BE",  enc) ||
+	   same_utf_encoding("UTF-32LE", enc)) &&
+	  (has_bom_prefix(data, len, utf32_be_bom, sizeof(utf32_be_bom)) ||
+	   has_bom_prefix(data, len, utf32_le_bom, sizeof(utf32_le_bom)))
+	);
+}
+
+int is_missing_required_utf_bom(const char *enc, const char *data, size_t len)
+{
+	return (
+	   (same_utf_encoding(enc, "UTF-16")) &&
+	   !(has_bom_prefix(data, len, utf16_be_bom, sizeof(utf16_be_bom)) ||
+	     has_bom_prefix(data, len, utf16_le_bom, sizeof(utf16_le_bom)))
+	) || (
+	   (same_utf_encoding(enc, "UTF-32")) &&
+	   !(has_bom_prefix(data, len, utf32_be_bom, sizeof(utf32_be_bom)) ||
+	     has_bom_prefix(data, len, utf32_le_bom, sizeof(utf32_le_bom)))
+	);
+}
+
 /*
  * Returns first character length in bytes for multi-byte `text` according to
  * `encoding`.
diff --git a/utf8.h b/utf8.h
index 6bbcf31..cce654a 100644
--- a/utf8.h
+++ b/utf8.h
@@ -70,4 +70,32 @@
 void strbuf_utf8_align(struct strbuf *buf, align_type position, unsigned int width,
 		       const char *s);
 
+/*
+ * If a data stream is declared as UTF-16BE or UTF-16LE, then a UTF-16
+ * BOM must not be used [1]. The same applies for the UTF-32 equivalents.
+ * The function returns true if this rule is violated.
+ *
+ * [1] http://unicode.org/faq/utf_bom.html#bom10
+ */
+int has_prohibited_utf_bom(const char *enc, const char *data, size_t len);
+
+/*
+ * If the endianness is not defined in the encoding name, then we
+ * require a BOM. The function returns true if a required BOM is missing.
+ *
+ * The Unicode standard instructs to assume big-endian if there in no
+ * BOM for UTF-16/32 [1][2]. However, the W3C/WHATWG encoding standard
+ * used in HTML5 recommends to assume little-endian to "deal with
+ * deployed content" [3].
+ *
+ * Therefore, strictly requiring a BOM seems to be the safest option for
+ * content in Git.
+ *
+ * [1] http://unicode.org/faq/utf_bom.html#gen6
+ * [2] http://www.unicode.org/versions/Unicode10.0.0/ch03.pdf
+ *     Section 3.10, D98, page 132
+ * [3] https://encoding.spec.whatwg.org/#utf-16le
+ */
+int is_missing_required_utf_bom(const char *enc, const char *data, size_t len);
+
 #endif
diff --git a/write_or_die.c b/write-or-die.c
similarity index 100%
rename from write_or_die.c
rename to write-or-die.c