Merge branch 'sg/test-i18ngrep' Test fixes. * sg/test-i18ngrep: t: make 'test_i18ngrep' more informative on failure t: validate 'test_i18ngrep's parameters t: move 'test_i18ncmp' and 'test_i18ngrep' to 'test-lib-functions.sh' t5536: let 'test_i18ngrep' read the file without redirection t5510: consolidate 'grep' and 'test_i18ngrep' patterns t4001: don't run 'git status' upstream of a pipe t6022: don't run 'git merge' upstream of a pipe t5812: add 'test_i18ngrep's missing filename parameter t5541: add 'test_i18ngrep's missing filename parameter

diff --git a/.clang-format b/.clang-format
index 611ab47..12a89f9 100644
--- a/.clang-format
+++ b/.clang-format

@@ -163,7 +163,7 @@
 PenaltyBreakFirstLessLess: 0
 PenaltyBreakString: 10
 PenaltyExcessCharacter: 100
-PenaltyReturnTypeOnItsOwnLine: 5
+PenaltyReturnTypeOnItsOwnLine: 60
 
 # Don't sort #include's
 SortIncludes: false

diff --git a/Documentation/Makefile b/Documentation/Makefile
index 4ae9ba5..6232143 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile

@@ -72,6 +72,7 @@
 TECH_DOCS += technical/hash-function-transition
 TECH_DOCS += technical/http-protocol
 TECH_DOCS += technical/index-format
+TECH_DOCS += technical/long-running-process-protocol
 TECH_DOCS += technical/pack-format
 TECH_DOCS += technical/pack-heuristics
 TECH_DOCS += technical/pack-protocol

diff --git a/Documentation/RelNotes/2.16.2.txt b/Documentation/RelNotes/2.16.2.txt
new file mode 100644
index 0000000..a216466
--- /dev/null
+++ b/Documentation/RelNotes/2.16.2.txt

@@ -0,0 +1,30 @@
+Git v2.16.2 Release Notes
+=========================
+
+Fixes since v2.16.1
+-------------------
+
+ * An old regression in "git describe --all $annotated_tag^0" has been
+   fixed.
+
+ * "git svn dcommit" did not take into account the fact that a
+   svn+ssh:// URL with a username@ (typically used for pushing) refers
+   to the same SVN repository without the username@ and failed when
+   svn.pushmergeinfo option is set.
+
+ * "git merge -Xours/-Xtheirs" learned to use our/their version when
+   resolving a conflicting updates to a symbolic link.
+
+ * "git clone $there $here" is allowed even when here directory exists
+   as long as it is an empty directory, but the command incorrectly
+   removed it upon a failure of the operation.
+
+ * "git stash -- <pathspec>" incorrectly blew away untracked files in
+   the directory that matched the pathspec, which has been corrected.
+
+ * "git add -p" was taught to ignore local changes to submodules as
+   they do not interfere with the partial addition of regular changes
+   anyway.
+
+
+Also contains various documentation updates and code clean-ups.

diff --git a/Documentation/RelNotes/2.17.0.txt b/Documentation/RelNotes/2.17.0.txt
new file mode 100644
index 0000000..1fe7b61
--- /dev/null
+++ b/Documentation/RelNotes/2.17.0.txt

@@ -0,0 +1,187 @@
+Git 2.17 Release Notes
+======================
+
+Updates since v2.16
+-------------------
+
+UI, Workflows & Features
+
+ * "diff" family of commands learned "--find-object=<object-id>" option
+   to limit the findings to changes that involve the named object.
+   (merge 4d8c51aa19 sb/diff-blobfind-pickaxe later to maint).
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * More perf tests for threaded grep
+   (merge 7b31b55db1 ab/perf-grep-threads later to maint).
+
+ * "perf" test output can be sent to codespeed server.
+   (merge 19cf57a92e cc/codespeed later to maint).
+
+ * The build procedure for perl/ part has been greatly simplified by
+   weaning ourselves off of MakeMaker.
+
+ * In preparation for implementing narrow/partial clone, the machinery
+   for checking object connectivity used by gc and fsck has been
+   taught that a missing object is OK when it is referenced by a
+   packfile specially marked as coming from trusted repository that
+   promises to make them available on-demand and lazily.
+
+ * The machinery to clone & fetch, which in turn involves packing and
+   unpacking objects, has been told how to omit certain objects using
+   the filtering mechanism introduced by another topic.  It now knows
+   to mark the resulting pack as a promisor pack to tolerate missing
+   objects, laying foundation for "narrow" clones.
+
+ * The first step to getting rid of mru API and using the
+   doubly-linked list API directly instead.
+
+ * Retire mru API as it does not give enough abstraction over
+   underlying list API to be worth it.
+
+ * Rewrite two more "git submodule" subcommands in C.
+
+ * The tracing machinery learned to report tweaking of environment
+   variables as well.
+   (merge 090a09272a nd/trace-with-env later to maint).
+
+ * Update Coccinelle rules to catch and optimize strbuf_addf(&buf, "%s", str)
+   (merge cd9a4b6d93 rs/strbuf-cocci-workaround later to maint).
+
+ * Prevent "clang-format" from breaking line after function return type.
+   (merge a3715d43e8 po/clang-format-functype-weight later to maint).
+
+ * The sequencer infrastructure is shared across "git cherry-pick",
+   "git rebase -i", etc., and has always spawned "git commit" when it
+   needs to create a commit.  It has been taught to do so internally,
+   when able, by reusing the codepath "git commit" itself uses, which
+   gives performance boost for a few tens of percents in some sample
+   scenarios.
+
+ * Push the submodule version of collision-detecting SHA-1 hash
+   implementation a bit harder on builders.
+
+ * Avoid mmapping small files while using packed refs (especially ones
+   with zero size, which would cause later munmap() to fail).
+   (merge ba41a8b600 kg/packed-ref-cache-fix later to maint).
+
+ * Conversion from uchar[20] to struct object_id continues.
+
+ * More tests for wildmatch functions.
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.16
+-----------------
+
+ * An old regression in "git describe --all $annotated_tag^0" has been
+   fixed.
+   (merge 1bba00130a dk/describe-all-output-fix later to maint).
+
+ * "git status" after moving a path in the working tree (hence making
+   it appear "removed") and then adding with the -N option (hence
+   making that appear "added") detected it as a rename, but did not
+   report the  old and new pathnames correctly.
+   (merge 176ea74793 nd/ita-wt-renames-in-status later to maint).
+
+ * "git svn dcommit" did not take into account the fact that a
+   svn+ssh:// URL with a username@ (typically used for pushing) refers
+   to the same SVN repository without the username@ and failed when
+   svn.pushmergeinfo option is set.
+   (merge 8aaed892fd jm/svn-pushmergeinfo-fix later to maint).
+
+ * API clean-up around revision traversal.
+   (merge 6fcec2f9ae rs/lose-leak-pending later to maint).
+
+ * "git merge -Xours/-Xtheirs" learned to use our/their version when
+   resolving a conflicting updates to a symbolic link.
+   (merge fd48b46474 jc/merge-symlink-ours-theirs later to maint).
+
+ * "git clone $there $here" is allowed even when here directory exists
+   as long as it is an empty directory, but the command incorrectly
+   removed it upon a failure of the operation.
+   (merge d45420c1c8 jk/abort-clone-with-existing-dest later to maint).
+
+ * "git commit --fixup" did not allow "-m<message>" option to be used
+   at the same time; allow it to annotate resulting commit with more
+   text.
+   (merge 30884c9afc ab/commit-m-with-fixup later to maint).
+
+ * When resetting the working tree files recursively, the working tree
+   of submodules are now also reset to match.
+   (merge 7dcc1f4df8 sb/submodule-update-reset-fix later to maint).
+
+ * "git stash -- <pathspec>" incorrectly blew away untracked files in
+   the directory that matched the pathspec, which has been corrected.
+   (merge bba067d2fa tg/stash-with-pathspec-fix later to maint).
+
+ * Instead of maintaining home-grown email address parsing code, ship
+   a copy of reasonably recent Mail::Address to be used as a fallback
+   in 'git send-email' when the platform lacks it.
+   (merge d60be8acab mm/send-email-fallback-to-local-mail-address later to maint).
+
+ * "git add -p" was taught to ignore local changes to submodules as
+   they do not interfere with the partial addition of regular changes
+   anyway.
+   (merge 12434efc1d nd/add-i-ignore-submodules later to maint).
+
+ * Avoid showing a warning message in the middle of a line of "git
+   diff" output.
+   (merge 4e056c989f nd/diff-flush-before-warning later to maint).
+
+ * The http tracing code, often used to debug connection issues,
+   learned to redact potentially sensitive information from its output
+   so that it can be more safely sharable.
+   (merge 8ba18e6fa4 jt/http-redact-cookies later to maint).
+
+ * Crash fix for a corner case where an error codepath tried to unlock
+   what it did not acquire lock on.
+   (merge 81fcb698e0 mr/packed-ref-store-fix later to maint).
+
+ * The split-index mode had a few corner case bugs fixed.
+   (merge ae59a4e44f tg/split-index-fixes later to maint).
+
+ * Assorted fixes to "git daemon".
+   (merge ed15e58efe jk/daemon-fixes later to maint).
+
+ * Completion of "git merge -s<strategy>" (in contrib/) did not work
+   well in non-C locale.
+   (merge 7cc763aaa3 nd/list-merge-strategy later to maint).
+
+ * Workaround for segfault with more recent versions of SVN.
+   (merge 7f6f75e97a ew/svn-branch-segfault-fix later to maint).
+
+ * Plug recently introduced leaks in fsck.
+   (merge ba3a08ca0e jt/fsck-code-cleanup later to maint).
+
+ * "git pull --rebase" did not pass verbosity setting down when
+   recursing into a submodule.
+   (merge a56771a668 sb/pull-rebase-submodule later to maint).
+
+ * The way "git reset --hard" reports the commit the updated HEAD
+   points at is made consistent with the way how the commit title is
+   generated by the other parts of the system.  This matters when the
+   title is spread across physically multiple lines.
+   (merge 1cf823fb68 tg/reset-hard-show-head-with-pretty later to maint).
+
+ * Other minor doc, test and build updates and code cleanups.
+   (merge e2a5a028c7 bw/oidmap-autoinit later to maint).
+   (merge f0a6068a9f ys/bisect-object-id-missing-conversion-fix later to maint).
+   (merge 30221a3389 as/read-tree-prefix-doc-fix later to maint).
+   (merge 9bd2ce5432 ab/doc-cat-file-e-still-shows-errors later to maint).
+   (merge ec3b4b06f8 cl/t9001-cleanup later to maint).
+   (merge e1b3f3dd38 ks/submodule-doc-updates later to maint).
+   (merge fbac558a9b rs/describe-unique-abbrev later to maint).
+   (merge 8462ff43e4 tb/crlf-conv-flags later to maint).
+   (merge 7d68bb0766 rb/hashmap-h-compilation-fix later to maint).
+   (merge 3449847168 cc/sha1-file-name later to maint).
+   (merge ad622a256f ds/use-get-be64 later to maint).
+   (merge f919ffebed sg/cocci-move-array later to maint).
+   (merge 4e801463c7 jc/mailinfo-cleanup-fix later to maint).
+   (merge ef5b3a6c5e nd/shared-index-fix later to maint).
+   (merge 9f5258cbb8 tz/doc-show-defaults-to-head later to maint).
+   (merge b780e4407d jc/worktree-add-short-help later to maint).
+   (merge ae239fc8e5 rs/cocci-strbuf-addf-to-addstr later to maint).
+   (merge 2e22a85e5c nd/ignore-glob-doc-update later to maint).

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 0e25b2c..f57e9cf 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt

@@ -3343,6 +3343,10 @@
 	was run. I.e., `upload-pack` will feed input intended for
 	`pack-objects` to the hook, and expects a completed packfile on
 	stdout.
+
+uploadpack.allowFilter::
+	If this option is set, `upload-pack` will advertise partial
+	clone and partial fetch object filtering.
 +
 Note that this configuration variable is ignored if it is seen in the
 repository-level config (this is a safety measure against fetching from

diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index 743af97..c330c01 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt

@@ -508,6 +508,15 @@
 See the 'pickaxe' entry in linkgit:gitdiffcore[7] for more
 information.
 
+--find-object=<object-id>::
+	Look for differences that change the number of occurrences of
+	the specified object. Similar to `-S`, just the argument is different
+	in that it doesn't search for a specific string but for a specific
+	object id.
++
+The object can be a blob or a submodule commit. It implies the `-t` option in
+`git-log` to also find trees.
+
 --pickaxe-all::
 	When `-S` or `-G` finds a change, show all the changes in that
 	changeset, not just the files that contain the change
@@ -516,6 +525,7 @@
 --pickaxe-regex::
 	Treat the <string> given to `-S` as an extended POSIX regular
 	expression to match.
+
 endif::git-format-patch[]
 
 -O<orderfile>::

diff --git a/Documentation/git-cat-file.txt b/Documentation/git-cat-file.txt
index fb09cd6..f90f09b 100644
--- a/Documentation/git-cat-file.txt
+++ b/Documentation/git-cat-file.txt

@@ -42,8 +42,9 @@
 	<object>.
 
 -e::
-	Suppress all output; instead exit with zero status if <object>
-	exists and is a valid object.
+	Exit with zero status if <object> exists and is a valid
+	object. If <object> is of an invalid format exit with non-zero and
+	emits an error on stderr.
 
 -p::
 	Pretty-print the contents of <object> based on its type.
@@ -168,7 +169,7 @@
 
 If `-s` is specified, the size of the <object> in bytes.
 
-If `-e` is specified, no output.
+If `-e` is specified, no output, unless the <object> is malformed.
 
 If `-p` is specified, the contents of <object> are pretty-printed.
 

diff --git a/Documentation/git-commit.txt b/Documentation/git-commit.txt
index 8c74a2c..f970a43 100644
--- a/Documentation/git-commit.txt
+++ b/Documentation/git-commit.txt

@@ -144,6 +144,8 @@
 	Use the given <msg> as the commit message.
 	If multiple `-m` options are given, their values are
 	concatenated as separate paragraphs.
++
+The `-m` option is mutually exclusive with `-c`, `-C`, and `-F`.
 
 -t <file>::
 --template=<file>::

diff --git a/Documentation/git-daemon.txt b/Documentation/git-daemon.txt
index 3c91db7..56d54a4 100644
--- a/Documentation/git-daemon.txt
+++ b/Documentation/git-daemon.txt

@@ -20,6 +20,7 @@
 	     [--inetd |
 	      [--listen=<host_or_ipaddr>] [--port=<n>]
 	      [--user=<user> [--group=<group>]]]
+	     [--log-destination=(stderr|syslog|none)]
 	     [<directory>...]
 
 DESCRIPTION
@@ -80,7 +81,8 @@
 	do not have the 'git-daemon-export-ok' file.
 
 --inetd::
-	Have the server run as an inetd service. Implies --syslog.
+	Have the server run as an inetd service. Implies --syslog (may be
+	overridden with `--log-destination=`).
 	Incompatible with --detach, --port, --listen, --user and --group
 	options.
 
@@ -110,8 +112,28 @@
 	zero for no limit.
 
 --syslog::
-	Log to syslog instead of stderr. Note that this option does not imply
-	--verbose, thus by default only error conditions will be logged.
+	Short for `--log-destination=syslog`.
+
+--log-destination=<destination>::
+	Send log messages to the specified destination.
+	Note that this option does not imply --verbose,
+	thus by default only error conditions will be logged.
+	The <destination> must be one of:
++
+--
+stderr::
+	Write to standard error.
+	Note that if `--detach` is specified,
+	the process disconnects from the real standard error,
+	making this destination effectively equivalent to `none`.
+syslog::
+	Write to syslog, using the `git-daemon` identifier.
+none::
+	Disable all logging.
+--
++
+The default destination is `syslog` if `--inetd` or `--detach` is specified,
+otherwise `stderr`.
 
 --user-path::
 --user-path=<path>::

diff --git a/Documentation/git-pack-objects.txt b/Documentation/git-pack-objects.txt
index aa403d0..81bc490 100644
--- a/Documentation/git-pack-objects.txt
+++ b/Documentation/git-pack-objects.txt

@@ -255,6 +255,17 @@
 The form '--missing=allow-any' will allow object traversal to continue
 if a missing object is encountered.  Missing objects will silently be
 omitted from the results.
++
+The form '--missing=allow-promisor' is like 'allow-any', but will only
+allow object traversal to continue for EXPECTED promisor missing objects.
+Unexpected missing object will raise an error.
+
+--exclude-promisor-objects::
+	Omit objects that are known to be in the promisor remote.  (This
+	option has the purpose of operating only on locally created objects,
+	so that when we repack, we still maintain a distinction between
+	locally created objects [without .promisor] and objects from the
+	promisor remote [with .promisor].)  This is used with partial clone.
 
 SEE ALSO
 --------

diff --git a/Documentation/git-read-tree.txt b/Documentation/git-read-tree.txt
index 72bd809..f2a07d5 100644
--- a/Documentation/git-read-tree.txt
+++ b/Documentation/git-read-tree.txt

@@ -81,12 +81,11 @@
 * when both sides add a path identically.  The resolution
   is to add that path.
 
---prefix=<prefix>/::
+--prefix=<prefix>::
 	Keep the current index contents, and read the contents
 	of the named tree-ish under the directory at `<prefix>`.
 	The command will refuse to overwrite entries that already
-	existed in the original index file. Note that the `<prefix>/`
-	value must end with a slash.
+	existed in the original index file.
 
 --exclude-per-directory=<gitignore>::
 	When running the command with `-u` and `-m` options, the

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index 8a861c1..d713951 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt

@@ -244,6 +244,11 @@
 	Keep the commits that do not change anything from its
 	parents in the result.
 
+--allow-empty-message::
+	By default, rebasing commits with an empty message will fail.
+	This option overrides that behavior, allowing commits with empty
+	messages to be rebased.
+
 --skip::
 	Restart the rebasing process by skipping the current patch.
 

diff --git a/Documentation/git-show.txt b/Documentation/git-show.txt
index 82a4125..e73ef54 100644
--- a/Documentation/git-show.txt
+++ b/Documentation/git-show.txt

@@ -9,7 +9,7 @@
 SYNOPSIS
 --------
 [verse]
-'git show' [options] <object>...
+'git show' [options] [<object>...]
 
 DESCRIPTION
 -----------
@@ -35,7 +35,7 @@
 OPTIONS
 -------
 <object>...::
-	The names of objects to show.
+	The names of objects to show (defaults to 'HEAD').
 	For a more complete list of ways to spell object names, see
 	"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
 

diff --git a/Documentation/git-status.txt b/Documentation/git-status.txt
index 81cab9a..72bfb87 100644
--- a/Documentation/git-status.txt
+++ b/Documentation/git-status.txt

@@ -149,14 +149,15 @@
 Short Format
 ~~~~~~~~~~~~
 
-In the short-format, the status of each path is shown as
+In the short-format, the status of each path is shown as one of these
+forms
 
-	XY PATH1 -> PATH2
+	XY PATH
+	XY ORIG_PATH -> PATH
 
-where `PATH1` is the path in the `HEAD`, and the " `-> PATH2`" part is
-shown only when `PATH1` corresponds to a different path in the
-index/worktree (i.e. the file is renamed). The `XY` is a two-letter
-status code.
+where `ORIG_PATH` is where the renamed/copied contents came
+from. `ORIG_PATH` is only shown when the entry is renamed or
+copied. The `XY` is a two-letter status code.
 
 The fields (including the `->`) are separated from each other by a
 single space. If a filename contains whitespace or other nonprintable
@@ -192,6 +193,8 @@
     [MARC]           index and work tree matches
     [ MARC]     M    work tree changed since index
     [ MARC]     D    deleted in work tree
+    [ D]        R    renamed in work tree
+    [ D]        C    copied in work tree
     -------------------------------------------------
     D           D    unmerged, both deleted
     A           U    unmerged, added by us
@@ -309,13 +312,13 @@
 		of similarity between the source and target of the
 		move or copy). For example "R100" or "C75".
     <path>      The pathname.  In a renamed/copied entry, this
-		is the path in the index and in the working tree.
+		is the target path.
     <sep>       When the `-z` option is used, the 2 pathnames are separated
 		with a NUL (ASCII 0x00) byte; otherwise, a tab (ASCII 0x09)
 		byte separates them.
-    <origPath>  The pathname in the commit at HEAD.  This is only
-		present in a renamed/copied entry, and tells
-		where the renamed/copied contents came from.
+    <origPath>  The pathname in the commit at HEAD or in the index.
+		This is only present in a renamed/copied entry, and
+		tells where the renamed/copied contents came from.
     --------------------------------------------------------
 
 Unmerged entries have the following format; the first character is

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index ff61200..71c5618 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt

@@ -70,8 +70,8 @@
 	Show the status of the submodules. This will print the SHA-1 of the
 	currently checked out commit for each submodule, along with the
 	submodule path and the output of 'git describe' for the
-	SHA-1. Each SHA-1 will be prefixed with `-` if the submodule is not
-	initialized, `+` if the currently checked out submodule commit
+	SHA-1. Each SHA-1 will possibly be prefixed with `-` if the submodule is
+	not initialized, `+` if the currently checked out submodule commit
 	does not match the SHA-1 found in the index of the containing
 	repository and `U` if the submodule has merge conflicts.
 +
@@ -132,15 +132,15 @@
 the submodules. The "updating" can be done in several ways depending
 on command line options and the value of `submodule.<name>.update`
 configuration variable. The command line option takes precedence over
-the configuration variable. if neither is given, a checkout is performed.
-update procedures supported both from the command line as well as setting
-`submodule.<name>.update`:
+the configuration variable. If neither is given, a 'checkout' is performed.
+The 'update' procedures supported both from the command line as well as
+through the `submodule.<name>.update` configuration are:
 
 	checkout;; the commit recorded in the superproject will be
 	    checked out in the submodule on a detached HEAD.
 +
 If `--force` is specified, the submodule will be checked out (using
-`git checkout --force` if appropriate), even if the commit specified
+`git checkout --force`), even if the commit specified
 in the index of the containing repository already matches the commit
 checked out in the submodule.
 
@@ -150,8 +150,8 @@
 	merge;; the commit recorded in the superproject will be merged
 	    into the current branch in the submodule.
 
-The following procedures are only available via the `submodule.<name>.update`
-configuration variable:
+The following 'update' procedures are only available via the
+`submodule.<name>.update` configuration variable:
 
 	custom command;; arbitrary shell command that takes a single
 	    argument (the sha1 of the commit recorded in the

diff --git a/Documentation/git.txt b/Documentation/git.txt
index 3f4161a..8163b57 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt

@@ -646,6 +646,16 @@
 	variable.
 	See `GIT_TRACE` for available trace output options.
 
+`GIT_TRACE_CURL_NO_DATA`::
+	When a curl trace is enabled (see `GIT_TRACE_CURL` above), do not dump
+	data (that is, only dump info lines and headers).
+
+`GIT_REDACT_COOKIES`::
+	This can be set to a comma-separated list of strings. When a curl trace
+	is enabled (see `GIT_TRACE_CURL` above), whenever a "Cookies:" header
+	sent by the client is dumped, values of cookies whose key is in that
+	list (case-sensitive) are redacted.
+
 `GIT_LITERAL_PATHSPECS`::
 	Setting this variable to `1` will cause Git to treat all
 	pathspecs literally, rather than as glob patterns. For example,

diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt
index 30687de..c21f5ca 100644
--- a/Documentation/gitattributes.txt
+++ b/Documentation/gitattributes.txt

@@ -392,46 +392,14 @@
 If the filter command (a string value) is defined via
 `filter.<driver>.process` then Git can process all blobs with a
 single filter invocation for the entire life of a single Git
-command. This is achieved by using a packet format (pkt-line,
-see technical/protocol-common.txt) based protocol over standard
-input and standard output as follows. All packets, except for the
-"*CONTENT" packets and the "0000" flush packet, are considered
-text and therefore are terminated by a LF.
+command. This is achieved by using the long-running process protocol
+(described in technical/long-running-process-protocol.txt).
 
-Git starts the filter when it encounters the first file
-that needs to be cleaned or smudged. After the filter started
-Git sends a welcome message ("git-filter-client"), a list of supported
-protocol version numbers, and a flush packet. Git expects to read a welcome
-response message ("git-filter-server"), exactly one protocol version number
-from the previously sent list, and a flush packet. All further
-communication will be based on the selected version. The remaining
-protocol description below documents "version=2". Please note that
-"version=42" in the example below does not exist and is only there
-to illustrate how the protocol would look like with more than one
-version.
-
-After the version negotiation Git sends a list of all capabilities that
-it supports and a flush packet. Git expects to read a list of desired
-capabilities, which must be a subset of the supported capabilities list,
-and a flush packet as response:
-------------------------
-packet:          git> git-filter-client
-packet:          git> version=2
-packet:          git> version=42
-packet:          git> 0000
-packet:          git< git-filter-server
-packet:          git< version=2
-packet:          git< 0000
-packet:          git> capability=clean
-packet:          git> capability=smudge
-packet:          git> capability=not-yet-invented
-packet:          git> 0000
-packet:          git< capability=clean
-packet:          git< capability=smudge
-packet:          git< 0000
-------------------------
-Supported filter capabilities in version 2 are "clean", "smudge",
-and "delay".
+When Git encounters the first file that needs to be cleaned or smudged,
+it starts the filter and performs the handshake. In the handshake, the
+welcome message sent by Git is "git-filter-client", only version 2 is
+suppported, and the supported capabilities are "clean", "smudge", and
+"delay".
 
 Afterwards Git sends a list of "key=value" pairs terminated with
 a flush packet. The list will contain at least the filter command
@@ -517,12 +485,6 @@
 with the next file that needs to be processed. Depending on the
 `filter.<driver>.required` flag Git will interpret that as error.
 
-After the filter has processed a command it is expected to wait for
-a "key=value" list containing the next command. Git will close
-the command pipe on exit. The filter is expected to detect EOF
-and exit gracefully on its own. Git will wait until the filter
-process has stopped.
-
 Delay
 ^^^^^
 

diff --git a/Documentation/gitignore.txt b/Documentation/gitignore.txt
index 63260f0..ff5d7f9 100644
--- a/Documentation/gitignore.txt
+++ b/Documentation/gitignore.txt

@@ -102,12 +102,11 @@
    (relative to the toplevel of the work tree if not from a
    `.gitignore` file).
 
- - Otherwise, Git treats the pattern as a shell glob suitable
-   for consumption by fnmatch(3) with the FNM_PATHNAME flag:
-   wildcards in the pattern will not match a / in the pathname.
-   For example, "Documentation/{asterisk}.html" matches
-   "Documentation/git.html" but not "Documentation/ppc/ppc.html"
-   or "tools/perf/Documentation/perf.html".
+ - Otherwise, Git treats the pattern as a shell glob: "`*`" matches
+   anything except "`/`", "`?`" matches any one character except "`/`"
+   and "`[]`" matches one character in a selected range. See
+   fnmatch(3) and the FNM_PATHNAME flag for a more detailed
+   description.
 
  - A leading slash matches the beginning of the pathname.
    For example, "/{asterisk}.c" matches "cat-file.c" but not

diff --git a/Documentation/gitremote-helpers.txt b/Documentation/gitremote-helpers.txt
index 4a584f3..4b8c93e 100644
--- a/Documentation/gitremote-helpers.txt
+++ b/Documentation/gitremote-helpers.txt

@@ -466,6 +466,13 @@
 	Transmit <string> as a push option. As the push option
 	must not contain LF or NUL characters, the string is not encoded.
 
+'option from-promisor' {'true'|'false'}::
+	Indicate that these objects are being fetched from a promisor.
+
+'option no-dependents' {'true'|'false'}::
+	Indicate that only the objects wanted need to be fetched, not
+	their dependents.
+
 SEE ALSO
 --------
 linkgit:git-remote[1]

diff --git a/Documentation/gitsubmodules.txt b/Documentation/gitsubmodules.txt
index 46cf120..4d6c177 100644
--- a/Documentation/gitsubmodules.txt
+++ b/Documentation/gitsubmodules.txt

@@ -36,8 +36,8 @@
 superproject expects the submodule’s working directory to be at.
 
 The section `submodule.foo.*` in the `.gitmodules` file gives additional
-hints to Gits porcelain layer such as where to obtain the submodule via
-the `submodule.foo.url` setting.
+hints to Git's porcelain layer. For example, the `submodule.foo.url`
+setting specifies where to obtain the submodule.
 
 Submodules can be used for at least two different use cases:
 
@@ -51,18 +51,21 @@
 
 2. Splitting a (logically single) project into multiple
    repositories and tying them back together. This can be used to
-   overcome current limitations of Gits implementation to have
+   overcome current limitations of Git's implementation to have
    finer grained access:
 
-    * Size of the git repository:
+    * Size of the Git repository:
       In its current form Git scales up poorly for large repositories containing
       content that is not compressed by delta computation between trees.
-      However you can also use submodules to e.g. hold large binary assets
-      and these repositories are then shallowly cloned such that you do not
+      For example, you can use submodules to hold large binary assets
+      and these repositories can be shallowly cloned such that you do not
       have a large history locally.
     * Transfer size:
       In its current form Git requires the whole working tree present. It
       does not allow partial trees to be transferred in fetch or clone.
+      If the project you work on consists of multiple repositories tied
+      together as submodules in a superproject, you can avoid fetching the
+      working trees of the repositories you are not interested in.
     * Access control:
       By restricting user access to submodules, this can be used to implement
       read/write policies for different users.
@@ -73,9 +76,10 @@
 Submodule operations can be configured using the following mechanisms
 (from highest to lowest precedence):
 
- * The command line for those commands that support taking submodule specs.
-   Most commands have a boolean flag '--recurse-submodules' whether to
-   recurse into submodules. Examples are `ls-files` or `checkout`.
+ * The command line for those commands that support taking submodules
+   as part of their pathspecs. Most commands have a boolean flag
+   `--recurse-submodules` which specify whether to recurse into submodules.
+   Examples are `grep` and `checkout`.
    Some commands take enums, such as `fetch` and `push`, where you can
    specify how submodules are affected.
 
@@ -87,8 +91,8 @@
 For example an effect from the submodule's `.gitignore` file
 would be observed when you run `git status --ignore-submodules=none` in
 the superproject. This collects information from the submodule's working
-directory by running `status` in the submodule, which does pay attention
-to its `.gitignore` file.
+directory by running `status` in the submodule while paying attention
+to the `.gitignore` file of the submodule.
 +
 The submodule's `$GIT_DIR/config` file would come into play when running
 `git push --recurse-submodules=check` in the superproject, as this would
@@ -97,20 +101,20 @@
 file.
 
  * The configuration file `$GIT_DIR/config` in the superproject.
-   Typical configuration at this place is controlling if a submodule
-   is recursed into at all via the `active` flag for example.
+   Git only recurses into active submodules (see "ACTIVE SUBMODULES"
+   section below).
 +
 If the submodule is not yet initialized, then the configuration
-inside the submodule does not exist yet, so configuration where to
+inside the submodule does not exist yet, so where to
 obtain the submodule from is configured here for example.
 
- * the `.gitmodules` file inside the superproject. Additionally to the
-   required mapping between submodule's name and path, a project usually
+ * The `.gitmodules` file inside the superproject. A project usually
    uses this file to suggest defaults for the upstream collection
-   of repositories.
+   of repositories for the mapping that is required between a
+   submodule's name and its path.
 +
-This file mainly serves as the mapping between name and path in
-the superproject, such that the submodule's git directory can be
+This file mainly serves as the mapping between the name and path of submodules
+in the superproject, such that the submodule's Git directory can be
 located.
 +
 If the submodule has never been initialized, this is the only place
@@ -137,8 +141,8 @@
 of the superproject.
 
  * Deinitialized submodule: A `gitlink`, and a `.gitmodules` entry,
-but no submodule working directory. The submodule’s git directory
-may be there as after deinitializing the git directory is kept around.
+but no submodule working directory. The submodule’s Git directory
+may be there as after deinitializing the Git directory is kept around.
 The directory which is supposed to be the working directory is empty instead.
 +
 A submodule can be deinitialized by running `git submodule deinit`.
@@ -160,6 +164,60 @@
 To completely remove a submodule, manually delete
 `$GIT_DIR/modules/<name>/`.
 
+ACTIVE SUBMODULES
+-----------------
+
+A submodule is considered active,
+
+  (a) if `submodule.<name>.active` is set to `true`
+     or
+  (b) if the submodule's path matches the pathspec in `submodule.active`
+     or
+  (c) if `submodule.<name>.url` is set.
+
+and these are evaluated in this order.
+
+For example:
+
+  [submodule "foo"]
+    active = false
+    url = https://example.org/foo
+  [submodule "bar"]
+    active = true
+    url = https://example.org/bar
+  [submodule "baz"]
+    url = https://example.org/baz
+
+In the above config only the submodule 'bar' and 'baz' are active,
+'bar' due to (a) and 'baz' due to (c). 'foo' is inactive because
+(a) takes precedence over (c)
+
+Note that (c) is a historical artefact and will be ignored if the
+(a) and (b) specify that the submodule is not active. In other words,
+if we have an `submodule.<name>.active` set to `false` or if the
+submodule's path is excluded in the pathspec in `submodule.active`, the
+url doesn't matter whether it is present or not. This is illustrated in
+the example that follows.
+
+  [submodule "foo"]
+    active = true
+    url = https://example.org/foo
+  [submodule "bar"]
+    url = https://example.org/bar
+  [submodule "baz"]
+    url = https://example.org/baz
+  [submodule "bob"]
+    ignore = true
+  [submodule]
+    active = b*
+    active = :(exclude) baz
+
+In here all submodules except 'baz' (foo, bar, bob) are active.
+'foo' due to its own active flag and all the others due to the
+submodule active pathspec, which specifies that any submodule
+starting with 'b' except 'baz' are also active, regardless of the
+presence of the .url field.
+
 Workflow for a third party library
 ----------------------------------
 

diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt
index 22f5c9b..7b27363 100644
--- a/Documentation/rev-list-options.txt
+++ b/Documentation/rev-list-options.txt

@@ -750,10 +750,21 @@
 if a missing object is encountered.  Missing objects will silently be
 omitted from the results.
 +
+The form '--missing=allow-promisor' is like 'allow-any', but will only
+allow object traversal to continue for EXPECTED promisor missing objects.
+Unexpected missing objects will raise an error.
++
 The form '--missing=print' is like 'allow-any', but will also print a
 list of the missing objects.  Object IDs are prefixed with a ``?'' character.
 endif::git-rev-list[]
 
+--exclude-promisor-objects::
+	(For internal use only.)  Prefilter object traversal at
+	promisor boundary.  This is used with partial clone.  This is
+	stronger than `--missing=allow-promisor` because it limits the
+	traversal, rather than just silencing errors about missing
+	objects.
+
 --no-walk[=(sorted|unsorted)]::
 	Only show the given commits, but do not traverse their ancestors.
 	This has no effect if a range is specified. If the argument

diff --git a/Documentation/technical/api-object-access.txt b/Documentation/technical/api-object-access.txt
index 03bb0e9..a1162e5 100644
--- a/Documentation/technical/api-object-access.txt
+++ b/Documentation/technical/api-object-access.txt

@@ -7,7 +7,7 @@
 * read_object_with_reference()
 * has_sha1_file()
 * write_sha1_file()
-* pretend_sha1_file()
+* pretend_object_file()
 * lookup_{object,commit,tag,blob,tree}
 * parse_{object,commit,tag,blob,tree}
 * Use of object flags

diff --git a/Documentation/technical/long-running-process-protocol.txt b/Documentation/technical/long-running-process-protocol.txt
new file mode 100644
index 0000000..aa0aa9a
--- /dev/null
+++ b/Documentation/technical/long-running-process-protocol.txt

@@ -0,0 +1,50 @@
+Long-running process protocol
+=============================
+
+This protocol is used when Git needs to communicate with an external
+process throughout the entire life of a single Git command. All
+communication is in pkt-line format (see technical/protocol-common.txt)
+over standard input and standard output.
+
+Handshake
+---------
+
+Git starts by sending a welcome message (for example,
+"git-filter-client"), a list of supported protocol version numbers, and
+a flush packet. Git expects to read the welcome message with "server"
+instead of "client" (for example, "git-filter-server"), exactly one
+protocol version number from the previously sent list, and a flush
+packet. All further communication will be based on the selected version.
+The remaining protocol description below documents "version=2". Please
+note that "version=42" in the example below does not exist and is only
+there to illustrate how the protocol would look like with more than one
+version.
+
+After the version negotiation Git sends a list of all capabilities that
+it supports and a flush packet. Git expects to read a list of desired
+capabilities, which must be a subset of the supported capabilities list,
+and a flush packet as response:
+------------------------
+packet:          git> git-filter-client
+packet:          git> version=2
+packet:          git> version=42
+packet:          git> 0000
+packet:          git< git-filter-server
+packet:          git< version=2
+packet:          git< 0000
+packet:          git> capability=clean
+packet:          git> capability=smudge
+packet:          git> capability=not-yet-invented
+packet:          git> 0000
+packet:          git< capability=clean
+packet:          git< capability=smudge
+packet:          git< 0000
+------------------------
+
+Shutdown
+--------
+
+Git will close
+the command pipe on exit. The filter is expected to detect EOF
+and exit gracefully on its own. Git will wait until the filter
+process has stopped.

diff --git a/Documentation/technical/pack-protocol.txt b/Documentation/technical/pack-protocol.txt
index cd31edc..7fee6b7 100644
--- a/Documentation/technical/pack-protocol.txt
+++ b/Documentation/technical/pack-protocol.txt

@@ -241,6 +241,7 @@
   upload-request    =  want-list
 		       *shallow-line
 		       *1depth-request
+		       [filter-request]
 		       flush-pkt
 
   want-list         =  first-want
@@ -256,6 +257,8 @@
   additional-want   =  PKT-LINE("want" SP obj-id)
 
   depth             =  1*DIGIT
+
+  filter-request    =  PKT-LINE("filter" SP filter-spec)
 ----
 
 Clients MUST send all the obj-ids it wants from the reference
@@ -278,6 +281,11 @@
 result are defined as shallow and marked as such in the server. This
 information is sent back to the client in the next step.
 
+The client can optionally request that pack-objects omit various
+objects from the packfile using one of several filtering techniques.
+These are intended for use with partial clone and partial fetch
+operations.  See `rev-list` for possible "filter-spec" values.
+
 Once all the 'want's and 'shallow's (and optional 'deepen') are
 transferred, clients MUST send a flush-pkt, to tell the server side
 that it is done sending the list.

diff --git a/Documentation/technical/protocol-capabilities.txt b/Documentation/technical/protocol-capabilities.txt
index 26dcc6f..332d209 100644
--- a/Documentation/technical/protocol-capabilities.txt
+++ b/Documentation/technical/protocol-capabilities.txt

@@ -309,3 +309,11 @@
 included in the push certificate.  A send-pack client MUST NOT
 send a push-cert packet unless the receive-pack server advertises
 this capability.
+
+filter
+------
+
+If the upload-pack server advertises the 'filter' capability,
+fetch-pack may send "filter" commands to request a partial clone
+or partial fetch and request that the server omit various objects
+from the packfile.

diff --git a/Documentation/technical/repository-version.txt b/Documentation/technical/repository-version.txt
index 00ad379..e03eacc 100644
--- a/Documentation/technical/repository-version.txt
+++ b/Documentation/technical/repository-version.txt

@@ -86,3 +86,15 @@
 When the config key `extensions.preciousObjects` is set to `true`,
 objects in the repository MUST NOT be deleted (e.g., by `git-prune` or
 `git repack -d`).
+
+`partialclone`
+~~~~~~~~~~~~~~
+
+When the config key `extensions.partialclone` is set, it indicates
+that the repo was created with a partial clone (or later performed
+a partial fetch) and that the remote may have omitted sending
+certain unwanted objects.  Such a remote is called a "promisor remote"
+and it promises that all such omitted objects can be fetched from it
+in the future.
+
+The value of this key is the name of the promisor remote.

diff --git a/GIT-VERSION-GEN b/GIT-VERSION-GEN
index 470f7b7..0c86f1c 100755
--- a/GIT-VERSION-GEN
+++ b/GIT-VERSION-GEN

@@ -1,7 +1,7 @@
 #!/bin/sh
 
 GVF=GIT-VERSION-FILE
-DEF_VER=v2.16.1
+DEF_VER=v2.16.GIT
 
 LF='
 '

diff --git a/INSTALL b/INSTALL
index ffb071e..808e07b 100644
--- a/INSTALL
+++ b/INSTALL

@@ -84,9 +84,24 @@
 
 	GIT_EXEC_PATH=`pwd`
 	PATH=`pwd`:$PATH
-	GITPERLLIB=`pwd`/perl/blib/lib
+	GITPERLLIB=`pwd`/perl/build/lib
 	export GIT_EXEC_PATH PATH GITPERLLIB
 
+ - By default (unless NO_PERL is provided) Git will ship various perl
+   scripts & libraries it needs. However, for simplicity it doesn't
+   use the ExtUtils::MakeMaker toolchain to decide where to place the
+   perl libraries. Depending on the system this can result in the perl
+   libraries not being where you'd like them if they're expected to be
+   used by things other than Git itself.
+
+   Manually supplying a perllibdir prefix should fix this, if this is
+   a problem you care about, e.g.:
+
+       prefix=/usr perllibdir=/usr/$(/usr/bin/perl -MConfig -wle 'print substr $Config{installsitelib}, 1 + length $Config{siteprefixexp}')
+
+   Will result in e.g. perllibdir=/usr/share/perl/5.26.1 on Debian,
+   perllibdir=/usr/share/perl5 (which we'd use by default) on CentOS.
+
  - Git is reasonably self-sufficient, but does depend on a few external
    programs and libraries.  Git can be used without most of them by adding
    the approriate "NO_<LIBRARY>=YesPlease" to the make command line or

diff --git a/Makefile b/Makefile
index 1a9b23b..c56fdc1 100644
--- a/Makefile
+++ b/Makefile

@@ -294,9 +294,6 @@
 #
 # Define PERL_PATH to the path of your Perl binary (usually /usr/bin/perl).
 #
-# Define NO_PERL_MAKEMAKER if you cannot use Makefiles generated by perl's
-# MakeMaker (e.g. using ActiveState under Cygwin).
-#
 # Define NO_PERL if you do not want Perl scripts or libraries at all.
 #
 # Define PYTHON_PATH to the path of your Python binary (often /usr/bin/python
@@ -479,6 +476,7 @@
 mergetoolsdir = $(gitexecdir)/mergetools
 sharedir = $(prefix)/share
 gitwebdir = $(sharedir)/gitweb
+perllibdir = $(sharedir)/perl5
 localedir = $(sharedir)/locale
 template_dir = share/git-core/templates
 htmldir = $(prefix)/share/doc/git-doc
@@ -492,7 +490,7 @@
 infodir_relative = $(patsubst $(prefix)/%,%,$(infodir))
 htmldir_relative = $(patsubst $(prefix)/%,%,$(htmldir))
 
-export prefix bindir sharedir sysconfdir gitwebdir localedir
+export prefix bindir sharedir sysconfdir gitwebdir perllibdir localedir
 
 CC = cc
 AR = ar
@@ -804,6 +802,7 @@
 LIB_OBJS += ewah/ewah_io.o
 LIB_OBJS += ewah/ewah_rlw.o
 LIB_OBJS += exec_cmd.o
+LIB_OBJS += fetch-object.o
 LIB_OBJS += fetch-pack.o
 LIB_OBJS += fsck.o
 LIB_OBJS += fsmonitor.o
@@ -832,7 +831,6 @@
 LIB_OBJS += merge-blobs.o
 LIB_OBJS += merge-recursive.o
 LIB_OBJS += mergesort.o
-LIB_OBJS += mru.o
 LIB_OBJS += name-hash.o
 LIB_OBJS += notes.o
 LIB_OBJS += notes-cache.o
@@ -1515,7 +1513,9 @@
 	LIB_OBJS += sha1dc_git.o
 ifdef DC_SHA1_EXTERNAL
 	ifdef DC_SHA1_SUBMODULE
+		ifneq ($(DC_SHA1_SUBMODULE),auto)
 $(error Only set DC_SHA1_EXTERNAL or DC_SHA1_SUBMODULE, not both)
+		endif
 	endif
 	BASIC_CFLAGS += -DDC_SHA1_EXTERNAL
 	EXTLIBS += -lsha1detectcoll
@@ -1543,9 +1543,6 @@
 	LIB_OBJS += compat/sha1-chunked.o
 	BASIC_CFLAGS += -DSHA1_MAX_BLOCK_SIZE="$(SHA1_MAX_BLOCK_SIZE)"
 endif
-ifdef NO_PERL_MAKEMAKER
-	export NO_PERL_MAKEMAKER
-endif
 ifdef NO_HSTRERROR
 	COMPAT_CFLAGS += -DNO_HSTRERROR
 	COMPAT_OBJS += compat/hstrerror.o
@@ -1732,8 +1729,10 @@
 DESTDIR_SQ = $(subst ','\'',$(DESTDIR))
 bindir_SQ = $(subst ','\'',$(bindir))
 bindir_relative_SQ = $(subst ','\'',$(bindir_relative))
+mandir_SQ = $(subst ','\'',$(mandir))
 mandir_relative_SQ = $(subst ','\'',$(mandir_relative))
 infodir_relative_SQ = $(subst ','\'',$(infodir_relative))
+perllibdir_SQ = $(subst ','\'',$(perllibdir))
 localedir_SQ = $(subst ','\'',$(localedir))
 gitexecdir_SQ = $(subst ','\'',$(gitexecdir))
 template_dir_SQ = $(subst ','\'',$(template_dir))
@@ -1844,9 +1843,6 @@
 	$(QUIET_SUBDIR0)git-gui $(QUIET_SUBDIR1) gitexecdir='$(gitexec_instdir_SQ)' all
 	$(QUIET_SUBDIR0)gitk-git $(QUIET_SUBDIR1) all
 endif
-ifndef NO_PERL
-	$(QUIET_SUBDIR0)perl $(QUIET_SUBDIR1) PERL_PATH='$(PERL_PATH_SQ)' prefix='$(prefix_SQ)' localedir='$(localedir_SQ)' all
-endif
 	$(QUIET_SUBDIR0)templates $(QUIET_SUBDIR1) SHELL_PATH='$(SHELL_PATH_SQ)' PERL_PATH='$(PERL_PATH_SQ)'
 
 please_set_SHELL_PATH_to_a_more_modern_shell:
@@ -1928,7 +1924,8 @@
 
 SCRIPT_DEFINES = $(SHELL_PATH_SQ):$(DIFF_SQ):$(GIT_VERSION):\
 	$(localedir_SQ):$(NO_CURL):$(USE_GETTEXT_SCHEME):$(SANE_TOOL_PATH_SQ):\
-	$(gitwebdir_SQ):$(PERL_PATH_SQ):$(SANE_TEXT_GREP):$(PAGER_ENV)
+	$(gitwebdir_SQ):$(PERL_PATH_SQ):$(SANE_TEXT_GREP):$(PAGER_ENV):\
+	$(perllibdir_SQ)
 define cmd_munge_script
 $(RM) $@ $@+ && \
 sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \
@@ -1972,23 +1969,12 @@
 $(SCRIPT_PERL_GEN): GIT-BUILD-OPTIONS
 
 ifndef NO_PERL
-$(SCRIPT_PERL_GEN): perl/perl.mak
+$(SCRIPT_PERL_GEN):
 
-perl/perl.mak: perl/PM.stamp
-
-perl/PM.stamp: FORCE
-	@$(FIND) perl -type f -name '*.pm' | sort >$@+ && \
-	$(PERL_PATH) -V >>$@+ && \
-	{ cmp $@+ $@ >/dev/null 2>/dev/null || mv $@+ $@; } && \
-	$(RM) $@+
-
-perl/perl.mak: GIT-CFLAGS GIT-PREFIX perl/Makefile perl/Makefile.PL
-	$(QUIET_SUBDIR0)perl $(QUIET_SUBDIR1) PERL_PATH='$(PERL_PATH_SQ)' prefix='$(prefix_SQ)' $(@F)
-
-PERL_DEFINES = $(PERL_PATH_SQ):$(PERLLIB_EXTRA_SQ)
-$(SCRIPT_PERL_GEN): % : %.perl perl/perl.mak GIT-PERL-DEFINES GIT-VERSION-FILE
+PERL_DEFINES = $(PERL_PATH_SQ):$(PERLLIB_EXTRA_SQ):$(perllibdir_SQ)
+$(SCRIPT_PERL_GEN): % : %.perl GIT-PERL-DEFINES GIT-VERSION-FILE
 	$(QUIET_GEN)$(RM) $@ $@+ && \
-	INSTLIBDIR=`MAKEFLAGS= $(MAKE) -C perl -s --no-print-directory instlibdir` && \
+	INSTLIBDIR='$(perllibdir_SQ)' && \
 	INSTLIBDIR_EXTRA='$(PERLLIB_EXTRA_SQ)' && \
 	INSTLIBDIR="$$INSTLIBDIR$${INSTLIBDIR_EXTRA:+:$$INSTLIBDIR_EXTRA}" && \
 	sed -e '1{' \
@@ -2312,6 +2298,21 @@
 po/build/locale/%/LC_MESSAGES/git.mo: po/%.po
 	$(QUIET_MSGFMT)mkdir -p $(dir $@) && $(MSGFMT) -o $@ $<
 
+LIB_PERL := $(wildcard perl/Git.pm perl/Git/*.pm perl/Git/*/*.pm perl/Git/*/*/*.pm)
+LIB_PERL_GEN := $(patsubst perl/%.pm,perl/build/lib/%.pm,$(LIB_PERL))
+
+ifndef NO_PERL
+all:: $(LIB_PERL_GEN)
+endif
+
+perl/build/lib/%.pm: perl/%.pm
+	$(QUIET_GEN)mkdir -p $(dir $@) && \
+	sed -e 's|@@LOCALEDIR@@|$(localedir_SQ)|g' < $< > $@
+
+perl/build/man/man3/Git.3pm: perl/Git.pm
+	$(QUIET_GEN)mkdir -p $(dir $@) && \
+	pod2man $< $@
+
 FIND_SOURCE_FILES = ( \
 	git ls-files \
 		'*.[hcS]' \
@@ -2572,7 +2573,9 @@
 	(cd '$(DESTDIR_SQ)$(localedir_SQ)' && umask 022 && $(TAR) xof -)
 endif
 ifndef NO_PERL
-	$(MAKE) -C perl prefix='$(prefix_SQ)' DESTDIR='$(DESTDIR_SQ)' install
+	$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(perllibdir_SQ)'
+	(cd perl/build/lib && $(TAR) cf - .) | \
+	(cd '$(DESTDIR_SQ)$(perllibdir_SQ)' && umask 022 && $(TAR) xof -)
 	$(MAKE) -C gitweb install
 endif
 ifndef NO_TCLTK
@@ -2622,12 +2625,17 @@
 install-gitweb:
 	$(MAKE) -C gitweb install
 
-install-doc:
+install-doc: install-man-perl
 	$(MAKE) -C Documentation install
 
-install-man:
+install-man: install-man-perl
 	$(MAKE) -C Documentation install-man
 
+install-man-perl: perl/build/man/man3/Git.3pm
+	$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(mandir_SQ)/man3'
+	(cd perl/build/man/man3 && $(TAR) cf - .) | \
+	(cd '$(DESTDIR_SQ)$(mandir_SQ)/man3' && umask 022 && $(TAR) xof -)
+
 install-html:
 	$(MAKE) -C Documentation install-html
 
@@ -2662,6 +2670,21 @@
 		$(GIT_TARNAME)/configure \
 		$(GIT_TARNAME)/version \
 		$(GIT_TARNAME)/git-gui/version
+ifdef DC_SHA1_SUBMODULE
+	@mkdir -p $(GIT_TARNAME)/sha1collisiondetection/lib
+	@cp sha1collisiondetection/LICENSE.txt \
+		$(GIT_TARNAME)/sha1collisiondetection/
+	@cp sha1collisiondetection/LICENSE.txt \
+		$(GIT_TARNAME)/sha1collisiondetection/
+	@cp sha1collisiondetection/lib/sha1.[ch] \
+		$(GIT_TARNAME)/sha1collisiondetection/lib/
+	@cp sha1collisiondetection/lib/ubc_check.[ch] \
+		$(GIT_TARNAME)/sha1collisiondetection/lib/
+	$(TAR) rf $(GIT_TARNAME).tar \
+		$(GIT_TARNAME)/sha1collisiondetection/LICENSE.txt \
+		$(GIT_TARNAME)/sha1collisiondetection/lib/sha1.[ch] \
+		$(GIT_TARNAME)/sha1collisiondetection/lib/ubc_check.[ch]
+endif
 	@$(RM) -r $(GIT_TARNAME)
 	gzip -f -9 $(GIT_TARNAME).tar
 
@@ -2719,7 +2742,7 @@
 	$(MAKE) -C Documentation/ clean
 ifndef NO_PERL
 	$(MAKE) -C gitweb clean
-	$(MAKE) -C perl clean
+	$(RM) -r perl/build/
 endif
 	$(MAKE) -C templates/ clean
 	$(MAKE) -C t/ clean

diff --git a/RelNotes b/RelNotes
index 0172894..7a6dc06 120000
--- a/RelNotes
+++ b/RelNotes

@@ -1 +1 @@
-Documentation/RelNotes/2.16.1.txt
\ No newline at end of file
+Documentation/RelNotes/2.17.0.txt
\ No newline at end of file

diff --git a/apply.c b/apply.c
index 321a9fa..40a368b 100644
--- a/apply.c
+++ b/apply.c

@@ -2263,8 +2263,8 @@ static void show_stats(struct apply_state *state, struct patch *patch)
 static int read_old_data(struct stat *st, struct patch *patch,
 			 const char *path, struct strbuf *buf)
 {
-	enum safe_crlf safe_crlf = patch->crlf_in_old ?
-		SAFE_CRLF_KEEP_CRLF : SAFE_CRLF_RENORMALIZE;
+	int conv_flags = patch->crlf_in_old ?
+		CONV_EOL_KEEP_CRLF : CONV_EOL_RENORMALIZE;
 	switch (st->st_mode & S_IFMT) {
 	case S_IFLNK:
 		if (strbuf_readlink(buf, path, st->st_size) < 0)
@@ -2281,7 +2281,7 @@ static int read_old_data(struct stat *st, struct patch *patch,
 		 * should never look at the index when explicit crlf option
 		 * is given.
 		 */
-		convert_to_git(NULL, path, buf->buf, buf->len, buf, safe_crlf);
+		convert_to_git(NULL, path, buf->buf, buf->len, buf, conv_flags);
 		return 0;
 	default:
 		return -1;
@@ -3154,7 +3154,7 @@ static int apply_binary(struct apply_state *state,
 		 * See if the old one matches what the patch
 		 * applies to.
 		 */
-		hash_sha1_file(img->buf, img->len, blob_type, oid.hash);
+		hash_object_file(img->buf, img->len, blob_type, &oid);
 		if (strcmp(oid_to_hex(&oid), patch->old_sha1_prefix))
 			return error(_("the patch applies to '%s' (%s), "
 				       "which does not match the "
@@ -3199,7 +3199,7 @@ static int apply_binary(struct apply_state *state,
 				     name);
 
 		/* verify that the result matches */
-		hash_sha1_file(img->buf, img->len, blob_type, oid.hash);
+		hash_object_file(img->buf, img->len, blob_type, &oid);
 		if (strcmp(oid_to_hex(&oid), patch->new_sha1_prefix))
 			return error(_("binary patch to '%s' creates incorrect result (expecting %s, got %s)"),
 				name, patch->new_sha1_prefix, oid_to_hex(&oid));
@@ -3554,7 +3554,7 @@ static int try_threeway(struct apply_state *state,
 
 	/* Preimage the patch was prepared for */
 	if (patch->is_new)
-		write_sha1_file("", 0, blob_type, pre_oid.hash);
+		write_object_file("", 0, blob_type, &pre_oid);
 	else if (get_oid(patch->old_sha1_prefix, &pre_oid) ||
 		 read_blob_object(&buf, &pre_oid, patch->old_mode))
 		return error(_("repository lacks the necessary blob to fall back on 3-way merge."));
@@ -3570,7 +3570,7 @@ static int try_threeway(struct apply_state *state,
 		return -1;
 	}
 	/* post_oid is theirs */
-	write_sha1_file(tmp_image.buf, tmp_image.len, blob_type, post_oid.hash);
+	write_object_file(tmp_image.buf, tmp_image.len, blob_type, &post_oid);
 	clear_image(&tmp_image);
 
 	/* our_oid is ours */
@@ -3583,7 +3583,7 @@ static int try_threeway(struct apply_state *state,
 			return error(_("cannot read the current contents of '%s'"),
 				     patch->old_name);
 	}
-	write_sha1_file(tmp_image.buf, tmp_image.len, blob_type, our_oid.hash);
+	write_object_file(tmp_image.buf, tmp_image.len, blob_type, &our_oid);
 	clear_image(&tmp_image);
 
 	/* in-core three-way merge between post and our using pre as base */
@@ -4291,7 +4291,7 @@ static int add_index_file(struct apply_state *state,
 			}
 			fill_stat_cache_info(ce, &st);
 		}
-		if (write_sha1_file(buf, size, blob_type, ce->oid.hash) < 0) {
+		if (write_object_file(buf, size, blob_type, &ce->oid) < 0) {
 			free(ce);
 			return error(_("unable to create backing store "
 				       "for newly created file %s"), path);

diff --git a/bisect.c b/bisect.c
index 2f3008b..f6d05bd 100644
--- a/bisect.c
+++ b/bisect.c

@@ -132,7 +132,7 @@ static void show_list(const char *debug, int counted, int nr,
 		unsigned flags = commit->object.flags;
 		enum object_type type;
 		unsigned long size;
-		char *buf = read_sha1_file(commit->object.sha1, &type, &size);
+		char *buf = read_sha1_file(commit->object.oid.hash, &type, &size);
 		const char *subject_start;
 		int subject_len;
 
@@ -144,10 +144,10 @@ static void show_list(const char *debug, int counted, int nr,
 			fprintf(stderr, "%3d", weight(p));
 		else
 			fprintf(stderr, "---");
-		fprintf(stderr, " %.*s", 8, sha1_to_hex(commit->object.sha1));
+		fprintf(stderr, " %.*s", 8, sha1_to_hex(commit->object.oid.hash));
 		for (pp = commit->parents; pp; pp = pp->next)
 			fprintf(stderr, " %.*s", 8,
-				sha1_to_hex(pp->item->object.sha1));
+				sha1_to_hex(pp->item->object.oid.hash));
 
 		subject_len = find_commit_subject(buf, &subject_start);
 		if (subject_len)
@@ -792,11 +792,9 @@ static void handle_skipped_merge_base(const struct object_id *mb)
  * - If one is "skipped", we can't know but we should warn.
  * - If we don't know, we should check it out and ask the user to test.
  */
-static void check_merge_bases(int no_checkout)
+static void check_merge_bases(int rev_nr, struct commit **rev, int no_checkout)
 {
 	struct commit_list *result;
-	int rev_nr;
-	struct commit **rev = get_bad_and_good_commits(&rev_nr);
 
 	result = get_merge_bases_many(rev[0], rev_nr - 1, rev + 1);
 
@@ -814,34 +812,21 @@ static void check_merge_bases(int no_checkout)
 		}
 	}
 
-	free(rev);
 	free_commit_list(result);
 }
 
-static int check_ancestors(const char *prefix)
+static int check_ancestors(int rev_nr, struct commit **rev, const char *prefix)
 {
 	struct rev_info revs;
-	struct object_array pending_copy;
 	int res;
 
 	bisect_rev_setup(&revs, prefix, "^%s", "%s", 0);
 
-	/* Save pending objects, so they can be cleaned up later. */
-	pending_copy = revs.pending;
-	revs.leak_pending = 1;
-
-	/*
-	 * bisect_common calls prepare_revision_walk right away, which
-	 * (together with .leak_pending = 1) makes us the sole owner of
-	 * the list of pending objects.
-	 */
 	bisect_common(&revs);
 	res = (revs.commits != NULL);
 
 	/* Clean up objects used, as they will be reused. */
-	clear_commit_marks_for_object_array(&pending_copy, ALL_REV_FLAGS);
-
-	object_array_clear(&pending_copy);
+	clear_commit_marks_many(rev_nr, rev, ALL_REV_FLAGS);
 
 	return res;
 }
@@ -858,7 +843,8 @@ static void check_good_are_ancestors_of_bad(const char *prefix, int no_checkout)
 {
 	char *filename = git_pathdup("BISECT_ANCESTORS_OK");
 	struct stat st;
-	int fd;
+	int fd, rev_nr;
+	struct commit **rev;
 
 	if (!current_bad_oid)
 		die(_("a %s revision is needed"), term_bad);
@@ -872,8 +858,10 @@ static void check_good_are_ancestors_of_bad(const char *prefix, int no_checkout)
 		goto done;
 
 	/* Check if all good revs are ancestor of the bad rev. */
-	if (check_ancestors(prefix))
-		check_merge_bases(no_checkout);
+	rev = get_bad_and_good_commits(&rev_nr);
+	if (check_ancestors(rev_nr, rev, prefix))
+		check_merge_bases(rev_nr, rev, no_checkout);
+	free(rev);
 
 	/* Create file BISECT_ANCESTORS_OK. */
 	fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY, 0600);

diff --git a/blame.c b/blame.c
index 2893f3c..1fc22b3 100644
--- a/blame.c
+++ b/blame.c

@@ -232,7 +232,7 @@ static struct commit *fake_working_tree_commit(struct diff_options *opt,
 	convert_to_git(&the_index, path, buf.buf, buf.len, &buf, 0);
 	origin->file.ptr = buf.buf;
 	origin->file.size = buf.len;
-	pretend_sha1_file(buf.buf, buf.len, OBJ_BLOB, origin->blob_oid.hash);
+	pretend_object_file(buf.buf, buf.len, OBJ_BLOB, &origin->blob_oid);
 
 	/*
 	 * Read the current index, replace the path entry with

diff --git a/builtin/am.c b/builtin/am.c
index acfe9d3..6661edc 100644
--- a/builtin/am.c
+++ b/builtin/am.c

@@ -1061,7 +1061,7 @@ static void am_setup(struct am_state *state, enum patch_format patch_format,
 	}
 	write_state_text(state, "scissors", str);
 
-	sq_quote_argv(&sb, state->git_apply_opts.argv, 0);
+	sq_quote_argv(&sb, state->git_apply_opts.argv);
 	write_state_text(state, "apply-opt", sb.buf);
 
 	if (state->rebasing)
@@ -1641,8 +1641,8 @@ static void do_commit(const struct am_state *state)
 		setenv("GIT_COMMITTER_DATE",
 			state->ignore_date ? "" : state->author_date, 1);
 
-	if (commit_tree(state->msg, state->msg_len, tree.hash, parents, commit.hash,
-				author, state->sign_commit))
+	if (commit_tree(state->msg, state->msg_len, &tree, parents, &commit,
+			author, state->sign_commit))
 		die(_("failed to write commit object"));
 
 	reflog_msg = getenv("GIT_REFLOG_ACTION");

diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index f5fa4fd..cf9ea5c 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c

@@ -475,6 +475,8 @@ static int batch_objects(struct batch_options *opt)
 
 		for_each_loose_object(batch_loose_object, &sa, 0);
 		for_each_packed_object(batch_packed_object, &sa, 0);
+		if (repository_format_partial_clone)
+			warning("This repository has extensions.partialClone set. Some objects may not be loaded.");
 
 		cb.opt = opt;
 		cb.expand = &data;

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 8bdc927..191b96c 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c

@@ -227,8 +227,7 @@ static int checkout_merged(int pos, const struct checkout *state)
 	 * (it also writes the merge result to the object database even
 	 * when it may contain conflicts).
 	 */
-	if (write_sha1_file(result_buf.ptr, result_buf.size,
-			    blob_type, oid.hash))
+	if (write_object_file(result_buf.ptr, result_buf.size, blob_type, &oid))
 		die(_("Unable to add merge result for '%s'"), path);
 	free(result_buf.ptr);
 	ce = make_cache_entry(mode, oid.hash, path, 2, 0);
@@ -791,7 +790,6 @@ static void orphaned_commit_warning(struct commit *old, struct commit *new)
 {
 	struct rev_info revs;
 	struct object *object = &old->object;
-	struct object_array refs;
 
 	init_revisions(&revs, NULL);
 	setup_revisions(0, NULL, &revs, NULL);
@@ -802,14 +800,6 @@ static void orphaned_commit_warning(struct commit *old, struct commit *new)
 	for_each_ref(add_pending_uninteresting_ref, &revs);
 	add_pending_oid(&revs, "HEAD", &new->object.oid, UNINTERESTING);
 
-	/* Save pending objects, so they can be cleaned up later. */
-	refs = revs.pending;
-	revs.leak_pending = 1;
-
-	/*
-	 * prepare_revision_walk (together with .leak_pending = 1) makes us
-	 * the sole owner of the list of pending objects.
-	 */
 	if (prepare_revision_walk(&revs))
 		die(_("internal error in revision walk"));
 	if (!(old->object.flags & UNINTERESTING))
@@ -818,9 +808,7 @@ static void orphaned_commit_warning(struct commit *old, struct commit *new)
 		describe_detached_head(_("Previous HEAD position was"), old);
 
 	/* Clean up objects used, as they will be reused. */
-	clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
-
-	object_array_clear(&refs);
+	clear_commit_marks_all(ALL_REV_FLAGS);
 }
 
 static int switch_branches(const struct checkout_opts *opts,

diff --git a/builtin/clone.c b/builtin/clone.c
index 2da71db..101c27a 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c

@@ -26,6 +26,7 @@
 #include "run-command.h"
 #include "connected.h"
 #include "packfile.h"
+#include "list-objects-filter-options.h"
 
 /*
  * Overall FIXMEs:
@@ -60,6 +61,7 @@ static struct string_list option_optional_reference = STRING_LIST_INIT_NODUP;
 static int option_dissociate;
 static int max_jobs = -1;
 static struct string_list option_recurse_submodules = STRING_LIST_INIT_NODUP;
+static struct list_objects_filter_options filter_options;
 
 static int recurse_submodules_cb(const struct option *opt,
 				 const char *arg, int unset)
@@ -135,6 +137,7 @@ static struct option builtin_clone_options[] = {
 			TRANSPORT_FAMILY_IPV4),
 	OPT_SET_INT('6', "ipv6", &family, N_("use IPv6 addresses only"),
 			TRANSPORT_FAMILY_IPV6),
+	OPT_PARSE_LIST_OBJECTS_FILTER(&filter_options),
 	OPT_END()
 };
 
@@ -473,7 +476,9 @@ static void clone_local(const char *src_repo, const char *dest_repo)
 }
 
 static const char *junk_work_tree;
+static int junk_work_tree_flags;
 static const char *junk_git_dir;
+static int junk_git_dir_flags;
 static enum {
 	JUNK_LEAVE_NONE,
 	JUNK_LEAVE_REPO,
@@ -502,12 +507,12 @@ static void remove_junk(void)
 
 	if (junk_git_dir) {
 		strbuf_addstr(&sb, junk_git_dir);
-		remove_dir_recursively(&sb, 0);
+		remove_dir_recursively(&sb, junk_git_dir_flags);
 		strbuf_reset(&sb);
 	}
 	if (junk_work_tree) {
 		strbuf_addstr(&sb, junk_work_tree);
-		remove_dir_recursively(&sb, 0);
+		remove_dir_recursively(&sb, junk_work_tree_flags);
 	}
 	strbuf_release(&sb);
 }
@@ -863,10 +868,15 @@ static void dissociate_from_references(void)
 	free(alternates);
 }
 
+static int dir_exists(const char *path)
+{
+	struct stat sb;
+	return !stat(path, &sb);
+}
+
 int cmd_clone(int argc, const char **argv, const char *prefix)
 {
 	int is_bundle = 0, is_local;
-	struct stat buf;
 	const char *repo_name, *repo, *work_tree, *git_dir;
 	char *path, *dir;
 	int dest_exists;
@@ -886,6 +896,8 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	struct refspec *refspec;
 	const char *fetch_pattern;
 
+	fetch_if_missing = 0;
+
 	packet_trace_identity("clone");
 	argc = parse_options(argc, argv, prefix, builtin_clone_options,
 			     builtin_clone_usage, 0);
@@ -938,7 +950,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		dir = guess_dir_name(repo_name, is_bundle, option_bare);
 	strip_trailing_slashes(dir);
 
-	dest_exists = !stat(dir, &buf);
+	dest_exists = dir_exists(dir);
 	if (dest_exists && !is_empty_dir(dir))
 		die(_("destination path '%s' already exists and is not "
 			"an empty directory."), dir);
@@ -949,7 +961,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		work_tree = NULL;
 	else {
 		work_tree = getenv("GIT_WORK_TREE");
-		if (work_tree && !stat(work_tree, &buf))
+		if (work_tree && dir_exists(work_tree))
 			die(_("working tree '%s' already exists."), work_tree);
 	}
 
@@ -967,14 +979,24 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		if (safe_create_leading_directories_const(work_tree) < 0)
 			die_errno(_("could not create leading directories of '%s'"),
 				  work_tree);
-		if (!dest_exists && mkdir(work_tree, 0777))
+		if (dest_exists)
+			junk_work_tree_flags |= REMOVE_DIR_KEEP_TOPLEVEL;
+		else if (mkdir(work_tree, 0777))
 			die_errno(_("could not create work tree dir '%s'"),
 				  work_tree);
 		junk_work_tree = work_tree;
 		set_git_work_tree(work_tree);
 	}
 
-	junk_git_dir = real_git_dir ? real_git_dir : git_dir;
+	if (real_git_dir) {
+		if (dir_exists(real_git_dir))
+			junk_git_dir_flags |= REMOVE_DIR_KEEP_TOPLEVEL;
+		junk_git_dir = real_git_dir;
+	} else {
+		if (dest_exists)
+			junk_git_dir_flags |= REMOVE_DIR_KEEP_TOPLEVEL;
+		junk_git_dir = git_dir;
+	}
 	if (safe_create_leading_directories_const(git_dir) < 0)
 		die(_("could not create leading directories of '%s'"), git_dir);
 
@@ -1073,6 +1095,8 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 			warning(_("--shallow-since is ignored in local clones; use file:// instead."));
 		if (option_not.nr)
 			warning(_("--shallow-exclude is ignored in local clones; use file:// instead."));
+		if (filter_options.choice)
+			warning(_("--filter is ignored in local clones; use file:// instead."));
 		if (!access(mkpath("%s/shallow", path), F_OK)) {
 			if (option_local > 0)
 				warning(_("source repository is shallow, ignoring --local"));
@@ -1101,7 +1125,13 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		transport_set_option(transport, TRANS_OPT_UPLOADPACK,
 				     option_upload_pack);
 
-	if (transport->smart_options && !deepen)
+	if (filter_options.choice) {
+		transport_set_option(transport, TRANS_OPT_LIST_OBJECTS_FILTER,
+				     filter_options.filter_spec);
+		transport_set_option(transport, TRANS_OPT_FROM_PROMISOR, "1");
+	}
+
+	if (transport->smart_options && !deepen && !filter_options.choice)
 		transport->smart_options->check_self_contained_and_connected = 1;
 
 	refs = transport_get_remote_refs(transport);
@@ -1161,13 +1191,17 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	write_refspec_config(src_ref_prefix, our_head_points_at,
 			remote_head_points_at, &branch_top);
 
+	if (filter_options.choice)
+		partial_clone_register("origin", &filter_options);
+
 	if (is_local)
 		clone_local(path, git_dir);
 	else if (refs && complete_refs_before_fetch)
 		transport_fetch_refs(transport, mapped_refs);
 
 	update_remote_refs(refs, mapped_refs, remote_head_points_at,
-			   branch_top.buf, reflog_msg.buf, transport, !is_local);
+			   branch_top.buf, reflog_msg.buf, transport,
+			   !is_local && !filter_options.choice);
 
 	update_head(our_head_points_at, remote_head, reflog_msg.buf);
 
@@ -1188,6 +1222,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	}
 
 	junk_mode = JUNK_LEAVE_REPO;
+	fetch_if_missing = 1;
 	err = checkout(submodule_progress);
 
 	strbuf_release(&reflog_msg);

diff --git a/builtin/commit-tree.c b/builtin/commit-tree.c
index 2177251..e5bdf57 100644
--- a/builtin/commit-tree.c
+++ b/builtin/commit-tree.c

@@ -117,8 +117,8 @@ int cmd_commit_tree(int argc, const char **argv, const char *prefix)
 			die_errno("git commit-tree: failed to read");
 	}
 
-	if (commit_tree(buffer.buf, buffer.len, tree_oid.hash, parents,
-			commit_oid.hash, NULL, sign_commit)) {
+	if (commit_tree(buffer.buf, buffer.len, &tree_oid, parents, &commit_oid,
+			NULL, sign_commit)) {
 		strbuf_release(&buffer);
 		return 1;
 	}

diff --git a/builtin/commit.c b/builtin/commit.c
index 8a87701..e8e8d13 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c

@@ -31,9 +31,7 @@
 #include "gpg-interface.h"
 #include "column.h"
 #include "sequencer.h"
-#include "notes-utils.h"
 #include "mailmap.h"
-#include "sigchain.h"
 
 static const char * const builtin_commit_usage[] = {
 	N_("git commit [<options>] [--] <pathspec>..."),
@@ -45,31 +43,6 @@ static const char * const builtin_status_usage[] = {
 	NULL
 };
 
-static const char implicit_ident_advice_noconfig[] =
-N_("Your name and email address were configured automatically based\n"
-"on your username and hostname. Please check that they are accurate.\n"
-"You can suppress this message by setting them explicitly. Run the\n"
-"following command and follow the instructions in your editor to edit\n"
-"your configuration file:\n"
-"\n"
-"    git config --global --edit\n"
-"\n"
-"After doing this, you may fix the identity used for this commit with:\n"
-"\n"
-"    git commit --amend --reset-author\n");
-
-static const char implicit_ident_advice_config[] =
-N_("Your name and email address were configured automatically based\n"
-"on your username and hostname. Please check that they are accurate.\n"
-"You can suppress this message by setting them explicitly:\n"
-"\n"
-"    git config --global user.name \"Your Name\"\n"
-"    git config --global user.email you@example.com\n"
-"\n"
-"After doing this, you may fix the identity used for this commit with:\n"
-"\n"
-"    git commit --amend --reset-author\n");
-
 static const char empty_amend_advice[] =
 N_("You asked to amend the most recent commit, but doing so would make\n"
 "it empty. You can repeat your command with --allow-empty, or you can\n"
@@ -93,8 +66,6 @@ N_("If you wish to skip this commit, use:\n"
 "Then \"git cherry-pick --continue\" will resume cherry-picking\n"
 "the remaining commits.\n");
 
-static GIT_PATH_FUNC(git_path_commit_editmsg, "COMMIT_EDITMSG")
-
 static const char *use_message_buffer;
 static struct lock_file index_lock; /* real index */
 static struct lock_file false_lock; /* used only for partial commits */
@@ -128,12 +99,7 @@ static char *sign_commit;
  * if editor is used, and only the whitespaces if the message
  * is specified explicitly.
  */
-static enum {
-	CLEANUP_SPACE,
-	CLEANUP_NONE,
-	CLEANUP_SCISSORS,
-	CLEANUP_ALL
-} cleanup_mode;
+static enum commit_msg_cleanup_mode cleanup_mode;
 static const char *cleanup_arg;
 
 static enum commit_whence whence;
@@ -673,7 +639,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 	struct strbuf sb = STRBUF_INIT;
 	const char *hook_arg1 = NULL;
 	const char *hook_arg2 = NULL;
-	int clean_message_contents = (cleanup_mode != CLEANUP_NONE);
+	int clean_message_contents = (cleanup_mode != COMMIT_MSG_CLEANUP_NONE);
 	int old_display_comment_prefix;
 
 	/* This checks and barfs if author is badly specified */
@@ -701,7 +667,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 		}
 	}
 
-	if (have_option_m) {
+	if (have_option_m && !fixup_message) {
 		strbuf_addbuf(&sb, &message);
 		hook_arg1 = "message";
 	} else if (logfile && !strcmp(logfile, "-")) {
@@ -731,6 +697,8 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 		ctx.output_encoding = get_commit_output_encoding();
 		format_commit_message(commit, "fixup! %s\n\n",
 				      &sb, &ctx);
+		if (have_option_m)
+			strbuf_addbuf(&sb, &message);
 		hook_arg1 = "message";
 	} else if (!stat(git_path_merge_msg(), &statbuf)) {
 		/*
@@ -812,7 +780,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 		struct ident_split ci, ai;
 
 		if (whence != FROM_COMMIT) {
-			if (cleanup_mode == CLEANUP_SCISSORS)
+			if (cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS)
 				wt_status_add_cut_line(s->fp);
 			status_printf_ln(s, GIT_COLOR_NORMAL,
 			    whence == FROM_MERGE
@@ -832,14 +800,15 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 		}
 
 		fprintf(s->fp, "\n");
-		if (cleanup_mode == CLEANUP_ALL)
+		if (cleanup_mode == COMMIT_MSG_CLEANUP_ALL)
 			status_printf(s, GIT_COLOR_NORMAL,
 				_("Please enter the commit message for your changes."
 				  " Lines starting\nwith '%c' will be ignored, and an empty"
 				  " message aborts the commit.\n"), comment_line_char);
-		else if (cleanup_mode == CLEANUP_SCISSORS && whence == FROM_COMMIT)
+		else if (cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS &&
+			 whence == FROM_COMMIT)
 			wt_status_add_cut_line(s->fp);
-		else /* CLEANUP_SPACE, that is. */
+		else /* COMMIT_MSG_CLEANUP_SPACE, that is. */
 			status_printf(s, GIT_COLOR_NORMAL,
 				_("Please enter the commit message for your changes."
 				  " Lines starting\n"
@@ -984,65 +953,6 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 	return 1;
 }
 
-static int rest_is_empty(struct strbuf *sb, int start)
-{
-	int i, eol;
-	const char *nl;
-
-	/* Check if the rest is just whitespace and Signed-off-by's. */
-	for (i = start; i < sb->len; i++) {
-		nl = memchr(sb->buf + i, '\n', sb->len - i);
-		if (nl)
-			eol = nl - sb->buf;
-		else
-			eol = sb->len;
-
-		if (strlen(sign_off_header) <= eol - i &&
-		    starts_with(sb->buf + i, sign_off_header)) {
-			i = eol;
-			continue;
-		}
-		while (i < eol)
-			if (!isspace(sb->buf[i++]))
-				return 0;
-	}
-
-	return 1;
-}
-
-/*
- * Find out if the message in the strbuf contains only whitespace and
- * Signed-off-by lines.
- */
-static int message_is_empty(struct strbuf *sb)
-{
-	if (cleanup_mode == CLEANUP_NONE && sb->len)
-		return 0;
-	return rest_is_empty(sb, 0);
-}
-
-/*
- * See if the user edited the message in the editor or left what
- * was in the template intact
- */
-static int template_untouched(struct strbuf *sb)
-{
-	struct strbuf tmpl = STRBUF_INIT;
-	const char *start;
-
-	if (cleanup_mode == CLEANUP_NONE && sb->len)
-		return 0;
-
-	if (!template_file || strbuf_read_file(&tmpl, template_file, 0) <= 0)
-		return 0;
-
-	strbuf_stripspace(&tmpl, cleanup_mode == CLEANUP_ALL);
-	if (!skip_prefix(sb->buf, tmpl.buf, &start))
-		start = sb->buf;
-	strbuf_release(&tmpl);
-	return rest_is_empty(sb, start - sb->buf);
-}
-
 static const char *find_author_by_nickname(const char *name)
 {
 	struct rev_info revs;
@@ -1197,8 +1107,8 @@ static int parse_and_validate_options(int argc, const char *argv[],
 		f++;
 	if (f > 1)
 		die(_("Only one of -c/-C/-F/--fixup can be used."));
-	if (have_option_m && f > 0)
-		die((_("Option -m cannot be combined with -c/-C/-F/--fixup.")));
+	if (have_option_m && (edit_message || use_message || logfile))
+		die((_("Option -m cannot be combined with -c/-C/-F.")));
 	if (f || have_option_m)
 		template_file = NULL;
 	if (edit_message)
@@ -1227,15 +1137,17 @@ static int parse_and_validate_options(int argc, const char *argv[],
 	if (argc == 0 && (also || (only && !amend && !allow_empty)))
 		die(_("No paths with --include/--only does not make sense."));
 	if (!cleanup_arg || !strcmp(cleanup_arg, "default"))
-		cleanup_mode = use_editor ? CLEANUP_ALL : CLEANUP_SPACE;
+		cleanup_mode = use_editor ? COMMIT_MSG_CLEANUP_ALL :
+					    COMMIT_MSG_CLEANUP_SPACE;
 	else if (!strcmp(cleanup_arg, "verbatim"))
-		cleanup_mode = CLEANUP_NONE;
+		cleanup_mode = COMMIT_MSG_CLEANUP_NONE;
 	else if (!strcmp(cleanup_arg, "whitespace"))
-		cleanup_mode = CLEANUP_SPACE;
+		cleanup_mode = COMMIT_MSG_CLEANUP_SPACE;
 	else if (!strcmp(cleanup_arg, "strip"))
-		cleanup_mode = CLEANUP_ALL;
+		cleanup_mode = COMMIT_MSG_CLEANUP_ALL;
 	else if (!strcmp(cleanup_arg, "scissors"))
-		cleanup_mode = use_editor ? CLEANUP_SCISSORS : CLEANUP_SPACE;
+		cleanup_mode = use_editor ? COMMIT_MSG_CLEANUP_SCISSORS :
+					    COMMIT_MSG_CLEANUP_SPACE;
 	else
 		die(_("Invalid cleanup mode %s"), cleanup_arg);
 
@@ -1437,98 +1349,6 @@ int cmd_status(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
-static const char *implicit_ident_advice(void)
-{
-	char *user_config = expand_user_path("~/.gitconfig", 0);
-	char *xdg_config = xdg_config_home("config");
-	int config_exists = file_exists(user_config) || file_exists(xdg_config);
-
-	free(user_config);
-	free(xdg_config);
-
-	if (config_exists)
-		return _(implicit_ident_advice_config);
-	else
-		return _(implicit_ident_advice_noconfig);
-
-}
-
-static void print_summary(const char *prefix, const struct object_id *oid,
-			  int initial_commit)
-{
-	struct rev_info rev;
-	struct commit *commit;
-	struct strbuf format = STRBUF_INIT;
-	const char *head;
-	struct pretty_print_context pctx = {0};
-	struct strbuf author_ident = STRBUF_INIT;
-	struct strbuf committer_ident = STRBUF_INIT;
-
-	commit = lookup_commit(oid);
-	if (!commit)
-		die(_("couldn't look up newly created commit"));
-	if (parse_commit(commit))
-		die(_("could not parse newly created commit"));
-
-	strbuf_addstr(&format, "format:%h] %s");
-
-	format_commit_message(commit, "%an <%ae>", &author_ident, &pctx);
-	format_commit_message(commit, "%cn <%ce>", &committer_ident, &pctx);
-	if (strbuf_cmp(&author_ident, &committer_ident)) {
-		strbuf_addstr(&format, "\n Author: ");
-		strbuf_addbuf_percentquote(&format, &author_ident);
-	}
-	if (author_date_is_interesting()) {
-		struct strbuf date = STRBUF_INIT;
-		format_commit_message(commit, "%ad", &date, &pctx);
-		strbuf_addstr(&format, "\n Date: ");
-		strbuf_addbuf_percentquote(&format, &date);
-		strbuf_release(&date);
-	}
-	if (!committer_ident_sufficiently_given()) {
-		strbuf_addstr(&format, "\n Committer: ");
-		strbuf_addbuf_percentquote(&format, &committer_ident);
-		if (advice_implicit_identity) {
-			strbuf_addch(&format, '\n');
-			strbuf_addstr(&format, implicit_ident_advice());
-		}
-	}
-	strbuf_release(&author_ident);
-	strbuf_release(&committer_ident);
-
-	init_revisions(&rev, prefix);
-	setup_revisions(0, NULL, &rev, NULL);
-
-	rev.diff = 1;
-	rev.diffopt.output_format =
-		DIFF_FORMAT_SHORTSTAT | DIFF_FORMAT_SUMMARY;
-
-	rev.verbose_header = 1;
-	rev.show_root_diff = 1;
-	get_commit_format(format.buf, &rev);
-	rev.always_show_header = 0;
-	rev.diffopt.detect_rename = 1;
-	rev.diffopt.break_opt = 0;
-	diff_setup_done(&rev.diffopt);
-
-	head = resolve_ref_unsafe("HEAD", 0, NULL, NULL);
-	if (!head)
-		die_errno(_("unable to resolve HEAD after creating commit"));
-	if (!strcmp(head, "HEAD"))
-		head = _("detached HEAD");
-	else
-		skip_prefix(head, "refs/heads/", &head);
-	printf("[%s%s ", head, initial_commit ? _(" (root-commit)") : "");
-
-	if (!log_tree_commit(&rev, commit)) {
-		rev.always_show_header = 1;
-		rev.use_terminator = 1;
-		log_tree_commit(&rev, commit);
-	}
-
-	strbuf_release(&format);
-}
-
 static int git_commit_config(const char *k, const char *v, void *cb)
 {
 	struct wt_status *s = cb;
@@ -1558,37 +1378,6 @@ static int git_commit_config(const char *k, const char *v, void *cb)
 	return git_status_config(k, v, s);
 }
 
-static int run_rewrite_hook(const struct object_id *oldoid,
-			    const struct object_id *newoid)
-{
-	struct child_process proc = CHILD_PROCESS_INIT;
-	const char *argv[3];
-	int code;
-	struct strbuf sb = STRBUF_INIT;
-
-	argv[0] = find_hook("post-rewrite");
-	if (!argv[0])
-		return 0;
-
-	argv[1] = "amend";
-	argv[2] = NULL;
-
-	proc.argv = argv;
-	proc.in = -1;
-	proc.stdout_to_stderr = 1;
-
-	code = start_command(&proc);
-	if (code)
-		return code;
-	strbuf_addf(&sb, "%s %s\n", oid_to_hex(oldoid), oid_to_hex(newoid));
-	sigchain_push(SIGPIPE, SIG_IGN);
-	write_in_full(proc.in, sb.buf, sb.len);
-	close(proc.in);
-	strbuf_release(&sb);
-	sigchain_pop(SIGPIPE);
-	return finish_command(&proc);
-}
-
 int run_commit_hook(int editor_is_used, const char *index_file, const char *name, ...)
 {
 	struct argv_array hook_env = ARGV_ARRAY_INIT;
@@ -1671,13 +1460,11 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 	struct strbuf sb = STRBUF_INIT;
 	struct strbuf author_ident = STRBUF_INIT;
 	const char *index_file, *reflog_msg;
-	char *nl;
 	struct object_id oid;
 	struct commit_list *parents = NULL;
 	struct stat statbuf;
 	struct commit *current_head = NULL;
 	struct commit_extra_header *extra = NULL;
-	struct ref_transaction *transaction;
 	struct strbuf err = STRBUF_INIT;
 
 	if (argc == 2 && !strcmp(argv[1], "-h"))
@@ -1768,17 +1555,17 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 	}
 
 	if (verbose || /* Truncate the message just before the diff, if any. */
-	    cleanup_mode == CLEANUP_SCISSORS)
+	    cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS)
 		strbuf_setlen(&sb, wt_status_locate_end(sb.buf, sb.len));
-	if (cleanup_mode != CLEANUP_NONE)
-		strbuf_stripspace(&sb, cleanup_mode == CLEANUP_ALL);
+	if (cleanup_mode != COMMIT_MSG_CLEANUP_NONE)
+		strbuf_stripspace(&sb, cleanup_mode == COMMIT_MSG_CLEANUP_ALL);
 
-	if (message_is_empty(&sb) && !allow_empty_message) {
+	if (message_is_empty(&sb, cleanup_mode) && !allow_empty_message) {
 		rollback_index_files();
 		fprintf(stderr, _("Aborting commit due to empty commit message.\n"));
 		exit(1);
 	}
-	if (template_untouched(&sb) && !allow_empty_message) {
+	if (template_untouched(&sb, template_file, cleanup_mode) && !allow_empty_message) {
 		rollback_index_files();
 		fprintf(stderr, _("Aborting commit; you did not edit the message.\n"));
 		exit(1);
@@ -1792,33 +1579,20 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 		append_merge_tag_headers(parents, &tail);
 	}
 
-	if (commit_tree_extended(sb.buf, sb.len, active_cache_tree->oid.hash,
-			 parents, oid.hash, author_ident.buf, sign_commit, extra)) {
+	if (commit_tree_extended(sb.buf, sb.len, &active_cache_tree->oid,
+				 parents, &oid, author_ident.buf, sign_commit,
+				 extra)) {
 		rollback_index_files();
 		die(_("failed to write commit object"));
 	}
 	strbuf_release(&author_ident);
 	free_commit_extra_headers(extra);
 
-	nl = strchr(sb.buf, '\n');
-	if (nl)
-		strbuf_setlen(&sb, nl + 1 - sb.buf);
-	else
-		strbuf_addch(&sb, '\n');
-	strbuf_insert(&sb, 0, reflog_msg, strlen(reflog_msg));
-	strbuf_insert(&sb, strlen(reflog_msg), ": ", 2);
-
-	transaction = ref_transaction_begin(&err);
-	if (!transaction ||
-	    ref_transaction_update(transaction, "HEAD", &oid,
-				   current_head
-				   ? &current_head->object.oid : &null_oid,
-				   0, sb.buf, &err) ||
-	    ref_transaction_commit(transaction, &err)) {
+	if (update_head_with_reflog(current_head, &oid, reflog_msg, &sb,
+				    &err)) {
 		rollback_index_files();
 		die("%s", err.buf);
 	}
-	ref_transaction_free(transaction);
 
 	unlink(git_path_cherry_pick_head());
 	unlink(git_path_revert_head());
@@ -1835,17 +1609,17 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 	rerere(0);
 	run_commit_hook(use_editor, get_index_file(), "post-commit", NULL);
 	if (amend && !no_post_rewrite) {
-		struct notes_rewrite_cfg *cfg;
-		cfg = init_copy_notes_for_rewrite("amend");
-		if (cfg) {
-			/* we are amending, so current_head is not NULL */
-			copy_note_for_rewrite(cfg, &current_head->object.oid, &oid);
-			finish_copy_notes_for_rewrite(cfg, "Notes added by 'git commit --amend'");
-		}
-		run_rewrite_hook(&current_head->object.oid, &oid);
+		commit_post_rewrite(current_head, &oid);
 	}
-	if (!quiet)
-		print_summary(prefix, &oid, !current_head);
+	if (!quiet) {
+		unsigned int flags = 0;
+
+		if (!current_head)
+			flags |= SUMMARY_INITIAL_COMMIT;
+		if (author_date_is_interesting())
+			flags |= SUMMARY_SHOW_AUTHOR_DATE;
+		print_commit_summary(prefix, &oid, flags);
+	}
 
 	UNLEAK(err);
 	UNLEAK(sb);

diff --git a/builtin/describe.c b/builtin/describe.c
index 3b0b204..c428984 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c

@@ -274,10 +274,13 @@ static void append_name(struct commit_name *n, struct strbuf *dst)
 		n->name_checked = 1;
 	}
 
-	if (n->tag)
+	if (n->tag) {
+		if (all)
+			strbuf_addstr(dst, "tags/");
 		strbuf_addstr(dst, n->tag->tag);
-	else
+	} else {
 		strbuf_addstr(dst, n->path);
+	}
 }
 
 static void append_suffix(int depth, const struct object_id *oid, struct strbuf *dst)
@@ -380,7 +383,7 @@ static void describe_commit(struct object_id *oid, struct strbuf *dst)
 	if (!match_cnt) {
 		struct object_id *cmit_oid = &cmit->object.oid;
 		if (always) {
-			strbuf_addstr(dst, find_unique_abbrev(cmit_oid->hash, abbrev));
+			strbuf_add_unique_abbrev(dst, cmit_oid->hash, abbrev);
 			if (suffix)
 				strbuf_addstr(dst, suffix);
 			return;

diff --git a/builtin/fetch-pack.c b/builtin/fetch-pack.c
index 366b9d1..a7bc136 100644
--- a/builtin/fetch-pack.c
+++ b/builtin/fetch-pack.c

@@ -53,6 +53,8 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 	struct oid_array shallow = OID_ARRAY_INIT;
 	struct string_list deepen_not = STRING_LIST_INIT_DUP;
 
+	fetch_if_missing = 0;
+
 	packet_trace_identity("fetch-pack");
 
 	memset(&args, 0, sizeof(args));
@@ -143,6 +145,22 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 			args.update_shallow = 1;
 			continue;
 		}
+		if (!strcmp("--from-promisor", arg)) {
+			args.from_promisor = 1;
+			continue;
+		}
+		if (!strcmp("--no-dependents", arg)) {
+			args.no_dependents = 1;
+			continue;
+		}
+		if (skip_prefix(arg, ("--" CL_ARG__FILTER "="), &arg)) {
+			parse_list_objects_filter(&args.filter_options, arg);
+			continue;
+		}
+		if (!strcmp(arg, ("--no-" CL_ARG__FILTER))) {
+			list_objects_filter_set_no_filter(&args.filter_options);
+			continue;
+		}
 		usage(fetch_pack_usage);
 	}
 	if (deepen_not.nr)

diff --git a/builtin/fetch.c b/builtin/fetch.c
index 7bbcd26..8ee998e 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c

@@ -19,6 +19,7 @@
 #include "argv-array.h"
 #include "utf8.h"
 #include "packfile.h"
+#include "list-objects-filter-options.h"
 
 static const char * const builtin_fetch_usage[] = {
 	N_("git fetch [<options>] [<repository> [<refspec>...]]"),
@@ -56,6 +57,7 @@ static int recurse_submodules_default = RECURSE_SUBMODULES_ON_DEMAND;
 static int shown_url = 0;
 static int refmap_alloc, refmap_nr;
 static const char **refmap_array;
+static struct list_objects_filter_options filter_options;
 
 static int git_fetch_config(const char *k, const char *v, void *cb)
 {
@@ -161,6 +163,7 @@ static struct option builtin_fetch_options[] = {
 			TRANSPORT_FAMILY_IPV4),
 	OPT_SET_INT('6', "ipv6", &family, N_("use IPv6 addresses only"),
 			TRANSPORT_FAMILY_IPV6),
+	OPT_PARSE_LIST_OBJECTS_FILTER(&filter_options),
 	OPT_END()
 };
 
@@ -1045,6 +1048,11 @@ static struct transport *prepare_transport(struct remote *remote, int deepen)
 		set_option(transport, TRANS_OPT_DEEPEN_RELATIVE, "yes");
 	if (update_shallow)
 		set_option(transport, TRANS_OPT_UPDATE_SHALLOW, "yes");
+	if (filter_options.choice) {
+		set_option(transport, TRANS_OPT_LIST_OBJECTS_FILTER,
+			   filter_options.filter_spec);
+		set_option(transport, TRANS_OPT_FROM_PROMISOR, "1");
+	}
 	return transport;
 }
 
@@ -1265,6 +1273,56 @@ static int fetch_multiple(struct string_list *list)
 	return result;
 }
 
+/*
+ * Fetching from the promisor remote should use the given filter-spec
+ * or inherit the default filter-spec from the config.
+ */
+static inline void fetch_one_setup_partial(struct remote *remote)
+{
+	/*
+	 * Explicit --no-filter argument overrides everything, regardless
+	 * of any prior partial clones and fetches.
+	 */
+	if (filter_options.no_filter)
+		return;
+
+	/*
+	 * If no prior partial clone/fetch and the current fetch DID NOT
+	 * request a partial-fetch, do a normal fetch.
+	 */
+	if (!repository_format_partial_clone && !filter_options.choice)
+		return;
+
+	/*
+	 * If this is the FIRST partial-fetch request, we enable partial
+	 * on this repo and remember the given filter-spec as the default
+	 * for subsequent fetches to this remote.
+	 */
+	if (!repository_format_partial_clone && filter_options.choice) {
+		partial_clone_register(remote->name, &filter_options);
+		return;
+	}
+
+	/*
+	 * We are currently limited to only ONE promisor remote and only
+	 * allow partial-fetches from the promisor remote.
+	 */
+	if (strcmp(remote->name, repository_format_partial_clone)) {
+		if (filter_options.choice)
+			die(_("--filter can only be used with the remote configured in core.partialClone"));
+		return;
+	}
+
+	/*
+	 * Do a partial-fetch from the promisor remote using either the
+	 * explicitly given filter-spec or inherit the filter-spec from
+	 * the config.
+	 */
+	if (!filter_options.choice)
+		partial_clone_get_default_filter_spec(&filter_options);
+	return;
+}
+
 static int fetch_one(struct remote *remote, int argc, const char **argv)
 {
 	static const char **refs = NULL;
@@ -1320,12 +1378,14 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
 {
 	int i;
 	struct string_list list = STRING_LIST_INIT_DUP;
-	struct remote *remote;
+	struct remote *remote = NULL;
 	int result = 0;
 	struct argv_array argv_gc_auto = ARGV_ARRAY_INIT;
 
 	packet_trace_identity("fetch");
 
+	fetch_if_missing = 0;
+
 	/* Record the command line for the reflog */
 	strbuf_addstr(&default_rla, "fetch");
 	for (i = 1; i < argc; i++)
@@ -1359,23 +1419,23 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
 	if (depth || deepen_since || deepen_not.nr)
 		deepen = 1;
 
+	if (filter_options.choice && !repository_format_partial_clone)
+		die("--filter can only be used when extensions.partialClone is set");
+
 	if (all) {
 		if (argc == 1)
 			die(_("fetch --all does not take a repository argument"));
 		else if (argc > 1)
 			die(_("fetch --all does not make sense with refspecs"));
 		(void) for_each_remote(get_one_remote_for_fetch, &list);
-		result = fetch_multiple(&list);
 	} else if (argc == 0) {
 		/* No arguments -- use default remote */
 		remote = remote_get(NULL);
-		result = fetch_one(remote, argc, argv);
 	} else if (multiple) {
 		/* All arguments are assumed to be remotes or groups */
 		for (i = 0; i < argc; i++)
 			if (!add_remote_or_group(argv[i], &list))
 				die(_("No such remote or remote group: %s"), argv[i]);
-		result = fetch_multiple(&list);
 	} else {
 		/* Single remote or group */
 		(void) add_remote_or_group(argv[0], &list);
@@ -1383,14 +1443,25 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
 			/* More than one remote */
 			if (argc > 1)
 				die(_("Fetching a group and specifying refspecs does not make sense"));
-			result = fetch_multiple(&list);
 		} else {
 			/* Zero or one remotes */
 			remote = remote_get(argv[0]);
-			result = fetch_one(remote, argc-1, argv+1);
+			argc--;
+			argv++;
 		}
 	}
 
+	if (remote) {
+		if (filter_options.choice || repository_format_partial_clone)
+			fetch_one_setup_partial(remote);
+		result = fetch_one(remote, argc, argv);
+	} else {
+		if (filter_options.choice)
+			die(_("--filter can only be used with the remote configured in core.partialClone"));
+		/* TODO should this also die if we have a previous partial-clone? */
+		result = fetch_multiple(&list);
+	}
+
 	if (!result && (recurse_submodules != RECURSE_SUBMODULES_OFF)) {
 		struct argv_array options = ARGV_ARRAY_INIT;
 

diff --git a/builtin/fsck.c b/builtin/fsck.c
index 04846d4..9981db2 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c

@@ -149,6 +149,15 @@ static int mark_object(struct object *obj, int type, void *data, struct fsck_opt
 	if (obj->flags & REACHABLE)
 		return 0;
 	obj->flags |= REACHABLE;
+
+	if (is_promisor_object(&obj->oid))
+		/*
+		 * Further recursion does not need to be performed on this
+		 * object since it is a promisor object (so it does not need to
+		 * be added to "pending").
+		 */
+		return 0;
+
 	if (!(obj->flags & HAS_OBJ)) {
 		if (parent && !has_object_file(&obj->oid)) {
 			printf("broken link from %7s %s\n",
@@ -171,7 +180,13 @@ static void mark_object_reachable(struct object *obj)
 
 static int traverse_one_object(struct object *obj)
 {
-	return fsck_walk(obj, obj, &fsck_walk_options);
+	int result = fsck_walk(obj, obj, &fsck_walk_options);
+
+	if (obj->type == OBJ_TREE) {
+		struct tree *tree = (struct tree *)obj;
+		free_tree_buffer(tree);
+	}
+	return result;
 }
 
 static int traverse_reachable(void)
@@ -208,6 +223,8 @@ static void check_reachable_object(struct object *obj)
 	 * do a full fsck
 	 */
 	if (!(obj->flags & HAS_OBJ)) {
+		if (is_promisor_object(&obj->oid))
+			return;
 		if (has_sha1_pack(obj->oid.hash))
 			return; /* it is in pack - forget about it */
 		printf("missing %s %s\n", printable_type(obj),
@@ -398,7 +415,7 @@ static void fsck_handle_reflog_oid(const char *refname, struct object_id *oid,
 					xstrfmt("%s@{%"PRItime"}", refname, timestamp));
 			obj->flags |= USED;
 			mark_object_reachable(obj);
-		} else {
+		} else if (!is_promisor_object(oid)) {
 			error("%s: invalid reflog entry %s", refname, oid_to_hex(oid));
 			errors_found |= ERROR_REACHABLE;
 		}
@@ -434,6 +451,14 @@ static int fsck_handle_ref(const char *refname, const struct object_id *oid,
 
 	obj = parse_object(oid);
 	if (!obj) {
+		if (is_promisor_object(oid)) {
+			/*
+			 * Increment default_refs anyway, because this is a
+			 * valid ref.
+			 */
+			 default_refs++;
+			 return 0;
+		}
 		error("%s: invalid sha1 pointer %s", refname, oid_to_hex(oid));
 		errors_found |= ERROR_REACHABLE;
 		/* We'll continue with the rest despite the error.. */
@@ -659,6 +684,9 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
 	int i;
 	struct alternate_object_database *alt;
 
+	/* fsck knows how to handle missing promisor objects */
+	fetch_if_missing = 0;
+
 	errors_found = 0;
 	check_replace_refs = 0;
 
@@ -731,6 +759,8 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
 			struct object *obj = lookup_object(oid.hash);
 
 			if (!obj || !(obj->flags & HAS_OBJ)) {
+				if (is_promisor_object(&oid))
+					continue;
 				error("%s: object missing", oid_to_hex(&oid));
 				errors_found |= ERROR_OBJECT;
 				continue;

diff --git a/builtin/gc.c b/builtin/gc.c
index 3c5eae0..77fa720 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c

@@ -458,6 +458,9 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
 			argv_array_push(&prune, prune_expire);
 			if (quiet)
 				argv_array_push(&prune, "--no-progress");
+			if (repository_format_partial_clone)
+				argv_array_push(&prune,
+						"--exclude-promisor-objects");
 			if (run_command_v_opt(prune.argv, RUN_GIT_CMD))
 				return error(FAILED_RUN, prune.argv[0]);
 		}

diff --git a/builtin/hash-object.c b/builtin/hash-object.c
index c532ff9..526da5c 100644
--- a/builtin/hash-object.c
+++ b/builtin/hash-object.c

@@ -24,7 +24,8 @@ static int hash_literally(struct object_id *oid, int fd, const char *type, unsig
 	if (strbuf_read(&buf, fd, 4096) < 0)
 		ret = -1;
 	else
-		ret = hash_sha1_file_literally(buf.buf, buf.len, type, oid, flags);
+		ret = hash_object_file_literally(buf.buf, buf.len, type, oid,
+						 flags);
 	strbuf_release(&buf);
 	return ret;
 }

diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 4c51aec..7e3e1a4 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c

@@ -91,7 +91,7 @@ static unsigned int input_offset, input_len;
 static off_t consumed_bytes;
 static off_t max_input_size;
 static unsigned deepest_delta;
-static git_SHA_CTX input_ctx;
+static git_hash_ctx input_ctx;
 static uint32_t input_crc32;
 static int input_fd, output_fd;
 static const char *curr_pack;
@@ -253,7 +253,7 @@ static void flush(void)
 	if (input_offset) {
 		if (output_fd >= 0)
 			write_or_die(output_fd, input_buffer, input_offset);
-		git_SHA1_Update(&input_ctx, input_buffer, input_offset);
+		the_hash_algo->update_fn(&input_ctx, input_buffer, input_offset);
 		memmove(input_buffer, input_buffer + input_offset, input_len);
 		input_offset = 0;
 	}
@@ -326,7 +326,7 @@ static const char *open_pack_file(const char *pack_name)
 		output_fd = -1;
 		nothread_data.pack_fd = input_fd;
 	}
-	git_SHA1_Init(&input_ctx);
+	the_hash_algo->init_fn(&input_ctx);
 	return pack_name;
 }
 
@@ -437,22 +437,22 @@ static int is_delta_type(enum object_type type)
 }
 
 static void *unpack_entry_data(off_t offset, unsigned long size,
-			       enum object_type type, unsigned char *sha1)
+			       enum object_type type, struct object_id *oid)
 {
 	static char fixed_buf[8192];
 	int status;
 	git_zstream stream;
 	void *buf;
-	git_SHA_CTX c;
+	git_hash_ctx c;
 	char hdr[32];
 	int hdrlen;
 
 	if (!is_delta_type(type)) {
 		hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(type), size) + 1;
-		git_SHA1_Init(&c);
-		git_SHA1_Update(&c, hdr, hdrlen);
+		the_hash_algo->init_fn(&c);
+		the_hash_algo->update_fn(&c, hdr, hdrlen);
 	} else
-		sha1 = NULL;
+		oid = NULL;
 	if (type == OBJ_BLOB && size > big_file_threshold)
 		buf = fixed_buf;
 	else
@@ -469,8 +469,8 @@ static void *unpack_entry_data(off_t offset, unsigned long size,
 		stream.avail_in = input_len;
 		status = git_inflate(&stream, 0);
 		use(input_len - stream.avail_in);
-		if (sha1)
-			git_SHA1_Update(&c, last_out, stream.next_out - last_out);
+		if (oid)
+			the_hash_algo->update_fn(&c, last_out, stream.next_out - last_out);
 		if (buf == fixed_buf) {
 			stream.next_out = buf;
 			stream.avail_out = sizeof(fixed_buf);
@@ -479,15 +479,15 @@ static void *unpack_entry_data(off_t offset, unsigned long size,
 	if (stream.total_out != size || status != Z_STREAM_END)
 		bad_object(offset, _("inflate returned %d"), status);
 	git_inflate_end(&stream);
-	if (sha1)
-		git_SHA1_Final(sha1, &c);
+	if (oid)
+		the_hash_algo->final_fn(oid->hash, &c);
 	return buf == fixed_buf ? NULL : buf;
 }
 
 static void *unpack_raw_entry(struct object_entry *obj,
 			      off_t *ofs_offset,
-			      unsigned char *ref_sha1,
-			      unsigned char *sha1)
+			      struct object_id *ref_oid,
+			      struct object_id *oid)
 {
 	unsigned char *p;
 	unsigned long size, c;
@@ -515,8 +515,8 @@ static void *unpack_raw_entry(struct object_entry *obj,
 
 	switch (obj->type) {
 	case OBJ_REF_DELTA:
-		hashcpy(ref_sha1, fill(20));
-		use(20);
+		hashcpy(ref_oid->hash, fill(the_hash_algo->rawsz));
+		use(the_hash_algo->rawsz);
 		break;
 	case OBJ_OFS_DELTA:
 		p = fill(1);
@@ -546,7 +546,7 @@ static void *unpack_raw_entry(struct object_entry *obj,
 	}
 	obj->hdr_size = consumed_bytes - obj->idx.offset;
 
-	data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, sha1);
+	data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, oid);
 	obj->idx.crc32 = input_crc32;
 	return data;
 }
@@ -958,9 +958,8 @@ static void resolve_delta(struct object_entry *delta_obj,
 	free(delta_data);
 	if (!result->data)
 		bad_object(delta_obj->idx.offset, _("failed to apply delta"));
-	hash_sha1_file(result->data, result->size,
-		       typename(delta_obj->real_type),
-		       delta_obj->idx.oid.hash);
+	hash_object_file(result->data, result->size,
+			 typename(delta_obj->real_type), &delta_obj->idx.oid);
 	sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 		    &delta_obj->idx.oid);
 	counter_lock();
@@ -1119,11 +1118,11 @@ static void *threaded_second_pass(void *data)
  * - calculate SHA1 of all non-delta objects;
  * - remember base (SHA1 or offset) for all deltas.
  */
-static void parse_pack_objects(unsigned char *sha1)
+static void parse_pack_objects(unsigned char *hash)
 {
 	int i, nr_delays = 0;
 	struct ofs_delta_entry *ofs_delta = ofs_deltas;
-	unsigned char ref_delta_sha1[20];
+	struct object_id ref_delta_oid;
 	struct stat st;
 
 	if (verbose)
@@ -1133,8 +1132,8 @@ static void parse_pack_objects(unsigned char *sha1)
 	for (i = 0; i < nr_objects; i++) {
 		struct object_entry *obj = &objects[i];
 		void *data = unpack_raw_entry(obj, &ofs_delta->offset,
-					      ref_delta_sha1,
-					      obj->idx.oid.hash);
+					      &ref_delta_oid,
+					      &obj->idx.oid);
 		obj->real_type = obj->type;
 		if (obj->type == OBJ_OFS_DELTA) {
 			nr_ofs_deltas++;
@@ -1142,7 +1141,7 @@ static void parse_pack_objects(unsigned char *sha1)
 			ofs_delta++;
 		} else if (obj->type == OBJ_REF_DELTA) {
 			ALLOC_GROW(ref_deltas, nr_ref_deltas + 1, ref_deltas_alloc);
-			hashcpy(ref_deltas[nr_ref_deltas].sha1, ref_delta_sha1);
+			hashcpy(ref_deltas[nr_ref_deltas].sha1, ref_delta_oid.hash);
 			ref_deltas[nr_ref_deltas].obj_no = i;
 			nr_ref_deltas++;
 		} else if (!data) {
@@ -1160,10 +1159,10 @@ static void parse_pack_objects(unsigned char *sha1)
 
 	/* Check pack integrity */
 	flush();
-	git_SHA1_Final(sha1, &input_ctx);
-	if (hashcmp(fill(20), sha1))
+	the_hash_algo->final_fn(hash, &input_ctx);
+	if (hashcmp(fill(the_hash_algo->rawsz), hash))
 		die(_("pack is corrupted (SHA1 mismatch)"));
-	use(20);
+	use(the_hash_algo->rawsz);
 
 	/* If input_fd is a file, we should have reached its end now. */
 	if (fstat(input_fd, &st))
@@ -1239,21 +1238,21 @@ static void resolve_deltas(void)
 /*
  * Third pass:
  * - append objects to convert thin pack to full pack if required
- * - write the final 20-byte SHA-1
+ * - write the final pack hash
  */
-static void fix_unresolved_deltas(struct sha1file *f);
-static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
+static void fix_unresolved_deltas(struct hashfile *f);
+static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_hash)
 {
 	if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) {
 		stop_progress(&progress);
-		/* Flush remaining pack final 20-byte SHA1. */
+		/* Flush remaining pack final hash. */
 		flush();
 		return;
 	}
 
 	if (fix_thin_pack) {
-		struct sha1file *f;
-		unsigned char read_sha1[20], tail_sha1[20];
+		struct hashfile *f;
+		unsigned char read_hash[GIT_MAX_RAWSZ], tail_hash[GIT_MAX_RAWSZ];
 		struct strbuf msg = STRBUF_INIT;
 		int nr_unresolved = nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas;
 		int nr_objects_initial = nr_objects;
@@ -1262,7 +1261,7 @@ static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned cha
 		REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
 		memset(objects + nr_objects + 1, 0,
 		       nr_unresolved * sizeof(*objects));
-		f = sha1fd(output_fd, curr_pack);
+		f = hashfd(output_fd, curr_pack);
 		fix_unresolved_deltas(f);
 		strbuf_addf(&msg, Q_("completed with %d local object",
 				     "completed with %d local objects",
@@ -1270,12 +1269,12 @@ static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned cha
 			    nr_objects - nr_objects_initial);
 		stop_progress_msg(&progress, msg.buf);
 		strbuf_release(&msg);
-		sha1close(f, tail_sha1, 0);
-		hashcpy(read_sha1, pack_sha1);
-		fixup_pack_header_footer(output_fd, pack_sha1,
+		hashclose(f, tail_hash, 0);
+		hashcpy(read_hash, pack_hash);
+		fixup_pack_header_footer(output_fd, pack_hash,
 					 curr_pack, nr_objects,
-					 read_sha1, consumed_bytes-20);
-		if (hashcmp(read_sha1, tail_sha1) != 0)
+					 read_hash, consumed_bytes-the_hash_algo->rawsz);
+		if (hashcmp(read_hash, tail_hash) != 0)
 			die(_("Unexpected tail checksum for %s "
 			      "(disk corruption?)"), curr_pack);
 	}
@@ -1286,7 +1285,7 @@ static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned cha
 		    nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
 }
 
-static int write_compressed(struct sha1file *f, void *in, unsigned int size)
+static int write_compressed(struct hashfile *f, void *in, unsigned int size)
 {
 	git_zstream stream;
 	int status;
@@ -1300,7 +1299,7 @@ static int write_compressed(struct sha1file *f, void *in, unsigned int size)
 		stream.next_out = outbuf;
 		stream.avail_out = sizeof(outbuf);
 		status = git_deflate(&stream, Z_FINISH);
-		sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
+		hashwrite(f, outbuf, sizeof(outbuf) - stream.avail_out);
 	} while (status == Z_OK);
 
 	if (status != Z_STREAM_END)
@@ -1310,7 +1309,7 @@ static int write_compressed(struct sha1file *f, void *in, unsigned int size)
 	return size;
 }
 
-static struct object_entry *append_obj_to_pack(struct sha1file *f,
+static struct object_entry *append_obj_to_pack(struct hashfile *f,
 			       const unsigned char *sha1, void *buf,
 			       unsigned long size, enum object_type type)
 {
@@ -1327,7 +1326,7 @@ static struct object_entry *append_obj_to_pack(struct sha1file *f,
 	}
 	header[n++] = c;
 	crc32_begin(f);
-	sha1write(f, header, n);
+	hashwrite(f, header, n);
 	obj[0].size = size;
 	obj[0].hdr_size = n;
 	obj[0].type = type;
@@ -1335,7 +1334,7 @@ static struct object_entry *append_obj_to_pack(struct sha1file *f,
 	obj[1].idx.offset = obj[0].idx.offset + n;
 	obj[1].idx.offset += write_compressed(f, buf, size);
 	obj[0].idx.crc32 = crc32_end(f);
-	sha1flush(f);
+	hashflush(f);
 	hashcpy(obj->idx.oid.hash, sha1);
 	return obj;
 }
@@ -1347,7 +1346,7 @@ static int delta_pos_compare(const void *_a, const void *_b)
 	return a->obj_no - b->obj_no;
 }
 
-static void fix_unresolved_deltas(struct sha1file *f)
+static void fix_unresolved_deltas(struct hashfile *f)
 {
 	struct ref_delta_entry **sorted_by_pos;
 	int i;
@@ -1389,15 +1388,60 @@ static void fix_unresolved_deltas(struct sha1file *f)
 	free(sorted_by_pos);
 }
 
+static const char *derive_filename(const char *pack_name, const char *suffix,
+				   struct strbuf *buf)
+{
+	size_t len;
+	if (!strip_suffix(pack_name, ".pack", &len))
+		die(_("packfile name '%s' does not end with '.pack'"),
+		    pack_name);
+	strbuf_add(buf, pack_name, len);
+	strbuf_addch(buf, '.');
+	strbuf_addstr(buf, suffix);
+	return buf->buf;
+}
+
+static void write_special_file(const char *suffix, const char *msg,
+			       const char *pack_name, const unsigned char *hash,
+			       const char **report)
+{
+	struct strbuf name_buf = STRBUF_INIT;
+	const char *filename;
+	int fd;
+	int msg_len = strlen(msg);
+
+	if (pack_name)
+		filename = derive_filename(pack_name, suffix, &name_buf);
+	else
+		filename = odb_pack_name(&name_buf, hash, suffix);
+
+	fd = odb_pack_keep(filename);
+	if (fd < 0) {
+		if (errno != EEXIST)
+			die_errno(_("cannot write %s file '%s'"),
+				  suffix, filename);
+	} else {
+		if (msg_len > 0) {
+			write_or_die(fd, msg, msg_len);
+			write_or_die(fd, "\n", 1);
+		}
+		if (close(fd) != 0)
+			die_errno(_("cannot close written %s file '%s'"),
+				  suffix, filename);
+		if (report)
+			*report = suffix;
+	}
+	strbuf_release(&name_buf);
+}
+
 static void final(const char *final_pack_name, const char *curr_pack_name,
 		  const char *final_index_name, const char *curr_index_name,
-		  const char *keep_name, const char *keep_msg,
-		  unsigned char *sha1)
+		  const char *keep_msg, const char *promisor_msg,
+		  unsigned char *hash)
 {
 	const char *report = "pack";
 	struct strbuf pack_name = STRBUF_INIT;
 	struct strbuf index_name = STRBUF_INIT;
-	struct strbuf keep_name_buf = STRBUF_INIT;
 	int err;
 
 	if (!from_stdin) {
@@ -1409,32 +1453,16 @@ static void final(const char *final_pack_name, const char *curr_pack_name,
 			die_errno(_("error while closing pack file"));
 	}
 
-	if (keep_msg) {
-		int keep_fd, keep_msg_len = strlen(keep_msg);
-
-		if (!keep_name)
-			keep_name = odb_pack_name(&keep_name_buf, sha1, "keep");
-
-		keep_fd = odb_pack_keep(keep_name);
-		if (keep_fd < 0) {
-			if (errno != EEXIST)
-				die_errno(_("cannot write keep file '%s'"),
-					  keep_name);
-		} else {
-			if (keep_msg_len > 0) {
-				write_or_die(keep_fd, keep_msg, keep_msg_len);
-				write_or_die(keep_fd, "\n", 1);
-			}
-			if (close(keep_fd) != 0)
-				die_errno(_("cannot close written keep file '%s'"),
-					  keep_name);
-			report = "keep";
-		}
-	}
+	if (keep_msg)
+		write_special_file("keep", keep_msg, final_pack_name, hash,
+				   &report);
+	if (promisor_msg)
+		write_special_file("promisor", promisor_msg, final_pack_name,
+				   hash, NULL);
 
 	if (final_pack_name != curr_pack_name) {
 		if (!final_pack_name)
-			final_pack_name = odb_pack_name(&pack_name, sha1, "pack");
+			final_pack_name = odb_pack_name(&pack_name, hash, "pack");
 		if (finalize_object_file(curr_pack_name, final_pack_name))
 			die(_("cannot store pack file"));
 	} else if (from_stdin)
@@ -1442,18 +1470,18 @@ static void final(const char *final_pack_name, const char *curr_pack_name,
 
 	if (final_index_name != curr_index_name) {
 		if (!final_index_name)
-			final_index_name = odb_pack_name(&index_name, sha1, "idx");
+			final_index_name = odb_pack_name(&index_name, hash, "idx");
 		if (finalize_object_file(curr_index_name, final_index_name))
 			die(_("cannot store index file"));
 	} else
 		chmod(final_index_name, 0444);
 
 	if (!from_stdin) {
-		printf("%s\n", sha1_to_hex(sha1));
+		printf("%s\n", sha1_to_hex(hash));
 	} else {
 		struct strbuf buf = STRBUF_INIT;
 
-		strbuf_addf(&buf, "%s\t%s\n", report, sha1_to_hex(sha1));
+		strbuf_addf(&buf, "%s\t%s\n", report, sha1_to_hex(hash));
 		write_or_die(1, buf.buf, buf.len);
 		strbuf_release(&buf);
 
@@ -1472,7 +1500,6 @@ static void final(const char *final_pack_name, const char *curr_pack_name,
 
 	strbuf_release(&index_name);
 	strbuf_release(&pack_name);
-	strbuf_release(&keep_name_buf);
 }
 
 static int git_index_pack_config(const char *k, const char *v, void *cb)
@@ -1615,32 +1642,26 @@ static void show_pack_info(int stat_only)
 	}
 }
 
-static const char *derive_filename(const char *pack_name, const char *suffix,
-				   struct strbuf *buf)
-{
-	size_t len;
-	if (!strip_suffix(pack_name, ".pack", &len))
-		die(_("packfile name '%s' does not end with '.pack'"),
-		    pack_name);
-	strbuf_add(buf, pack_name, len);
-	strbuf_addstr(buf, suffix);
-	return buf->buf;
-}
-
 int cmd_index_pack(int argc, const char **argv, const char *prefix)
 {
 	int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
 	const char *curr_index;
 	const char *index_name = NULL, *pack_name = NULL;
-	const char *keep_name = NULL, *keep_msg = NULL;
-	struct strbuf index_name_buf = STRBUF_INIT,
-		      keep_name_buf = STRBUF_INIT;
+	const char *keep_msg = NULL;
+	const char *promisor_msg = NULL;
+	struct strbuf index_name_buf = STRBUF_INIT;
 	struct pack_idx_entry **idx_objects;
 	struct pack_idx_option opts;
-	unsigned char pack_sha1[20];
+	unsigned char pack_hash[GIT_MAX_RAWSZ];
 	unsigned foreign_nr = 1;	/* zero is a "good" value, assume bad */
 	int report_end_of_input = 0;
 
+	/*
+	 * index-pack never needs to fetch missing objects, since it only
+	 * accesses the repo to do hash collision checks
+	 */
+	fetch_if_missing = 0;
+
 	if (argc == 2 && !strcmp(argv[1], "-h"))
 		usage(index_pack_usage);
 
@@ -1678,6 +1699,8 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 				stat_only = 1;
 			} else if (skip_to_optional_arg(arg, "--keep", &keep_msg)) {
 				; /* nothing to do */
+			} else if (skip_to_optional_arg(arg, "--promisor", &promisor_msg)) {
+				; /* already parsed */
 			} else if (starts_with(arg, "--threads=")) {
 				char *end;
 				nr_threads = strtoul(arg+10, &end, 0);
@@ -1740,9 +1763,7 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 	if (from_stdin && !startup_info->have_repository)
 		die(_("--stdin requires a git repository"));
 	if (!index_name && pack_name)
-		index_name = derive_filename(pack_name, ".idx", &index_name_buf);
-	if (keep_msg && !keep_name && pack_name)
-		keep_name = derive_filename(pack_name, ".keep", &keep_name_buf);
+		index_name = derive_filename(pack_name, "idx", &index_name_buf);
 
 	if (verify) {
 		if (!index_name)
@@ -1768,11 +1789,11 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 	if (show_stat)
 		obj_stat = xcalloc(st_add(nr_objects, 1), sizeof(struct object_stat));
 	ofs_deltas = xcalloc(nr_objects, sizeof(struct ofs_delta_entry));
-	parse_pack_objects(pack_sha1);
+	parse_pack_objects(pack_hash);
 	if (report_end_of_input)
 		write_in_full(2, "\0", 1);
 	resolve_deltas();
-	conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
+	conclude_pack(fix_thin_pack, curr_pack, pack_hash);
 	free(ofs_deltas);
 	free(ref_deltas);
 	if (strict)
@@ -1784,19 +1805,18 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 	ALLOC_ARRAY(idx_objects, nr_objects);
 	for (i = 0; i < nr_objects; i++)
 		idx_objects[i] = &objects[i].idx;
-	curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
+	curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_hash);
 	free(idx_objects);
 
 	if (!verify)
 		final(pack_name, curr_pack,
 		      index_name, curr_index,
-		      keep_name, keep_msg,
-		      pack_sha1);
+		      keep_msg, promisor_msg,
+		      pack_hash);
 	else
 		close(input_fd);
 	free(objects);
 	strbuf_release(&index_name_buf);
-	strbuf_release(&keep_name_buf);
 	if (pack_name == NULL)
 		free((void *) curr_pack);
 	if (index_name == NULL)

diff --git a/builtin/log.c b/builtin/log.c
index 14fdf39..94ee177 100644
--- a/builtin/log.c
+++ b/builtin/log.c

@@ -29,6 +29,8 @@
 #include "gpg-interface.h"
 #include "progress.h"
 
+#define MAIL_DEFAULT_WRAP 72
+
 /* Set a default date-time format for git log ("log.date" config variable) */
 static const char *default_date_mode = NULL;
 
@@ -188,8 +190,8 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 	if (rev->show_notes)
 		init_display_notes(&rev->notes_opt);
 
-	if (rev->diffopt.pickaxe || rev->diffopt.filter ||
-	    rev->diffopt.flags.follow_renames)
+	if ((rev->diffopt.pickaxe_opts & DIFF_PICKAXE_KINDS_MASK) ||
+	    rev->diffopt.filter || rev->diffopt.flags.follow_renames)
 		rev->always_show_header = 0;
 
 	if (source)
@@ -1044,7 +1046,7 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
 
 	shortlog_init(&log);
 	log.wrap_lines = 1;
-	log.wrap = 72;
+	log.wrap = MAIL_DEFAULT_WRAP;
 	log.in1 = 2;
 	log.in2 = 4;
 	log.file = rev->diffopt.file;
@@ -1061,6 +1063,7 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
 
 	memcpy(&opts, &rev->diffopt, sizeof(opts));
 	opts.output_format = DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
+	opts.stat_width = MAIL_DEFAULT_WRAP;
 
 	diff_setup_done(&opts);
 
@@ -1614,6 +1617,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		(!rev.diffopt.output_format ||
 		 rev.diffopt.output_format == DIFF_FORMAT_PATCH))
 		rev.diffopt.output_format = DIFF_FORMAT_DIFFSTAT | DIFF_FORMAT_SUMMARY;
+	if (!rev.diffopt.stat_width)
+		rev.diffopt.stat_width = MAIL_DEFAULT_WRAP;
 
 	/* Always generate a patch */
 	rev.diffopt.output_format |= DIFF_FORMAT_PATCH;

diff --git a/builtin/merge.c b/builtin/merge.c
index 30264cf..92ba99a 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c

@@ -820,8 +820,8 @@ static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
 	pptr = commit_list_append(head, pptr);
 	pptr = commit_list_append(remoteheads->item, pptr);
 	prepare_to_commit(remoteheads);
-	if (commit_tree(merge_msg.buf, merge_msg.len, result_tree.hash, parents,
-			result_commit.hash, NULL, sign_commit))
+	if (commit_tree(merge_msg.buf, merge_msg.len, &result_tree, parents,
+			&result_commit, NULL, sign_commit))
 		die(_("failed to write commit object"));
 	finish(head, remoteheads, &result_commit, "In-index merge");
 	drop_save();
@@ -845,8 +845,8 @@ static int finish_automerge(struct commit *head,
 		commit_list_insert(head, &parents);
 	strbuf_addch(&merge_msg, '\n');
 	prepare_to_commit(remoteheads);
-	if (commit_tree(merge_msg.buf, merge_msg.len, result_tree->hash, parents,
-			result_commit.hash, NULL, sign_commit))
+	if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
+			&result_commit, NULL, sign_commit))
 		die(_("failed to write commit object"));
 	strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
 	finish(head, remoteheads, &result_commit, buf.buf);

diff --git a/builtin/mktag.c b/builtin/mktag.c
index 031b750..beb5528 100644
--- a/builtin/mktag.c
+++ b/builtin/mktag.c

@@ -151,7 +151,7 @@ static int verify_tag(char *buffer, unsigned long size)
 int cmd_mktag(int argc, const char **argv, const char *prefix)
 {
 	struct strbuf buf = STRBUF_INIT;
-	unsigned char result_sha1[20];
+	struct object_id result;
 
 	if (argc != 1)
 		usage("git mktag");
@@ -165,10 +165,10 @@ int cmd_mktag(int argc, const char **argv, const char *prefix)
 	if (verify_tag(buf.buf, buf.len) < 0)
 		die("invalid tag signature file");
 
-	if (write_sha1_file(buf.buf, buf.len, tag_type, result_sha1) < 0)
+	if (write_object_file(buf.buf, buf.len, tag_type, &result) < 0)
 		die("unable to write tag file");
 
 	strbuf_release(&buf);
-	printf("%s\n", sha1_to_hex(result_sha1));
+	printf("%s\n", oid_to_hex(&result));
 	return 0;
 }

diff --git a/builtin/mktree.c b/builtin/mktree.c
index da0fd8c..8dd9f52 100644
--- a/builtin/mktree.c
+++ b/builtin/mktree.c

@@ -40,7 +40,7 @@ static int ent_compare(const void *a_, const void *b_)
 				 b->name, b->len, b->mode);
 }
 
-static void write_tree(unsigned char *sha1)
+static void write_tree(struct object_id *oid)
 {
 	struct strbuf buf;
 	size_t size;
@@ -57,7 +57,7 @@ static void write_tree(unsigned char *sha1)
 		strbuf_add(&buf, ent->sha1, 20);
 	}
 
-	write_sha1_file(buf.buf, buf.len, tree_type, sha1);
+	write_object_file(buf.buf, buf.len, tree_type, oid);
 	strbuf_release(&buf);
 }
 
@@ -142,7 +142,7 @@ static void mktree_line(char *buf, size_t len, int nul_term_line, int allow_miss
 int cmd_mktree(int ac, const char **av, const char *prefix)
 {
 	struct strbuf sb = STRBUF_INIT;
-	unsigned char sha1[20];
+	struct object_id oid;
 	int nul_term_line = 0;
 	int allow_missing = 0;
 	int is_batch_mode = 0;
@@ -181,8 +181,8 @@ int cmd_mktree(int ac, const char **av, const char *prefix)
 			 */
 			; /* skip creating an empty tree */
 		} else {
-			write_tree(sha1);
-			puts(sha1_to_hex(sha1));
+			write_tree(&oid);
+			puts(oid_to_hex(&oid));
 			fflush(stdout);
 		}
 		used=0; /* reset tree entry buffer for re-use in batch mode */

diff --git a/builtin/notes.c b/builtin/notes.c
index 7c81761..39304ba 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c

@@ -198,9 +198,9 @@ static void prepare_note_data(const struct object_id *object, struct note_data *
 	}
 }
 
-static void write_note_data(struct note_data *d, unsigned char *sha1)
+static void write_note_data(struct note_data *d, struct object_id *oid)
 {
-	if (write_sha1_file(d->buf.buf, d->buf.len, blob_type, sha1)) {
+	if (write_object_file(d->buf.buf, d->buf.len, blob_type, oid)) {
 		error(_("unable to write note object"));
 		if (d->edit_path)
 			error(_("the note contents have been left in %s"),
@@ -459,7 +459,7 @@ static int add(int argc, const char **argv, const char *prefix)
 
 	prepare_note_data(&object, &d, note ? note->hash : NULL);
 	if (d.buf.len || allow_empty) {
-		write_note_data(&d, new_note.hash);
+		write_note_data(&d, &new_note);
 		if (add_note(t, &object, &new_note, combine_notes_overwrite))
 			die("BUG: combine_notes_overwrite failed");
 		commit_notes(t, "Notes added by 'git notes add'");
@@ -619,7 +619,7 @@ static int append_edit(int argc, const char **argv, const char *prefix)
 	}
 
 	if (d.buf.len || allow_empty) {
-		write_note_data(&d, new_note.hash);
+		write_note_data(&d, &new_note);
 		if (add_note(t, &object, &new_note, combine_notes_overwrite))
 			die("BUG: combine_notes_overwrite failed");
 		logmsg = xstrfmt("Notes added by 'git notes %s'", argv[0]);

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 6b9cfc2..5c674b2 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c

@@ -26,7 +26,7 @@
 #include "reachable.h"
 #include "sha1-array.h"
 #include "argv-array.h"
-#include "mru.h"
+#include "list.h"
 #include "packfile.h"
 
 static const char *pack_usage[] = {
@@ -75,6 +75,8 @@ static int use_bitmap_index = -1;
 static int write_bitmap_index;
 static uint16_t write_bitmap_options;
 
+static int exclude_promisor_objects;
+
 static unsigned long delta_cache_size = 0;
 static unsigned long max_delta_cache_size = 256 * 1024 * 1024;
 static unsigned long cache_max_small_delta_size = 1000;
@@ -84,8 +86,9 @@ static unsigned long window_memory_limit = 0;
 static struct list_objects_filter_options filter_options;
 
 enum missing_action {
-	MA_ERROR = 0,    /* fail if any missing objects are encountered */
-	MA_ALLOW_ANY,    /* silently allow ALL missing objects */
+	MA_ERROR = 0,      /* fail if any missing objects are encountered */
+	MA_ALLOW_ANY,      /* silently allow ALL missing objects */
+	MA_ALLOW_PROMISOR, /* silently allow all missing PROMISOR objects */
 };
 static enum missing_action arg_missing_action;
 static show_object_fn fn_show_object;
@@ -161,7 +164,7 @@ static unsigned long do_compress(void **pptr, unsigned long size)
 	return stream.total_out;
 }
 
-static unsigned long write_large_blob_data(struct git_istream *st, struct sha1file *f,
+static unsigned long write_large_blob_data(struct git_istream *st, struct hashfile *f,
 					   const struct object_id *oid)
 {
 	git_zstream stream;
@@ -185,7 +188,7 @@ static unsigned long write_large_blob_data(struct git_istream *st, struct sha1fi
 			stream.next_out = obuf;
 			stream.avail_out = sizeof(obuf);
 			zret = git_deflate(&stream, readlen ? 0 : Z_FINISH);
-			sha1write(f, obuf, stream.next_out - obuf);
+			hashwrite(f, obuf, stream.next_out - obuf);
 			olen += stream.next_out - obuf;
 		}
 		if (stream.avail_in)
@@ -230,7 +233,7 @@ static int check_pack_inflate(struct packed_git *p,
 		stream.total_in == len) ? 0 : -1;
 }
 
-static void copy_pack_data(struct sha1file *f,
+static void copy_pack_data(struct hashfile *f,
 		struct packed_git *p,
 		struct pack_window **w_curs,
 		off_t offset,
@@ -243,14 +246,14 @@ static void copy_pack_data(struct sha1file *f,
 		in = use_pack(p, w_curs, offset, &avail);
 		if (avail > len)
 			avail = (unsigned long)len;
-		sha1write(f, in, avail);
+		hashwrite(f, in, avail);
 		offset += avail;
 		len -= avail;
 	}
 }
 
 /* Return 0 if we will bust the pack-size limit */
-static unsigned long write_no_reuse_object(struct sha1file *f, struct object_entry *entry,
+static unsigned long write_no_reuse_object(struct hashfile *f, struct object_entry *entry,
 					   unsigned long limit, int usable_delta)
 {
 	unsigned long size, datalen;
@@ -323,8 +326,8 @@ static unsigned long write_no_reuse_object(struct sha1file *f, struct object_ent
 			free(buf);
 			return 0;
 		}
-		sha1write(f, header, hdrlen);
-		sha1write(f, dheader + pos, sizeof(dheader) - pos);
+		hashwrite(f, header, hdrlen);
+		hashwrite(f, dheader + pos, sizeof(dheader) - pos);
 		hdrlen += sizeof(dheader) - pos;
 	} else if (type == OBJ_REF_DELTA) {
 		/*
@@ -337,8 +340,8 @@ static unsigned long write_no_reuse_object(struct sha1file *f, struct object_ent
 			free(buf);
 			return 0;
 		}
-		sha1write(f, header, hdrlen);
-		sha1write(f, entry->delta->idx.oid.hash, 20);
+		hashwrite(f, header, hdrlen);
+		hashwrite(f, entry->delta->idx.oid.hash, 20);
 		hdrlen += 20;
 	} else {
 		if (limit && hdrlen + datalen + 20 >= limit) {
@@ -347,13 +350,13 @@ static unsigned long write_no_reuse_object(struct sha1file *f, struct object_ent
 			free(buf);
 			return 0;
 		}
-		sha1write(f, header, hdrlen);
+		hashwrite(f, header, hdrlen);
 	}
 	if (st) {
 		datalen = write_large_blob_data(st, f, &entry->idx.oid);
 		close_istream(st);
 	} else {
-		sha1write(f, buf, datalen);
+		hashwrite(f, buf, datalen);
 		free(buf);
 	}
 
@@ -361,7 +364,7 @@ static unsigned long write_no_reuse_object(struct sha1file *f, struct object_ent
 }
 
 /* Return 0 if we will bust the pack-size limit */
-static off_t write_reuse_object(struct sha1file *f, struct object_entry *entry,
+static off_t write_reuse_object(struct hashfile *f, struct object_entry *entry,
 				unsigned long limit, int usable_delta)
 {
 	struct packed_git *p = entry->in_pack;
@@ -412,8 +415,8 @@ static off_t write_reuse_object(struct sha1file *f, struct object_entry *entry,
 			unuse_pack(&w_curs);
 			return 0;
 		}
-		sha1write(f, header, hdrlen);
-		sha1write(f, dheader + pos, sizeof(dheader) - pos);
+		hashwrite(f, header, hdrlen);
+		hashwrite(f, dheader + pos, sizeof(dheader) - pos);
 		hdrlen += sizeof(dheader) - pos;
 		reused_delta++;
 	} else if (type == OBJ_REF_DELTA) {
@@ -421,8 +424,8 @@ static off_t write_reuse_object(struct sha1file *f, struct object_entry *entry,
 			unuse_pack(&w_curs);
 			return 0;
 		}
-		sha1write(f, header, hdrlen);
-		sha1write(f, entry->delta->idx.oid.hash, 20);
+		hashwrite(f, header, hdrlen);
+		hashwrite(f, entry->delta->idx.oid.hash, 20);
 		hdrlen += 20;
 		reused_delta++;
 	} else {
@@ -430,7 +433,7 @@ static off_t write_reuse_object(struct sha1file *f, struct object_entry *entry,
 			unuse_pack(&w_curs);
 			return 0;
 		}
-		sha1write(f, header, hdrlen);
+		hashwrite(f, header, hdrlen);
 	}
 	copy_pack_data(f, p, &w_curs, offset, datalen);
 	unuse_pack(&w_curs);
@@ -439,7 +442,7 @@ static off_t write_reuse_object(struct sha1file *f, struct object_entry *entry,
 }
 
 /* Return 0 if we will bust the pack-size limit */
-static off_t write_object(struct sha1file *f,
+static off_t write_object(struct hashfile *f,
 			  struct object_entry *entry,
 			  off_t write_offset)
 {
@@ -512,7 +515,7 @@ enum write_one_status {
 	WRITE_ONE_RECURSIVE = 2 /* already scheduled to be written */
 };
 
-static enum write_one_status write_one(struct sha1file *f,
+static enum write_one_status write_one(struct hashfile *f,
 				       struct object_entry *e,
 				       off_t *offset)
 {
@@ -731,7 +734,7 @@ static struct object_entry **compute_write_order(void)
 	return wo;
 }
 
-static off_t write_reused_pack(struct sha1file *f)
+static off_t write_reused_pack(struct hashfile *f)
 {
 	unsigned char buffer[8192];
 	off_t to_write, total;
@@ -762,7 +765,7 @@ static off_t write_reused_pack(struct sha1file *f)
 		if (read_pack > to_write)
 			read_pack = to_write;
 
-		sha1write(f, buffer, read_pack);
+		hashwrite(f, buffer, read_pack);
 		to_write -= read_pack;
 
 		/*
@@ -791,7 +794,7 @@ static const char no_split_warning[] = N_(
 static void write_pack_file(void)
 {
 	uint32_t i = 0, j;
-	struct sha1file *f;
+	struct hashfile *f;
 	off_t offset;
 	uint32_t nr_remaining = nr_result;
 	time_t last_mtime = 0;
@@ -807,7 +810,7 @@ static void write_pack_file(void)
 		char *pack_tmp_name = NULL;
 
 		if (pack_to_stdout)
-			f = sha1fd_throughput(1, "<stdout>", progress_state);
+			f = hashfd_throughput(1, "<stdout>", progress_state);
 		else
 			f = create_tmp_packfile(&pack_tmp_name);
 
@@ -834,11 +837,11 @@ static void write_pack_file(void)
 		 * If so, rewrite it like in fast-import
 		 */
 		if (pack_to_stdout) {
-			sha1close(f, oid.hash, CSUM_CLOSE);
+			hashclose(f, oid.hash, CSUM_CLOSE);
 		} else if (nr_written == nr_remaining) {
-			sha1close(f, oid.hash, CSUM_FSYNC);
+			hashclose(f, oid.hash, CSUM_FSYNC);
 		} else {
-			int fd = sha1close(f, oid.hash, 0);
+			int fd = hashclose(f, oid.hash, 0);
 			fixup_pack_header_footer(fd, oid.hash, pack_tmp_name,
 						 nr_written, oid.hash, offset);
 			close(fd);
@@ -1006,8 +1009,8 @@ static int want_object_in_pack(const struct object_id *oid,
 			       struct packed_git **found_pack,
 			       off_t *found_offset)
 {
-	struct mru_entry *entry;
 	int want;
+	struct list_head *pos;
 
 	if (!exclude && local && has_loose_object_nonlocal(oid->hash))
 		return 0;
@@ -1023,8 +1026,8 @@ static int want_object_in_pack(const struct object_id *oid,
 			return want;
 	}
 
-	for (entry = packed_git_mru.head; entry; entry = entry->next) {
-		struct packed_git *p = entry->item;
+	list_for_each(pos, &packed_git_mru) {
+		struct packed_git *p = list_entry(pos, struct packed_git, mru);
 		off_t offset;
 
 		if (p == *found_pack)
@@ -1041,7 +1044,7 @@ static int want_object_in_pack(const struct object_id *oid,
 			}
 			want = want_found_object(exclude, p);
 			if (!exclude && want > 0)
-				mru_mark(&packed_git_mru, entry);
+				list_move(&p->mru, &packed_git_mru);
 			if (want != -1)
 				return want;
 		}
@@ -2578,6 +2581,20 @@ static void show_object__ma_allow_any(struct object *obj, const char *name, void
 	show_object(obj, name, data);
 }
 
+static void show_object__ma_allow_promisor(struct object *obj, const char *name, void *data)
+{
+	assert(arg_missing_action == MA_ALLOW_PROMISOR);
+
+	/*
+	 * Quietly ignore EXPECTED missing objects.  This avoids problems with
+	 * staging them now and getting an odd error later.
+	 */
+	if (!has_object_file(&obj->oid) && is_promisor_object(&obj->oid))
+		return;
+
+	show_object(obj, name, data);
+}
+
 static int option_parse_missing_action(const struct option *opt,
 				       const char *arg, int unset)
 {
@@ -2592,10 +2609,18 @@ static int option_parse_missing_action(const struct option *opt,
 
 	if (!strcmp(arg, "allow-any")) {
 		arg_missing_action = MA_ALLOW_ANY;
+		fetch_if_missing = 0;
 		fn_show_object = show_object__ma_allow_any;
 		return 0;
 	}
 
+	if (!strcmp(arg, "allow-promisor")) {
+		arg_missing_action = MA_ALLOW_PROMISOR;
+		fetch_if_missing = 0;
+		fn_show_object = show_object__ma_allow_promisor;
+		return 0;
+	}
+
 	die(_("invalid value for --missing"));
 	return 0;
 }
@@ -2768,7 +2793,7 @@ static void loosen_unused_packed_objects(struct rev_info *revs)
 			if (!packlist_find(&to_pack, oid.hash, NULL) &&
 			    !has_sha1_pack_kept_or_nonlocal(&oid) &&
 			    !loosened_object_can_be_discarded(&oid, p->mtime))
-				if (force_object_loose(oid.hash, p->mtime))
+				if (force_object_loose(&oid, p->mtime))
 					die("unable to force loose object");
 		}
 	}
@@ -3009,6 +3034,8 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 		{ OPTION_CALLBACK, 0, "missing", NULL, N_("action"),
 		  N_("handling for missing objects"), PARSE_OPT_NONEG,
 		  option_parse_missing_action },
+		OPT_BOOL(0, "exclude-promisor-objects", &exclude_promisor_objects,
+			 N_("do not pack objects in promisor packfiles")),
 		OPT_END(),
 	};
 
@@ -3054,6 +3081,12 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 		argv_array_push(&rp, "--unpacked");
 	}
 
+	if (exclude_promisor_objects) {
+		use_internal_rev_list = 1;
+		fetch_if_missing = 0;
+		argv_array_push(&rp, "--exclude-promisor-objects");
+	}
+
 	if (!reuse_object)
 		reuse_delta = 0;
 	if (pack_compression_level == -1)

diff --git a/builtin/prune.c b/builtin/prune.c
index d2fdae6..4cfec82 100644
--- a/builtin/prune.c
+++ b/builtin/prune.c

@@ -101,12 +101,15 @@ int cmd_prune(int argc, const char **argv, const char *prefix)
 {
 	struct rev_info revs;
 	struct progress *progress = NULL;
+	int exclude_promisor_objects = 0;
 	const struct option options[] = {
 		OPT__DRY_RUN(&show_only, N_("do not remove, show only")),
 		OPT__VERBOSE(&verbose, N_("report pruned objects")),
 		OPT_BOOL(0, "progress", &show_progress, N_("show progress")),
 		OPT_EXPIRY_DATE(0, "expire", &expire,
 				N_("expire objects older than <time>")),
+		OPT_BOOL(0, "exclude-promisor-objects", &exclude_promisor_objects,
+			 N_("limit traversal to objects outside promisor packfiles")),
 		OPT_END()
 	};
 	char *s;
@@ -139,6 +142,10 @@ int cmd_prune(int argc, const char **argv, const char *prefix)
 		show_progress = isatty(2);
 	if (show_progress)
 		progress = start_delayed_progress(_("Checking connectivity"), 0);
+	if (exclude_promisor_objects) {
+		fetch_if_missing = 0;
+		revs.exclude_promisor_objects = 1;
+	}
 
 	mark_reachable_objects(&revs, 1, expire, progress);
 	stop_progress(&progress);

diff --git a/builtin/pull.c b/builtin/pull.c
index 511dbbe..1876271 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c

@@ -574,6 +574,7 @@ static int rebase_submodules(void)
 	cp.no_stdin = 1;
 	argv_array_pushl(&cp.args, "submodule", "update",
 				   "--recursive", "--rebase", NULL);
+	argv_push_verbosity(&cp.args);
 
 	return run_command(&cp);
 }
@@ -586,6 +587,7 @@ static int update_submodules(void)
 	cp.no_stdin = 1;
 	argv_array_pushl(&cp.args, "submodule", "update",
 				   "--recursive", "--checkout", NULL);
+	argv_push_verbosity(&cp.args);
 
 	return run_command(&cp);
 }

diff --git a/builtin/rebase--helper.c b/builtin/rebase--helper.c
index 7daee54..ad07470 100644
--- a/builtin/rebase--helper.c
+++ b/builtin/rebase--helper.c

@@ -22,6 +22,8 @@ int cmd_rebase__helper(int argc, const char **argv, const char *prefix)
 	struct option options[] = {
 		OPT_BOOL(0, "ff", &opts.allow_ff, N_("allow fast-forward")),
 		OPT_BOOL(0, "keep-empty", &keep_empty, N_("keep empty commits")),
+		OPT_BOOL(0, "allow-empty-message", &opts.allow_empty_message,
+			N_("allow commits with empty messages")),
 		OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
 				CONTINUE),
 		OPT_CMDMODE(0, "abort", &command, N_("abort rebase"),
@@ -43,7 +45,7 @@ int cmd_rebase__helper(int argc, const char **argv, const char *prefix)
 		OPT_END()
 	};
 
-	git_config(git_default_config, NULL);
+	sequencer_init_config(&opts);
 	git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
 
 	opts.action = REPLAY_INTERACTIVE_REBASE;

diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index b7ce7c7..75e7f18 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c

@@ -69,7 +69,7 @@ static int sent_capabilities;
 static int shallow_update;
 static const char *alt_shallow_file;
 static struct strbuf push_cert = STRBUF_INIT;
-static unsigned char push_cert_sha1[20];
+static struct object_id push_cert_oid;
 static struct signature_check sigcheck;
 static const char *push_cert_nonce;
 static const char *cert_nonce_seed;
@@ -633,8 +633,9 @@ static void prepare_push_cert_sha1(struct child_process *proc)
 		int bogs /* beginning_of_gpg_sig */;
 
 		already_done = 1;
-		if (write_sha1_file(push_cert.buf, push_cert.len, "blob", push_cert_sha1))
-			hashclr(push_cert_sha1);
+		if (write_object_file(push_cert.buf, push_cert.len, "blob",
+				      &push_cert_oid))
+			oidclr(&push_cert_oid);
 
 		memset(&sigcheck, '\0', sizeof(sigcheck));
 		sigcheck.result = 'N';
@@ -655,9 +656,9 @@ static void prepare_push_cert_sha1(struct child_process *proc)
 		strbuf_release(&gpg_status);
 		nonce_status = check_nonce(push_cert.buf, bogs);
 	}
-	if (!is_null_sha1(push_cert_sha1)) {
+	if (!is_null_oid(&push_cert_oid)) {
 		argv_array_pushf(&proc->env_array, "GIT_PUSH_CERT=%s",
-				 sha1_to_hex(push_cert_sha1));
+				 oid_to_hex(&push_cert_oid));
 		argv_array_pushf(&proc->env_array, "GIT_PUSH_CERT_SIGNER=%s",
 				 sigcheck.signer ? sigcheck.signer : "");
 		argv_array_pushf(&proc->env_array, "GIT_PUSH_CERT_KEY=%s",

diff --git a/builtin/repack.c b/builtin/repack.c
index f17a68a..7bdb401 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c

@@ -83,7 +83,8 @@ static void remove_pack_on_signal(int signo)
 
 /*
  * Adds all packs hex strings to the fname list, which do not
- * have a corresponding .keep file.
+ * have a corresponding .keep or .promisor file. These packs are not to
+ * be kept if we are going to pack everything into one file.
  */
 static void get_non_kept_pack_filenames(struct string_list *fname_list)
 {
@@ -101,7 +102,8 @@ static void get_non_kept_pack_filenames(struct string_list *fname_list)
 
 		fname = xmemdupz(e->d_name, len);
 
-		if (!file_exists(mkpath("%s/%s.keep", packdir, fname)))
+		if (!file_exists(mkpath("%s/%s.keep", packdir, fname)) &&
+		    !file_exists(mkpath("%s/%s.promisor", packdir, fname)))
 			string_list_append_nodup(fname_list, fname);
 		else
 			free(fname);
@@ -232,6 +234,8 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	argv_array_push(&cmd.args, "--all");
 	argv_array_push(&cmd.args, "--reflog");
 	argv_array_push(&cmd.args, "--indexed-objects");
+	if (repository_format_partial_clone)
+		argv_array_push(&cmd.args, "--exclude-promisor-objects");
 	if (window)
 		argv_array_pushf(&cmd.args, "--window=%s", window);
 	if (window_memory)

diff --git a/builtin/replace.c b/builtin/replace.c
index 10078ae..83d3235 100644
--- a/builtin/replace.c
+++ b/builtin/replace.c

@@ -355,7 +355,7 @@ static void check_one_mergetag(struct commit *commit,
 	struct tag *tag;
 	int i;
 
-	hash_sha1_file(extra->value, extra->len, typename(OBJ_TAG), tag_oid.hash);
+	hash_object_file(extra->value, extra->len, typename(OBJ_TAG), &tag_oid);
 	tag = lookup_tag(&tag_oid);
 	if (!tag)
 		die(_("bad mergetag in commit '%s'"), ref);
@@ -410,7 +410,7 @@ static int create_graft(int argc, const char **argv, int force)
 
 	check_mergetags(commit, argc, argv);
 
-	if (write_sha1_file(buf.buf, buf.len, commit_type, new.hash))
+	if (write_object_file(buf.buf, buf.len, commit_type, &new))
 		die(_("could not write replacement commit for: '%s'"), old_ref);
 
 	strbuf_release(&buf);

diff --git a/builtin/reset.c b/builtin/reset.c
index e15f595..5da0f75 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c

@@ -106,24 +106,16 @@ static int reset_index(const struct object_id *oid, int reset_type, int quiet)
 
 static void print_new_head_line(struct commit *commit)
 {
-	const char *hex, *body;
-	const char *msg;
+	struct strbuf buf = STRBUF_INIT;
 
-	hex = find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV);
-	printf(_("HEAD is now at %s"), hex);
-	msg = logmsg_reencode(commit, NULL, get_log_output_encoding());
-	body = strstr(msg, "\n\n");
-	if (body) {
-		const char *eol;
-		size_t len;
-		body = skip_blank_lines(body + 2);
-		eol = strchr(body, '\n');
-		len = eol ? eol - body : strlen(body);
-		printf(" %.*s\n", (int) len, body);
-	}
-	else
-		printf("\n");
-	unuse_commit_buffer(commit, msg);
+	printf(_("HEAD is now at %s"),
+		find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV));
+
+	pp_commit_easy(CMIT_FMT_ONELINE, commit, &buf);
+	if (buf.len > 0)
+		printf(" %s", buf.buf);
+	putchar('\n');
+	strbuf_release(&buf);
 }
 
 static void update_index_from_diff(struct diff_queue_struct *q,

diff --git a/builtin/rev-list.c b/builtin/rev-list.c
index d5345b6..48300d9 100644
--- a/builtin/rev-list.c
+++ b/builtin/rev-list.c

@@ -15,6 +15,7 @@
 #include "progress.h"
 #include "reflog-walk.h"
 #include "oidset.h"
+#include "packfile.h"
 
 static const char rev_list_usage[] =
 "git rev-list [OPTION] <commit-id>... [ -- paths... ]\n"
@@ -67,6 +68,7 @@ enum missing_action {
 	MA_ERROR = 0,    /* fail if any missing objects are encountered */
 	MA_ALLOW_ANY,    /* silently allow ALL missing objects */
 	MA_PRINT,        /* print ALL missing objects in special section */
+	MA_ALLOW_PROMISOR, /* silently allow all missing PROMISOR objects */
 };
 static enum missing_action arg_missing_action;
 
@@ -197,6 +199,12 @@ static void finish_commit(struct commit *commit, void *data)
 
 static inline void finish_object__ma(struct object *obj)
 {
+	/*
+	 * Whether or not we try to dynamically fetch missing objects
+	 * from the server, we currently DO NOT have the object.  We
+	 * can either print, allow (ignore), or conditionally allow
+	 * (ignore) them.
+	 */
 	switch (arg_missing_action) {
 	case MA_ERROR:
 		die("missing blob object '%s'", oid_to_hex(&obj->oid));
@@ -209,25 +217,36 @@ static inline void finish_object__ma(struct object *obj)
 		oidset_insert(&missing_objects, &obj->oid);
 		return;
 
+	case MA_ALLOW_PROMISOR:
+		if (is_promisor_object(&obj->oid))
+			return;
+		die("unexpected missing blob object '%s'",
+		    oid_to_hex(&obj->oid));
+		return;
+
 	default:
 		BUG("unhandled missing_action");
 		return;
 	}
 }
 
-static void finish_object(struct object *obj, const char *name, void *cb_data)
+static int finish_object(struct object *obj, const char *name, void *cb_data)
 {
 	struct rev_list_info *info = cb_data;
-	if (obj->type == OBJ_BLOB && !has_object_file(&obj->oid))
+	if (obj->type == OBJ_BLOB && !has_object_file(&obj->oid)) {
 		finish_object__ma(obj);
+		return 1;
+	}
 	if (info->revs->verify_objects && !obj->parsed && obj->type != OBJ_COMMIT)
 		parse_object(&obj->oid);
+	return 0;
 }
 
 static void show_object(struct object *obj, const char *name, void *cb_data)
 {
 	struct rev_list_info *info = cb_data;
-	finish_object(obj, name, cb_data);
+	if (finish_object(obj, name, cb_data))
+		return;
 	display_progress(progress, ++progress_counter);
 	if (info->flags & REV_LIST_QUIET)
 		return;
@@ -315,11 +334,19 @@ static inline int parse_missing_action_value(const char *value)
 
 	if (!strcmp(value, "allow-any")) {
 		arg_missing_action = MA_ALLOW_ANY;
+		fetch_if_missing = 0;
 		return 1;
 	}
 
 	if (!strcmp(value, "print")) {
 		arg_missing_action = MA_PRINT;
+		fetch_if_missing = 0;
+		return 1;
+	}
+
+	if (!strcmp(value, "allow-promisor")) {
+		arg_missing_action = MA_ALLOW_PROMISOR;
+		fetch_if_missing = 0;
 		return 1;
 	}
 
@@ -344,6 +371,35 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 	init_revisions(&revs, prefix);
 	revs.abbrev = DEFAULT_ABBREV;
 	revs.commit_format = CMIT_FMT_UNSPECIFIED;
+
+	/*
+	 * Scan the argument list before invoking setup_revisions(), so that we
+	 * know if fetch_if_missing needs to be set to 0.
+	 *
+	 * "--exclude-promisor-objects" acts as a pre-filter on missing objects
+	 * by not crossing the boundary from realized objects to promisor
+	 * objects.
+	 *
+	 * Let "--missing" to conditionally set fetch_if_missing.
+	 */
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+		if (!strcmp(arg, "--exclude-promisor-objects")) {
+			fetch_if_missing = 0;
+			revs.exclude_promisor_objects = 1;
+			break;
+		}
+	}
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+		if (skip_prefix(arg, "--missing=", &arg)) {
+			if (revs.exclude_promisor_objects)
+				die(_("cannot combine --exclude-promisor-objects and --missing"));
+			if (parse_missing_action_value(arg))
+				break;
+		}
+	}
+
 	argc = setup_revisions(argc, argv, &revs, NULL);
 
 	memset(&info, 0, sizeof(info));
@@ -404,7 +460,7 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 			continue;
 		}
 		if (!strcmp(arg, ("--no-" CL_ARG__FILTER))) {
-			list_objects_filter_release(&filter_options);
+			list_objects_filter_set_no_filter(&filter_options);
 			continue;
 		}
 		if (!strcmp(arg, "--filter-print-omitted")) {
@@ -412,9 +468,10 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 			continue;
 		}
 
-		if (skip_prefix(arg, "--missing=", &arg) &&
-		    parse_missing_action_value(arg))
-			continue;
+		if (!strcmp(arg, "--exclude-promisor-objects"))
+			continue; /* already handled above */
+		if (skip_prefix(arg, "--missing=", &arg))
+			continue; /* already handled above */
 
 		usage(rev_list_usage);
 

diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index 74aa644..96d06a5 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c

@@ -516,7 +516,7 @@ static int cmd_parseopt(int argc, const char **argv, const char *prefix)
 			PARSE_OPT_SHELL_EVAL);
 
 	strbuf_addstr(&parsed, " --");
-	sq_quote_argv(&parsed, argv, 0);
+	sq_quote_argv(&parsed, argv);
 	puts(parsed.buf);
 	return 0;
 }
@@ -526,7 +526,7 @@ static int cmd_sq_quote(int argc, const char **argv)
 	struct strbuf buf = STRBUF_INIT;
 
 	if (argc)
-		sq_quote_argv(&buf, argv, 0);
+		sq_quote_argv(&buf, argv);
 	printf("%s\n", buf.buf);
 	strbuf_release(&buf);
 

diff --git a/builtin/revert.c b/builtin/revert.c
index b9d927e..76f0a35 100644
--- a/builtin/revert.c
+++ b/builtin/revert.c

@@ -208,7 +208,7 @@ int cmd_revert(int argc, const char **argv, const char *prefix)
 	if (isatty(0))
 		opts.edit = 1;
 	opts.action = REPLAY_REVERT;
-	git_config(git_default_config, NULL);
+	sequencer_init_config(&opts);
 	res = run_sequencer(argc, argv, &opts);
 	if (res < 0)
 		die(_("revert failed"));
@@ -221,7 +221,7 @@ int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
 	int res;
 
 	opts.action = REPLAY_PICK;
-	git_config(git_default_config, NULL);
+	sequencer_init_config(&opts);
 	res = run_sequencer(argc, argv, &opts);
 	if (res < 0)
 		die(_("cherry-pick failed"));

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index a5c4a8a..b1daca9 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c

@@ -20,6 +20,7 @@
 #define OPT_QUIET (1 << 0)
 #define OPT_CACHED (1 << 1)
 #define OPT_RECURSIVE (1 << 2)
+#define OPT_FORCE (1 << 3)
 
 typedef void (*each_submodule_fn)(const struct cache_entry *list_item,
 				  void *cb_data);
@@ -50,6 +51,20 @@ static char *get_default_remote(void)
 	return ret;
 }
 
+static int print_default_remote(int argc, const char **argv, const char *prefix)
+{
+	const char *remote;
+
+	if (argc != 1)
+		die(_("submodule--helper print-default-remote takes no arguments"));
+
+	remote = get_default_remote();
+	if (remote)
+		printf("%s\n", remote);
+
+	return 0;
+}
+
 static int starts_with_dot_slash(const char *str)
 {
 	return str[0] == '.' && is_dir_sep(str[1]);
@@ -358,6 +373,25 @@ static void module_list_active(struct module_list *list)
 	*list = active_modules;
 }
 
+static char *get_up_path(const char *path)
+{
+	int i;
+	struct strbuf sb = STRBUF_INIT;
+
+	for (i = count_slashes(path); i; i--)
+		strbuf_addstr(&sb, "../");
+
+	/*
+	 * Check if 'path' ends with slash or not
+	 * for having the same output for dir/sub_dir
+	 * and dir/sub_dir/
+	 */
+	if (!is_dir_sep(path[strlen(path) - 1]))
+		strbuf_addstr(&sb, "../");
+
+	return strbuf_detach(&sb, NULL);
+}
+
 static int module_list(int argc, const char **argv, const char *prefix)
 {
 	int i;
@@ -718,6 +752,309 @@ static int module_name(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
+struct sync_cb {
+	const char *prefix;
+	unsigned int flags;
+};
+
+#define SYNC_CB_INIT { NULL, 0 }
+
+static void sync_submodule(const char *path, const char *prefix,
+			   unsigned int flags)
+{
+	const struct submodule *sub;
+	char *remote_key = NULL;
+	char *sub_origin_url, *super_config_url, *displaypath;
+	struct strbuf sb = STRBUF_INIT;
+	struct child_process cp = CHILD_PROCESS_INIT;
+	char *sub_config_path = NULL;
+
+	if (!is_submodule_active(the_repository, path))
+		return;
+
+	sub = submodule_from_path(&null_oid, path);
+
+	if (sub && sub->url) {
+		if (starts_with_dot_dot_slash(sub->url) ||
+		    starts_with_dot_slash(sub->url)) {
+			char *remote_url, *up_path;
+			char *remote = get_default_remote();
+			strbuf_addf(&sb, "remote.%s.url", remote);
+
+			if (git_config_get_string(sb.buf, &remote_url))
+				remote_url = xgetcwd();
+
+			up_path = get_up_path(path);
+			sub_origin_url = relative_url(remote_url, sub->url, up_path);
+			super_config_url = relative_url(remote_url, sub->url, NULL);
+
+			free(remote);
+			free(up_path);
+			free(remote_url);
+		} else {
+			sub_origin_url = xstrdup(sub->url);
+			super_config_url = xstrdup(sub->url);
+		}
+	} else {
+		sub_origin_url = xstrdup("");
+		super_config_url = xstrdup("");
+	}
+
+	displaypath = get_submodule_displaypath(path, prefix);
+
+	if (!(flags & OPT_QUIET))
+		printf(_("Synchronizing submodule url for '%s'\n"),
+			 displaypath);
+
+	strbuf_reset(&sb);
+	strbuf_addf(&sb, "submodule.%s.url", sub->name);
+	if (git_config_set_gently(sb.buf, super_config_url))
+		die(_("failed to register url for submodule path '%s'"),
+		      displaypath);
+
+	if (!is_submodule_populated_gently(path, NULL))
+		goto cleanup;
+
+	prepare_submodule_repo_env(&cp.env_array);
+	cp.git_cmd = 1;
+	cp.dir = path;
+	argv_array_pushl(&cp.args, "submodule--helper",
+			 "print-default-remote", NULL);
+
+	strbuf_reset(&sb);
+	if (capture_command(&cp, &sb, 0))
+		die(_("failed to get the default remote for submodule '%s'"),
+		      path);
+
+	strbuf_strip_suffix(&sb, "\n");
+	remote_key = xstrfmt("remote.%s.url", sb.buf);
+
+	strbuf_reset(&sb);
+	submodule_to_gitdir(&sb, path);
+	strbuf_addstr(&sb, "/config");
+
+	if (git_config_set_in_file_gently(sb.buf, remote_key, sub_origin_url))
+		die(_("failed to update remote for submodule '%s'"),
+		      path);
+
+	if (flags & OPT_RECURSIVE) {
+		struct child_process cpr = CHILD_PROCESS_INIT;
+
+		cpr.git_cmd = 1;
+		cpr.dir = path;
+		prepare_submodule_repo_env(&cpr.env_array);
+
+		argv_array_push(&cpr.args, "--super-prefix");
+		argv_array_pushf(&cpr.args, "%s/", displaypath);
+		argv_array_pushl(&cpr.args, "submodule--helper", "sync",
+				 "--recursive", NULL);
+
+		if (flags & OPT_QUIET)
+			argv_array_push(&cpr.args, "--quiet");
+
+		if (run_command(&cpr))
+			die(_("failed to recurse into submodule '%s'"),
+			      path);
+	}
+
+cleanup:
+	free(super_config_url);
+	free(sub_origin_url);
+	strbuf_release(&sb);
+	free(remote_key);
+	free(displaypath);
+	free(sub_config_path);
+}
+
+static void sync_submodule_cb(const struct cache_entry *list_item, void *cb_data)
+{
+	struct sync_cb *info = cb_data;
+	sync_submodule(list_item->name, info->prefix, info->flags);
+
+}
+
+static int module_sync(int argc, const char **argv, const char *prefix)
+{
+	struct sync_cb info = SYNC_CB_INIT;
+	struct pathspec pathspec;
+	struct module_list list = MODULE_LIST_INIT;
+	int quiet = 0;
+	int recursive = 0;
+
+	struct option module_sync_options[] = {
+		OPT__QUIET(&quiet, N_("Suppress output of synchronizing submodule url")),
+		OPT_BOOL(0, "recursive", &recursive,
+			N_("Recurse into nested submodules")),
+		OPT_END()
+	};
+
+	const char *const git_submodule_helper_usage[] = {
+		N_("git submodule--helper sync [--quiet] [--recursive] [<path>]"),
+		NULL
+	};
+
+	argc = parse_options(argc, argv, prefix, module_sync_options,
+			     git_submodule_helper_usage, 0);
+
+	if (module_list_compute(argc, argv, prefix, &pathspec, &list) < 0)
+		return 1;
+
+	info.prefix = prefix;
+	if (quiet)
+		info.flags |= OPT_QUIET;
+	if (recursive)
+		info.flags |= OPT_RECURSIVE;
+
+	for_each_listed_submodule(&list, sync_submodule_cb, &info);
+
+	return 0;
+}
+
+struct deinit_cb {
+	const char *prefix;
+	unsigned int flags;
+};
+#define DEINIT_CB_INIT { NULL, 0 }
+
+static void deinit_submodule(const char *path, const char *prefix,
+			     unsigned int flags)
+{
+	const struct submodule *sub;
+	char *displaypath = NULL;
+	struct child_process cp_config = CHILD_PROCESS_INIT;
+	struct strbuf sb_config = STRBUF_INIT;
+	char *sub_git_dir = xstrfmt("%s/.git", path);
+
+	sub = submodule_from_path(&null_oid, path);
+
+	if (!sub || !sub->name)
+		goto cleanup;
+
+	displaypath = get_submodule_displaypath(path, prefix);
+
+	/* remove the submodule work tree (unless the user already did it) */
+	if (is_directory(path)) {
+		struct strbuf sb_rm = STRBUF_INIT;
+		const char *format;
+
+		/*
+		 * protect submodules containing a .git directory
+		 * NEEDSWORK: instead of dying, automatically call
+		 * absorbgitdirs and (possibly) warn.
+		 */
+		if (is_directory(sub_git_dir))
+			die(_("Submodule work tree '%s' contains a .git "
+			      "directory (use 'rm -rf' if you really want "
+			      "to remove it including all of its history)"),
+			    displaypath);
+
+		if (!(flags & OPT_FORCE)) {
+			struct child_process cp_rm = CHILD_PROCESS_INIT;
+			cp_rm.git_cmd = 1;
+			argv_array_pushl(&cp_rm.args, "rm", "-qn",
+					 path, NULL);
+
+			if (run_command(&cp_rm))
+				die(_("Submodule work tree '%s' contains local "
+				      "modifications; use '-f' to discard them"),
+				      displaypath);
+		}
+
+		strbuf_addstr(&sb_rm, path);
+
+		if (!remove_dir_recursively(&sb_rm, 0))
+			format = _("Cleared directory '%s'\n");
+		else
+			format = _("Could not remove submodule work tree '%s'\n");
+
+		if (!(flags & OPT_QUIET))
+			printf(format, displaypath);
+
+		strbuf_release(&sb_rm);
+	}
+
+	if (mkdir(path, 0777))
+		printf(_("could not create empty submodule directory %s"),
+		      displaypath);
+
+	cp_config.git_cmd = 1;
+	argv_array_pushl(&cp_config.args, "config", "--get-regexp", NULL);
+	argv_array_pushf(&cp_config.args, "submodule.%s\\.", sub->name);
+
+	/* remove the .git/config entries (unless the user already did it) */
+	if (!capture_command(&cp_config, &sb_config, 0) && sb_config.len) {
+		char *sub_key = xstrfmt("submodule.%s", sub->name);
+		/*
+		 * remove the whole section so we have a clean state when
+		 * the user later decides to init this submodule again
+		 */
+		git_config_rename_section_in_file(NULL, sub_key, NULL);
+		if (!(flags & OPT_QUIET))
+			printf(_("Submodule '%s' (%s) unregistered for path '%s'\n"),
+				 sub->name, sub->url, displaypath);
+		free(sub_key);
+	}
+
+cleanup:
+	free(displaypath);
+	free(sub_git_dir);
+	strbuf_release(&sb_config);
+}
+
+static void deinit_submodule_cb(const struct cache_entry *list_item,
+				void *cb_data)
+{
+	struct deinit_cb *info = cb_data;
+	deinit_submodule(list_item->name, info->prefix, info->flags);
+}
+
+static int module_deinit(int argc, const char **argv, const char *prefix)
+{
+	struct deinit_cb info = DEINIT_CB_INIT;
+	struct pathspec pathspec;
+	struct module_list list = MODULE_LIST_INIT;
+	int quiet = 0;
+	int force = 0;
+	int all = 0;
+
+	struct option module_deinit_options[] = {
+		OPT__QUIET(&quiet, N_("Suppress submodule status output")),
+		OPT__FORCE(&force, N_("Remove submodule working trees even if they contain local changes")),
+		OPT_BOOL(0, "all", &all, N_("Unregister all submodules")),
+		OPT_END()
+	};
+
+	const char *const git_submodule_helper_usage[] = {
+		N_("git submodule deinit [--quiet] [-f | --force] [--all | [--] [<path>...]]"),
+		NULL
+	};
+
+	argc = parse_options(argc, argv, prefix, module_deinit_options,
+			     git_submodule_helper_usage, 0);
+
+	if (all && argc) {
+		error("pathspec and --all are incompatible");
+		usage_with_options(git_submodule_helper_usage,
+				   module_deinit_options);
+	}
+
+	if (!argc && !all)
+		die(_("Use '--all' if you really want to deinitialize all submodules"));
+
+	if (module_list_compute(argc, argv, prefix, &pathspec, &list) < 0)
+		BUG("module_list_compute should not choke on empty pathspec");
+
+	info.prefix = prefix;
+	if (quiet)
+		info.flags |= OPT_QUIET;
+	if (force)
+		info.flags |= OPT_FORCE;
+
+	for_each_listed_submodule(&list, deinit_submodule_cb, &info);
+
+	return 0;
+}
+
 static int clone_submodule(const char *path, const char *gitdir, const char *url,
 			   const char *depth, struct string_list *reference,
 			   int quiet, int progress)
@@ -1498,6 +1835,9 @@ static struct cmd_struct commands[] = {
 	{"resolve-relative-url-test", resolve_relative_url_test, 0},
 	{"init", module_init, SUPPORT_SUPER_PREFIX},
 	{"status", module_status, SUPPORT_SUPER_PREFIX},
+	{"print-default-remote", print_default_remote, 0},
+	{"sync", module_sync, SUPPORT_SUPER_PREFIX},
+	{"deinit", module_deinit, 0},
 	{"remote-branch", resolve_remote_submodule_branch, 0},
 	{"push-check", push_check, 0},
 	{"absorb-git-dirs", absorb_git_dirs, SUPPORT_SUPER_PREFIX},

diff --git a/builtin/tag.c b/builtin/tag.c
index a7e6a5b..8885e21 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c

@@ -187,7 +187,7 @@ static int build_tag_object(struct strbuf *buf, int sign, struct object_id *resu
 {
 	if (sign && do_sign(buf) < 0)
 		return error(_("unable to sign the tag"));
-	if (write_sha1_file(buf->buf, buf->len, tag_type, result->hash) < 0)
+	if (write_object_file(buf->buf, buf->len, tag_type, result) < 0)
 		return error(_("unable to write tag file"));
 	return 0;
 }

diff --git a/builtin/unpack-objects.c b/builtin/unpack-objects.c
index 62ea264..7235d2f 100644
--- a/builtin/unpack-objects.c
+++ b/builtin/unpack-objects.c

@@ -21,7 +21,7 @@ static unsigned char buffer[4096];
 static unsigned int offset, len;
 static off_t consumed_bytes;
 static off_t max_input_size;
-static git_SHA_CTX ctx;
+static git_hash_ctx ctx;
 static struct fsck_options fsck_options = FSCK_OPTIONS_STRICT;
 
 /*
@@ -62,7 +62,7 @@ static void *fill(int min)
 	if (min > sizeof(buffer))
 		die("cannot fill %d bytes", min);
 	if (offset) {
-		git_SHA1_Update(&ctx, buffer, offset);
+		the_hash_algo->update_fn(&ctx, buffer, offset);
 		memmove(buffer, buffer + offset, len);
 		offset = 0;
 	}
@@ -172,7 +172,8 @@ static void write_cached_object(struct object *obj, struct obj_buffer *obj_buf)
 {
 	struct object_id oid;
 
-	if (write_sha1_file(obj_buf->buffer, obj_buf->size, typename(obj->type), oid.hash) < 0)
+	if (write_object_file(obj_buf->buffer, obj_buf->size,
+			      typename(obj->type), &oid) < 0)
 		die("failed to write object %s", oid_to_hex(&obj->oid));
 	obj->flags |= FLAG_WRITTEN;
 }
@@ -237,14 +238,16 @@ static void write_object(unsigned nr, enum object_type type,
 			 void *buf, unsigned long size)
 {
 	if (!strict) {
-		if (write_sha1_file(buf, size, typename(type), obj_list[nr].oid.hash) < 0)
+		if (write_object_file(buf, size, typename(type),
+				      &obj_list[nr].oid) < 0)
 			die("failed to write object");
 		added_object(nr, type, buf, size);
 		free(buf);
 		obj_list[nr].obj = NULL;
 	} else if (type == OBJ_BLOB) {
 		struct blob *blob;
-		if (write_sha1_file(buf, size, typename(type), obj_list[nr].oid.hash) < 0)
+		if (write_object_file(buf, size, typename(type),
+				      &obj_list[nr].oid) < 0)
 			die("failed to write object");
 		added_object(nr, type, buf, size);
 		free(buf);
@@ -258,7 +261,7 @@ static void write_object(unsigned nr, enum object_type type,
 	} else {
 		struct object *obj;
 		int eaten;
-		hash_sha1_file(buf, size, typename(type), obj_list[nr].oid.hash);
+		hash_object_file(buf, size, typename(type), &obj_list[nr].oid);
 		added_object(nr, type, buf, size);
 		obj = parse_object_buffer(&obj_list[nr].oid, type, size, buf,
 					  &eaten);
@@ -345,8 +348,8 @@ static void unpack_delta_entry(enum object_type type, unsigned long delta_size,
 	struct object_id base_oid;
 
 	if (type == OBJ_REF_DELTA) {
-		hashcpy(base_oid.hash, fill(GIT_SHA1_RAWSZ));
-		use(GIT_SHA1_RAWSZ);
+		hashcpy(base_oid.hash, fill(the_hash_algo->rawsz));
+		use(the_hash_algo->rawsz);
 		delta_data = get_data(delta_size);
 		if (dry_run || !delta_data) {
 			free(delta_data);
@@ -564,15 +567,15 @@ int cmd_unpack_objects(int argc, const char **argv, const char *prefix)
 		/* We don't take any non-flag arguments now.. Maybe some day */
 		usage(unpack_usage);
 	}
-	git_SHA1_Init(&ctx);
+	the_hash_algo->init_fn(&ctx);
 	unpack_all();
-	git_SHA1_Update(&ctx, buffer, offset);
-	git_SHA1_Final(oid.hash, &ctx);
+	the_hash_algo->update_fn(&ctx, buffer, offset);
+	the_hash_algo->final_fn(oid.hash, &ctx);
 	if (strict)
 		write_rest();
-	if (hashcmp(fill(GIT_SHA1_RAWSZ), oid.hash))
+	if (hashcmp(fill(the_hash_algo->rawsz), oid.hash))
 		die("final sha1 did not match");
-	use(GIT_SHA1_RAWSZ);
+	use(the_hash_algo->rawsz);
 
 	/* Write the last part of the buffer to stdout */
 	while (len) {

diff --git a/builtin/worktree.c b/builtin/worktree.c
index 7cef5b1..9efdc22 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c

@@ -14,7 +14,7 @@
 #include "worktree.h"
 
 static const char * const worktree_usage[] = {
-	N_("git worktree add [<options>] <path> [<branch>]"),
+	N_("git worktree add [<options>] <path> [<commit-ish>]"),
 	N_("git worktree list [<options>]"),
 	N_("git worktree lock [<options>] <path>"),
 	N_("git worktree prune [<options>]"),

diff --git a/bulk-checkin.c b/bulk-checkin.c
index 3310fd2..8bcd1c8 100644
--- a/bulk-checkin.c
+++ b/bulk-checkin.c

@@ -12,7 +12,7 @@ static struct bulk_checkin_state {
 	unsigned plugged:1;
 
 	char *pack_tmp_name;
-	struct sha1file *f;
+	struct hashfile *f;
 	off_t offset;
 	struct pack_idx_option pack_idx_opts;
 
@@ -35,9 +35,9 @@ static void finish_bulk_checkin(struct bulk_checkin_state *state)
 		unlink(state->pack_tmp_name);
 		goto clear_exit;
 	} else if (state->nr_written == 1) {
-		sha1close(state->f, oid.hash, CSUM_FSYNC);
+		hashclose(state->f, oid.hash, CSUM_FSYNC);
 	} else {
-		int fd = sha1close(state->f, oid.hash, 0);
+		int fd = hashclose(state->f, oid.hash, 0);
 		fixup_pack_header_footer(fd, oid.hash, state->pack_tmp_name,
 					 state->nr_written, oid.hash,
 					 state->offset);
@@ -93,7 +93,7 @@ static int already_written(struct bulk_checkin_state *state, unsigned char sha1[
  * with a new pack.
  */
 static int stream_to_pack(struct bulk_checkin_state *state,
-			  git_SHA_CTX *ctx, off_t *already_hashed_to,
+			  git_hash_ctx *ctx, off_t *already_hashed_to,
 			  int fd, size_t size, enum object_type type,
 			  const char *path, unsigned flags)
 {
@@ -127,7 +127,7 @@ static int stream_to_pack(struct bulk_checkin_state *state,
 				if (rsize < hsize)
 					hsize = rsize;
 				if (hsize)
-					git_SHA1_Update(ctx, ibuf, hsize);
+					the_hash_algo->update_fn(ctx, ibuf, hsize);
 				*already_hashed_to = offset;
 			}
 			s.next_in = ibuf;
@@ -149,7 +149,7 @@ static int stream_to_pack(struct bulk_checkin_state *state,
 					return -1;
 				}
 
-				sha1write(state->f, obuf, written);
+				hashwrite(state->f, obuf, written);
 				state->offset += written;
 			}
 			s.next_out = obuf;
@@ -192,10 +192,10 @@ static int deflate_to_pack(struct bulk_checkin_state *state,
 			   unsigned flags)
 {
 	off_t seekback, already_hashed_to;
-	git_SHA_CTX ctx;
+	git_hash_ctx ctx;
 	unsigned char obuf[16384];
 	unsigned header_len;
-	struct sha1file_checkpoint checkpoint;
+	struct hashfile_checkpoint checkpoint;
 	struct pack_idx_entry *idx = NULL;
 
 	seekback = lseek(fd, 0, SEEK_CUR);
@@ -204,8 +204,8 @@ static int deflate_to_pack(struct bulk_checkin_state *state,
 
 	header_len = xsnprintf((char *)obuf, sizeof(obuf), "%s %" PRIuMAX,
 			       typename(type), (uintmax_t)size) + 1;
-	git_SHA1_Init(&ctx);
-	git_SHA1_Update(&ctx, obuf, header_len);
+	the_hash_algo->init_fn(&ctx);
+	the_hash_algo->update_fn(&ctx, obuf, header_len);
 
 	/* Note: idx is non-NULL when we are writing */
 	if ((flags & HASH_WRITE_OBJECT) != 0)
@@ -216,7 +216,7 @@ static int deflate_to_pack(struct bulk_checkin_state *state,
 	while (1) {
 		prepare_to_stream(state, flags);
 		if (idx) {
-			sha1file_checkpoint(state->f, &checkpoint);
+			hashfile_checkpoint(state->f, &checkpoint);
 			idx->offset = state->offset;
 			crc32_begin(state->f);
 		}
@@ -230,19 +230,19 @@ static int deflate_to_pack(struct bulk_checkin_state *state,
 		 */
 		if (!idx)
 			die("BUG: should not happen");
-		sha1file_truncate(state->f, &checkpoint);
+		hashfile_truncate(state->f, &checkpoint);
 		state->offset = checkpoint.offset;
 		finish_bulk_checkin(state);
 		if (lseek(fd, seekback, SEEK_SET) == (off_t) -1)
 			return error("cannot seek back");
 	}
-	git_SHA1_Final(result_sha1, &ctx);
+	the_hash_algo->final_fn(result_sha1, &ctx);
 	if (!idx)
 		return 0;
 
 	idx->crc32 = crc32_end(state->f);
 	if (already_written(state, result_sha1)) {
-		sha1file_truncate(state->f, &checkpoint);
+		hashfile_truncate(state->f, &checkpoint);
 		state->offset = checkpoint.offset;
 		free(idx);
 	} else {

diff --git a/bundle.c b/bundle.c
index 9329096..efe547e 100644
--- a/bundle.c
+++ b/bundle.c

@@ -134,7 +134,6 @@ int verify_bundle(struct bundle_header *header, int verbose)
 	struct ref_list *p = &header->prerequisites;
 	struct rev_info revs;
 	const char *argv[] = {NULL, "--all", NULL};
-	struct object_array refs;
 	struct commit *commit;
 	int i, ret = 0, req_nr;
 	const char *message = _("Repository lacks these prerequisite commits:");
@@ -157,14 +156,6 @@ int verify_bundle(struct bundle_header *header, int verbose)
 	req_nr = revs.pending.nr;
 	setup_revisions(2, argv, &revs, NULL);
 
-	/* Save pending objects, so they can be cleaned up later. */
-	refs = revs.pending;
-	revs.leak_pending = 1;
-
-	/*
-	 * prepare_revision_walk (together with .leak_pending = 1) makes us
-	 * the sole owner of the list of pending objects.
-	 */
 	if (prepare_revision_walk(&revs))
 		die(_("revision walk setup failed"));
 
@@ -173,18 +164,24 @@ int verify_bundle(struct bundle_header *header, int verbose)
 		if (commit->object.flags & PREREQ_MARK)
 			i--;
 
-	for (i = 0; i < req_nr; i++)
-		if (!(refs.objects[i].item->flags & SHOWN)) {
-			if (++ret == 1)
-				error("%s", message);
-			error("%s %s", oid_to_hex(&refs.objects[i].item->oid),
-				refs.objects[i].name);
-		}
+	for (i = 0; i < p->nr; i++) {
+		struct ref_list_entry *e = p->list + i;
+		struct object *o = parse_object(&e->oid);
+		assert(o); /* otherwise we'd have returned early */
+		if (o->flags & SHOWN)
+			continue;
+		if (++ret == 1)
+			error("%s", message);
+		error("%s %s", oid_to_hex(&e->oid), e->name);
+	}
 
 	/* Clean up objects used, as they will be reused. */
-	clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
-
-	object_array_clear(&refs);
+	for (i = 0; i < p->nr; i++) {
+		struct ref_list_entry *e = p->list + i;
+		commit = lookup_commit_reference_gently(&e->oid, 1);
+		if (commit)
+			clear_commit_marks(commit, ALL_REV_FLAGS);
+	}
 
 	if (verbose) {
 		struct ref_list *r;

diff --git a/cache-tree.c b/cache-tree.c
index e03e72c..c52e430 100644
--- a/cache-tree.c
+++ b/cache-tree.c

@@ -84,9 +84,8 @@ static struct cache_tree_sub *find_subtree(struct cache_tree *it,
 	down->namelen = pathlen;
 
 	if (pos < it->subtree_nr)
-		memmove(it->down + pos + 1,
-			it->down + pos,
-			sizeof(down) * (it->subtree_nr - pos - 1));
+		MOVE_ARRAY(it->down + pos + 1, it->down + pos,
+			   it->subtree_nr - pos - 1);
 	it->down[pos] = down;
 	return down;
 }
@@ -400,16 +399,16 @@ static int update_one(struct cache_tree *it,
 	}
 
 	if (repair) {
-		unsigned char sha1[20];
-		hash_sha1_file(buffer.buf, buffer.len, tree_type, sha1);
-		if (has_sha1_file(sha1))
-			hashcpy(it->oid.hash, sha1);
+		struct object_id oid;
+		hash_object_file(buffer.buf, buffer.len, tree_type, &oid);
+		if (has_sha1_file(oid.hash))
+			oidcpy(&it->oid, &oid);
 		else
 			to_invalidate = 1;
-	} else if (dryrun)
-		hash_sha1_file(buffer.buf, buffer.len, tree_type,
-			       it->oid.hash);
-	else if (write_sha1_file(buffer.buf, buffer.len, tree_type, it->oid.hash)) {
+	} else if (dryrun) {
+		hash_object_file(buffer.buf, buffer.len, tree_type, &it->oid);
+	} else if (write_object_file(buffer.buf, buffer.len, tree_type,
+				     &it->oid)) {
 		strbuf_release(&buffer);
 		return -1;
 	}
@@ -608,7 +607,7 @@ int write_index_as_tree(unsigned char *sha1, struct index_state *index_state, co
 
 	hold_lock_file_for_update(&lock_file, index_path, LOCK_DIE_ON_ERROR);
 
-	entries = read_index_from(index_state, index_path);
+	entries = read_index_from(index_state, index_path, get_git_dir());
 	if (entries < 0) {
 		ret = WRITE_TREE_UNREADABLE_INDEX;
 		goto out;

diff --git a/cache.h b/cache.h
index d8b975a..21fbcc2 100644
--- a/cache.h
+++ b/cache.h

@@ -4,7 +4,7 @@
 #include "git-compat-util.h"
 #include "strbuf.h"
 #include "hashmap.h"
-#include "mru.h"
+#include "list.h"
 #include "advice.h"
 #include "gettext.h"
 #include "convert.h"
@@ -16,31 +16,6 @@
 #include "sha1-array.h"
 #include "repository.h"
 
-#ifndef platform_SHA_CTX
-/*
- * platform's underlying implementation of SHA-1; could be OpenSSL,
- * blk_SHA, Apple CommonCrypto, etc...  Note that including
- * SHA1_HEADER may have already defined platform_SHA_CTX for our
- * own implementations like block-sha1 and ppc-sha1, so we list
- * the default for OpenSSL compatible SHA-1 implementations here.
- */
-#define platform_SHA_CTX	SHA_CTX
-#define platform_SHA1_Init	SHA1_Init
-#define platform_SHA1_Update	SHA1_Update
-#define platform_SHA1_Final    	SHA1_Final
-#endif
-
-#define git_SHA_CTX		platform_SHA_CTX
-#define git_SHA1_Init		platform_SHA1_Init
-#define git_SHA1_Update		platform_SHA1_Update
-#define git_SHA1_Final		platform_SHA1_Final
-
-#ifdef SHA1_MAX_BLOCK_SIZE
-#include "compat/sha1-chunked.h"
-#undef git_SHA1_Update
-#define git_SHA1_Update		git_SHA1_Update_Chunked
-#endif
-
 #include <zlib.h>
 typedef struct git_zstream {
 	z_stream z;
@@ -345,7 +320,8 @@ struct index_state {
 	struct split_index *split_index;
 	struct cache_time timestamp;
 	unsigned name_hash_initialized : 1,
-		 initialized : 1;
+		 initialized : 1,
+		 drop_cache_tree : 1;
 	struct hashmap name_hash;
 	struct hashmap dir_hash;
 	unsigned char sha1[20];
@@ -371,7 +347,7 @@ extern void free_name_hash(struct index_state *istate);
 #define active_cache_tree (the_index.cache_tree)
 
 #define read_cache() read_index(&the_index)
-#define read_cache_from(path) read_index_from(&the_index, (path))
+#define read_cache_from(path) read_index_from(&the_index, (path), (get_git_dir()))
 #define read_cache_preload(pathspec) read_index_preload(&the_index, (pathspec))
 #define is_cache_unborn() is_index_unborn(&the_index)
 #define read_cache_unmerged() read_index_unmerged(&the_index)
@@ -616,7 +592,8 @@ extern int read_index(struct index_state *);
 extern int read_index_preload(struct index_state *, const struct pathspec *pathspec);
 extern int do_read_index(struct index_state *istate, const char *path,
 			 int must_exist); /* for testting only! */
-extern int read_index_from(struct index_state *, const char *path);
+extern int read_index_from(struct index_state *, const char *path,
+			   const char *gitdir);
 extern int is_index_unborn(struct index_state *);
 extern int read_index_unmerged(struct index_state *);
 
@@ -914,10 +891,13 @@ extern int grafts_replace_parents;
 #define GIT_REPO_VERSION 0
 #define GIT_REPO_VERSION_READ 1
 extern int repository_format_precious_objects;
+extern char *repository_format_partial_clone;
+extern const char *core_partial_clone_filter_default;
 
 struct repository_format {
 	int version;
 	int precious_objects;
+	char *partial_clone; /* value of extensions.partialclone */
 	int is_bare;
 	int hash_algo;
 	char *work_tree;
@@ -957,12 +937,10 @@ extern void check_repository_format(void);
 #define TYPE_CHANGED    0x0040
 
 /*
- * Return the name of the file in the local object database that would
- * be used to store a loose object with the specified sha1.  The
- * return value is a pointer to a statically allocated buffer that is
- * overwritten each time the function is called.
+ * Put in `buf` the name of the file in the local object database that
+ * would be used to store a loose object with the specified sha1.
  */
-extern const char *sha1_file_name(const unsigned char *sha1);
+extern void sha1_file_name(struct strbuf *buf, const unsigned char *sha1);
 
 /*
  * Return an abbreviated sha1 unique within this repository's object database.
@@ -1029,7 +1007,7 @@ static inline void hashclr(unsigned char *hash)
 
 static inline void oidclr(struct object_id *oid)
 {
-	hashclr(oid->hash);
+	memset(oid->hash, 0, GIT_MAX_RAWSZ);
 }
 
 
@@ -1047,8 +1025,6 @@ extern const struct object_id empty_tree_oid;
 	"\xe6\x9d\xe2\x9b\xb2\xd1\xd6\x43\x4b\x8b" \
 	"\x29\xae\x77\x5a\xd8\xc2\xe4\x8c\x53\x91"
 extern const struct object_id empty_blob_oid;
-#define EMPTY_BLOB_SHA1_BIN (empty_blob_oid.hash)
-
 
 static inline int is_empty_blob_sha1(const unsigned char *sha1)
 {
@@ -1238,11 +1214,22 @@ static inline const unsigned char *lookup_replace_object(const unsigned char *sh
 
 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 extern int sha1_object_info(const unsigned char *, unsigned long *);
-extern int hash_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1);
-extern int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
-extern int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type, struct object_id *oid, unsigned flags);
-extern int pretend_sha1_file(void *, unsigned long, enum object_type, unsigned char *);
-extern int force_object_loose(const unsigned char *sha1, time_t mtime);
+
+extern int hash_object_file(const void *buf, unsigned long len,
+			    const char *type, struct object_id *oid);
+
+extern int write_object_file(const void *buf, unsigned long len,
+			     const char *type, struct object_id *oid);
+
+extern int hash_object_file_literally(const void *buf, unsigned long len,
+				      const char *type, struct object_id *oid,
+				      unsigned flags);
+
+extern int pretend_object_file(void *, unsigned long, enum object_type,
+			       struct object_id *oid);
+
+extern int force_object_loose(const struct object_id *oid, time_t mtime);
+
 extern int git_open_cloexec(const char *name, int flags);
 #define git_open(name) git_open_cloexec(name, O_RDONLY)
 extern void *map_sha1_file(const unsigned char *sha1, unsigned long *size);
@@ -1635,6 +1622,7 @@ struct pack_window {
 
 extern struct packed_git {
 	struct packed_git *next;
+	struct list_head mru;
 	struct pack_window *windows;
 	off_t pack_size;
 	const void *index_data;
@@ -1648,7 +1636,8 @@ extern struct packed_git {
 	unsigned pack_local:1,
 		 pack_keep:1,
 		 freshened:1,
-		 do_not_close:1;
+		 do_not_close:1,
+		 pack_promisor:1;
 	unsigned char sha1[20];
 	struct revindex_entry *revindex;
 	/* something like ".git/objects/pack/xxxxx.pack" */
@@ -1656,10 +1645,9 @@ extern struct packed_git {
 } *packed_git;
 
 /*
- * A most-recently-used ordered version of the packed_git list, which can
- * be iterated instead of packed_git (and marked via mru_mark).
+ * A most-recently-used ordered version of the packed_git list.
  */
-extern struct mru packed_git_mru;
+extern struct list_head packed_git_mru;
 
 struct pack_entry {
 	off_t offset;
@@ -1787,6 +1775,14 @@ struct object_info {
 #define OBJECT_INFO_QUICK 8
 extern int sha1_object_info_extended(const unsigned char *, struct object_info *, unsigned flags);
 
+/*
+ * Set this to 0 to prevent sha1_object_info_extended() from fetching missing
+ * blobs. This has a difference only if extensions.partialClone is set.
+ *
+ * Its default value is 1.
+ */
+extern int fetch_if_missing;
+
 /* Dumb servers support */
 extern int update_server_info(int);
 

diff --git a/ci/lib-travisci.sh b/ci/lib-travisci.sh
index 07f27c7..1efee55 100755
--- a/ci/lib-travisci.sh
+++ b/ci/lib-travisci.sh

@@ -21,8 +21,6 @@
 	fi
 }
 
-good_trees_file="$HOME/travis-cache/good-trees"
-
 # Save some info about the current commit's tree, so we can skip the build
 # job if we encounter the same tree again and can provide a useful info
 # message.
@@ -83,7 +81,10 @@
 # and installing dependencies.
 set -ex
 
-mkdir -p "$HOME/travis-cache"
+cache_dir="$HOME/travis-cache"
+good_trees_file="$cache_dir/good-trees"
+
+mkdir -p "$cache_dir"
 
 skip_branch_tip_with_tag
 skip_good_tree

diff --git a/ci/run-linux32-build.sh b/ci/run-linux32-build.sh
index c19c50c..2c60d2e 100755
--- a/ci/run-linux32-build.sh
+++ b/ci/run-linux32-build.sh

@@ -3,31 +3,58 @@
 # Build and test Git in a 32-bit environment
 #
 # Usage:
-#   run-linux32-build.sh [host-user-id]
+#   run-linux32-build.sh <host-user-id>
 #
 
-set -x
+set -ex
+
+if test $# -ne 1 || test -z "$1"
+then
+	echo >&2 "usage: run-linux32-build.sh <host-user-id>"
+	exit 1
+fi
 
 # Update packages to the latest available versions
 linux32 --32bit i386 sh -c '
     apt update >/dev/null &&
     apt install -y build-essential libcurl4-openssl-dev libssl-dev \
 	libexpat-dev gettext python >/dev/null
-' &&
+'
 
 # If this script runs inside a docker container, then all commands are
 # usually executed as root. Consequently, the host user might not be
 # able to access the test output files.
-# If a host user id is given, then create a user "ci" with the host user
-# id to make everything accessible to the host user.
-HOST_UID=$1 &&
-CI_USER=$USER &&
-test -z $HOST_UID || (CI_USER="ci" && useradd -u $HOST_UID $CI_USER) &&
+# If a non 0 host user id is given, then create a user "ci" with that
+# user id to make everything accessible to the host user.
+HOST_UID=$1
+if test $HOST_UID -eq 0
+then
+	# Just in case someone does want to run the test suite as root.
+	CI_USER=root
+else
+	CI_USER=ci
+	if test "$(id -u $CI_USER 2>/dev/null)" = $HOST_UID
+	then
+		echo "user '$CI_USER' already exists with the requested ID $HOST_UID"
+	else
+		useradd -u $HOST_UID $CI_USER
+	fi
+
+	# Due to a bug the test suite was run as root in the past, so
+	# a prove state file created back then is only accessible by
+	# root.  Now that bug is fixed, the test suite is run as a
+	# regular user, but the prove state file coming from Travis
+	# CI's cache might still be owned by root.
+	# Make sure that this user has rights to any cached files,
+	# including an existing prove state file.
+	test -n "$cache_dir" && chown -R $HOST_UID:$HOST_UID "$cache_dir"
+fi
 
 # Build and test
 linux32 --32bit i386 su -m -l $CI_USER -c '
-    cd /usr/src/git &&
-    ln -s /tmp/travis-cache/.prove t/.prove &&
-    make --jobs=2 &&
-    make --quiet test
+	set -ex
+	cd /usr/src/git
+	test -n "$cache_dir" && ln -s "$cache_dir/.prove" t/.prove
+	make --jobs=2
+	make --quiet test
 '

diff --git a/ci/run-linux32-docker.sh b/ci/run-linux32-docker.sh
index 4f191c5..2163790 100755
--- a/ci/run-linux32-docker.sh
+++ b/ci/run-linux32-docker.sh

@@ -9,7 +9,9 @@
 
 # Use the following command to debug the docker build locally:
 # $ docker run -itv "${PWD}:/usr/src/git" --entrypoint /bin/bash daald/ubuntu32:xenial
-# root@container:/# /usr/src/git/ci/run-linux32-build.sh
+# root@container:/# /usr/src/git/ci/run-linux32-build.sh <host-user-id>
+
+container_cache_dir=/tmp/travis-cache
 
 docker run \
 	--interactive \
@@ -18,8 +20,9 @@
 	--env GIT_PROVE_OPTS \
 	--env GIT_TEST_OPTS \
 	--env GIT_TEST_CLONE_2GB \
+	--env cache_dir="$container_cache_dir" \
 	--volume "${PWD}:/usr/src/git" \
-	--volume "${HOME}/travis-cache:/tmp/travis-cache" \
+	--volume "$cache_dir:$container_cache_dir" \
 	daald/ubuntu32:xenial \
 	/usr/src/git/ci/run-linux32-build.sh $(id -u $USER)
 

diff --git a/ci/run-tests.sh b/ci/run-tests.sh
index 22355f0..73e273f 100755
--- a/ci/run-tests.sh
+++ b/ci/run-tests.sh

@@ -5,8 +5,13 @@
 
 . ${0%/*}/lib-travisci.sh
 
-ln -s $HOME/travis-cache/.prove t/.prove
+ln -s "$cache_dir/.prove" t/.prove
+
 make --quiet test
+if test "$jobname" = "linux-gcc"
+then
+	GIT_TEST_SPLIT_INDEX=YesPlease make --quiet test
+fi
 
 check_unignored_build_artifacts
 

diff --git a/combine-diff.c b/combine-diff.c
index 2505de1..18c74da 100644
--- a/combine-diff.c
+++ b/combine-diff.c

@@ -1053,7 +1053,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 			if (is_file) {
 				struct strbuf buf = STRBUF_INIT;
 
-				if (convert_to_git(&the_index, elem->path, result, len, &buf, safe_crlf)) {
+				if (convert_to_git(&the_index, elem->path, result, len, &buf, global_conv_flags_eol)) {
 					free(result);
 					result = strbuf_detach(&buf, &len);
 					result_size = len;
@@ -1438,7 +1438,7 @@ void diff_tree_combined(const struct object_id *oid,
 			opt->flags.follow_renames	||
 			opt->break_opt != -1	||
 			opt->detect_rename	||
-			opt->pickaxe		||
+			(opt->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)	||
 			opt->filter;
 
 

diff --git a/commit.c b/commit.c
index cab8d44..e8a49b9 100644
--- a/commit.c
+++ b/commit.c

@@ -126,10 +126,8 @@ int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 	ALLOC_GROW(commit_graft, commit_graft_nr + 1, commit_graft_alloc);
 	commit_graft_nr++;
 	if (pos < commit_graft_nr)
-		memmove(commit_graft + pos + 1,
-			commit_graft + pos,
-			(commit_graft_nr - pos - 1) *
-			sizeof(*commit_graft));
+		MOVE_ARRAY(commit_graft + pos + 1, commit_graft + pos,
+			   commit_graft_nr - pos - 1);
 	commit_graft[pos] = graft;
 	return 0;
 }
@@ -547,7 +545,7 @@ void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
 	struct commit_list *list = NULL;
 
 	while (nr--) {
-		commit_list_insert(*commit, &list);
+		clear_commit_marks_1(&list, *commit, mark);
 		commit++;
 	}
 	while (list)
@@ -559,20 +557,6 @@ void clear_commit_marks(struct commit *commit, unsigned int mark)
 	clear_commit_marks_many(1, &commit, mark);
 }
 
-void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark)
-{
-	struct object *object;
-	struct commit *commit;
-	unsigned int i;
-
-	for (i = 0; i < a->nr; i++) {
-		object = a->objects[i].item;
-		commit = lookup_commit_reference_gently(&object->oid, 1);
-		if (commit)
-			clear_commit_marks(commit, mark);
-	}
-}
-
 struct commit *pop_commit(struct commit_list **stack)
 {
 	struct commit_list *top = *stack;
@@ -929,8 +913,7 @@ static int remove_redundant(struct commit **array, int cnt)
 			if (work[j]->object.flags & PARENT1)
 				redundant[filled_index[j]] = 1;
 		clear_commit_marks(array[i], all_flags);
-		for (j = 0; j < filled; j++)
-			clear_commit_marks(work[j], all_flags);
+		clear_commit_marks_many(filled, work, all_flags);
 		free_commit_list(common);
 	}
 
@@ -1395,9 +1378,8 @@ void free_commit_extra_headers(struct commit_extra_header *extra)
 	}
 }
 
-int commit_tree(const char *msg, size_t msg_len,
-		const unsigned char *tree,
-		struct commit_list *parents, unsigned char *ret,
+int commit_tree(const char *msg, size_t msg_len, const struct object_id *tree,
+		struct commit_list *parents, struct object_id *ret,
 		const char *author, const char *sign_commit)
 {
 	struct commit_extra_header *extra = NULL, **tail = &extra;
@@ -1526,8 +1508,8 @@ N_("Warning: commit message did not conform to UTF-8.\n"
    "variable i18n.commitencoding to the encoding your project uses.\n");
 
 int commit_tree_extended(const char *msg, size_t msg_len,
-			 const unsigned char *tree,
-			 struct commit_list *parents, unsigned char *ret,
+			 const struct object_id *tree,
+			 struct commit_list *parents, struct object_id *ret,
 			 const char *author, const char *sign_commit,
 			 struct commit_extra_header *extra)
 {
@@ -1535,7 +1517,7 @@ int commit_tree_extended(const char *msg, size_t msg_len,
 	int encoding_is_utf8;
 	struct strbuf buffer;
 
-	assert_sha1_type(tree, OBJ_TREE);
+	assert_sha1_type(tree->hash, OBJ_TREE);
 
 	if (memchr(msg, '\0', msg_len))
 		return error("a NUL byte in commit log message not allowed.");
@@ -1544,7 +1526,7 @@ int commit_tree_extended(const char *msg, size_t msg_len,
 	encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
 
 	strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
-	strbuf_addf(&buffer, "tree %s\n", sha1_to_hex(tree));
+	strbuf_addf(&buffer, "tree %s\n", oid_to_hex(tree));
 
 	/*
 	 * NOTE! This ordering means that the same exact tree merged with a
@@ -1583,7 +1565,7 @@ int commit_tree_extended(const char *msg, size_t msg_len,
 		goto out;
 	}
 
-	result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret);
+	result = write_object_file(buffer.buf, buffer.len, commit_type, ret);
 out:
 	strbuf_release(&buffer);
 	return result;

diff --git a/commit.h b/commit.h
index 8c68ca1..0fb8271 100644
--- a/commit.h
+++ b/commit.h

@@ -140,7 +140,6 @@ struct commit *pop_commit(struct commit_list **stack);
 
 void clear_commit_marks(struct commit *commit, unsigned int mark);
 void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark);
-void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark);
 
 
 enum rev_sort_order {
@@ -263,14 +262,15 @@ extern void append_merge_tag_headers(struct commit_list *parents,
 				     struct commit_extra_header ***tail);
 
 extern int commit_tree(const char *msg, size_t msg_len,
-		       const unsigned char *tree,
-		       struct commit_list *parents, unsigned char *ret,
+		       const struct object_id *tree,
+		       struct commit_list *parents, struct object_id *ret,
 		       const char *author, const char *sign_commit);
 
 extern int commit_tree_extended(const char *msg, size_t msg_len,
-				const unsigned char *tree,
-				struct commit_list *parents, unsigned char *ret,
-				const char *author, const char *sign_commit,
+				const struct object_id *tree,
+				struct commit_list *parents,
+				struct object_id *ret, const char *author,
+				const char *sign_commit,
 				struct commit_extra_header *);
 
 extern struct commit_extra_header *read_commit_extra_headers(struct commit *, const char **);

diff --git a/config.c b/config.c
index e617c20..b0c20e6 100644
--- a/config.c
+++ b/config.c

@@ -1149,11 +1149,14 @@ static int git_default_core_config(const char *var, const char *value)
 	}
 
 	if (!strcmp(var, "core.safecrlf")) {
+		int eol_rndtrp_die;
 		if (value && !strcasecmp(value, "warn")) {
-			safe_crlf = SAFE_CRLF_WARN;
+			global_conv_flags_eol = CONV_EOL_RNDTRP_WARN;
 			return 0;
 		}
-		safe_crlf = git_config_bool(var, value);
+		eol_rndtrp_die = git_config_bool(var, value);
+		global_conv_flags_eol = eol_rndtrp_die ?
+			CONV_EOL_RNDTRP_DIE : CONV_EOL_RNDTRP_WARN;
 		return 0;
 	}
 
@@ -1251,6 +1254,11 @@ static int git_default_core_config(const char *var, const char *value)
 		return 0;
 	}
 
+	if (!strcmp(var, "core.partialclonefilter")) {
+		return git_config_string(&core_partial_clone_filter_default,
+					 var, value);
+	}
+
 	/* Add other config variables here and to Documentation/config.txt. */
 	return 0;
 }

diff --git a/connected.c b/connected.c
index 4a47f33..91feb78 100644
--- a/connected.c
+++ b/connected.c

@@ -56,6 +56,8 @@ int check_connected(oid_iterate_fn fn, void *cb_data,
 	argv_array_push(&rev_list.args,"rev-list");
 	argv_array_push(&rev_list.args, "--objects");
 	argv_array_push(&rev_list.args, "--stdin");
+	if (repository_format_partial_clone)
+		argv_array_push(&rev_list.args, "--exclude-promisor-objects");
 	argv_array_push(&rev_list.args, "--not");
 	argv_array_push(&rev_list.args, "--all");
 	argv_array_push(&rev_list.args, "--quiet");

diff --git a/contrib/coccinelle/strbuf.cocci b/contrib/coccinelle/strbuf.cocci
index 1d580e4..e34eada 100644
--- a/contrib/coccinelle/strbuf.cocci
+++ b/contrib/coccinelle/strbuf.cocci

@@ -1,21 +1,6 @@
 @ strbuf_addf_with_format_only @
 expression E;
-constant fmt;
-@@
-  strbuf_addf(E,
-(
-  fmt
-|
-  _(fmt)
-)
-  );
-
-@ script:python @
-fmt << strbuf_addf_with_format_only.fmt;
-@@
-cocci.include_match("%" not in fmt)
-
-@ extends strbuf_addf_with_format_only @
+constant fmt !~ "%";
 @@
 - strbuf_addf
 + strbuf_addstr
@@ -29,8 +14,9 @@
 
 @@
 expression E1, E2;
+format F =~ "s";
 @@
-- strbuf_addf(E1, "%s", E2);
+- strbuf_addf(E1, "%@F@", E2);
 + strbuf_addstr(E1, E2);
 
 @@

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 3683c77..88813e9 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash

@@ -594,7 +594,7 @@
 
 __git_list_merge_strategies ()
 {
-	git merge -s help 2>&1 |
+	LANG=C LC_ALL=C git merge -s help 2>&1 |
 	sed -n -e '/[Aa]vailable strategies are: /,/^$/{
 		s/\.$//
 		s/.*://

diff --git a/contrib/examples/git-difftool.perl b/contrib/examples/git-difftool.perl
index df59bdf..fb0fd0b 100755
--- a/contrib/examples/git-difftool.perl
+++ b/contrib/examples/git-difftool.perl

@@ -13,7 +13,7 @@
 use 5.008;
 use strict;
 use warnings;
-use Error qw(:try);
+use Git::Error qw(:try);
 use File::Basename qw(dirname);
 use File::Copy;
 use File::Find;

diff --git a/convert.c b/convert.c
index 1a41a48..cc562f6 100644
--- a/convert.c
+++ b/convert.c

@@ -193,30 +193,30 @@ static enum eol output_eol(enum crlf_action crlf_action)
 	return core_eol;
 }
 
-static void check_safe_crlf(const char *path, enum crlf_action crlf_action,
+static void check_global_conv_flags_eol(const char *path, enum crlf_action crlf_action,
 			    struct text_stat *old_stats, struct text_stat *new_stats,
-			    enum safe_crlf checksafe)
+			    int conv_flags)
 {
 	if (old_stats->crlf && !new_stats->crlf ) {
 		/*
 		 * CRLFs would not be restored by checkout
 		 */
-		if (checksafe == SAFE_CRLF_WARN)
+		if (conv_flags & CONV_EOL_RNDTRP_DIE)
+			die(_("CRLF would be replaced by LF in %s."), path);
+		else if (conv_flags & CONV_EOL_RNDTRP_WARN)
 			warning(_("CRLF will be replaced by LF in %s.\n"
 				  "The file will have its original line"
 				  " endings in your working directory."), path);
-		else /* i.e. SAFE_CRLF_FAIL */
-			die(_("CRLF would be replaced by LF in %s."), path);
 	} else if (old_stats->lonelf && !new_stats->lonelf ) {
 		/*
 		 * CRLFs would be added by checkout
 		 */
-		if (checksafe == SAFE_CRLF_WARN)
+		if (conv_flags & CONV_EOL_RNDTRP_DIE)
+			die(_("LF would be replaced by CRLF in %s"), path);
+		else if (conv_flags & CONV_EOL_RNDTRP_WARN)
 			warning(_("LF will be replaced by CRLF in %s.\n"
 				  "The file will have its original line"
 				  " endings in your working directory."), path);
-		else /* i.e. SAFE_CRLF_FAIL */
-			die(_("LF would be replaced by CRLF in %s"), path);
 	}
 }
 
@@ -268,7 +268,7 @@ static int will_convert_lf_to_crlf(size_t len, struct text_stat *stats,
 static int crlf_to_git(const struct index_state *istate,
 		       const char *path, const char *src, size_t len,
 		       struct strbuf *buf,
-		       enum crlf_action crlf_action, enum safe_crlf checksafe)
+		       enum crlf_action crlf_action, int conv_flags)
 {
 	struct text_stat stats;
 	char *dst;
@@ -298,12 +298,12 @@ static int crlf_to_git(const struct index_state *istate,
 		 * unless we want to renormalize in a merge or
 		 * cherry-pick.
 		 */
-		if ((checksafe != SAFE_CRLF_RENORMALIZE) &&
+		if ((!(conv_flags & CONV_EOL_RENORMALIZE)) &&
 		    has_crlf_in_index(istate, path))
 			convert_crlf_into_lf = 0;
 	}
-	if ((checksafe == SAFE_CRLF_WARN ||
-	    (checksafe == SAFE_CRLF_FAIL)) && len) {
+	if (((conv_flags & CONV_EOL_RNDTRP_WARN) ||
+	     ((conv_flags & CONV_EOL_RNDTRP_DIE) && len))) {
 		struct text_stat new_stats;
 		memcpy(&new_stats, &stats, sizeof(new_stats));
 		/* simulate "git add" */
@@ -316,7 +316,7 @@ static int crlf_to_git(const struct index_state *istate,
 			new_stats.crlf += new_stats.lonelf;
 			new_stats.lonelf = 0;
 		}
-		check_safe_crlf(path, crlf_action, &stats, &new_stats, checksafe);
+		check_global_conv_flags_eol(path, crlf_action, &stats, &new_stats, conv_flags);
 	}
 	if (!convert_crlf_into_lf)
 		return 0;
@@ -898,7 +898,7 @@ static int ident_to_git(const char *path, const char *src, size_t len,
 static int ident_to_worktree(const char *path, const char *src, size_t len,
                              struct strbuf *buf, int ident)
 {
-	unsigned char sha1[20];
+	struct object_id oid;
 	char *to_free = NULL, *dollar, *spc;
 	int cnt;
 
@@ -912,7 +912,7 @@ static int ident_to_worktree(const char *path, const char *src, size_t len,
 	/* are we "faking" in place editing ? */
 	if (src == buf->buf)
 		to_free = strbuf_detach(buf, NULL);
-	hash_sha1_file(src, len, "blob", sha1);
+	hash_object_file(src, len, "blob", &oid);
 
 	strbuf_grow(buf, len + cnt * 43);
 	for (;;) {
@@ -969,7 +969,7 @@ static int ident_to_worktree(const char *path, const char *src, size_t len,
 
 		/* step 4: substitute */
 		strbuf_addstr(buf, "Id: ");
-		strbuf_add(buf, sha1_to_hex(sha1), 40);
+		strbuf_addstr(buf, oid_to_hex(&oid));
 		strbuf_addstr(buf, " $");
 	}
 	strbuf_add(buf, src, len);
@@ -1129,7 +1129,7 @@ const char *get_convert_attr_ascii(const char *path)
 
 int convert_to_git(const struct index_state *istate,
 		   const char *path, const char *src, size_t len,
-                   struct strbuf *dst, enum safe_crlf checksafe)
+		   struct strbuf *dst, int conv_flags)
 {
 	int ret = 0;
 	struct conv_attrs ca;
@@ -1144,8 +1144,8 @@ int convert_to_git(const struct index_state *istate,
 		src = dst->buf;
 		len = dst->len;
 	}
-	if (checksafe != SAFE_CRLF_KEEP_CRLF) {
-		ret |= crlf_to_git(istate, path, src, len, dst, ca.crlf_action, checksafe);
+	if (!(conv_flags & CONV_EOL_KEEP_CRLF)) {
+		ret |= crlf_to_git(istate, path, src, len, dst, ca.crlf_action, conv_flags);
 		if (ret && dst) {
 			src = dst->buf;
 			len = dst->len;
@@ -1156,7 +1156,7 @@ int convert_to_git(const struct index_state *istate,
 
 void convert_to_git_filter_fd(const struct index_state *istate,
 			      const char *path, int fd, struct strbuf *dst,
-			      enum safe_crlf checksafe)
+			      int conv_flags)
 {
 	struct conv_attrs ca;
 	convert_attrs(&ca, path);
@@ -1167,7 +1167,7 @@ void convert_to_git_filter_fd(const struct index_state *istate,
 	if (!apply_filter(path, NULL, 0, fd, dst, ca.drv, CAP_CLEAN, NULL))
 		die("%s: clean filter '%s' failed", path, ca.drv->name);
 
-	crlf_to_git(istate, path, dst->buf, dst->len, dst, ca.crlf_action, checksafe);
+	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);
 }
 
@@ -1226,7 +1226,7 @@ int renormalize_buffer(const struct index_state *istate, const char *path,
 		src = dst->buf;
 		len = dst->len;
 	}
-	return ret | convert_to_git(istate, path, src, len, dst, SAFE_CRLF_RENORMALIZE);
+	return ret | convert_to_git(istate, path, src, len, dst, CONV_EOL_RENORMALIZE);
 }
 
 /*****************************************************************

diff --git a/convert.h b/convert.h
index 4f2da22..65ab3e5 100644
--- a/convert.h
+++ b/convert.h

@@ -8,15 +8,12 @@
 
 struct index_state;
 
-enum safe_crlf {
-	SAFE_CRLF_FALSE = 0,
-	SAFE_CRLF_FAIL = 1,
-	SAFE_CRLF_WARN = 2,
-	SAFE_CRLF_RENORMALIZE = 3,
-	SAFE_CRLF_KEEP_CRLF = 4
-};
+#define CONV_EOL_RNDTRP_DIE   (1<<0) /* Die if CRLF to LF to CRLF is different */
+#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 */
 
-extern enum safe_crlf safe_crlf;
+extern int global_conv_flags_eol;
 
 enum auto_crlf {
 	AUTO_CRLF_FALSE = 0,
@@ -66,7 +63,7 @@ extern const char *get_convert_attr_ascii(const char *path);
 /* returns 1 if *dst was used */
 extern int convert_to_git(const struct index_state *istate,
 			  const char *path, const char *src, size_t len,
-			  struct strbuf *dst, enum safe_crlf checksafe);
+			  struct strbuf *dst, int conv_flags);
 extern int convert_to_working_tree(const char *path, const char *src,
 				   size_t len, struct strbuf *dst);
 extern int async_convert_to_working_tree(const char *path, const char *src,
@@ -85,7 +82,7 @@ static inline int would_convert_to_git(const struct index_state *istate,
 extern void convert_to_git_filter_fd(const struct index_state *istate,
 				     const char *path, int fd,
 				     struct strbuf *dst,
-				     enum safe_crlf checksafe);
+				     int conv_flags);
 extern int would_convert_to_git_filter_fd(const char *path);
 
 /*****************************************************************

diff --git a/csum-file.c b/csum-file.c
index 2adae04..5eda7fb 100644
--- a/csum-file.c
+++ b/csum-file.c

@@ -11,7 +11,7 @@
 #include "progress.h"
 #include "csum-file.h"
 
-static void flush(struct sha1file *f, const void *buf, unsigned int count)
+static void flush(struct hashfile *f, const void *buf, unsigned int count)
 {
 	if (0 <= f->check_fd && count)  {
 		unsigned char check_buffer[8192];
@@ -42,28 +42,28 @@ static void flush(struct sha1file *f, const void *buf, unsigned int count)
 	}
 }
 
-void sha1flush(struct sha1file *f)
+void hashflush(struct hashfile *f)
 {
 	unsigned offset = f->offset;
 
 	if (offset) {
-		git_SHA1_Update(&f->ctx, f->buffer, offset);
+		the_hash_algo->update_fn(&f->ctx, f->buffer, offset);
 		flush(f, f->buffer, offset);
 		f->offset = 0;
 	}
 }
 
-int sha1close(struct sha1file *f, unsigned char *result, unsigned int flags)
+int hashclose(struct hashfile *f, unsigned char *result, unsigned int flags)
 {
 	int fd;
 
-	sha1flush(f);
-	git_SHA1_Final(f->buffer, &f->ctx);
+	hashflush(f);
+	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 */
-		flush(f, f->buffer, 20);
+		flush(f, f->buffer, the_hash_algo->rawsz);
 		if (flags & CSUM_FSYNC)
 			fsync_or_die(f->fd, f->name);
 		if (close(f->fd))
@@ -86,7 +86,7 @@ int sha1close(struct sha1file *f, unsigned char *result, unsigned int flags)
 	return fd;
 }
 
-void sha1write(struct sha1file *f, const void *buf, unsigned int count)
+void hashwrite(struct hashfile *f, const void *buf, unsigned int count)
 {
 	while (count) {
 		unsigned offset = f->offset;
@@ -110,7 +110,7 @@ void sha1write(struct sha1file *f, const void *buf, unsigned int count)
 		buf = (char *) buf + nr;
 		left -= nr;
 		if (!left) {
-			git_SHA1_Update(&f->ctx, data, offset);
+			the_hash_algo->update_fn(&f->ctx, data, offset);
 			flush(f, data, offset);
 			offset = 0;
 		}
@@ -118,15 +118,15 @@ void sha1write(struct sha1file *f, const void *buf, unsigned int count)
 	}
 }
 
-struct sha1file *sha1fd(int fd, const char *name)
+struct hashfile *hashfd(int fd, const char *name)
 {
-	return sha1fd_throughput(fd, name, NULL);
+	return hashfd_throughput(fd, name, NULL);
 }
 
-struct sha1file *sha1fd_check(const char *name)
+struct hashfile *hashfd_check(const char *name)
 {
 	int sink, check;
-	struct sha1file *f;
+	struct hashfile *f;
 
 	sink = open("/dev/null", O_WRONLY);
 	if (sink < 0)
@@ -134,14 +134,14 @@ struct sha1file *sha1fd_check(const char *name)
 	check = open(name, O_RDONLY);
 	if (check < 0)
 		die_errno("unable to open '%s'", name);
-	f = sha1fd(sink, name);
+	f = hashfd(sink, name);
 	f->check_fd = check;
 	return f;
 }
 
-struct sha1file *sha1fd_throughput(int fd, const char *name, struct progress *tp)
+struct hashfile *hashfd_throughput(int fd, const char *name, struct progress *tp)
 {
-	struct sha1file *f = xmalloc(sizeof(*f));
+	struct hashfile *f = xmalloc(sizeof(*f));
 	f->fd = fd;
 	f->check_fd = -1;
 	f->offset = 0;
@@ -149,18 +149,18 @@ struct sha1file *sha1fd_throughput(int fd, const char *name, struct progress *tp
 	f->tp = tp;
 	f->name = name;
 	f->do_crc = 0;
-	git_SHA1_Init(&f->ctx);
+	the_hash_algo->init_fn(&f->ctx);
 	return f;
 }
 
-void sha1file_checkpoint(struct sha1file *f, struct sha1file_checkpoint *checkpoint)
+void hashfile_checkpoint(struct hashfile *f, struct hashfile_checkpoint *checkpoint)
 {
-	sha1flush(f);
+	hashflush(f);
 	checkpoint->offset = f->total;
 	checkpoint->ctx = f->ctx;
 }
 
-int sha1file_truncate(struct sha1file *f, struct sha1file_checkpoint *checkpoint)
+int hashfile_truncate(struct hashfile *f, struct hashfile_checkpoint *checkpoint)
 {
 	off_t offset = checkpoint->offset;
 
@@ -169,17 +169,17 @@ int sha1file_truncate(struct sha1file *f, struct sha1file_checkpoint *checkpoint
 		return -1;
 	f->total = offset;
 	f->ctx = checkpoint->ctx;
-	f->offset = 0; /* sha1flush() was called in checkpoint */
+	f->offset = 0; /* hashflush() was called in checkpoint */
 	return 0;
 }
 
-void crc32_begin(struct sha1file *f)
+void crc32_begin(struct hashfile *f)
 {
 	f->crc32 = crc32(0, NULL, 0);
 	f->do_crc = 1;
 }
 
-uint32_t crc32_end(struct sha1file *f)
+uint32_t crc32_end(struct hashfile *f)
 {
 	f->do_crc = 0;
 	return f->crc32;

diff --git a/csum-file.h b/csum-file.h
index 7530927..992e5c0 100644
--- a/csum-file.h
+++ b/csum-file.h

@@ -4,11 +4,11 @@
 struct progress;
 
 /* A SHA1-protected file */
-struct sha1file {
+struct hashfile {
 	int fd;
 	int check_fd;
 	unsigned int offset;
-	git_SHA_CTX ctx;
+	git_hash_ctx ctx;
 	off_t total;
 	struct progress *tp;
 	const char *name;
@@ -18,36 +18,36 @@ struct sha1file {
 };
 
 /* Checkpoint */
-struct sha1file_checkpoint {
+struct hashfile_checkpoint {
 	off_t offset;
-	git_SHA_CTX ctx;
+	git_hash_ctx ctx;
 };
 
-extern void sha1file_checkpoint(struct sha1file *, struct sha1file_checkpoint *);
-extern int sha1file_truncate(struct sha1file *, struct sha1file_checkpoint *);
+extern void hashfile_checkpoint(struct hashfile *, struct hashfile_checkpoint *);
+extern int hashfile_truncate(struct hashfile *, struct hashfile_checkpoint *);
 
-/* sha1close flags */
+/* hashclose flags */
 #define CSUM_CLOSE	1
 #define CSUM_FSYNC	2
 
-extern struct sha1file *sha1fd(int fd, const char *name);
-extern struct sha1file *sha1fd_check(const char *name);
-extern struct sha1file *sha1fd_throughput(int fd, const char *name, struct progress *tp);
-extern int sha1close(struct sha1file *, unsigned char *, unsigned int);
-extern void sha1write(struct sha1file *, const void *, unsigned int);
-extern void sha1flush(struct sha1file *f);
-extern void crc32_begin(struct sha1file *);
-extern uint32_t crc32_end(struct sha1file *);
+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 void hashwrite(struct hashfile *, const void *, unsigned int);
+extern void hashflush(struct hashfile *f);
+extern void crc32_begin(struct hashfile *);
+extern uint32_t crc32_end(struct hashfile *);
 
-static inline void sha1write_u8(struct sha1file *f, uint8_t data)
+static inline void hashwrite_u8(struct hashfile *f, uint8_t data)
 {
-	sha1write(f, &data, sizeof(data));
+	hashwrite(f, &data, sizeof(data));
 }
 
-static inline void sha1write_be32(struct sha1file *f, uint32_t data)
+static inline void hashwrite_be32(struct hashfile *f, uint32_t data)
 {
 	data = htonl(data);
-	sha1write(f, &data, sizeof(data));
+	hashwrite(f, &data, sizeof(data));
 }
 
 #endif

diff --git a/daemon.c b/daemon.c
index e37e343..fe833ea 100644
--- a/daemon.c
+++ b/daemon.c

@@ -9,7 +9,12 @@
 #define initgroups(x, y) (0) /* nothing */
 #endif
 
-static int log_syslog;
+static enum log_destination {
+	LOG_DESTINATION_UNSET = -1,
+	LOG_DESTINATION_NONE = 0,
+	LOG_DESTINATION_STDERR = 1,
+	LOG_DESTINATION_SYSLOG = 2,
+} log_destination = LOG_DESTINATION_UNSET;
 static int verbose;
 static int reuseaddr;
 static int informative_errors;
@@ -25,6 +30,7 @@ static const char daemon_usage[] =
 "           [--access-hook=<path>]\n"
 "           [--inetd | [--listen=<host_or_ipaddr>] [--port=<n>]\n"
 "                      [--detach] [--user=<user> [--group=<group>]]\n"
+"           [--log-destination=(stderr|syslog|none)]\n"
 "           [<directory>...]";
 
 /* List of acceptable pathname prefixes */
@@ -74,11 +80,14 @@ static const char *get_ip_address(struct hostinfo *hi)
 
 static void logreport(int priority, const char *err, va_list params)
 {
-	if (log_syslog) {
+	switch (log_destination) {
+	case LOG_DESTINATION_SYSLOG: {
 		char buf[1024];
 		vsnprintf(buf, sizeof(buf), err, params);
 		syslog(priority, "%s", buf);
-	} else {
+		break;
+	}
+	case LOG_DESTINATION_STDERR:
 		/*
 		 * Since stderr is set to buffered mode, the
 		 * logging of different processes will not overlap
@@ -88,6 +97,11 @@ static void logreport(int priority, const char *err, va_list params)
 		vfprintf(stderr, err, params);
 		fputc('\n', stderr);
 		fflush(stderr);
+		break;
+	case LOG_DESTINATION_NONE:
+		break;
+	case LOG_DESTINATION_UNSET:
+		BUG("log destination not initialized correctly");
 	}
 }
 
@@ -597,6 +611,7 @@ static char *parse_host_arg(struct hostinfo *hi, char *extra_args, int buflen)
 		if (strncasecmp("host=", extra_args, 5) == 0) {
 			val = extra_args + 5;
 			vallen = strlen(val) + 1;
+			loginfo("Extended attribute \"host\": %s", val);
 			if (*val) {
 				/* Split <host>:<port> at colon. */
 				char *host;
@@ -647,9 +662,11 @@ static void parse_extra_args(struct hostinfo *hi, struct argv_array *env,
 		}
 	}
 
-	if (git_protocol.len > 0)
+	if (git_protocol.len > 0) {
+		loginfo("Extended attribute \"protocol\": %s", git_protocol.buf);
 		argv_array_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=%s",
 				 git_protocol.buf);
+	}
 	strbuf_release(&git_protocol);
 }
 
@@ -757,14 +774,8 @@ static int execute(void)
 	alarm(0);
 
 	len = strlen(line);
-	if (pktlen != len)
-		loginfo("Extended attributes (%d bytes) exist <%.*s>",
-			(int) pktlen - len,
-			(int) pktlen - len, line + len + 1);
-	if (len && line[len-1] == '\n') {
-		line[--len] = 0;
-		pktlen--;
-	}
+	if (len && line[len-1] == '\n')
+		line[len-1] = 0;
 
 	/* parse additional args hidden behind a NUL byte */
 	if (len != pktlen)
@@ -1289,7 +1300,6 @@ int cmd_main(int argc, const char **argv)
 		}
 		if (!strcmp(arg, "--inetd")) {
 			inetd_mode = 1;
-			log_syslog = 1;
 			continue;
 		}
 		if (!strcmp(arg, "--verbose")) {
@@ -1297,9 +1307,22 @@ int cmd_main(int argc, const char **argv)
 			continue;
 		}
 		if (!strcmp(arg, "--syslog")) {
-			log_syslog = 1;
+			log_destination = LOG_DESTINATION_SYSLOG;
 			continue;
 		}
+		if (skip_prefix(arg, "--log-destination=", &v)) {
+			if (!strcmp(v, "syslog")) {
+				log_destination = LOG_DESTINATION_SYSLOG;
+				continue;
+			} else if (!strcmp(v, "stderr")) {
+				log_destination = LOG_DESTINATION_STDERR;
+				continue;
+			} else if (!strcmp(v, "none")) {
+				log_destination = LOG_DESTINATION_NONE;
+				continue;
+			} else
+				die("unknown log destination '%s'", v);
+		}
 		if (!strcmp(arg, "--export-all")) {
 			export_all_trees = 1;
 			continue;
@@ -1356,7 +1379,6 @@ int cmd_main(int argc, const char **argv)
 		}
 		if (!strcmp(arg, "--detach")) {
 			detach = 1;
-			log_syslog = 1;
 			continue;
 		}
 		if (skip_prefix(arg, "--user=", &v)) {
@@ -1402,7 +1424,14 @@ int cmd_main(int argc, const char **argv)
 		usage(daemon_usage);
 	}
 
-	if (log_syslog) {
+	if (log_destination == LOG_DESTINATION_UNSET) {
+		if (inetd_mode || detach)
+			log_destination = LOG_DESTINATION_SYSLOG;
+		else
+			log_destination = LOG_DESTINATION_STDERR;
+	}
+
+	if (log_destination == LOG_DESTINATION_SYSLOG) {
 		openlog("git-daemon", LOG_PID, LOG_DAEMON);
 		set_die_routine(daemon_die);
 	} else

diff --git a/diff-lib.c b/diff-lib.c
index 8104603..a228e1a 100644
--- a/diff-lib.c
+++ b/diff-lib.c

@@ -92,6 +92,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 	int diff_unmerged_stage = revs->max_count;
 	unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
 			      ? CE_MATCH_RACY_IS_DIRTY : 0);
+	uint64_t start = getnanotime();
 
 	diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
 
@@ -246,6 +247,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 	}
 	diffcore_std(&revs->diffopt);
 	diff_flush(&revs->diffopt);
+	trace_performance_since(start, "diff-files");
 	return 0;
 }
 
@@ -512,6 +514,7 @@ static int diff_cache(struct rev_info *revs,
 int run_diff_index(struct rev_info *revs, int cached)
 {
 	struct object_array_entry *ent;
+	uint64_t start = getnanotime();
 
 	ent = revs->pending.objects;
 	if (diff_cache(revs, &ent->item->oid, ent->name, cached))
@@ -521,6 +524,7 @@ int run_diff_index(struct rev_info *revs, int cached)
 	diffcore_fix_diff_index(&revs->diffopt);
 	diffcore_std(&revs->diffopt);
 	diff_flush(&revs->diffopt);
+	trace_performance_since(start, "diff-index");
 	return 0;
 }
 

diff --git a/diff.c b/diff.c
index fb22b19..21c3838 100644
--- a/diff.c
+++ b/diff.c

@@ -246,7 +246,7 @@ static int parse_ws_error_highlight(const char *arg)
  */
 void init_diff_ui_defaults(void)
 {
-	diff_detect_rename_default = 1;
+	diff_detect_rename_default = DIFF_DETECT_RENAME;
 }
 
 int git_diff_heuristic_config(const char *var, const char *value, void *cb)
@@ -3520,13 +3520,13 @@ int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
 {
 	int size_only = flags & CHECK_SIZE_ONLY;
 	int err = 0;
+	int conv_flags = global_conv_flags_eol;
 	/*
 	 * demote FAIL to WARN to allow inspecting the situation
 	 * instead of refusing.
 	 */
-	enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
-				    ? SAFE_CRLF_WARN
-				    : safe_crlf);
+	if (conv_flags & CONV_EOL_RNDTRP_DIE)
+		conv_flags = CONV_EOL_RNDTRP_WARN;
 
 	if (!DIFF_FILE_VALID(s))
 		die("internal error: asking to populate invalid file.");
@@ -3603,7 +3603,7 @@ int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
 		/*
 		 * Convert from working tree format to canonical git format
 		 */
-		if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, crlf_warn)) {
+		if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, conv_flags)) {
 			size_t size = 0;
 			munmap(s->data, s->size);
 			s->should_munmap = 0;
@@ -4086,6 +4086,7 @@ void diff_setup(struct diff_options *options)
 	options->interhunkcontext = diff_interhunk_context_default;
 	options->ws_error_highlight = ws_error_highlight_default;
 	options->flags.rename_empty = 1;
+	options->objfind = NULL;
 
 	/* pathchange left =NULL by default */
 	options->change = diff_change;
@@ -4110,22 +4111,20 @@ void diff_setup(struct diff_options *options)
 
 void diff_setup_done(struct diff_options *options)
 {
-	int count = 0;
+	unsigned check_mask = DIFF_FORMAT_NAME |
+			      DIFF_FORMAT_NAME_STATUS |
+			      DIFF_FORMAT_CHECKDIFF |
+			      DIFF_FORMAT_NO_OUTPUT;
 
 	if (options->set_default)
 		options->set_default(options);
 
-	if (options->output_format & DIFF_FORMAT_NAME)
-		count++;
-	if (options->output_format & DIFF_FORMAT_NAME_STATUS)
-		count++;
-	if (options->output_format & DIFF_FORMAT_CHECKDIFF)
-		count++;
-	if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
-		count++;
-	if (count > 1)
+	if (HAS_MULTI_BITS(options->output_format & check_mask))
 		die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
 
+	if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
+		die(_("-G, -S and --find-object are mutually exclusive"));
+
 	/*
 	 * Most of the time we can say "there are changes"
 	 * only by checking if there are changed paths, but
@@ -4175,7 +4174,7 @@ void diff_setup_done(struct diff_options *options)
 	/*
 	 * Also pickaxe would not work very well if you do not say recursive
 	 */
-	if (options->pickaxe)
+	if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
 		options->flags.recursive = 1;
 	/*
 	 * When patches are generated, submodules diffed against the work tree
@@ -4489,6 +4488,23 @@ static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *ar
 	return 1;
 }
 
+static int parse_objfind_opt(struct diff_options *opt, const char *arg)
+{
+	struct object_id oid;
+
+	if (get_oid(arg, &oid))
+		return error("unable to resolve '%s'", arg);
+
+	if (!opt->objfind)
+		opt->objfind = xcalloc(1, sizeof(*opt->objfind));
+
+	opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
+	opt->flags.recursive = 1;
+	opt->flags.tree_in_recursive = 1;
+	oidset_insert(opt->objfind, &oid);
+	return 1;
+}
+
 int diff_opt_parse(struct diff_options *options,
 		   const char **av, int ac, const char *prefix)
 {
@@ -4736,7 +4752,8 @@ int diff_opt_parse(struct diff_options *options,
 	else if ((argcount = short_opt('O', av, &optarg))) {
 		options->orderfile = prefix_filename(prefix, optarg);
 		return argcount;
-	}
+	} else if (skip_prefix(arg, "--find-object=", &arg))
+		return parse_objfind_opt(options, arg);
 	else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
 		int offending = parse_diff_filter_opt(optarg, options);
 		if (offending)
@@ -5454,6 +5471,7 @@ N_("you may want to set your %s variable to at least "
 
 void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
 {
+	fflush(stdout);
 	if (degraded_cc)
 		warning(_(degrade_cc_to_c_warning));
 	else if (needed)
@@ -5783,7 +5801,7 @@ void diffcore_std(struct diff_options *options)
 		if (options->break_opt != -1)
 			diffcore_merge_broken();
 	}
-	if (options->pickaxe)
+	if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
 		diffcore_pickaxe(options);
 	if (options->orderfile)
 		diffcore_order(options->orderfile);

diff --git a/diff.h b/diff.h
index 7cf276f..6bd278a 100644
--- a/diff.h
+++ b/diff.h

@@ -7,6 +7,7 @@
 #include "tree-walk.h"
 #include "pathspec.h"
 #include "object.h"
+#include "oidset.h"
 
 struct rev_info;
 struct diff_options;
@@ -91,7 +92,6 @@ struct diff_flags {
 	unsigned override_submodule_config:1;
 	unsigned dirstat_by_line:1;
 	unsigned funccontext:1;
-	unsigned pickaxe_ignore_case:1;
 	unsigned default_follow_renames:1;
 };
 
@@ -146,7 +146,7 @@ struct diff_options {
 	int skip_stat_unmatch;
 	int line_termination;
 	int output_format;
-	int pickaxe_opts;
+	unsigned pickaxe_opts;
 	int rename_score;
 	int rename_limit;
 	int needed_rename_limit;
@@ -178,6 +178,8 @@ struct diff_options {
 	enum diff_words_type word_diff;
 	enum diff_submodule_format submodule_format;
 
+	struct oidset *objfind;
+
 	/* this is set by diffcore for DIFF_FORMAT_PATCH */
 	int found_changes;
 
@@ -330,6 +332,13 @@ extern void diff_setup_done(struct diff_options *);
 
 #define DIFF_PICKAXE_KIND_S	4 /* traditional plumbing counter */
 #define DIFF_PICKAXE_KIND_G	8 /* grep in the patch */
+#define DIFF_PICKAXE_KIND_OBJFIND	16 /* specific object IDs */
+
+#define DIFF_PICKAXE_KINDS_MASK (DIFF_PICKAXE_KIND_S | \
+				 DIFF_PICKAXE_KIND_G | \
+				 DIFF_PICKAXE_KIND_OBJFIND)
+
+#define DIFF_PICKAXE_IGNORE_CASE	32
 
 extern void diffcore_std(struct diff_options *);
 extern void diffcore_fix_diff_index(struct diff_options *);

diff --git a/diffcore-pickaxe.c b/diffcore-pickaxe.c
index 9476bd2..239ce51 100644
--- a/diffcore-pickaxe.c
+++ b/diffcore-pickaxe.c

@@ -124,13 +124,20 @@ static int pickaxe_match(struct diff_filepair *p, struct diff_options *o,
 	mmfile_t mf1, mf2;
 	int ret;
 
-	if (!o->pickaxe[0])
-		return 0;
-
 	/* ignore unmerged */
 	if (!DIFF_FILE_VALID(p->one) && !DIFF_FILE_VALID(p->two))
 		return 0;
 
+	if (o->objfind) {
+		return  (DIFF_FILE_VALID(p->one) &&
+			 oidset_contains(o->objfind, &p->one->oid)) ||
+			(DIFF_FILE_VALID(p->two) &&
+			 oidset_contains(o->objfind, &p->two->oid));
+	}
+
+	if (!o->pickaxe[0])
+		return 0;
+
 	if (o->flags.allow_textconv) {
 		textconv_one = get_textconv(p->one);
 		textconv_two = get_textconv(p->two);
@@ -222,33 +229,34 @@ void diffcore_pickaxe(struct diff_options *o)
 
 	if (opts & (DIFF_PICKAXE_REGEX | DIFF_PICKAXE_KIND_G)) {
 		int cflags = REG_EXTENDED | REG_NEWLINE;
-		if (o->flags.pickaxe_ignore_case)
+		if (o->pickaxe_opts & DIFF_PICKAXE_IGNORE_CASE)
 			cflags |= REG_ICASE;
 		regcomp_or_die(&regex, needle, cflags);
 		regexp = &regex;
-	} else if (o->flags.pickaxe_ignore_case &&
-		   has_non_ascii(needle)) {
-		struct strbuf sb = STRBUF_INIT;
-		int cflags = REG_NEWLINE | REG_ICASE;
+	} else if (opts & DIFF_PICKAXE_KIND_S) {
+		if (o->pickaxe_opts & DIFF_PICKAXE_IGNORE_CASE &&
+		    has_non_ascii(needle)) {
+			struct strbuf sb = STRBUF_INIT;
+			int cflags = REG_NEWLINE | REG_ICASE;
 
-		basic_regex_quote_buf(&sb, needle);
-		regcomp_or_die(&regex, sb.buf, cflags);
-		strbuf_release(&sb);
-		regexp = &regex;
-	} else {
-		kws = kwsalloc(o->flags.pickaxe_ignore_case
-			       ? tolower_trans_tbl : NULL);
-		kwsincr(kws, needle, strlen(needle));
-		kwsprep(kws);
+			basic_regex_quote_buf(&sb, needle);
+			regcomp_or_die(&regex, sb.buf, cflags);
+			strbuf_release(&sb);
+			regexp = &regex;
+		} else {
+			kws = kwsalloc(o->pickaxe_opts & DIFF_PICKAXE_IGNORE_CASE
+				       ? tolower_trans_tbl : NULL);
+			kwsincr(kws, needle, strlen(needle));
+			kwsprep(kws);
+		}
 	}
 
-	/* Might want to warn when both S and G are on; I don't care... */
 	pickaxe(&diff_queued_diff, o, regexp, kws,
 		(opts & DIFF_PICKAXE_KIND_G) ? diff_grep : has_changes);
 
 	if (regexp)
 		regfree(regexp);
-	else
+	if (kws)
 		kwsfree(kws);
 	return;
 }

diff --git a/diffcore-rename.c b/diffcore-rename.c
index 245e999..0b7e498 100644
--- a/diffcore-rename.c
+++ b/diffcore-rename.c

@@ -57,8 +57,8 @@ static int add_rename_dst(struct diff_filespec *two)
 	ALLOC_GROW(rename_dst, rename_dst_nr + 1, rename_dst_alloc);
 	rename_dst_nr++;
 	if (first < rename_dst_nr)
-		memmove(rename_dst + first + 1, rename_dst + first,
-			(rename_dst_nr - first - 1) * sizeof(*rename_dst));
+		MOVE_ARRAY(rename_dst + first + 1, rename_dst + first,
+			   rename_dst_nr - first - 1);
 	rename_dst[first].two = alloc_filespec(two->path);
 	fill_filespec(rename_dst[first].two, &two->oid, two->oid_valid,
 		      two->mode);
@@ -98,8 +98,8 @@ static struct diff_rename_src *register_rename_src(struct diff_filepair *p)
 	ALLOC_GROW(rename_src, rename_src_nr + 1, rename_src_alloc);
 	rename_src_nr++;
 	if (first < rename_src_nr)
-		memmove(rename_src + first + 1, rename_src + first,
-			(rename_src_nr - first - 1) * sizeof(*rename_src));
+		MOVE_ARRAY(rename_src + first + 1, rename_src + first,
+			   rename_src_nr - first - 1);
 	rename_src[first].p = p;
 	rename_src[first].score = score;
 	return &(rename_src[first]);
@@ -260,8 +260,8 @@ static unsigned int hash_filespec(struct diff_filespec *filespec)
 	if (!filespec->oid_valid) {
 		if (diff_populate_filespec(filespec, 0))
 			return 0;
-		hash_sha1_file(filespec->data, filespec->size, "blob",
-			       filespec->oid.hash);
+		hash_object_file(filespec->data, filespec->size, "blob",
+				 &filespec->oid);
 	}
 	return sha1hash(filespec->oid.hash);
 }

diff --git a/dir.c b/dir.c
index 7c4b45e..536416f 100644
--- a/dir.c
+++ b/dir.c

@@ -231,12 +231,10 @@ int within_depth(const char *name, int namelen,
  *     1 along with { data, size } of the (possibly augmented) buffer
  *       when successful.
  *
- * Optionally updates the given sha1_stat with the given OID (when valid).
+ * Optionally updates the given oid_stat with the given OID (when valid).
  */
-static int do_read_blob(const struct object_id *oid,
-			struct sha1_stat *sha1_stat,
-			size_t *size_out,
-			char **data_out)
+static int do_read_blob(const struct object_id *oid, struct oid_stat *oid_stat,
+			size_t *size_out, char **data_out)
 {
 	enum object_type type;
 	unsigned long sz;
@@ -251,9 +249,9 @@ static int do_read_blob(const struct object_id *oid,
 		return -1;
 	}
 
-	if (sha1_stat) {
-		memset(&sha1_stat->stat, 0, sizeof(sha1_stat->stat));
-		hashcpy(sha1_stat->sha1, oid->hash);
+	if (oid_stat) {
+		memset(&oid_stat->stat, 0, sizeof(oid_stat->stat));
+		oidcpy(&oid_stat->oid, oid);
 	}
 
 	if (sz == 0) {
@@ -654,9 +652,8 @@ void add_exclude(const char *string, const char *base,
 
 static int read_skip_worktree_file_from_index(const struct index_state *istate,
 					      const char *path,
-					      size_t *size_out,
-					      char **data_out,
-					      struct sha1_stat *sha1_stat)
+					      size_t *size_out, char **data_out,
+					      struct oid_stat *oid_stat)
 {
 	int pos, len;
 
@@ -667,7 +664,7 @@ static int read_skip_worktree_file_from_index(const struct index_state *istate,
 	if (!ce_skip_worktree(istate->cache[pos]))
 		return -1;
 
-	return do_read_blob(&istate->cache[pos]->oid, sha1_stat, size_out, data_out);
+	return do_read_blob(&istate->cache[pos]->oid, oid_stat, size_out, data_out);
 }
 
 /*
@@ -747,8 +744,8 @@ static struct untracked_cache_dir *lookup_untracked(struct untracked_cache *uc,
 	FLEX_ALLOC_MEM(d, name, name, len);
 
 	ALLOC_GROW(dir->dirs, dir->dirs_nr + 1, dir->dirs_alloc);
-	memmove(dir->dirs + first + 1, dir->dirs + first,
-		(dir->dirs_nr - first) * sizeof(*dir->dirs));
+	MOVE_ARRAY(dir->dirs + first + 1, dir->dirs + first,
+		   dir->dirs_nr - first);
 	dir->dirs_nr++;
 	dir->dirs[first] = d;
 	return d;
@@ -795,9 +792,8 @@ static int add_excludes_from_buffer(char *buf, size_t size,
  * ss_valid is non-zero, "ss" must contain good value as input.
  */
 static int add_excludes(const char *fname, const char *base, int baselen,
-			struct exclude_list *el,
-			struct index_state *istate,
-			struct sha1_stat *sha1_stat)
+			struct exclude_list *el, struct index_state *istate,
+			struct oid_stat *oid_stat)
 {
 	struct stat st;
 	int r;
@@ -815,16 +811,16 @@ static int add_excludes(const char *fname, const char *base, int baselen,
 			return -1;
 		r = read_skip_worktree_file_from_index(istate, fname,
 						       &size, &buf,
-						       sha1_stat);
+						       oid_stat);
 		if (r != 1)
 			return r;
 	} else {
 		size = xsize_t(st.st_size);
 		if (size == 0) {
-			if (sha1_stat) {
-				fill_stat_data(&sha1_stat->stat, &st);
-				hashcpy(sha1_stat->sha1, EMPTY_BLOB_SHA1_BIN);
-				sha1_stat->valid = 1;
+			if (oid_stat) {
+				fill_stat_data(&oid_stat->stat, &st);
+				oidcpy(&oid_stat->oid, &empty_blob_oid);
+				oid_stat->valid = 1;
 			}
 			close(fd);
 			return 0;
@@ -837,22 +833,23 @@ static int add_excludes(const char *fname, const char *base, int baselen,
 		}
 		buf[size++] = '\n';
 		close(fd);
-		if (sha1_stat) {
+		if (oid_stat) {
 			int pos;
-			if (sha1_stat->valid &&
-			    !match_stat_data_racy(istate, &sha1_stat->stat, &st))
+			if (oid_stat->valid &&
+			    !match_stat_data_racy(istate, &oid_stat->stat, &st))
 				; /* no content change, ss->sha1 still good */
 			else if (istate &&
 				 (pos = index_name_pos(istate, fname, strlen(fname))) >= 0 &&
 				 !ce_stage(istate->cache[pos]) &&
 				 ce_uptodate(istate->cache[pos]) &&
 				 !would_convert_to_git(istate, fname))
-				hashcpy(sha1_stat->sha1,
-					istate->cache[pos]->oid.hash);
+				oidcpy(&oid_stat->oid,
+				       &istate->cache[pos]->oid);
 			else
-				hash_sha1_file(buf, size, "blob", sha1_stat->sha1);
-			fill_stat_data(&sha1_stat->stat, &st);
-			sha1_stat->valid = 1;
+				hash_object_file(buf, size, "blob",
+						 &oid_stat->oid);
+			fill_stat_data(&oid_stat->stat, &st);
+			oid_stat->valid = 1;
 		}
 	}
 
@@ -930,7 +927,7 @@ struct exclude_list *add_exclude_list(struct dir_struct *dir,
  * Used to set up core.excludesfile and .git/info/exclude lists.
  */
 static void add_excludes_from_file_1(struct dir_struct *dir, const char *fname,
-				     struct sha1_stat *sha1_stat)
+				     struct oid_stat *oid_stat)
 {
 	struct exclude_list *el;
 	/*
@@ -941,7 +938,7 @@ static void add_excludes_from_file_1(struct dir_struct *dir, const char *fname,
 	if (!dir->untracked)
 		dir->unmanaged_exclude_files++;
 	el = add_exclude_list(dir, EXC_FILE, fname);
-	if (add_excludes(fname, "", 0, el, NULL, sha1_stat) < 0)
+	if (add_excludes(fname, "", 0, el, NULL, oid_stat) < 0)
 		die("cannot use %s as an exclude file", fname);
 }
 
@@ -1180,7 +1177,7 @@ static void prep_exclude(struct dir_struct *dir,
 
 	while (current < baselen) {
 		const char *cp;
-		struct sha1_stat sha1_stat;
+		struct oid_stat oid_stat;
 
 		stk = xcalloc(1, sizeof(*stk));
 		if (current < 0) {
@@ -1223,8 +1220,8 @@ static void prep_exclude(struct dir_struct *dir,
 		}
 
 		/* Try to read per-directory file */
-		hashclr(sha1_stat.sha1);
-		sha1_stat.valid = 0;
+		oidclr(&oid_stat.oid);
+		oid_stat.valid = 0;
 		if (dir->exclude_per_dir &&
 		    /*
 		     * If we know that no files have been added in
@@ -1252,7 +1249,7 @@ static void prep_exclude(struct dir_struct *dir,
 			strbuf_addstr(&sb, dir->exclude_per_dir);
 			el->src = strbuf_detach(&sb, NULL);
 			add_excludes(el->src, el->src, stk->baselen, el, istate,
-				     untracked ? &sha1_stat : NULL);
+				     untracked ? &oid_stat : NULL);
 		}
 		/*
 		 * NEEDSWORK: when untracked cache is enabled, prep_exclude()
@@ -1269,9 +1266,9 @@ static void prep_exclude(struct dir_struct *dir,
 		 * order, though, if you do that.
 		 */
 		if (untracked &&
-		    hashcmp(sha1_stat.sha1, untracked->exclude_sha1)) {
+		    hashcmp(oid_stat.oid.hash, untracked->exclude_sha1)) {
 			invalidate_gitignore(dir->untracked, untracked);
-			hashcpy(untracked->exclude_sha1, sha1_stat.sha1);
+			hashcpy(untracked->exclude_sha1, oid_stat.oid.hash);
 		}
 		dir->exclude_stack = stk;
 		current = stk->baselen;
@@ -2228,13 +2225,13 @@ static struct untracked_cache_dir *validate_untracked_cache(struct dir_struct *d
 
 	/* Validate $GIT_DIR/info/exclude and core.excludesfile */
 	root = dir->untracked->root;
-	if (hashcmp(dir->ss_info_exclude.sha1,
-		    dir->untracked->ss_info_exclude.sha1)) {
+	if (oidcmp(&dir->ss_info_exclude.oid,
+		   &dir->untracked->ss_info_exclude.oid)) {
 		invalidate_gitignore(dir->untracked, root);
 		dir->untracked->ss_info_exclude = dir->ss_info_exclude;
 	}
-	if (hashcmp(dir->ss_excludes_file.sha1,
-		    dir->untracked->ss_excludes_file.sha1)) {
+	if (oidcmp(&dir->ss_excludes_file.oid,
+		   &dir->untracked->ss_excludes_file.oid)) {
 		invalidate_gitignore(dir->untracked, root);
 		dir->untracked->ss_excludes_file = dir->ss_excludes_file;
 	}
@@ -2248,6 +2245,7 @@ int read_directory(struct dir_struct *dir, struct index_state *istate,
 		   const char *path, int len, const struct pathspec *pathspec)
 {
 	struct untracked_cache_dir *untracked;
+	uint64_t start = getnanotime();
 
 	if (has_symlink_leading_path(path, len))
 		return dir->nr;
@@ -2286,6 +2284,7 @@ int read_directory(struct dir_struct *dir, struct index_state *istate,
 		dir->nr = i;
 	}
 
+	trace_performance_since(start, "read directory %.*s", len, path);
 	if (dir->untracked) {
 		static struct trace_key trace_untracked_stats = TRACE_KEY_INIT(UNTRACKED_STATS);
 		trace_printf_key(&trace_untracked_stats,
@@ -2638,8 +2637,8 @@ void write_untracked_extension(struct strbuf *out, struct untracked_cache *untra
 	FLEX_ALLOC_MEM(ouc, exclude_per_dir, untracked->exclude_per_dir, len);
 	stat_data_to_disk(&ouc->info_exclude_stat, &untracked->ss_info_exclude.stat);
 	stat_data_to_disk(&ouc->excludes_file_stat, &untracked->ss_excludes_file.stat);
-	hashcpy(ouc->info_exclude_sha1, untracked->ss_info_exclude.sha1);
-	hashcpy(ouc->excludes_file_sha1, untracked->ss_excludes_file.sha1);
+	hashcpy(ouc->info_exclude_sha1, untracked->ss_info_exclude.oid.hash);
+	hashcpy(ouc->excludes_file_sha1, untracked->ss_excludes_file.oid.hash);
 	ouc->dir_flags = htonl(untracked->dir_flags);
 
 	varint_len = encode_varint(untracked->ident.len, varbuf);
@@ -2816,13 +2815,12 @@ static void read_sha1(size_t pos, void *cb)
 	rd->data += 20;
 }
 
-static void load_sha1_stat(struct sha1_stat *sha1_stat,
-			   const unsigned char *data,
-			   const unsigned char *sha1)
+static void load_oid_stat(struct oid_stat *oid_stat, const unsigned char *data,
+			  const unsigned char *sha1)
 {
-	stat_data_from_disk(&sha1_stat->stat, data);
-	hashcpy(sha1_stat->sha1, sha1);
-	sha1_stat->valid = 1;
+	stat_data_from_disk(&oid_stat->stat, data);
+	hashcpy(oid_stat->oid.hash, sha1);
+	oid_stat->valid = 1;
 }
 
 struct untracked_cache *read_untracked_extension(const void *data, unsigned long sz)
@@ -2850,12 +2848,12 @@ struct untracked_cache *read_untracked_extension(const void *data, unsigned long
 	uc = xcalloc(1, sizeof(*uc));
 	strbuf_init(&uc->ident, ident_len);
 	strbuf_add(&uc->ident, ident, ident_len);
-	load_sha1_stat(&uc->ss_info_exclude,
-		       next + ouc_offset(info_exclude_stat),
-		       next + ouc_offset(info_exclude_sha1));
-	load_sha1_stat(&uc->ss_excludes_file,
-		       next + ouc_offset(excludes_file_stat),
-		       next + ouc_offset(excludes_file_sha1));
+	load_oid_stat(&uc->ss_info_exclude,
+		      next + ouc_offset(info_exclude_stat),
+		      next + ouc_offset(info_exclude_sha1));
+	load_oid_stat(&uc->ss_excludes_file,
+		      next + ouc_offset(excludes_file_stat),
+		      next + ouc_offset(excludes_file_sha1));
 	uc->dir_flags = get_be32(next + ouc_offset(dir_flags));
 	exclude_per_dir = (const char *)next + ouc_offset(exclude_per_dir);
 	uc->exclude_per_dir = xstrdup(exclude_per_dir);

diff --git a/dir.h b/dir.h
index 11a047b..e7bb786 100644
--- a/dir.h
+++ b/dir.h

@@ -74,9 +74,9 @@ struct exclude_list_group {
 	struct exclude_list *el;
 };
 
-struct sha1_stat {
+struct oid_stat {
 	struct stat_data stat;
-	unsigned char sha1[20];
+	struct object_id oid;
 	int valid;
 };
 
@@ -124,8 +124,8 @@ struct untracked_cache_dir {
 };
 
 struct untracked_cache {
-	struct sha1_stat ss_info_exclude;
-	struct sha1_stat ss_excludes_file;
+	struct oid_stat ss_info_exclude;
+	struct oid_stat ss_excludes_file;
 	const char *exclude_per_dir;
 	struct strbuf ident;
 	/*
@@ -195,8 +195,8 @@ struct dir_struct {
 
 	/* Enable untracked file cache if set */
 	struct untracked_cache *untracked;
-	struct sha1_stat ss_info_exclude;
-	struct sha1_stat ss_excludes_file;
+	struct oid_stat ss_info_exclude;
+	struct oid_stat ss_excludes_file;
 	unsigned unmanaged_exclude_files;
 };
 

diff --git a/environment.c b/environment.c
index 63ac38a..de8431e 100644
--- a/environment.c
+++ b/environment.c

@@ -27,6 +27,8 @@ int warn_ambiguous_refs = 1;
 int warn_on_object_refname_ambiguity = 1;
 int ref_paranoia = -1;
 int repository_format_precious_objects;
+char *repository_format_partial_clone;
+const char *core_partial_clone_filter_default;
 const char *git_commit_encoding;
 const char *git_log_output_encoding;
 const char *apply_default_whitespace;
@@ -49,7 +51,7 @@ enum auto_crlf auto_crlf = AUTO_CRLF_FALSE;
 int check_replace_refs = 1;
 char *git_replace_ref_base;
 enum eol core_eol = EOL_UNSET;
-enum safe_crlf safe_crlf = SAFE_CRLF_WARN;
+int global_conv_flags_eol = CONV_EOL_RNDTRP_WARN;
 unsigned whitespace_rule_cfg = WS_DEFAULT_RULE;
 enum branch_track git_branch_track = BRANCH_TRACK_REMOTE;
 enum rebase_setup_type autorebase = AUTOREBASE_NEVER;

diff --git a/fast-import.c b/fast-import.c
index b70ac02..0f818cd 100644
--- a/fast-import.c
+++ b/fast-import.c

@@ -316,7 +316,7 @@ static struct atom_str **atom_table;
 /* The .pack file being generated */
 static struct pack_idx_option pack_idx_opts;
 static unsigned int pack_id;
-static struct sha1file *pack_file;
+static struct hashfile *pack_file;
 static struct packed_git *pack_data;
 static struct packed_git **all_packs;
 static off_t pack_size;
@@ -905,12 +905,12 @@ static void start_packfile(void)
 
 	p->pack_fd = pack_fd;
 	p->do_not_close = 1;
-	pack_file = sha1fd(pack_fd, p->pack_name);
+	pack_file = hashfd(pack_fd, p->pack_name);
 
 	hdr.hdr_signature = htonl(PACK_SIGNATURE);
 	hdr.hdr_version = htonl(2);
 	hdr.hdr_entries = 0;
-	sha1write(pack_file, &hdr, sizeof(hdr));
+	hashwrite(pack_file, &hdr, sizeof(hdr));
 
 	pack_data = p;
 	pack_size = sizeof(hdr);
@@ -1016,7 +1016,7 @@ static void end_packfile(void)
 		struct tag *t;
 
 		close_pack_windows(pack_data);
-		sha1close(pack_file, cur_pack_oid.hash, 0);
+		hashclose(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);
@@ -1092,15 +1092,15 @@ static int store_object(
 	unsigned char hdr[96];
 	struct object_id oid;
 	unsigned long hdrlen, deltalen;
-	git_SHA_CTX c;
+	git_hash_ctx c;
 	git_zstream s;
 
 	hdrlen = xsnprintf((char *)hdr, sizeof(hdr), "%s %lu",
 			   typename(type), (unsigned long)dat->len) + 1;
-	git_SHA1_Init(&c);
-	git_SHA1_Update(&c, hdr, hdrlen);
-	git_SHA1_Update(&c, dat->buf, dat->len);
-	git_SHA1_Final(oid.hash, &c);
+	the_hash_algo->init_fn(&c);
+	the_hash_algo->update_fn(&c, hdr, hdrlen);
+	the_hash_algo->update_fn(&c, dat->buf, dat->len);
+	the_hash_algo->final_fn(oid.hash, &c);
 	if (oidout)
 		oidcpy(oidout, &oid);
 
@@ -1118,11 +1118,13 @@ static int store_object(
 		return 1;
 	}
 
-	if (last && last->data.buf && last->depth < max_depth && dat->len > 20) {
+	if (last && last->data.buf && last->depth < max_depth
+		&& dat->len > the_hash_algo->rawsz) {
+
 		delta_count_attempts_by_type[type]++;
 		delta = diff_delta(last->data.buf, last->data.len,
 			dat->buf, dat->len,
-			&deltalen, dat->len - 20);
+			&deltalen, dat->len - the_hash_algo->rawsz);
 	} else
 		delta = NULL;
 
@@ -1180,23 +1182,23 @@ static int store_object(
 
 		hdrlen = encode_in_pack_object_header(hdr, sizeof(hdr),
 						      OBJ_OFS_DELTA, deltalen);
-		sha1write(pack_file, hdr, hdrlen);
+		hashwrite(pack_file, hdr, hdrlen);
 		pack_size += hdrlen;
 
 		hdr[pos] = ofs & 127;
 		while (ofs >>= 7)
 			hdr[--pos] = 128 | (--ofs & 127);
-		sha1write(pack_file, hdr + pos, sizeof(hdr) - pos);
+		hashwrite(pack_file, hdr + pos, sizeof(hdr) - pos);
 		pack_size += sizeof(hdr) - pos;
 	} else {
 		e->depth = 0;
 		hdrlen = encode_in_pack_object_header(hdr, sizeof(hdr),
 						      type, dat->len);
-		sha1write(pack_file, hdr, hdrlen);
+		hashwrite(pack_file, hdr, hdrlen);
 		pack_size += hdrlen;
 	}
 
-	sha1write(pack_file, out, s.total_out);
+	hashwrite(pack_file, out, s.total_out);
 	pack_size += s.total_out;
 
 	e->idx.crc32 = crc32_end(pack_file);
@@ -1215,9 +1217,9 @@ static int store_object(
 	return 0;
 }
 
-static void truncate_pack(struct sha1file_checkpoint *checkpoint)
+static void truncate_pack(struct hashfile_checkpoint *checkpoint)
 {
-	if (sha1file_truncate(pack_file, checkpoint))
+	if (hashfile_truncate(pack_file, checkpoint))
 		die_errno("cannot truncate pack to skip duplicate");
 	pack_size = checkpoint->offset;
 }
@@ -1231,9 +1233,9 @@ static void stream_blob(uintmax_t len, struct object_id *oidout, uintmax_t mark)
 	struct object_id oid;
 	unsigned long hdrlen;
 	off_t offset;
-	git_SHA_CTX c;
+	git_hash_ctx c;
 	git_zstream s;
-	struct sha1file_checkpoint checkpoint;
+	struct hashfile_checkpoint checkpoint;
 	int status = Z_OK;
 
 	/* Determine if we should auto-checkpoint. */
@@ -1241,13 +1243,13 @@ static void stream_blob(uintmax_t len, struct object_id *oidout, uintmax_t mark)
 		|| (pack_size + 60 + len) < pack_size)
 		cycle_packfile();
 
-	sha1file_checkpoint(pack_file, &checkpoint);
+	hashfile_checkpoint(pack_file, &checkpoint);
 	offset = checkpoint.offset;
 
 	hdrlen = xsnprintf((char *)out_buf, out_sz, "blob %" PRIuMAX, len) + 1;
 
-	git_SHA1_Init(&c);
-	git_SHA1_Update(&c, out_buf, hdrlen);
+	the_hash_algo->init_fn(&c);
+	the_hash_algo->update_fn(&c, out_buf, hdrlen);
 
 	crc32_begin(pack_file);
 
@@ -1265,7 +1267,7 @@ static void stream_blob(uintmax_t len, struct object_id *oidout, uintmax_t mark)
 			if (!n && feof(stdin))
 				die("EOF in data (%" PRIuMAX " bytes remaining)", len);
 
-			git_SHA1_Update(&c, in_buf, n);
+			the_hash_algo->update_fn(&c, in_buf, n);
 			s.next_in = in_buf;
 			s.avail_in = n;
 			len -= n;
@@ -1275,7 +1277,7 @@ static void stream_blob(uintmax_t len, struct object_id *oidout, uintmax_t mark)
 
 		if (!s.avail_out || status == Z_STREAM_END) {
 			size_t n = s.next_out - out_buf;
-			sha1write(pack_file, out_buf, n);
+			hashwrite(pack_file, out_buf, n);
 			pack_size += n;
 			s.next_out = out_buf;
 			s.avail_out = out_sz;
@@ -1291,7 +1293,7 @@ static void stream_blob(uintmax_t len, struct object_id *oidout, uintmax_t mark)
 		}
 	}
 	git_deflate_end(&s);
-	git_SHA1_Final(oid.hash, &c);
+	the_hash_algo->final_fn(oid.hash, &c);
 
 	if (oidout)
 		oidcpy(oidout, &oid);
@@ -1350,25 +1352,25 @@ static void *gfi_unpack_entry(
 {
 	enum object_type type;
 	struct packed_git *p = all_packs[oe->pack_id];
-	if (p == pack_data && p->pack_size < (pack_size + 20)) {
+	if (p == pack_data && p->pack_size < (pack_size + the_hash_algo->rawsz)) {
 		/* The object is stored in the packfile we are writing to
 		 * and we have modified it since the last time we scanned
 		 * back to read a previously written object.  If an old
-		 * window covered [p->pack_size, p->pack_size + 20) its
+		 * window covered [p->pack_size, p->pack_size + rawsz) its
 		 * data is stale and is not valid.  Closing all windows
 		 * and updating the packfile length ensures we can read
 		 * the newly written data.
 		 */
 		close_pack_windows(p);
-		sha1flush(pack_file);
+		hashflush(pack_file);
 
-		/* We have to offer 20 bytes additional on the end of
+		/* We have to offer rawsz bytes additional on the end of
 		 * the packfile as the core unpacker code assumes the
 		 * footer is present at the file end and must promise
-		 * at least 20 bytes within any window it maps.  But
+		 * at least rawsz bytes within any window it maps.  But
 		 * we don't actually create the footer here.
 		 */
-		p->pack_size = pack_size + 20;
+		p->pack_size = pack_size + the_hash_algo->rawsz;
 	}
 	return unpack_entry(p, oe->idx.offset, &type, sizep);
 }
@@ -2204,7 +2206,7 @@ static void construct_path_with_fanout(const char *hex_sha1,
 		unsigned char fanout, char *path)
 {
 	unsigned int i = 0, j = 0;
-	if (fanout >= 20)
+	if (fanout >= the_hash_algo->rawsz)
 		die("Too large fanout (%u)", fanout);
 	while (fanout) {
 		path[i++] = hex_sha1[j++];
@@ -2212,8 +2214,8 @@ static void construct_path_with_fanout(const char *hex_sha1,
 		path[i++] = '/';
 		fanout--;
 	}
-	memcpy(path + i, hex_sha1 + j, GIT_SHA1_HEXSZ - j);
-	path[i + GIT_SHA1_HEXSZ - j] = '\0';
+	memcpy(path + i, hex_sha1 + j, the_hash_algo->hexsz - j);
+	path[i + the_hash_algo->hexsz - j] = '\0';
 }
 
 static uintmax_t do_change_note_fanout(

diff --git a/fetch-object.c b/fetch-object.c
new file mode 100644
index 0000000..853624f
--- /dev/null
+++ b/fetch-object.c

@@ -0,0 +1,45 @@
+#include "cache.h"
+#include "packfile.h"
+#include "pkt-line.h"
+#include "strbuf.h"
+#include "transport.h"
+#include "fetch-object.h"
+
+static void fetch_refs(const char *remote_name, struct ref *ref)
+{
+	struct remote *remote;
+	struct transport *transport;
+	int original_fetch_if_missing = fetch_if_missing;
+
+	fetch_if_missing = 0;
+	remote = remote_get(remote_name);
+	if (!remote->url[0])
+		die(_("Remote with no URL"));
+	transport = transport_get(remote, remote->url[0]);
+
+	transport_set_option(transport, TRANS_OPT_FROM_PROMISOR, "1");
+	transport_set_option(transport, TRANS_OPT_NO_DEPENDENTS, "1");
+	transport_fetch_refs(transport, ref);
+	fetch_if_missing = original_fetch_if_missing;
+}
+
+void fetch_object(const char *remote_name, const unsigned char *sha1)
+{
+	struct ref *ref = alloc_ref(sha1_to_hex(sha1));
+	hashcpy(ref->old_oid.hash, sha1);
+	fetch_refs(remote_name, ref);
+}
+
+void fetch_objects(const char *remote_name, const struct oid_array *to_fetch)
+{
+	struct ref *ref = NULL;
+	int i;
+
+	for (i = 0; i < to_fetch->nr; i++) {
+		struct ref *new_ref = alloc_ref(oid_to_hex(&to_fetch->oid[i]));
+		oidcpy(&new_ref->old_oid, &to_fetch->oid[i]);
+		new_ref->next = ref;
+		ref = new_ref;
+	}
+	fetch_refs(remote_name, ref);
+}

diff --git a/fetch-object.h b/fetch-object.h
new file mode 100644
index 0000000..4b269d0
--- /dev/null
+++ b/fetch-object.h

@@ -0,0 +1,11 @@
+#ifndef FETCH_OBJECT_H
+#define FETCH_OBJECT_H
+
+#include "sha1-array.h"
+
+extern void fetch_object(const char *remote_name, const unsigned char *sha1);
+
+extern void fetch_objects(const char *remote_name,
+			  const struct oid_array *to_fetch);
+
+#endif

diff --git a/fetch-pack.c b/fetch-pack.c
index 9f6b07a..8253d74 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c

@@ -29,6 +29,7 @@ static int deepen_not_ok;
 static int fetch_fsck_objects = -1;
 static int transfer_fsck_objects = -1;
 static int agent_supported;
+static int server_supports_filtering;
 static struct lock_file shallow_lock;
 static const char *alternate_shallow_file;
 
@@ -379,6 +380,8 @@ static int find_common(struct fetch_pack_args *args,
 			if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 			if (agent_supported)    strbuf_addf(&c, " agent=%s",
 							    git_user_agent_sanitized());
+			if (args->filter_options.choice)
+				strbuf_addstr(&c, " filter");
 			packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 			strbuf_release(&c);
 		} else
@@ -407,6 +410,9 @@ static int find_common(struct fetch_pack_args *args,
 			packet_buf_write(&req_buf, "deepen-not %s", s->string);
 		}
 	}
+	if (server_supports_filtering && args->filter_options.choice)
+		packet_buf_write(&req_buf, "filter %s",
+				 args->filter_options.filter_spec);
 	packet_buf_flush(&req_buf);
 	state_len = req_buf.len;
 
@@ -450,6 +456,8 @@ static int find_common(struct fetch_pack_args *args,
 
 	flushes = 0;
 	retval = -1;
+	if (args->no_dependents)
+		goto done;
 	while ((oid = get_rev())) {
 		packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
 		print_verbose(args, "have %s", oid_to_hex(oid));
@@ -709,6 +717,7 @@ static int everything_local(struct fetch_pack_args *args,
 {
 	struct ref *ref;
 	int retval;
+	int old_save_commit_buffer = save_commit_buffer;
 	timestamp_t cutoff = 0;
 
 	save_commit_buffer = 0;
@@ -735,29 +744,31 @@ static int everything_local(struct fetch_pack_args *args,
 		}
 	}
 
-	if (!args->deepen) {
-		for_each_ref(mark_complete_oid, NULL);
-		for_each_cached_alternate(mark_alternate_complete);
-		commit_list_sort_by_date(&complete);
-		if (cutoff)
-			mark_recent_complete_commits(args, cutoff);
-	}
+	if (!args->no_dependents) {
+		if (!args->deepen) {
+			for_each_ref(mark_complete_oid, NULL);
+			for_each_cached_alternate(mark_alternate_complete);
+			commit_list_sort_by_date(&complete);
+			if (cutoff)
+				mark_recent_complete_commits(args, cutoff);
+		}
 
-	/*
-	 * Mark all complete remote refs as common refs.
-	 * Don't mark them common yet; the server has to be told so first.
-	 */
-	for (ref = *refs; ref; ref = ref->next) {
-		struct object *o = deref_tag(lookup_object(ref->old_oid.hash),
-					     NULL, 0);
+		/*
+		 * Mark all complete remote refs as common refs.
+		 * Don't mark them common yet; the server has to be told so first.
+		 */
+		for (ref = *refs; ref; ref = ref->next) {
+			struct object *o = deref_tag(lookup_object(ref->old_oid.hash),
+						     NULL, 0);
 
-		if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
-			continue;
+			if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
+				continue;
 
-		if (!(o->flags & SEEN)) {
-			rev_list_push((struct commit *)o, COMMON_REF | SEEN);
+			if (!(o->flags & SEEN)) {
+				rev_list_push((struct commit *)o, COMMON_REF | SEEN);
 
-			mark_common((struct commit *)o, 1, 1);
+				mark_common((struct commit *)o, 1, 1);
+			}
 		}
 	}
 
@@ -777,6 +788,9 @@ static int everything_local(struct fetch_pack_args *args,
 		print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
 			      ref->name);
 	}
+
+	save_commit_buffer = old_save_commit_buffer;
+
 	return retval;
 }
 
@@ -833,7 +847,7 @@ static int get_pack(struct fetch_pack_args *args,
 		argv_array_push(&cmd.args, alternate_shallow_file);
 	}
 
-	if (do_keep) {
+	if (do_keep || args->from_promisor) {
 		if (pack_lockfile)
 			cmd.out = -1;
 		cmd_name = "index-pack";
@@ -843,7 +857,7 @@ static int get_pack(struct fetch_pack_args *args,
 			argv_array_push(&cmd.args, "-v");
 		if (args->use_thin_pack)
 			argv_array_push(&cmd.args, "--fix-thin");
-		if (args->lock_pack || unpack_limit) {
+		if (do_keep && (args->lock_pack || unpack_limit)) {
 			char hostname[HOST_NAME_MAX + 1];
 			if (xgethostname(hostname, sizeof(hostname)))
 				xsnprintf(hostname, sizeof(hostname), "localhost");
@@ -853,6 +867,8 @@ static int get_pack(struct fetch_pack_args *args,
 		}
 		if (args->check_self_contained_and_connected)
 			argv_array_push(&cmd.args, "--check-self-contained-and-connected");
+		if (args->from_promisor)
+			argv_array_push(&cmd.args, "--promisor");
 	}
 	else {
 		cmd_name = "unpack-objects";
@@ -964,6 +980,13 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 	else
 		prefer_ofs_delta = 0;
 
+	if (server_supports("filter")) {
+		server_supports_filtering = 1;
+		print_verbose(args, _("Server supports filter"));
+	} else if (args->filter_options.choice) {
+		warning("filtering not recognized by server, ignoring");
+	}
+
 	if ((agent_feature = server_feature_value("agent", &agent_len))) {
 		agent_supported = 1;
 		if (agent_len)

diff --git a/fetch-pack.h b/fetch-pack.h
index b6aeb43..3e224a1 100644
--- a/fetch-pack.h
+++ b/fetch-pack.h

@@ -3,6 +3,7 @@
 
 #include "string-list.h"
 #include "run-command.h"
+#include "list-objects-filter-options.h"
 
 struct oid_array;
 
@@ -12,6 +13,7 @@ struct fetch_pack_args {
 	int depth;
 	const char *deepen_since;
 	const struct string_list *deepen_not;
+	struct list_objects_filter_options filter_options;
 	unsigned deepen_relative:1;
 	unsigned quiet:1;
 	unsigned keep_pack:1;
@@ -29,6 +31,14 @@ struct fetch_pack_args {
 	unsigned cloning:1;
 	unsigned update_shallow:1;
 	unsigned deepen:1;
+	unsigned from_promisor:1;
+
+	/*
+	 * If 1, fetch_pack() will also not modify any object flags.
+	 * This allows fetch_pack() to safely be called by any function,
+	 * regardless of which object flags it uses (if any).
+	 */
+	unsigned no_dependents:1;
 };
 
 /*

diff --git a/git-add--interactive.perl b/git-add--interactive.perl
index 28b325d..964c3a7 100755
--- a/git-add--interactive.perl
+++ b/git-add--interactive.perl

@@ -262,7 +262,7 @@
 		}
 	}
 
-	for (run_cmd_pipe(qw(git diff-files --numstat --summary --raw --), @ARGV)) {
+	for (run_cmd_pipe(qw(git diff-files --ignore-submodules=dirty --numstat --summary --raw --), @ARGV)) {
 		if (($add, $del, $file) =
 		    /^([-\d]+)	([-\d]+)	(.*)/) {
 			$file = unquote_path($file);

diff --git a/git-rebase--am.sh b/git-rebase--am.sh
index 14c5078..0f78051 100644
--- a/git-rebase--am.sh
+++ b/git-rebase--am.sh

@@ -46,6 +46,7 @@
 	# 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

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index d47bd29..81c5b42 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh

@@ -281,7 +281,7 @@
 
 	test -d "$rewritten" &&
 		pick_one_preserving_merges "$@" && return
-	output eval git cherry-pick $allow_rerere_autoupdate \
+	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 $ff "$@"
 
@@ -406,6 +406,7 @@
 			;;
 		*)
 			output eval git cherry-pick $allow_rerere_autoupdate \
+				$allow_empty_message \
 				${gpg_sign_opt:+$(git rev-parse --sq-quote "$gpg_sign_opt")} \
 				"$strategy_args" "$@" ||
 				die_with_patch $sha1 "$(eval_gettext "Could not pick \$sha1")"
@@ -559,7 +560,8 @@
 
 		mark_action_done
 		do_pick $sha1 "$rest"
-		git commit --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} || {
+		git commit --amend --no-post-rewrite ${gpg_sign_opt:+"$gpg_sign_opt"} \
+			$allow_empty_message || {
 			warn "$(eval_gettext "\
 Could not amend commit after successfully picking \$sha1... \$rest
 This is most likely due to an empty commit message, or the pre-commit hook
@@ -607,7 +609,7 @@
 			# This is an intermediate commit; its message will only be
 			# used in case of trouble.  So use the long version:
 			do_with_author output git commit --amend --no-verify -F "$squash_msg" \
-				${gpg_sign_opt:+"$gpg_sign_opt"} ||
+				${gpg_sign_opt:+"$gpg_sign_opt"} $allow_empty_message ||
 				die_failed_squash $sha1 "$rest"
 			;;
 		*)
@@ -615,13 +617,13 @@
 			if test -f "$fixup_msg"
 			then
 				do_with_author git commit --amend --no-verify -F "$fixup_msg" \
-					${gpg_sign_opt:+"$gpg_sign_opt"} ||
+					${gpg_sign_opt:+"$gpg_sign_opt"} $allow_empty_message ||
 					die_failed_squash $sha1 "$rest"
 			else
 				cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
 				rm -f "$GIT_DIR"/MERGE_MSG
 				do_with_author git commit --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e \
-					${gpg_sign_opt:+"$gpg_sign_opt"} ||
+					${gpg_sign_opt:+"$gpg_sign_opt"} $allow_empty_message ||
 					die_failed_squash $sha1 "$rest"
 			fi
 			rm -f "$squash_msg" "$fixup_msg"
@@ -754,7 +756,8 @@
 continue)
 	if test ! -d "$rewritten"
 	then
-		exec git rebase--helper ${force_rebase:+--no-ff} --continue
+		exec git rebase--helper ${force_rebase:+--no-ff} $allow_empty_message \
+			--continue
 	fi
 	# do we have anything to commit?
 	if git diff-index --cached --quiet HEAD --
@@ -794,11 +797,11 @@
 You have uncommitted changes in your working tree. Please commit them
 first and then run 'git rebase --continue' again.")"
 			do_with_author git commit --amend --no-verify -F "$msg" -e \
-				${gpg_sign_opt:+"$gpg_sign_opt"} ||
+				${gpg_sign_opt:+"$gpg_sign_opt"} $allow_empty_message ||
 				die "$(gettext "Could not commit staged changes.")"
 		else
 			do_with_author git commit --no-verify -F "$msg" -e \
-				${gpg_sign_opt:+"$gpg_sign_opt"} ||
+				${gpg_sign_opt:+"$gpg_sign_opt"} $allow_empty_message ||
 				die "$(gettext "Could not commit staged changes.")"
 		fi
 	fi
@@ -817,7 +820,8 @@
 
 	if test ! -d "$rewritten"
 	then
-		exec git rebase--helper ${force_rebase:+--no-ff} --continue
+		exec git rebase--helper ${force_rebase:+--no-ff} $allow_empty_message \
+			--continue
 	fi
 	do_rest
 	return 0
@@ -1016,7 +1020,8 @@
 if test -z "$rebase_root" && test ! -d "$rewritten"
 then
 	require_clean_work_tree "rebase"
-	exec git rebase--helper ${force_rebase:+--no-ff} --continue
+	exec git rebase--helper ${force_rebase:+--no-ff} $allow_empty_message \
+		--continue
 fi
 do_rest
 

diff --git a/git-rebase--merge.sh b/git-rebase--merge.sh
index 06a4723..1831e58 100644
--- a/git-rebase--merge.sh
+++ b/git-rebase--merge.sh

@@ -27,7 +27,8 @@
 	cmt=$(cat "$state_dir/current")
 	if ! git diff-index --quiet --ignore-submodules HEAD --
 	then
-		if ! git commit ${gpg_sign_opt:+"$gpg_sign_opt"} --no-verify -C "$cmt"
+		if ! git commit ${gpg_sign_opt:+"$gpg_sign_opt"} $allow_empty_message \
+			--no-verify -C "$cmt"
 		then
 			echo "Commit failed, please do not call \"git commit\""
 			echo "directly, but instead do one of the following: "

diff --git a/git-rebase.sh b/git-rebase.sh
index fd72a35..b353c33 100755
--- a/git-rebase.sh
+++ b/git-rebase.sh

@@ -24,6 +24,7 @@
 i,interactive!     let the user edit the list of commits to rebase
 x,exec=!           add exec lines after each commit of the editable list
 k,keep-empty	   preserve empty commits during rebase
+allow-empty-message allow rebasing commits with empty messages
 f,force-rebase!    force rebase even if branch is up to date
 X,strategy-option=! pass the argument through to the merge strategy
 stat!              display a diffstat of what changed upstream
@@ -89,6 +90,7 @@
 preserve_merges=
 autosquash=
 keep_empty=
+allow_empty_message=
 test "$(git config --bool rebase.autosquash)" = "true" && autosquash=t
 case "$(git config --bool commit.gpgsign)" in
 true)	gpg_sign_opt=-S ;;
@@ -262,6 +264,9 @@
 	--keep-empty)
 		keep_empty=yes
 		;;
+	--allow-empty-message)
+		allow_empty_message=--allow-empty-message
+		;;
 	--preserve-merges)
 		preserve_merges=t
 		test -z "$interactive_rebase" && interactive_rebase=implied

diff --git a/git-send-email.perl b/git-send-email.perl
index edcc6d3..bbf4dea 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl

@@ -26,10 +26,11 @@
 use Term::ANSIColor;
 use File::Temp qw/ tempdir tempfile /;
 use File::Spec::Functions qw(catdir catfile);
-use Error qw(:try);
+use Git::Error qw(:try);
 use Cwd qw(abs_path cwd);
 use Git;
 use Git::I18N;
+use Git::Mail::Address;
 
 Getopt::Long::Configure qw/ pass_through /;
 
@@ -489,7 +490,7 @@
 ($repocommitter) = Git::ident_person(@repo, 'committer');
 
 sub parse_address_line {
-	return Git::parse_mailboxes($_[0]);
+	return map { $_->format } Mail::Address->parse($_[0]);
 }
 
 sub split_addrs {

diff --git a/git-stash.sh b/git-stash.sh
index 1114005..fc8f8ae 100755
--- a/git-stash.sh
+++ b/git-stash.sh

@@ -322,10 +322,9 @@
 
 		if test $# != 0
 		then
-			git reset -q -- "$@"
-			git ls-files -z --modified -- "$@" |
+			git add -u -- "$@" |
 			git checkout-index -z --force --stdin
-			git clean --force -q -d -- "$@"
+			git diff-index -p --cached --binary HEAD -- "$@" | git apply --index -R
 		else
 			git reset --hard -q
 		fi

diff --git a/git-submodule.sh b/git-submodule.sh
index 156255a..2491496 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh

@@ -428,60 +428,7 @@
 		shift
 	done
 
-	if test -n "$deinit_all" && test "$#" -ne 0
-	then
-		echo >&2 "$(eval_gettext "pathspec and --all are incompatible")"
-		usage
-	fi
-	if test $# = 0 && test -z "$deinit_all"
-	then
-		die "$(eval_gettext "Use '--all' if you really want to deinitialize all submodules")"
-	fi
-
-	{
-		git submodule--helper list --prefix "$wt_prefix" "$@" ||
-		echo "#unmatched" $?
-	} |
-	while read -r mode sha1 stage sm_path
-	do
-		die_if_unmatched "$mode" "$sha1"
-		name=$(git submodule--helper name "$sm_path") || exit
-
-		displaypath=$(git submodule--helper relative-path "$sm_path" "$wt_prefix")
-
-		# Remove the submodule work tree (unless the user already did it)
-		if test -d "$sm_path"
-		then
-			# Protect submodules containing a .git directory
-			if test -d "$sm_path/.git"
-			then
-				die "$(eval_gettext "\
-Submodule work tree '\$displaypath' contains a .git directory
-(use 'rm -rf' if you really want to remove it including all of its history)")"
-			fi
-
-			if test -z "$force"
-			then
-				git rm -qn "$sm_path" ||
-				die "$(eval_gettext "Submodule work tree '\$displaypath' contains local modifications; use '-f' to discard them")"
-			fi
-			rm -rf "$sm_path" &&
-			say "$(eval_gettext "Cleared directory '\$displaypath'")" ||
-			say "$(eval_gettext "Could not remove submodule work tree '\$displaypath'")"
-		fi
-
-		mkdir "$sm_path" || say "$(eval_gettext "Could not create empty submodule directory '\$displaypath'")"
-
-		# Remove the .git/config entries (unless the user already did it)
-		if test -n "$(git config --get-regexp submodule."$name\.")"
-		then
-			# Remove the whole section so we have a clean state when
-			# the user later decides to init this submodule again
-			url=$(git config submodule."$name".url)
-			git config --remove-section submodule."$name" 2>/dev/null &&
-			say "$(eval_gettext "Submodule '\$name' (\$url) unregistered for path '\$displaypath'")"
-		fi
-	done
+	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper deinit ${GIT_QUIET:+--quiet} ${prefix:+--prefix "$prefix"} ${force:+--force} ${deinit_all:+--all} "$@"
 }
 
 is_tip_reachable () (
@@ -1036,63 +983,8 @@
 			;;
 		esac
 	done
-	cd_to_toplevel
-	{
-		git submodule--helper list --prefix "$wt_prefix" "$@" ||
-		echo "#unmatched" $?
-	} |
-	while read -r mode sha1 stage sm_path
-	do
-		die_if_unmatched "$mode" "$sha1"
 
-		# skip inactive submodules
-		if ! git submodule--helper is-active "$sm_path"
-		then
-			continue
-		fi
-
-		name=$(git submodule--helper name "$sm_path")
-		url=$(git config -f .gitmodules --get submodule."$name".url)
-
-		# Possibly a url relative to parent
-		case "$url" in
-		./*|../*)
-			# rewrite foo/bar as ../.. to find path from
-			# submodule work tree to superproject work tree
-			up_path="$(printf '%s\n' "$sm_path" | sed "s/[^/][^/]*/../g")" &&
-			# guarantee a trailing /
-			up_path=${up_path%/}/ &&
-			# path from submodule work tree to submodule origin repo
-			sub_origin_url=$(git submodule--helper resolve-relative-url "$url" "$up_path") &&
-			# path from superproject work tree to submodule origin repo
-			super_config_url=$(git submodule--helper resolve-relative-url "$url") || exit
-			;;
-		*)
-			sub_origin_url="$url"
-			super_config_url="$url"
-			;;
-		esac
-
-		displaypath=$(git submodule--helper relative-path "$prefix$sm_path" "$wt_prefix")
-		say "$(eval_gettext "Synchronizing submodule url for '\$displaypath'")"
-		git config submodule."$name".url "$super_config_url"
-
-		if test -e "$sm_path"/.git
-		then
-		(
-			sanitize_submodule_env
-			cd "$sm_path"
-			remote=$(get_default_remote)
-			git config remote."$remote".url "$sub_origin_url"
-
-			if test -n "$recursive"
-			then
-				prefix="$prefix$sm_path/"
-				eval cmd_sync
-			fi
-		)
-		fi
-	done
+	git ${wt_prefix:+-C "$wt_prefix"} ${prefix:+--super-prefix "$prefix"} submodule--helper sync ${GIT_QUIET:+--quiet} ${recursive:+--recursive} "$@"
 }
 
 cmd_absorbgitdirs()

diff --git a/git-svn.perl b/git-svn.perl
index aa242d4..a6b6c3e 100755
--- a/git-svn.perl
+++ b/git-svn.perl

@@ -931,6 +931,7 @@
 		# information from different SVN repos, and paths
 		# which are not underneath this repository root.
 		my $rooturl = $gs->repos_root;
+	        Git::SVN::remove_username($rooturl);
 		foreach my $d (@$linear_refs) {
 			my %parentshash;
 			read_commit_parents(\%parentshash, $d);
@@ -1199,6 +1200,11 @@
 	$ctx->copy($src, $rev, $dst)
 		unless $_dry_run;
 
+	# Release resources held by ctx before creating another SVN::Ra
+	# so destruction is orderly.  This seems necessary with SVN 1.9.5
+	# to avoid segfaults.
+	$ctx = undef;
+
 	$gs->fetch_all;
 }
 

diff --git a/hash.h b/hash.h
index 7d7a864..7c8238b 100644
--- a/hash.h
+++ b/hash.h

@@ -15,6 +15,31 @@
 #include "block-sha1/sha1.h"
 #endif
 
+#ifndef platform_SHA_CTX
+/*
+ * platform's underlying implementation of SHA-1; could be OpenSSL,
+ * blk_SHA, Apple CommonCrypto, etc...  Note that the relevant
+ * SHA-1 header may have already defined platform_SHA_CTX for our
+ * own implementations like block-sha1 and ppc-sha1, so we list
+ * the default for OpenSSL compatible SHA-1 implementations here.
+ */
+#define platform_SHA_CTX	SHA_CTX
+#define platform_SHA1_Init	SHA1_Init
+#define platform_SHA1_Update	SHA1_Update
+#define platform_SHA1_Final    	SHA1_Final
+#endif
+
+#define git_SHA_CTX		platform_SHA_CTX
+#define git_SHA1_Init		platform_SHA1_Init
+#define git_SHA1_Update		platform_SHA1_Update
+#define git_SHA1_Final		platform_SHA1_Final
+
+#ifdef SHA1_MAX_BLOCK_SIZE
+#include "compat/sha1-chunked.h"
+#undef git_SHA1_Update
+#define git_SHA1_Update		git_SHA1_Update_Chunked
+#endif
+
 /*
  * Note that these constants are suitable for indexing the hash_algos array and
  * comparing against each other, but are otherwise arbitrary, so they should not
@@ -30,9 +55,15 @@
 /* Number of algorithms supported (including unknown). */
 #define GIT_HASH_NALGOS (GIT_HASH_SHA1 + 1)
 
-typedef void (*git_hash_init_fn)(void *ctx);
-typedef void (*git_hash_update_fn)(void *ctx, const void *in, size_t len);
-typedef void (*git_hash_final_fn)(unsigned char *hash, void *ctx);
+/* A suitably aligned type for stack allocations of hash contexts. */
+union git_hash_ctx {
+	git_SHA_CTX sha1;
+};
+typedef union git_hash_ctx git_hash_ctx;
+
+typedef void (*git_hash_init_fn)(git_hash_ctx *ctx);
+typedef void (*git_hash_update_fn)(git_hash_ctx *ctx, const void *in, size_t len);
+typedef void (*git_hash_final_fn)(unsigned char *hash, git_hash_ctx *ctx);
 
 struct git_hash_algo {
 	/*
@@ -44,9 +75,6 @@ struct git_hash_algo {
 	/* A four-byte version identifier, used in pack indices. */
 	uint32_t format_id;
 
-	/* The size of a hash context (e.g. git_SHA_CTX). */
-	size_t ctxsz;
-
 	/* The length of the hash in binary. */
 	size_t rawsz;
 

diff --git a/hashmap.h b/hashmap.h
index 7ce79f3..d375d9c 100644
--- a/hashmap.h
+++ b/hashmap.h

@@ -400,7 +400,6 @@ static inline void hashmap_disable_item_counting(struct hashmap *map)
  */
 static inline void hashmap_enable_item_counting(struct hashmap *map)
 {
-	void *item;
 	unsigned int n = 0;
 	struct hashmap_iter iter;
 
@@ -408,7 +407,7 @@ static inline void hashmap_enable_item_counting(struct hashmap *map)
 		return;
 
 	hashmap_iter_init(map, &iter);
-	while ((item = hashmap_iter_next(&iter)))
+	while (hashmap_iter_next(&iter))
 		n++;
 
 	map->do_count_items = 1;

diff --git a/http-push.c b/http-push.c
index 14435ab..0913f8a 100644
--- a/http-push.c
+++ b/http-push.c

@@ -915,6 +915,10 @@ static struct remote_lock *lock_remote(const char *path, long timeout)
 				lock->timeout = -1;
 			}
 			XML_ParserFree(parser);
+		} else {
+			fprintf(stderr,
+				"error: curl result=%d, HTTP code=%ld\n",
+				results.curl_result, results.http_code);
 		}
 	} else {
 		fprintf(stderr, "Unable to start LOCK request\n");

diff --git a/http-walker.c b/http-walker.c
index 1ae8363..07c2b1a 100644
--- a/http-walker.c
+++ b/http-walker.c

@@ -544,8 +544,10 @@ static int fetch_object(struct walker *walker, unsigned char *sha1)
 	} else if (hashcmp(obj_req->sha1, req->real_sha1)) {
 		ret = error("File %s has bad hash", hex);
 	} else if (req->rename < 0) {
-		ret = error("unable to write sha1 filename %s",
-			    sha1_file_name(req->sha1));
+		struct strbuf buf = STRBUF_INIT;
+		sha1_file_name(&buf, req->sha1);
+		ret = error("unable to write sha1 filename %s", buf.buf);
+		strbuf_release(&buf);
 	}
 
 	release_http_object_request(req);

diff --git a/http.c b/http.c
index 5977712..3175502 100644
--- a/http.c
+++ b/http.c

@@ -13,8 +13,11 @@
 #include "transport.h"
 #include "packfile.h"
 #include "protocol.h"
+#include "string-list.h"
 
 static struct trace_key trace_curl = TRACE_KEY_INIT(CURL);
+static int trace_curl_data = 1;
+static struct string_list cookies_to_redact = STRING_LIST_INIT_DUP;
 #if LIBCURL_VERSION_NUM >= 0x070a08
 long int git_curl_ipresolve = CURL_IPRESOLVE_WHATEVER;
 #else
@@ -575,6 +578,54 @@ static void redact_sensitive_header(struct strbuf *header)
 		/* Everything else is opaque and possibly sensitive */
 		strbuf_setlen(header,  sensitive_header - header->buf);
 		strbuf_addstr(header, " <redacted>");
+	} else if (cookies_to_redact.nr &&
+		   skip_prefix(header->buf, "Cookie:", &sensitive_header)) {
+		struct strbuf redacted_header = STRBUF_INIT;
+		char *cookie;
+
+		while (isspace(*sensitive_header))
+			sensitive_header++;
+
+		/*
+		 * The contents of header starting from sensitive_header will
+		 * subsequently be overridden, so it is fine to mutate this
+		 * string (hence the assignment to "char *").
+		 */
+		cookie = (char *) sensitive_header;
+
+		while (cookie) {
+			char *equals;
+			char *semicolon = strstr(cookie, "; ");
+			if (semicolon)
+				*semicolon = 0;
+			equals = strchrnul(cookie, '=');
+			if (!equals) {
+				/* invalid cookie, just append and continue */
+				strbuf_addstr(&redacted_header, cookie);
+				continue;
+			}
+			*equals = 0; /* temporarily set to NUL for lookup */
+			if (string_list_lookup(&cookies_to_redact, cookie)) {
+				strbuf_addstr(&redacted_header, cookie);
+				strbuf_addstr(&redacted_header, "=<redacted>");
+			} else {
+				*equals = '=';
+				strbuf_addstr(&redacted_header, cookie);
+			}
+			if (semicolon) {
+				/*
+				 * There are more cookies. (Or, for some
+				 * reason, the input string ends in "; ".)
+				 */
+				strbuf_addstr(&redacted_header, "; ");
+				cookie = semicolon + strlen("; ");
+			} else {
+				cookie = NULL;
+			}
+		}
+
+		strbuf_setlen(header, sensitive_header - header->buf);
+		strbuf_addbuf(header, &redacted_header);
 	}
 }
 
@@ -645,24 +696,32 @@ static int curl_trace(CURL *handle, curl_infotype type, char *data, size_t size,
 		curl_dump_header(text, (unsigned char *)data, size, DO_FILTER);
 		break;
 	case CURLINFO_DATA_OUT:
-		text = "=> Send data";
-		curl_dump_data(text, (unsigned char *)data, size);
+		if (trace_curl_data) {
+			text = "=> Send data";
+			curl_dump_data(text, (unsigned char *)data, size);
+		}
 		break;
 	case CURLINFO_SSL_DATA_OUT:
-		text = "=> Send SSL data";
-		curl_dump_data(text, (unsigned char *)data, size);
+		if (trace_curl_data) {
+			text = "=> Send SSL data";
+			curl_dump_data(text, (unsigned char *)data, size);
+		}
 		break;
 	case CURLINFO_HEADER_IN:
 		text = "<= Recv header";
 		curl_dump_header(text, (unsigned char *)data, size, NO_FILTER);
 		break;
 	case CURLINFO_DATA_IN:
-		text = "<= Recv data";
-		curl_dump_data(text, (unsigned char *)data, size);
+		if (trace_curl_data) {
+			text = "<= Recv data";
+			curl_dump_data(text, (unsigned char *)data, size);
+		}
 		break;
 	case CURLINFO_SSL_DATA_IN:
-		text = "<= Recv SSL data";
-		curl_dump_data(text, (unsigned char *)data, size);
+		if (trace_curl_data) {
+			text = "<= Recv SSL data";
+			curl_dump_data(text, (unsigned char *)data, size);
+		}
 		break;
 
 	default:		/* we ignore unknown types by default */
@@ -807,6 +866,13 @@ static CURL *get_curl_handle(void)
 	if (getenv("GIT_CURL_VERBOSE"))
 		curl_easy_setopt(result, CURLOPT_VERBOSE, 1L);
 	setup_curl_trace(result);
+	if (getenv("GIT_TRACE_CURL_NO_DATA"))
+		trace_curl_data = 0;
+	if (getenv("GIT_REDACT_COOKIES")) {
+		string_list_split(&cookies_to_redact,
+				  getenv("GIT_REDACT_COOKIES"), ',', -1);
+		string_list_sort(&cookies_to_redact);
+	}
 
 	curl_easy_setopt(result, CURLOPT_USERAGENT,
 		user_agent ? user_agent : git_user_agent());
@@ -2168,7 +2234,7 @@ struct http_object_request *new_http_object_request(const char *base_url,
 	unsigned char *sha1)
 {
 	char *hex = sha1_to_hex(sha1);
-	const char *filename;
+	struct strbuf filename = STRBUF_INIT;
 	char prevfile[PATH_MAX];
 	int prevlocal;
 	char prev_buf[PREV_BUF_SIZE];
@@ -2180,14 +2246,15 @@ struct http_object_request *new_http_object_request(const char *base_url,
 	hashcpy(freq->sha1, sha1);
 	freq->localfile = -1;
 
-	filename = sha1_file_name(sha1);
+	sha1_file_name(&filename, sha1);
 	snprintf(freq->tmpfile, sizeof(freq->tmpfile),
-		 "%s.temp", filename);
+		 "%s.temp", filename.buf);
 
-	snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
+	snprintf(prevfile, sizeof(prevfile), "%s.prev", filename.buf);
 	unlink_or_warn(prevfile);
 	rename(freq->tmpfile, prevfile);
 	unlink_or_warn(freq->tmpfile);
+	strbuf_release(&filename);
 
 	if (freq->localfile != -1)
 		error("fd leakage in start: %d", freq->localfile);
@@ -2302,6 +2369,7 @@ void process_http_object_request(struct http_object_request *freq)
 int finish_http_object_request(struct http_object_request *freq)
 {
 	struct stat st;
+	struct strbuf filename = STRBUF_INIT;
 
 	close(freq->localfile);
 	freq->localfile = -1;
@@ -2327,8 +2395,10 @@ int finish_http_object_request(struct http_object_request *freq)
 		unlink_or_warn(freq->tmpfile);
 		return -1;
 	}
-	freq->rename =
-		finalize_object_file(freq->tmpfile, sha1_file_name(freq->sha1));
+
+	sha1_file_name(&filename, freq->sha1);
+	freq->rename = finalize_object_file(freq->tmpfile, filename.buf);
+	strbuf_release(&filename);
 
 	return freq->rename;
 }

diff --git a/list-objects-filter-options.c b/list-objects-filter-options.c
index 4c5b34e..6a3cc98 100644
--- a/list-objects-filter-options.c
+++ b/list-objects-filter-options.c

@@ -21,29 +21,36 @@
  * subordinate commands when necessary.  We also "intern" the arg for
  * the convenience of the current command.
  */
-int parse_list_objects_filter(struct list_objects_filter_options *filter_options,
-			      const char *arg)
+static int gently_parse_list_objects_filter(
+	struct list_objects_filter_options *filter_options,
+	const char *arg,
+	struct strbuf *errbuf)
 {
 	const char *v0;
 
-	if (filter_options->choice)
-		die(_("multiple object filter types cannot be combined"));
+	if (filter_options->choice) {
+		if (errbuf) {
+			strbuf_init(errbuf, 0);
+			strbuf_addstr(
+				errbuf,
+				_("multiple filter-specs cannot be combined"));
+		}
+		return 1;
+	}
 
 	filter_options->filter_spec = strdup(arg);
 
 	if (!strcmp(arg, "blob:none")) {
 		filter_options->choice = LOFC_BLOB_NONE;
 		return 0;
-	}
 
-	if (skip_prefix(arg, "blob:limit=", &v0)) {
-		if (!git_parse_ulong(v0, &filter_options->blob_limit_value))
-			die(_("invalid filter-spec expression '%s'"), arg);
-		filter_options->choice = LOFC_BLOB_LIMIT;
-		return 0;
-	}
+	} else if (skip_prefix(arg, "blob:limit=", &v0)) {
+		if (git_parse_ulong(v0, &filter_options->blob_limit_value)) {
+			filter_options->choice = LOFC_BLOB_LIMIT;
+			return 0;
+		}
 
-	if (skip_prefix(arg, "sparse:oid=", &v0)) {
+	} else if (skip_prefix(arg, "sparse:oid=", &v0)) {
 		struct object_context oc;
 		struct object_id sparse_oid;
 
@@ -57,15 +64,27 @@ int parse_list_objects_filter(struct list_objects_filter_options *filter_options
 			filter_options->sparse_oid_value = oiddup(&sparse_oid);
 		filter_options->choice = LOFC_SPARSE_OID;
 		return 0;
-	}
 
-	if (skip_prefix(arg, "sparse:path=", &v0)) {
+	} else if (skip_prefix(arg, "sparse:path=", &v0)) {
 		filter_options->choice = LOFC_SPARSE_PATH;
 		filter_options->sparse_path_value = strdup(v0);
 		return 0;
 	}
 
-	die(_("invalid filter-spec expression '%s'"), arg);
+	if (errbuf) {
+		strbuf_init(errbuf, 0);
+		strbuf_addf(errbuf, "invalid filter-spec '%s'", arg);
+	}
+	memset(filter_options, 0, sizeof(*filter_options));
+	return 1;
+}
+
+int parse_list_objects_filter(struct list_objects_filter_options *filter_options,
+			      const char *arg)
+{
+	struct strbuf buf = STRBUF_INIT;
+	if (gently_parse_list_objects_filter(filter_options, arg, &buf))
+		die("%s", buf.buf);
 	return 0;
 }
 
@@ -75,7 +94,7 @@ int opt_parse_list_objects_filter(const struct option *opt,
 	struct list_objects_filter_options *filter_options = opt->value;
 
 	if (unset || !arg) {
-		list_objects_filter_release(filter_options);
+		list_objects_filter_set_no_filter(filter_options);
 		return 0;
 	}
 
@@ -90,3 +109,44 @@ void list_objects_filter_release(
 	free(filter_options->sparse_path_value);
 	memset(filter_options, 0, sizeof(*filter_options));
 }
+
+void partial_clone_register(
+	const char *remote,
+	const struct list_objects_filter_options *filter_options)
+{
+	/*
+	 * Record the name of the partial clone remote in the
+	 * config and in the global variable -- the latter is
+	 * used throughout to indicate that partial clone is
+	 * enabled and to expect missing objects.
+	 */
+	if (repository_format_partial_clone &&
+	    *repository_format_partial_clone &&
+	    strcmp(remote, repository_format_partial_clone))
+		die(_("cannot change partial clone promisor remote"));
+
+	git_config_set("core.repositoryformatversion", "1");
+	git_config_set("extensions.partialclone", remote);
+
+	repository_format_partial_clone = xstrdup(remote);
+
+	/*
+	 * Record the initial filter-spec in the config as
+	 * the default for subsequent fetches from this remote.
+	 */
+	core_partial_clone_filter_default =
+		xstrdup(filter_options->filter_spec);
+	git_config_set("core.partialclonefilter",
+		       core_partial_clone_filter_default);
+}
+
+void partial_clone_get_default_filter_spec(
+	struct list_objects_filter_options *filter_options)
+{
+	/*
+	 * Parse default value, but silently ignore it if it is invalid.
+	 */
+	gently_parse_list_objects_filter(filter_options,
+					 core_partial_clone_filter_default,
+					 NULL);
+}

diff --git a/list-objects-filter-options.h b/list-objects-filter-options.h
index eea44a1..0000a61 100644
--- a/list-objects-filter-options.h
+++ b/list-objects-filter-options.h

@@ -31,6 +31,11 @@ struct list_objects_filter_options {
 	enum list_objects_filter_choice choice;
 
 	/*
+	 * Choice is LOFC_DISABLED because "--no-filter" was requested.
+	 */
+	unsigned int no_filter : 1;
+
+	/*
 	 * Parsed values (fields) from within the filter-spec.  These are
 	 * choice-specific; not all values will be defined for any given
 	 * choice.
@@ -58,4 +63,17 @@ int opt_parse_list_objects_filter(const struct option *opt,
 void list_objects_filter_release(
 	struct list_objects_filter_options *filter_options);
 
+static inline void list_objects_filter_set_no_filter(
+	struct list_objects_filter_options *filter_options)
+{
+	list_objects_filter_release(filter_options);
+	filter_options->no_filter = 1;
+}
+
+void partial_clone_register(
+	const char *remote,
+	const struct list_objects_filter_options *filter_options);
+void partial_clone_get_default_filter_spec(
+	struct list_objects_filter_options *filter_options);
+
 #endif /* LIST_OBJECTS_FILTER_OPTIONS_H */

diff --git a/list-objects.c b/list-objects.c
index 0966cdc..168bef6 100644
--- a/list-objects.c
+++ b/list-objects.c

@@ -9,6 +9,7 @@
 #include "list-objects.h"
 #include "list-objects-filter.h"
 #include "list-objects-filter-options.h"
+#include "packfile.h"
 
 static void process_blob(struct rev_info *revs,
 			 struct blob *blob,
@@ -30,6 +31,20 @@ static void process_blob(struct rev_info *revs,
 	if (obj->flags & (UNINTERESTING | SEEN))
 		return;
 
+	/*
+	 * Pre-filter known-missing objects when explicitly requested.
+	 * Otherwise, a missing object error message may be reported
+	 * later (depending on other filtering criteria).
+	 *
+	 * Note that this "--exclude-promisor-objects" pre-filtering
+	 * may cause the actual filter to report an incomplete list
+	 * of missing objects.
+	 */
+	if (revs->exclude_promisor_objects &&
+	    !has_object_file(&obj->oid) &&
+	    is_promisor_object(&obj->oid))
+		return;
+
 	pathlen = path->len;
 	strbuf_addstr(path, name);
 	if (filter_fn)
@@ -91,6 +106,8 @@ static void process_tree(struct rev_info *revs,
 		all_entries_interesting: entry_not_interesting;
 	int baselen = base->len;
 	enum list_objects_filter_result r = LOFR_MARK_SEEN | LOFR_DO_SHOW;
+	int gently = revs->ignore_missing_links ||
+		     revs->exclude_promisor_objects;
 
 	if (!revs->tree_objects)
 		return;
@@ -98,9 +115,19 @@ static void process_tree(struct rev_info *revs,
 		die("bad tree object");
 	if (obj->flags & (UNINTERESTING | SEEN))
 		return;
-	if (parse_tree_gently(tree, revs->ignore_missing_links) < 0) {
+	if (parse_tree_gently(tree, gently) < 0) {
 		if (revs->ignore_missing_links)
 			return;
+
+		/*
+		 * Pre-filter known-missing tree objects when explicitly
+		 * requested.  This may cause the actual filter to report
+		 * an incomplete list of missing objects.
+		 */
+		if (revs->exclude_promisor_objects &&
+		    is_promisor_object(&obj->oid))
+			return;
+
 		die("bad tree object %s", oid_to_hex(&obj->oid));
 	}
 

diff --git a/log-tree.c b/log-tree.c
index fca29d4..fc0cc0d 100644
--- a/log-tree.c
+++ b/log-tree.c

@@ -499,7 +499,7 @@ static void show_one_mergetag(struct commit *commit,
 	int status, nth;
 	size_t payload_size, gpg_message_offset;
 
-	hash_sha1_file(extra->value, extra->len, typename(OBJ_TAG), oid.hash);
+	hash_object_file(extra->value, extra->len, typename(OBJ_TAG), &oid);
 	tag = lookup_tag(&oid);
 	if (!tag)
 		return; /* error message already given */

diff --git a/mailinfo.c b/mailinfo.c
index a89db22..d04142c 100644
--- a/mailinfo.c
+++ b/mailinfo.c

@@ -1167,11 +1167,13 @@ void clear_mailinfo(struct mailinfo *mi)
 	strbuf_release(&mi->inbody_header_accum);
 	free(mi->message_id);
 
-	for (i = 0; mi->p_hdr_data[i]; i++)
-		strbuf_release(mi->p_hdr_data[i]);
+	if (mi->p_hdr_data)
+		for (i = 0; mi->p_hdr_data[i]; i++)
+			strbuf_release(mi->p_hdr_data[i]);
 	free(mi->p_hdr_data);
-	for (i = 0; mi->s_hdr_data[i]; i++)
-		strbuf_release(mi->s_hdr_data[i]);
+	if (mi->s_hdr_data)
+		for (i = 0; mi->s_hdr_data[i]; i++)
+			strbuf_release(mi->s_hdr_data[i]);
 	free(mi->s_hdr_data);
 
 	while (mi->content < mi->content_top) {

diff --git a/match-trees.c b/match-trees.c
index 396b733..0ca99d5 100644
--- a/match-trees.c
+++ b/match-trees.c

@@ -158,22 +158,20 @@ static void match_trees(const struct object_id *hash1,
 }
 
 /*
- * A tree "hash1" has a subdirectory at "prefix".  Come up with a
- * tree object by replacing it with another tree "hash2".
+ * A tree "oid1" has a subdirectory at "prefix".  Come up with a tree object by
+ * replacing it with another tree "oid2".
  */
-static int splice_tree(const unsigned char *hash1,
-		       const char *prefix,
-		       const unsigned char *hash2,
-		       unsigned char *result)
+static int splice_tree(const struct object_id *oid1, const char *prefix,
+		       const struct object_id *oid2, struct object_id *result)
 {
 	char *subpath;
 	int toplen;
 	char *buf;
 	unsigned long sz;
 	struct tree_desc desc;
-	unsigned char *rewrite_here;
-	const unsigned char *rewrite_with;
-	unsigned char subtree[20];
+	struct object_id *rewrite_here;
+	const struct object_id *rewrite_with;
+	struct object_id subtree;
 	enum object_type type;
 	int status;
 
@@ -182,9 +180,9 @@ static int splice_tree(const unsigned char *hash1,
 	if (*subpath)
 		subpath++;
 
-	buf = read_sha1_file(hash1, &type, &sz);
+	buf = read_sha1_file(oid1->hash, &type, &sz);
 	if (!buf)
-		die("cannot read tree %s", sha1_to_hex(hash1));
+		die("cannot read tree %s", oid_to_hex(oid1));
 	init_tree_desc(&desc, buf, sz);
 
 	rewrite_here = NULL;
@@ -197,26 +195,26 @@ static int splice_tree(const unsigned char *hash1,
 		if (strlen(name) == toplen &&
 		    !memcmp(name, prefix, toplen)) {
 			if (!S_ISDIR(mode))
-				die("entry %s in tree %s is not a tree",
-				    name, sha1_to_hex(hash1));
-			rewrite_here = (unsigned char *) oid->hash;
+				die("entry %s in tree %s is not a tree", name,
+				    oid_to_hex(oid1));
+			rewrite_here = (struct object_id *)oid;
 			break;
 		}
 		update_tree_entry(&desc);
 	}
 	if (!rewrite_here)
-		die("entry %.*s not found in tree %s",
-		    toplen, prefix, sha1_to_hex(hash1));
+		die("entry %.*s not found in tree %s", toplen, prefix,
+		    oid_to_hex(oid1));
 	if (*subpath) {
-		status = splice_tree(rewrite_here, subpath, hash2, subtree);
+		status = splice_tree(rewrite_here, subpath, oid2, &subtree);
 		if (status)
 			return status;
-		rewrite_with = subtree;
+		rewrite_with = &subtree;
+	} else {
+		rewrite_with = oid2;
 	}
-	else
-		rewrite_with = hash2;
-	hashcpy(rewrite_here, rewrite_with);
-	status = write_sha1_file(buf, sz, tree_type, result);
+	oidcpy(rewrite_here, rewrite_with);
+	status = write_object_file(buf, sz, tree_type, result);
 	free(buf);
 	return status;
 }
@@ -280,7 +278,7 @@ void shift_tree(const struct object_id *hash1,
 	if (!*add_prefix)
 		return;
 
-	splice_tree(hash1->hash, add_prefix, hash2->hash, shifted->hash);
+	splice_tree(hash1, add_prefix, hash2, shifted);
 }
 
 /*
@@ -334,7 +332,7 @@ void shift_tree_by(const struct object_id *hash1,
 		 * shift tree2 down by adding shift_prefix above it
 		 * to match tree1.
 		 */
-		splice_tree(hash1->hash, shift_prefix, hash2->hash, shifted->hash);
+		splice_tree(hash1, shift_prefix, hash2, shifted);
 	else
 		/*
 		 * shift tree2 up by removing shift_prefix from it

diff --git a/merge-recursive.c b/merge-recursive.c
index 0fc580d..6ff971f 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c

@@ -513,6 +513,25 @@ static void record_df_conflict_files(struct merge_options *o,
 
 struct rename {
 	struct diff_filepair *pair;
+	/*
+	 * Purpose of src_entry and dst_entry:
+	 *
+	 * If 'before' is renamed to 'after' then src_entry will contain
+	 * the versions of 'before' from the merge_base, HEAD, and MERGE in
+	 * stages 1, 2, and 3; dst_entry will contain the respective
+	 * versions of 'after' in corresponding locations.  Thus, we have a
+	 * total of six modes and oids, though some will be null.  (Stage 0
+	 * is ignored; we're interested in handling conflicts.)
+	 *
+	 * Since we don't turn on break-rewrites by default, neither
+	 * src_entry nor dst_entry can have all three of their stages have
+	 * non-null oids, meaning at most four of the six will be non-null.
+	 * Also, since this is a rename, both src_entry and dst_entry will
+	 * have at least one non-null oid, meaning at least two will be
+	 * non-null.  Of the six oids, a typical rename will have three be
+	 * non-null.  Only two implies a rename/delete, and four implies a
+	 * rename/add.
+	 */
 	struct stage_data *src_entry;
 	struct stage_data *dst_entry;
 	unsigned processed:1;
@@ -1009,8 +1028,9 @@ static int merge_file_1(struct merge_options *o,
 			if ((merge_status < 0) || !result_buf.ptr)
 				ret = err(o, _("Failed to execute internal merge"));
 
-			if (!ret && write_sha1_file(result_buf.ptr, result_buf.size,
-						    blob_type, result->oid.hash))
+			if (!ret &&
+			    write_object_file(result_buf.ptr, result_buf.size,
+					      blob_type, &result->oid))
 				ret = err(o, _("Unable to add %s to database"),
 					  a->path);
 
@@ -1026,10 +1046,19 @@ static int merge_file_1(struct merge_options *o,
 						       &b->oid,
 						       !o->call_depth);
 		} else if (S_ISLNK(a->mode)) {
-			oidcpy(&result->oid, &a->oid);
-
-			if (!oid_eq(&a->oid, &b->oid))
-				result->clean = 0;
+			switch (o->recursive_variant) {
+			case MERGE_RECURSIVE_NORMAL:
+				oidcpy(&result->oid, &a->oid);
+				if (!oid_eq(&a->oid, &b->oid))
+					result->clean = 0;
+				break;
+			case MERGE_RECURSIVE_OURS:
+				oidcpy(&result->oid, &a->oid);
+				break;
+			case MERGE_RECURSIVE_THEIRS:
+				oidcpy(&result->oid, &b->oid);
+				break;
+			}
 		} else
 			die("BUG: unsupported object type in the tree");
 	}
@@ -1989,10 +2018,10 @@ int merge_trees(struct merge_options *o,
 		get_files_dirs(o, merge);
 
 		entries = get_unmerged();
-		record_df_conflict_files(o, entries);
 		re_head  = get_renames(o, head, common, head, merge, entries);
 		re_merge = get_renames(o, merge, common, head, merge, entries);
 		clean = process_renames(o, re_head, re_merge);
+		record_df_conflict_files(o, entries);
 		if (clean < 0)
 			goto cleanup;
 		for (i = entries->nr-1; 0 <= i; i--) {

diff --git a/mru.c b/mru.c
deleted file mode 100644
index 9dedae0..0000000
--- a/mru.c
+++ /dev/null

@@ -1,50 +0,0 @@
-#include "cache.h"
-#include "mru.h"
-
-void mru_append(struct mru *mru, void *item)
-{
-	struct mru_entry *cur = xmalloc(sizeof(*cur));
-	cur->item = item;
-	cur->prev = mru->tail;
-	cur->next = NULL;
-
-	if (mru->tail)
-		mru->tail->next = cur;
-	else
-		mru->head = cur;
-	mru->tail = cur;
-}
-
-void mru_mark(struct mru *mru, struct mru_entry *entry)
-{
-	/* If we're already at the front of the list, nothing to do */
-	if (mru->head == entry)
-		return;
-
-	/* Otherwise, remove us from our current slot... */
-	if (entry->prev)
-		entry->prev->next = entry->next;
-	if (entry->next)
-		entry->next->prev = entry->prev;
-	else
-		mru->tail = entry->prev;
-
-	/* And insert us at the beginning. */
-	entry->prev = NULL;
-	entry->next = mru->head;
-	if (mru->head)
-		mru->head->prev = entry;
-	mru->head = entry;
-}
-
-void mru_clear(struct mru *mru)
-{
-	struct mru_entry *p = mru->head;
-
-	while (p) {
-		struct mru_entry *to_free = p;
-		p = p->next;
-		free(to_free);
-	}
-	mru->head = mru->tail = NULL;
-}

diff --git a/mru.h b/mru.h
deleted file mode 100644
index 42e4aea..0000000
--- a/mru.h
+++ /dev/null

@@ -1,45 +0,0 @@
-#ifndef MRU_H
-#define MRU_H
-
-/**
- * A simple most-recently-used cache, backed by a doubly-linked list.
- *
- * Usage is roughly:
- *
- *   // Create a list.  Zero-initialization is required.
- *   static struct mru cache;
- *   mru_append(&cache, item);
- *   ...
- *
- *   // Iterate in MRU order.
- *   struct mru_entry *p;
- *   for (p = cache.head; p; p = p->next) {
- *	if (matches(p->item))
- *		break;
- *   }
- *
- *   // Mark an item as used, moving it to the front of the list.
- *   mru_mark(&cache, p);
- *
- *   // Reset the list to empty, cleaning up all resources.
- *   mru_clear(&cache);
- *
- * Note that you SHOULD NOT call mru_mark() and then continue traversing the
- * list; it reorders the marked item to the front of the list, and therefore
- * you will begin traversing the whole list again.
- */
-
-struct mru_entry {
-	void *item;
-	struct mru_entry *prev, *next;
-};
-
-struct mru {
-	struct mru_entry *head, *tail;
-};
-
-void mru_append(struct mru *mru, void *item);
-void mru_mark(struct mru *mru, struct mru_entry *entry);
-void mru_clear(struct mru *mru);
-
-#endif /* MRU_H */

diff --git a/name-hash.c b/name-hash.c
index 45c98db..ada66f0 100644
--- a/name-hash.c
+++ b/name-hash.c

@@ -578,6 +578,8 @@ static void threaded_lazy_init_name_hash(
 
 static void lazy_init_name_hash(struct index_state *istate)
 {
+	uint64_t start = getnanotime();
+
 	if (istate->name_hash_initialized)
 		return;
 	hashmap_init(&istate->name_hash, cache_entry_cmp, NULL, istate->cache_nr);
@@ -600,6 +602,7 @@ static void lazy_init_name_hash(struct index_state *istate)
 	}
 
 	istate->name_hash_initialized = 1;
+	trace_performance_since(start, "initialize name hash");
 }
 
 /*

diff --git a/notes-cache.c b/notes-cache.c
index 17ee860..398e61d 100644
--- a/notes-cache.c
+++ b/notes-cache.c

@@ -54,10 +54,10 @@ int notes_cache_write(struct notes_cache *c)
 	if (!c->tree.dirty)
 		return 0;
 
-	if (write_notes_tree(&c->tree, tree_oid.hash))
+	if (write_notes_tree(&c->tree, &tree_oid))
 		return -1;
-	if (commit_tree(c->validity, strlen(c->validity), tree_oid.hash, NULL,
-			commit_oid.hash, NULL, NULL) < 0)
+	if (commit_tree(c->validity, strlen(c->validity), &tree_oid, NULL,
+			&commit_oid, NULL, NULL) < 0)
 		return -1;
 	if (update_ref("update notes cache", c->tree.update_ref, &commit_oid,
 		       NULL, 0, UPDATE_REFS_QUIET_ON_ERR) < 0)
@@ -88,7 +88,7 @@ int notes_cache_put(struct notes_cache *c, struct object_id *key_oid,
 {
 	struct object_id value_oid;
 
-	if (write_sha1_file(data, size, "blob", value_oid.hash) < 0)
+	if (write_object_file(data, size, "blob", &value_oid) < 0)
 		return -1;
 	return add_note(&c->tree, key_oid, &value_oid, NULL);
 }

diff --git a/notes-merge.c b/notes-merge.c
index 0f6573c..c09c5e0 100644
--- a/notes-merge.c
+++ b/notes-merge.c

@@ -642,9 +642,8 @@ int notes_merge(struct notes_merge_options *o,
 		struct commit_list *parents = NULL;
 		commit_list_insert(remote, &parents); /* LIFO order */
 		commit_list_insert(local, &parents);
-		create_notes_commit(local_tree, parents,
-				    o->commit_msg.buf, o->commit_msg.len,
-				    result_oid->hash);
+		create_notes_commit(local_tree, parents, o->commit_msg.buf,
+				    o->commit_msg.len, result_oid);
 	}
 
 found_result:
@@ -718,8 +717,8 @@ int notes_merge_commit(struct notes_merge_options *o,
 		strbuf_setlen(&path, baselen);
 	}
 
-	create_notes_commit(partial_tree, partial_commit->parents,
-			    msg, strlen(msg), result_oid->hash);
+	create_notes_commit(partial_tree, partial_commit->parents, msg,
+			    strlen(msg), result_oid);
 	unuse_commit_buffer(partial_commit, buffer);
 	if (o->verbosity >= 4)
 		printf("Finalized notes merge commit: %s\n",

diff --git a/notes-utils.c b/notes-utils.c
index 5c8e70c..02407fe 100644
--- a/notes-utils.c
+++ b/notes-utils.c

@@ -6,13 +6,13 @@
 
 void create_notes_commit(struct notes_tree *t, struct commit_list *parents,
 			 const char *msg, size_t msg_len,
-			 unsigned char *result_sha1)
+			 struct object_id *result_oid)
 {
 	struct object_id tree_oid;
 
 	assert(t->initialized);
 
-	if (write_notes_tree(t, tree_oid.hash))
+	if (write_notes_tree(t, &tree_oid))
 		die("Failed to write notes tree to database");
 
 	if (!parents) {
@@ -27,7 +27,8 @@ void create_notes_commit(struct notes_tree *t, struct commit_list *parents,
 		/* else: t->ref points to nothing, assume root/orphan commit */
 	}
 
-	if (commit_tree(msg, msg_len, tree_oid.hash, parents, result_sha1, NULL, NULL))
+	if (commit_tree(msg, msg_len, &tree_oid, parents, result_oid, NULL,
+			NULL))
 		die("Failed to commit notes tree to database");
 }
 
@@ -47,7 +48,7 @@ void commit_notes(struct notes_tree *t, const char *msg)
 	strbuf_addstr(&buf, msg);
 	strbuf_complete_line(&buf);
 
-	create_notes_commit(t, NULL, buf.buf, buf.len, commit_oid.hash);
+	create_notes_commit(t, NULL, buf.buf, buf.len, &commit_oid);
 	strbuf_insert(&buf, 0, "notes: ", 7); /* commit message starts at index 7 */
 	update_ref(buf.buf, t->update_ref, &commit_oid, NULL, 0,
 		   UPDATE_REFS_DIE_ON_ERR);

diff --git a/notes-utils.h b/notes-utils.h
index 1190578..5d79cbe 100644
--- a/notes-utils.h
+++ b/notes-utils.h

@@ -15,7 +15,8 @@
  * The resulting commit SHA1 is stored in result_sha1.
  */
 void create_notes_commit(struct notes_tree *t, struct commit_list *parents,
-			 const char *msg, size_t msg_len, unsigned char *result_sha1);
+			 const char *msg, size_t msg_len,
+			 struct object_id *result_oid);
 
 void commit_notes(struct notes_tree *t, const char *msg);
 

diff --git a/notes.c b/notes.c
index c7f21fa..ce9a8f5 100644
--- a/notes.c
+++ b/notes.c

@@ -270,8 +270,8 @@ static int note_tree_insert(struct notes_tree *t, struct int_node *tree,
 				if (!oidcmp(&l->val_oid, &entry->val_oid))
 					return 0;
 
-				ret = combine_notes(l->val_oid.hash,
-						    entry->val_oid.hash);
+				ret = combine_notes(&l->val_oid,
+						    &entry->val_oid);
 				if (!ret && is_null_oid(&l->val_oid))
 					note_tree_remove(t, tree, n, entry);
 				free(entry);
@@ -667,7 +667,7 @@ static int tree_write_stack_finish_subtree(struct tree_write_stack *tws)
 		ret = tree_write_stack_finish_subtree(n);
 		if (ret)
 			return ret;
-		ret = write_sha1_file(n->buf.buf, n->buf.len, tree_type, s.hash);
+		ret = write_object_file(n->buf.buf, n->buf.len, tree_type, &s);
 		if (ret)
 			return ret;
 		strbuf_release(&n->buf);
@@ -786,8 +786,8 @@ static int prune_notes_helper(const struct object_id *object_oid,
 	return 0;
 }
 
-int combine_notes_concatenate(unsigned char *cur_sha1,
-		const unsigned char *new_sha1)
+int combine_notes_concatenate(struct object_id *cur_oid,
+			      const struct object_id *new_oid)
 {
 	char *cur_msg = NULL, *new_msg = NULL, *buf;
 	unsigned long cur_len, new_len, buf_len;
@@ -795,18 +795,18 @@ int combine_notes_concatenate(unsigned char *cur_sha1,
 	int ret;
 
 	/* read in both note blob objects */
-	if (!is_null_sha1(new_sha1))
-		new_msg = read_sha1_file(new_sha1, &new_type, &new_len);
+	if (!is_null_oid(new_oid))
+		new_msg = read_sha1_file(new_oid->hash, &new_type, &new_len);
 	if (!new_msg || !new_len || new_type != OBJ_BLOB) {
 		free(new_msg);
 		return 0;
 	}
-	if (!is_null_sha1(cur_sha1))
-		cur_msg = read_sha1_file(cur_sha1, &cur_type, &cur_len);
+	if (!is_null_oid(cur_oid))
+		cur_msg = read_sha1_file(cur_oid->hash, &cur_type, &cur_len);
 	if (!cur_msg || !cur_len || cur_type != OBJ_BLOB) {
 		free(cur_msg);
 		free(new_msg);
-		hashcpy(cur_sha1, new_sha1);
+		oidcpy(cur_oid, new_oid);
 		return 0;
 	}
 
@@ -825,20 +825,20 @@ int combine_notes_concatenate(unsigned char *cur_sha1,
 	free(new_msg);
 
 	/* create a new blob object from buf */
-	ret = write_sha1_file(buf, buf_len, blob_type, cur_sha1);
+	ret = write_object_file(buf, buf_len, blob_type, cur_oid);
 	free(buf);
 	return ret;
 }
 
-int combine_notes_overwrite(unsigned char *cur_sha1,
-		const unsigned char *new_sha1)
+int combine_notes_overwrite(struct object_id *cur_oid,
+			    const struct object_id *new_oid)
 {
-	hashcpy(cur_sha1, new_sha1);
+	oidcpy(cur_oid, new_oid);
 	return 0;
 }
 
-int combine_notes_ignore(unsigned char *cur_sha1,
-		const unsigned char *new_sha1)
+int combine_notes_ignore(struct object_id *cur_oid,
+			 const struct object_id *new_oid)
 {
 	return 0;
 }
@@ -848,17 +848,17 @@ int combine_notes_ignore(unsigned char *cur_sha1,
  * newlines removed.
  */
 static int string_list_add_note_lines(struct string_list *list,
-				      const unsigned char *sha1)
+				      const struct object_id *oid)
 {
 	char *data;
 	unsigned long len;
 	enum object_type t;
 
-	if (is_null_sha1(sha1))
+	if (is_null_oid(oid))
 		return 0;
 
 	/* read_sha1_file NUL-terminates */
-	data = read_sha1_file(sha1, &t, &len);
+	data = read_sha1_file(oid->hash, &t, &len);
 	if (t != OBJ_BLOB || !data || !len) {
 		free(data);
 		return t != OBJ_BLOB || !data;
@@ -884,17 +884,17 @@ static int string_list_join_lines_helper(struct string_list_item *item,
 	return 0;
 }
 
-int combine_notes_cat_sort_uniq(unsigned char *cur_sha1,
-		const unsigned char *new_sha1)
+int combine_notes_cat_sort_uniq(struct object_id *cur_oid,
+				const struct object_id *new_oid)
 {
 	struct string_list sort_uniq_list = STRING_LIST_INIT_DUP;
 	struct strbuf buf = STRBUF_INIT;
 	int ret = 1;
 
 	/* read both note blob objects into unique_lines */
-	if (string_list_add_note_lines(&sort_uniq_list, cur_sha1))
+	if (string_list_add_note_lines(&sort_uniq_list, cur_oid))
 		goto out;
-	if (string_list_add_note_lines(&sort_uniq_list, new_sha1))
+	if (string_list_add_note_lines(&sort_uniq_list, new_oid))
 		goto out;
 	string_list_remove_empty_items(&sort_uniq_list, 0);
 	string_list_sort(&sort_uniq_list);
@@ -905,7 +905,7 @@ int combine_notes_cat_sort_uniq(unsigned char *cur_sha1,
 				 string_list_join_lines_helper, &buf))
 		goto out;
 
-	ret = write_sha1_file(buf.buf, buf.len, blob_type, cur_sha1);
+	ret = write_object_file(buf.buf, buf.len, blob_type, cur_oid);
 
 out:
 	strbuf_release(&buf);
@@ -1123,11 +1123,12 @@ int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
 	return for_each_note_helper(t, t->root, 0, 0, flags, fn, cb_data);
 }
 
-int write_notes_tree(struct notes_tree *t, unsigned char *result)
+int write_notes_tree(struct notes_tree *t, struct object_id *result)
 {
 	struct tree_write_stack root;
 	struct write_each_note_data cb_data;
 	int ret;
+	int flags;
 
 	if (!t)
 		t = &default_notes_tree;
@@ -1141,12 +1142,12 @@ int write_notes_tree(struct notes_tree *t, unsigned char *result)
 	cb_data.next_non_note = t->first_non_note;
 
 	/* Write tree objects representing current notes tree */
-	ret = for_each_note(t, FOR_EACH_NOTE_DONT_UNPACK_SUBTREES |
-				FOR_EACH_NOTE_YIELD_SUBTREES,
-			write_each_note, &cb_data) ||
-		write_each_non_note_until(NULL, &cb_data) ||
-		tree_write_stack_finish_subtree(&root) ||
-		write_sha1_file(root.buf.buf, root.buf.len, tree_type, result);
+	flags = FOR_EACH_NOTE_DONT_UNPACK_SUBTREES |
+		FOR_EACH_NOTE_YIELD_SUBTREES;
+	ret = for_each_note(t, flags, write_each_note, &cb_data) ||
+	      write_each_non_note_until(NULL, &cb_data) ||
+	      tree_write_stack_finish_subtree(&root) ||
+	      write_object_file(root.buf.buf, root.buf.len, tree_type, result);
 	strbuf_release(&root.buf);
 	return ret;
 }

diff --git a/notes.h b/notes.h
index 3848c2f..0433f45 100644
--- a/notes.h
+++ b/notes.h

@@ -9,27 +9,32 @@
  * When adding a new note annotating the same object as an existing note, it is
  * up to the caller to decide how to combine the two notes. The decision is
  * made by passing in a function of the following form. The function accepts
- * two SHA1s -- of the existing note and the new note, respectively. The
+ * two object_ids -- of the existing note and the new note, respectively. The
  * function then combines the notes in whatever way it sees fit, and writes the
- * resulting SHA1 into the first SHA1 argument (cur_sha1). A non-zero return
+ * resulting oid into the first argument (cur_oid). A non-zero return
  * value indicates failure.
  *
- * The two given SHA1s shall both be non-NULL and different from each other.
- * Either of them (but not both) may be == null_sha1, which indicates an
- * empty/non-existent note. If the resulting SHA1 (cur_sha1) is == null_sha1,
+ * The two given object_ids shall both be non-NULL and different from each
+ * other. Either of them (but not both) may be == null_oid, which indicates an
+ * empty/non-existent note. If the resulting oid (cur_oid) is == null_oid,
  * the note will be removed from the notes tree.
  *
  * The default combine_notes function (you get this when passing NULL) is
  * combine_notes_concatenate(), which appends the contents of the new note to
  * the contents of the existing note.
  */
-typedef int (*combine_notes_fn)(unsigned char *cur_sha1, const unsigned char *new_sha1);
+typedef int (*combine_notes_fn)(struct object_id *cur_oid,
+				const struct object_id *new_oid);
 
 /* Common notes combinators */
-int combine_notes_concatenate(unsigned char *cur_sha1, const unsigned char *new_sha1);
-int combine_notes_overwrite(unsigned char *cur_sha1, const unsigned char *new_sha1);
-int combine_notes_ignore(unsigned char *cur_sha1, const unsigned char *new_sha1);
-int combine_notes_cat_sort_uniq(unsigned char *cur_sha1, const unsigned char *new_sha1);
+int combine_notes_concatenate(struct object_id *cur_oid,
+			      const struct object_id *new_oid);
+int combine_notes_overwrite(struct object_id *cur_oid,
+			    const struct object_id *new_oid);
+int combine_notes_ignore(struct object_id *cur_oid,
+			 const struct object_id *new_oid);
+int combine_notes_cat_sort_uniq(struct object_id *cur_oid,
+				const struct object_id *new_oid);
 
 /*
  * Notes tree object
@@ -212,7 +217,7 @@ int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
  * Write the given notes_tree structure to the object database
  *
  * Creates a new tree object encapsulating the current state of the given
- * notes_tree, and stores its SHA1 into the 'result' argument.
+ * notes_tree, and stores its object id into the 'result' argument.
  *
  * Returns zero on success, non-zero on failure.
  *
@@ -220,7 +225,7 @@ int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
  * this function has returned zero. Please also remember to create a
  * corresponding commit object, and update the appropriate notes ref.
  */
-int write_notes_tree(struct notes_tree *t, unsigned char *result);
+int write_notes_tree(struct notes_tree *t, struct object_id *result);
 
 /* Flags controlling the operation of prune */
 #define NOTES_PRUNE_VERBOSE 1

diff --git a/object.c b/object.c
index b9a4a0e..9e6f9ff 100644
--- a/object.c
+++ b/object.c

@@ -252,7 +252,7 @@ struct object *parse_object(const struct object_id *oid)
 	if (obj && obj->parsed)
 		return obj;
 
-	if ((obj && obj->type == OBJ_BLOB) ||
+	if ((obj && obj->type == OBJ_BLOB && has_object_file(oid)) ||
 	    (!obj && has_object_file(oid) &&
 	     sha1_object_info(oid->hash, NULL) == OBJ_BLOB)) {
 		if (check_sha1_signature(repl, NULL, 0, NULL) < 0) {
@@ -434,3 +434,14 @@ void clear_object_flags(unsigned flags)
 			obj->flags &= ~flags;
 	}
 }
+
+void clear_commit_marks_all(unsigned int flags)
+{
+	int i;
+
+	for (i = 0; i < obj_hash_size; i++) {
+		struct object *obj = obj_hash[i];
+		if (obj && obj->type == OBJ_COMMIT)
+			obj->flags &= ~flags;
+	}
+}

diff --git a/object.h b/object.h
index f34461d..87563d9 100644
--- a/object.h
+++ b/object.h

@@ -149,4 +149,9 @@ void object_array_clear(struct object_array *array);
 
 void clear_object_flags(unsigned flags);
 
+/*
+ * Clear the specified object flags from all in-core commit objects.
+ */
+extern void clear_commit_marks_all(unsigned int flags);
+
 #endif /* OBJECT_H */

diff --git a/oidmap.c b/oidmap.c
index 6db4fff..d9fb19b 100644
--- a/oidmap.c
+++ b/oidmap.c

@@ -33,12 +33,19 @@ void oidmap_free(struct oidmap *map, int free_entries)
 
 void *oidmap_get(const struct oidmap *map, const struct object_id *key)
 {
+	if (!map->map.cmpfn)
+		return NULL;
+
 	return hashmap_get_from_hash(&map->map, hash(key), key);
 }
 
 void *oidmap_remove(struct oidmap *map, const struct object_id *key)
 {
 	struct hashmap_entry entry;
+
+	if (!map->map.cmpfn)
+		oidmap_init(map, 0);
+
 	hashmap_entry_init(&entry, hash(key));
 	return hashmap_remove(&map->map, &entry, key);
 }
@@ -46,6 +53,10 @@ void *oidmap_remove(struct oidmap *map, const struct object_id *key)
 void *oidmap_put(struct oidmap *map, void *entry)
 {
 	struct oidmap_entry *to_put = entry;
+
+	if (!map->map.cmpfn)
+		oidmap_init(map, 0);
+
 	hashmap_entry_init(&to_put->internal_entry, hash(&to_put->oid));
 	return hashmap_put(&map->map, to_put);
 }

diff --git a/pack-bitmap-write.c b/pack-bitmap-write.c
index a8df5ce..e01f992 100644
--- a/pack-bitmap-write.c
+++ b/pack-bitmap-write.c

@@ -440,19 +440,19 @@ void bitmap_writer_select_commits(struct commit **indexed_commits,
 }
 
 
-static int sha1write_ewah_helper(void *f, const void *buf, size_t len)
+static int hashwrite_ewah_helper(void *f, const void *buf, size_t len)
 {
-	/* sha1write will die on error */
-	sha1write(f, buf, len);
+	/* hashwrite will die on error */
+	hashwrite(f, buf, len);
 	return len;
 }
 
 /**
  * Write the bitmap index to disk
  */
-static inline void dump_bitmap(struct sha1file *f, struct ewah_bitmap *bitmap)
+static inline void dump_bitmap(struct hashfile *f, struct ewah_bitmap *bitmap)
 {
-	if (ewah_serialize_to(bitmap, sha1write_ewah_helper, f) < 0)
+	if (ewah_serialize_to(bitmap, hashwrite_ewah_helper, f) < 0)
 		die("Failed to write bitmap index");
 }
 
@@ -462,7 +462,7 @@ static const unsigned char *sha1_access(size_t pos, void *table)
 	return index[pos]->oid.hash;
 }
 
-static void write_selected_commits_v1(struct sha1file *f,
+static void write_selected_commits_v1(struct hashfile *f,
 				      struct pack_idx_entry **index,
 				      uint32_t index_nr)
 {
@@ -477,15 +477,15 @@ static void write_selected_commits_v1(struct sha1file *f,
 		if (commit_pos < 0)
 			die("BUG: trying to write commit not in index");
 
-		sha1write_be32(f, commit_pos);
-		sha1write_u8(f, stored->xor_offset);
-		sha1write_u8(f, stored->flags);
+		hashwrite_be32(f, commit_pos);
+		hashwrite_u8(f, stored->xor_offset);
+		hashwrite_u8(f, stored->flags);
 
 		dump_bitmap(f, stored->write_as);
 	}
 }
 
-static void write_hash_cache(struct sha1file *f,
+static void write_hash_cache(struct hashfile *f,
 			     struct pack_idx_entry **index,
 			     uint32_t index_nr)
 {
@@ -494,7 +494,7 @@ static void write_hash_cache(struct sha1file *f,
 	for (i = 0; i < index_nr; ++i) {
 		struct object_entry *entry = (struct object_entry *)index[i];
 		uint32_t hash_value = htonl(entry->hash);
-		sha1write(f, &hash_value, sizeof(hash_value));
+		hashwrite(f, &hash_value, sizeof(hash_value));
 	}
 }
 
@@ -511,13 +511,13 @@ void bitmap_writer_finish(struct pack_idx_entry **index,
 	static uint16_t default_version = 1;
 	static uint16_t flags = BITMAP_OPT_FULL_DAG;
 	struct strbuf tmp_file = STRBUF_INIT;
-	struct sha1file *f;
+	struct hashfile *f;
 
 	struct bitmap_disk_header header;
 
 	int fd = odb_mkstemp(&tmp_file, "pack/tmp_bitmap_XXXXXX");
 
-	f = sha1fd(fd, tmp_file.buf);
+	f = hashfd(fd, tmp_file.buf);
 
 	memcpy(header.magic, BITMAP_IDX_SIGNATURE, sizeof(BITMAP_IDX_SIGNATURE));
 	header.version = htons(default_version);
@@ -525,7 +525,7 @@ void bitmap_writer_finish(struct pack_idx_entry **index,
 	header.entry_count = htonl(writer.selected_nr);
 	hashcpy(header.checksum, writer.pack_checksum);
 
-	sha1write(f, &header, sizeof(header));
+	hashwrite(f, &header, sizeof(header));
 	dump_bitmap(f, writer.commits);
 	dump_bitmap(f, writer.trees);
 	dump_bitmap(f, writer.blobs);
@@ -535,7 +535,7 @@ void bitmap_writer_finish(struct pack_idx_entry **index,
 	if (options & BITMAP_OPT_HASH_CACHE)
 		write_hash_cache(f, index, index_nr);
 
-	sha1close(f, NULL, CSUM_FSYNC);
+	hashclose(f, NULL, CSUM_FSYNC);
 
 	if (adjust_shared_perm(tmp_file.buf))
 		die_errno("unable to make temporary bitmap file readable");

diff --git a/pack-check.c b/pack-check.c
index 073c1fb..403a572 100644
--- a/pack-check.c
+++ b/pack-check.c

@@ -41,7 +41,7 @@ int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
 	} while (len);
 
 	index_crc = p->index_data;
-	index_crc += 2 + 256 + p->num_objects * (20/4) + nr;
+	index_crc += 2 + 256 + p->num_objects * (the_hash_algo->rawsz/4) + nr;
 
 	return data_crc != ntohl(*index_crc);
 }
@@ -54,7 +54,7 @@ static int verify_packfile(struct packed_git *p,
 {
 	off_t index_size = p->index_size;
 	const unsigned char *index_base = p->index_data;
-	git_SHA_CTX ctx;
+	git_hash_ctx ctx;
 	unsigned char hash[GIT_MAX_RAWSZ], *pack_sig;
 	off_t offset = 0, pack_sig_ofs = 0;
 	uint32_t nr_objects, i;
@@ -64,24 +64,24 @@ static int verify_packfile(struct packed_git *p,
 	if (!is_pack_valid(p))
 		return error("packfile %s cannot be accessed", p->pack_name);
 
-	git_SHA1_Init(&ctx);
+	the_hash_algo->init_fn(&ctx);
 	do {
 		unsigned long remaining;
 		unsigned char *in = use_pack(p, w_curs, offset, &remaining);
 		offset += remaining;
 		if (!pack_sig_ofs)
-			pack_sig_ofs = p->pack_size - 20;
+			pack_sig_ofs = p->pack_size - the_hash_algo->rawsz;
 		if (offset > pack_sig_ofs)
 			remaining -= (unsigned int)(offset - pack_sig_ofs);
-		git_SHA1_Update(&ctx, in, remaining);
+		the_hash_algo->update_fn(&ctx, in, remaining);
 	} while (offset < pack_sig_ofs);
-	git_SHA1_Final(hash, &ctx);
+	the_hash_algo->final_fn(hash, &ctx);
 	pack_sig = use_pack(p, w_curs, pack_sig_ofs, NULL);
 	if (hashcmp(hash, pack_sig))
-		err = error("%s SHA1 checksum mismatch",
+		err = error("%s pack checksum mismatch",
 			    p->pack_name);
-	if (hashcmp(index_base + index_size - 40, pack_sig))
-		err = error("%s SHA1 does not match its index",
+	if (hashcmp(index_base + index_size - the_hash_algo->hexsz, pack_sig))
+		err = error("%s pack checksum does not match its index",
 			    p->pack_name);
 	unuse_pack(w_curs);
 
@@ -165,8 +165,8 @@ int verify_pack_index(struct packed_git *p)
 {
 	off_t index_size;
 	const unsigned char *index_base;
-	git_SHA_CTX ctx;
-	unsigned char sha1[20];
+	git_hash_ctx ctx;
+	unsigned char hash[GIT_MAX_RAWSZ];
 	int err = 0;
 
 	if (open_pack_index(p))
@@ -175,11 +175,11 @@ int verify_pack_index(struct packed_git *p)
 	index_base = p->index_data;
 
 	/* Verify SHA1 sum of the index file */
-	git_SHA1_Init(&ctx);
-	git_SHA1_Update(&ctx, index_base, (unsigned int)(index_size - 20));
-	git_SHA1_Final(sha1, &ctx);
-	if (hashcmp(sha1, index_base + index_size - 20))
-		err = error("Packfile index for %s SHA1 mismatch",
+	the_hash_algo->init_fn(&ctx);
+	the_hash_algo->update_fn(&ctx, index_base, (unsigned int)(index_size - the_hash_algo->rawsz));
+	the_hash_algo->final_fn(hash, &ctx);
+	if (hashcmp(hash, index_base + index_size - the_hash_algo->rawsz))
+		err = error("Packfile index for %s hash mismatch",
 			    p->pack_name);
 	return err;
 }

diff --git a/pack-revindex.c b/pack-revindex.c
index 1b7ebd8..ff5f62c 100644
--- a/pack-revindex.c
+++ b/pack-revindex.c

@@ -134,10 +134,8 @@ static void create_pack_revindex(struct packed_git *p)
 			if (!(off & 0x80000000)) {
 				p->revindex[i].offset = off;
 			} else {
-				p->revindex[i].offset =
-					((uint64_t)ntohl(*off_64++)) << 32;
-				p->revindex[i].offset |=
-					ntohl(*off_64++);
+				p->revindex[i].offset = get_be64(off_64);
+				off_64 += 2;
 			}
 			p->revindex[i].nr = i;
 		}

diff --git a/pack-write.c b/pack-write.c
index fea6284..d775c74 100644
--- a/pack-write.c
+++ b/pack-write.c

@@ -46,7 +46,7 @@ const char *write_idx_file(const char *index_name, struct pack_idx_entry **objec
 			   int nr_objects, const struct pack_idx_option *opts,
 			   const unsigned char *sha1)
 {
-	struct sha1file *f;
+	struct hashfile *f;
 	struct pack_idx_entry **sorted_by_sha, **list, **last;
 	off_t last_obj_offset = 0;
 	uint32_t array[256];
@@ -68,7 +68,7 @@ const char *write_idx_file(const char *index_name, struct pack_idx_entry **objec
 
 	if (opts->flags & WRITE_IDX_VERIFY) {
 		assert(index_name);
-		f = sha1fd_check(index_name);
+		f = hashfd_check(index_name);
 	} else {
 		if (!index_name) {
 			struct strbuf tmp_file = STRBUF_INIT;
@@ -80,7 +80,7 @@ const char *write_idx_file(const char *index_name, struct pack_idx_entry **objec
 			if (fd < 0)
 				die_errno("unable to create '%s'", index_name);
 		}
-		f = sha1fd(fd, index_name);
+		f = hashfd(fd, index_name);
 	}
 
 	/* if last object's offset is >= 2^31 we should use index V2 */
@@ -91,7 +91,7 @@ const char *write_idx_file(const char *index_name, struct pack_idx_entry **objec
 		struct pack_idx_header hdr;
 		hdr.idx_signature = htonl(PACK_IDX_SIGNATURE);
 		hdr.idx_version = htonl(index_version);
-		sha1write(f, &hdr, sizeof(hdr));
+		hashwrite(f, &hdr, sizeof(hdr));
 	}
 
 	/*
@@ -110,7 +110,7 @@ const char *write_idx_file(const char *index_name, struct pack_idx_entry **objec
 		array[i] = htonl(next - sorted_by_sha);
 		list = next;
 	}
-	sha1write(f, array, 256 * 4);
+	hashwrite(f, array, 256 * 4);
 
 	/*
 	 * Write the actual SHA1 entries..
@@ -120,9 +120,9 @@ const char *write_idx_file(const char *index_name, struct pack_idx_entry **objec
 		struct pack_idx_entry *obj = *list++;
 		if (index_version < 2) {
 			uint32_t offset = htonl(obj->offset);
-			sha1write(f, &offset, 4);
+			hashwrite(f, &offset, 4);
 		}
-		sha1write(f, obj->oid.hash, 20);
+		hashwrite(f, obj->oid.hash, the_hash_algo->rawsz);
 		if ((opts->flags & WRITE_IDX_STRICT) &&
 		    (i && !oidcmp(&list[-2]->oid, &obj->oid)))
 			die("The same object %s appears twice in the pack",
@@ -137,7 +137,7 @@ const char *write_idx_file(const char *index_name, struct pack_idx_entry **objec
 		for (i = 0; i < nr_objects; i++) {
 			struct pack_idx_entry *obj = *list++;
 			uint32_t crc32_val = htonl(obj->crc32);
-			sha1write(f, &crc32_val, 4);
+			hashwrite(f, &crc32_val, 4);
 		}
 
 		/* write the 32-bit offset table */
@@ -150,7 +150,7 @@ const char *write_idx_file(const char *index_name, struct pack_idx_entry **objec
 				  ? (0x80000000 | nr_large_offset++)
 				  : obj->offset);
 			offset = htonl(offset);
-			sha1write(f, &offset, 4);
+			hashwrite(f, &offset, 4);
 		}
 
 		/* write the large offset table */
@@ -164,25 +164,25 @@ const char *write_idx_file(const char *index_name, struct pack_idx_entry **objec
 				continue;
 			split[0] = htonl(offset >> 32);
 			split[1] = htonl(offset & 0xffffffff);
-			sha1write(f, split, 8);
+			hashwrite(f, split, 8);
 			nr_large_offset--;
 		}
 	}
 
-	sha1write(f, sha1, 20);
-	sha1close(f, NULL, ((opts->flags & WRITE_IDX_VERIFY)
+	hashwrite(f, sha1, the_hash_algo->rawsz);
+	hashclose(f, NULL, ((opts->flags & WRITE_IDX_VERIFY)
 			    ? CSUM_CLOSE : CSUM_FSYNC));
 	return index_name;
 }
 
-off_t write_pack_header(struct sha1file *f, uint32_t nr_entries)
+off_t write_pack_header(struct hashfile *f, uint32_t nr_entries)
 {
 	struct pack_header hdr;
 
 	hdr.hdr_signature = htonl(PACK_SIGNATURE);
 	hdr.hdr_version = htonl(PACK_VERSION);
 	hdr.hdr_entries = htonl(nr_entries);
-	sha1write(f, &hdr, sizeof(hdr));
+	hashwrite(f, &hdr, sizeof(hdr));
 	return sizeof(hdr);
 }
 
@@ -203,20 +203,20 @@ off_t write_pack_header(struct sha1file *f, uint32_t nr_entries)
  * interested in the resulting SHA1 of pack data above partial_pack_offset.
  */
 void fixup_pack_header_footer(int pack_fd,
-			 unsigned char *new_pack_sha1,
+			 unsigned char *new_pack_hash,
 			 const char *pack_name,
 			 uint32_t object_count,
-			 unsigned char *partial_pack_sha1,
+			 unsigned char *partial_pack_hash,
 			 off_t partial_pack_offset)
 {
 	int aligned_sz, buf_sz = 8 * 1024;
-	git_SHA_CTX old_sha1_ctx, new_sha1_ctx;
+	git_hash_ctx old_hash_ctx, new_hash_ctx;
 	struct pack_header hdr;
 	char *buf;
 	ssize_t read_result;
 
-	git_SHA1_Init(&old_sha1_ctx);
-	git_SHA1_Init(&new_sha1_ctx);
+	the_hash_algo->init_fn(&old_hash_ctx);
+	the_hash_algo->init_fn(&new_hash_ctx);
 
 	if (lseek(pack_fd, 0, SEEK_SET) != 0)
 		die_errno("Failed seeking to start of '%s'", pack_name);
@@ -228,9 +228,9 @@ void fixup_pack_header_footer(int pack_fd,
 			  pack_name);
 	if (lseek(pack_fd, 0, SEEK_SET) != 0)
 		die_errno("Failed seeking to start of '%s'", pack_name);
-	git_SHA1_Update(&old_sha1_ctx, &hdr, sizeof(hdr));
+	the_hash_algo->update_fn(&old_hash_ctx, &hdr, sizeof(hdr));
 	hdr.hdr_entries = htonl(object_count);
-	git_SHA1_Update(&new_sha1_ctx, &hdr, sizeof(hdr));
+	the_hash_algo->update_fn(&new_hash_ctx, &hdr, sizeof(hdr));
 	write_or_die(pack_fd, &hdr, sizeof(hdr));
 	partial_pack_offset -= sizeof(hdr);
 
@@ -238,28 +238,28 @@ void fixup_pack_header_footer(int pack_fd,
 	aligned_sz = buf_sz - sizeof(hdr);
 	for (;;) {
 		ssize_t m, n;
-		m = (partial_pack_sha1 && partial_pack_offset < aligned_sz) ?
+		m = (partial_pack_hash && partial_pack_offset < aligned_sz) ?
 			partial_pack_offset : aligned_sz;
 		n = xread(pack_fd, buf, m);
 		if (!n)
 			break;
 		if (n < 0)
 			die_errno("Failed to checksum '%s'", pack_name);
-		git_SHA1_Update(&new_sha1_ctx, buf, n);
+		the_hash_algo->update_fn(&new_hash_ctx, buf, n);
 
 		aligned_sz -= n;
 		if (!aligned_sz)
 			aligned_sz = buf_sz;
 
-		if (!partial_pack_sha1)
+		if (!partial_pack_hash)
 			continue;
 
-		git_SHA1_Update(&old_sha1_ctx, buf, n);
+		the_hash_algo->update_fn(&old_hash_ctx, buf, n);
 		partial_pack_offset -= n;
 		if (partial_pack_offset == 0) {
-			unsigned char sha1[20];
-			git_SHA1_Final(sha1, &old_sha1_ctx);
-			if (hashcmp(sha1, partial_pack_sha1) != 0)
+			unsigned char hash[GIT_MAX_RAWSZ];
+			the_hash_algo->final_fn(hash, &old_hash_ctx);
+			if (hashcmp(hash, partial_pack_hash) != 0)
 				die("Unexpected checksum for %s "
 				    "(disk corruption?)", pack_name);
 			/*
@@ -267,23 +267,24 @@ void fixup_pack_header_footer(int pack_fd,
 			 * pack, which also means making partial_pack_offset
 			 * big enough not to matter anymore.
 			 */
-			git_SHA1_Init(&old_sha1_ctx);
+			the_hash_algo->init_fn(&old_hash_ctx);
 			partial_pack_offset = ~partial_pack_offset;
 			partial_pack_offset -= MSB(partial_pack_offset, 1);
 		}
 	}
 	free(buf);
 
-	if (partial_pack_sha1)
-		git_SHA1_Final(partial_pack_sha1, &old_sha1_ctx);
-	git_SHA1_Final(new_pack_sha1, &new_sha1_ctx);
-	write_or_die(pack_fd, new_pack_sha1, 20);
+	if (partial_pack_hash)
+		the_hash_algo->final_fn(partial_pack_hash, &old_hash_ctx);
+	the_hash_algo->final_fn(new_pack_hash, &new_hash_ctx);
+	write_or_die(pack_fd, new_pack_hash, the_hash_algo->rawsz);
 	fsync_or_die(pack_fd, pack_name);
 }
 
 char *index_pack_lockfile(int ip_out)
 {
-	char packname[46];
+	char packname[GIT_MAX_HEXSZ + 6];
+	const int len = the_hash_algo->hexsz + 6;
 
 	/*
 	 * The first thing we expect from index-pack's output
@@ -292,9 +293,9 @@ char *index_pack_lockfile(int ip_out)
 	 * case, we need it to remove the corresponding .keep file
 	 * later on.  If we don't get that then tough luck with it.
 	 */
-	if (read_in_full(ip_out, packname, 46) == 46 && packname[45] == '\n') {
+	if (read_in_full(ip_out, packname, len) == len && packname[len-1] == '\n') {
 		const char *name;
-		packname[45] = 0;
+		packname[len-1] = 0;
 		if (skip_prefix(packname, "keep\t", &name))
 			return xstrfmt("%s/pack/pack-%s.keep",
 				       get_object_directory(), name);
@@ -332,14 +333,14 @@ int encode_in_pack_object_header(unsigned char *hdr, int hdr_len,
 	return n;
 }
 
-struct sha1file *create_tmp_packfile(char **pack_tmp_name)
+struct hashfile *create_tmp_packfile(char **pack_tmp_name)
 {
 	struct strbuf tmpname = STRBUF_INIT;
 	int fd;
 
 	fd = odb_mkstemp(&tmpname, "pack/tmp_pack_XXXXXX");
 	*pack_tmp_name = strbuf_detach(&tmpname, NULL);
-	return sha1fd(fd, *pack_tmp_name);
+	return hashfd(fd, *pack_tmp_name);
 }
 
 void finish_tmp_packfile(struct strbuf *name_buffer,

diff --git a/pack.h b/pack.h
index 8294341..34a9d45 100644
--- a/pack.h
+++ b/pack.h

@@ -81,7 +81,7 @@ extern const char *write_idx_file(const char *index_name, struct pack_idx_entry
 extern int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, off_t len, unsigned int nr);
 extern int verify_pack_index(struct packed_git *);
 extern int verify_pack(struct packed_git *, verify_fn fn, struct progress *, uint32_t);
-extern off_t write_pack_header(struct sha1file *f, uint32_t);
+extern off_t write_pack_header(struct hashfile *f, uint32_t);
 extern void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t, unsigned char *, off_t);
 extern char *index_pack_lockfile(int fd);
 
@@ -98,7 +98,7 @@ extern int encode_in_pack_object_header(unsigned char *hdr, int hdr_len,
 #define PH_ERROR_PROTOCOL	(-3)
 extern int read_pack_header(int fd, struct pack_header *);
 
-extern struct sha1file *create_tmp_packfile(char **pack_tmp_name);
+extern struct hashfile *create_tmp_packfile(char **pack_tmp_name);
 extern void finish_tmp_packfile(struct strbuf *name_buffer, const char *pack_tmp_name, struct pack_idx_entry **written_list, uint32_t nr_written, struct pack_idx_option *pack_idx_opts, unsigned char sha1[]);
 
 #endif

diff --git a/packfile.c b/packfile.c
index 4a5fe7a..7dbe873 100644
--- a/packfile.c
+++ b/packfile.c

@@ -1,5 +1,5 @@
 #include "cache.h"
-#include "mru.h"
+#include "list.h"
 #include "pack.h"
 #include "dir.h"
 #include "mergesort.h"
@@ -8,6 +8,11 @@
 #include "list.h"
 #include "streaming.h"
 #include "sha1-lookup.h"
+#include "commit.h"
+#include "object.h"
+#include "tag.h"
+#include "tree-walk.h"
+#include "tree.h"
 
 char *odb_pack_name(struct strbuf *buf,
 		    const unsigned char *sha1,
@@ -40,7 +45,7 @@ static unsigned int pack_max_fds;
 static size_t peak_pack_mapped;
 static size_t pack_mapped;
 struct packed_git *packed_git;
-struct mru packed_git_mru;
+LIST_HEAD(packed_git_mru);
 
 #define SZ_FMT PRIuMAX
 static inline uintmax_t sz_fmt(size_t s) { return s; }
@@ -643,10 +648,10 @@ struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
 		return NULL;
 
 	/*
-	 * ".pack" is long enough to hold any suffix we're adding (and
+	 * ".promisor" is long enough to hold any suffix we're adding (and
 	 * the use xsnprintf double-checks that)
 	 */
-	alloc = st_add3(path_len, strlen(".pack"), 1);
+	alloc = st_add3(path_len, strlen(".promisor"), 1);
 	p = alloc_packed_git(alloc);
 	memcpy(p->pack_name, path, path_len);
 
@@ -654,6 +659,10 @@ struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
 	if (!access(p->pack_name, F_OK))
 		p->pack_keep = 1;
 
+	xsnprintf(p->pack_name + path_len, alloc - path_len, ".promisor");
+	if (!access(p->pack_name, F_OK))
+		p->pack_promisor = 1;
+
 	xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
 	if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
 		free(p);
@@ -781,7 +790,8 @@ static void prepare_packed_git_one(char *objdir, int local)
 		if (ends_with(de->d_name, ".idx") ||
 		    ends_with(de->d_name, ".pack") ||
 		    ends_with(de->d_name, ".bitmap") ||
-		    ends_with(de->d_name, ".keep"))
+		    ends_with(de->d_name, ".keep") ||
+		    ends_with(de->d_name, ".promisor"))
 			string_list_append(&garbage, path.buf);
 		else
 			report_garbage(PACKDIR_FILE_GARBAGE, path.buf);
@@ -866,9 +876,10 @@ static void prepare_packed_git_mru(void)
 {
 	struct packed_git *p;
 
-	mru_clear(&packed_git_mru);
+	INIT_LIST_HEAD(&packed_git_mru);
+
 	for (p = packed_git; p; p = p->next)
-		mru_append(&packed_git_mru, p);
+		list_add_tail(&p->mru, &packed_git_mru);
 }
 
 static int prepare_packed_git_run_once = 0;
@@ -1702,8 +1713,7 @@ off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
 			return off;
 		index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
 		check_pack_index_ptr(p, index);
-		return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
-				   ntohl(*((uint32_t *)(index + 4)));
+		return get_be64(index);
 	}
 }
 
@@ -1831,15 +1841,16 @@ static int fill_pack_entry(const unsigned char *sha1,
  */
 int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
 {
-	struct mru_entry *p;
+	struct list_head *pos;
 
 	prepare_packed_git();
 	if (!packed_git)
 		return 0;
 
-	for (p = packed_git_mru.head; p; p = p->next) {
-		if (fill_pack_entry(sha1, e, p->item)) {
-			mru_mark(&packed_git_mru, p);
+	list_for_each(pos, &packed_git_mru) {
+		struct packed_git *p = list_entry(pos, struct packed_git, mru);
+		if (fill_pack_entry(sha1, e, p)) {
+			list_move(&p->mru, &packed_git_mru);
 			return 1;
 		}
 	}
@@ -1889,6 +1900,9 @@ int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
 	for (p = packed_git; p; p = p->next) {
 		if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
 			continue;
+		if ((flags & FOR_EACH_OBJECT_PROMISOR_ONLY) &&
+		    !p->pack_promisor)
+			continue;
 		if (open_pack_index(p)) {
 			pack_errors = 1;
 			continue;
@@ -1899,3 +1913,61 @@ int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
 	}
 	return r ? r : pack_errors;
 }
+
+static int add_promisor_object(const struct object_id *oid,
+			       struct packed_git *pack,
+			       uint32_t pos,
+			       void *set_)
+{
+	struct oidset *set = set_;
+	struct object *obj = parse_object(oid);
+	if (!obj)
+		return 1;
+
+	oidset_insert(set, oid);
+
+	/*
+	 * If this is a tree, commit, or tag, the objects it refers
+	 * to are also promisor objects. (Blobs refer to no objects.)
+	 */
+	if (obj->type == OBJ_TREE) {
+		struct tree *tree = (struct tree *)obj;
+		struct tree_desc desc;
+		struct name_entry entry;
+		if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
+			/*
+			 * Error messages are given when packs are
+			 * verified, so do not print any here.
+			 */
+			return 0;
+		while (tree_entry_gently(&desc, &entry))
+			oidset_insert(set, entry.oid);
+	} else if (obj->type == OBJ_COMMIT) {
+		struct commit *commit = (struct commit *) obj;
+		struct commit_list *parents = commit->parents;
+
+		oidset_insert(set, &commit->tree->object.oid);
+		for (; parents; parents = parents->next)
+			oidset_insert(set, &parents->item->object.oid);
+	} else if (obj->type == OBJ_TAG) {
+		struct tag *tag = (struct tag *) obj;
+		oidset_insert(set, &tag->tagged->oid);
+	}
+	return 0;
+}
+
+int is_promisor_object(const struct object_id *oid)
+{
+	static struct oidset promisor_objects;
+	static int promisor_objects_prepared;
+
+	if (!promisor_objects_prepared) {
+		if (repository_format_partial_clone) {
+			for_each_packed_object(add_promisor_object,
+					       &promisor_objects,
+					       FOR_EACH_OBJECT_PROMISOR_ONLY);
+		}
+		promisor_objects_prepared = 1;
+	}
+	return oidset_contains(&promisor_objects, oid);
+}

diff --git a/packfile.h b/packfile.h
index 0cdeb54..a7fca59 100644
--- a/packfile.h
+++ b/packfile.h

@@ -1,6 +1,8 @@
 #ifndef PACKFILE_H
 #define PACKFILE_H
 
+#include "oidset.h"
+
 /*
  * Generate the filename to be used for a pack file with checksum "sha1" and
  * extension "ext". The result is written into the strbuf "buf", overwriting
@@ -125,6 +127,11 @@ extern int has_sha1_pack(const unsigned char *sha1);
 extern int has_pack_index(const unsigned char *sha1);
 
 /*
+ * Only iterate over packs obtained from the promisor remote.
+ */
+#define FOR_EACH_OBJECT_PROMISOR_ONLY 2
+
+/*
  * Iterate over packed objects in both the local
  * repository and any alternates repositories (unless the
  * FOR_EACH_OBJECT_LOCAL_ONLY flag, defined in cache.h, is set).
@@ -135,4 +142,10 @@ typedef int each_packed_object_fn(const struct object_id *oid,
 				  void *data);
 extern int for_each_packed_object(each_packed_object_fn, void *, unsigned flags);
 
+/*
+ * Return 1 if an object in a promisor packfile is or refers to the given
+ * object, 0 otherwise.
+ */
+extern int is_promisor_object(const struct object_id *oid);
+
 #endif

diff --git a/parse-options.c b/parse-options.c
index fca7159..d02eb8b 100644
--- a/parse-options.c
+++ b/parse-options.c

@@ -525,7 +525,7 @@ int parse_options_step(struct parse_opt_ctx_t *ctx,
 
 int parse_options_end(struct parse_opt_ctx_t *ctx)
 {
-	memmove(ctx->out + ctx->cpidx, ctx->argv, ctx->argc * sizeof(*ctx->out));
+	MOVE_ARRAY(ctx->out + ctx->cpidx, ctx->argv, ctx->argc);
 	ctx->out[ctx->cpidx + ctx->argc] = NULL;
 	return ctx->cpidx + ctx->argc;
 }

diff --git a/perl/.gitignore b/perl/.gitignore
index 0f1fc27..84c048a 100644
--- a/perl/.gitignore
+++ b/perl/.gitignore

@@ -1,8 +1 @@
-perl.mak
-perl.mak.old
-MYMETA.json
-MYMETA.yml
-blib
-blibdirs
-pm_to_blib
-PM.stamp
+/build/

diff --git a/perl/Git.pm b/perl/Git.pm
index ffa09ac..9d60d79 100644
--- a/perl/Git.pm
+++ b/perl/Git.pm

@@ -101,7 +101,7 @@
 
 
 use Carp qw(carp croak); # but croak is bad - throw instead
-use Error qw(:try);
+use Git::Error qw(:try);
 use Cwd qw(abs_path cwd);
 use IPC::Open2 qw(open2);
 use Fcntl qw(SEEK_SET SEEK_CUR);
@@ -880,77 +880,6 @@
 	return "$ident[0] <$ident[1]>";
 }
 
-=item parse_mailboxes
-
-Return an array of mailboxes extracted from a string.
-
-=cut
-
-# Very close to Mail::Address's parser, but we still have minor
-# differences in some cases (see t9000 for examples).
-sub parse_mailboxes {
-	my $re_comment = qr/\((?:[^)]*)\)/;
-	my $re_quote = qr/"(?:[^\"\\]|\\.)*"/;
-	my $re_word = qr/(?:[^]["\s()<>:;@\\,.]|\\.)+/;
-
-	# divide the string in tokens of the above form
-	my $re_token = qr/(?:$re_quote|$re_word|$re_comment|\S)/;
-	my @tokens = map { $_ =~ /\s*($re_token)\s*/g } @_;
-	my $end_of_addr_seen = 0;
-
-	# add a delimiter to simplify treatment for the last mailbox
-	push @tokens, ",";
-
-	my (@addr_list, @phrase, @address, @comment, @buffer) = ();
-	foreach my $token (@tokens) {
-		if ($token =~ /^[,;]$/) {
-			# if buffer still contains undeterminated strings
-			# append it at the end of @address or @phrase
-			if ($end_of_addr_seen) {
-				push @phrase, @buffer;
-			} else {
-				push @address, @buffer;
-			}
-
-			my $str_phrase = join ' ', @phrase;
-			my $str_address = join '', @address;
-			my $str_comment = join ' ', @comment;
-
-			# quote are necessary if phrase contains
-			# special characters
-			if ($str_phrase =~ /[][()<>:;@\\,.\000-\037\177]/) {
-				$str_phrase =~ s/(^|[^\\])"/$1/g;
-				$str_phrase = qq["$str_phrase"];
-			}
-
-			# add "<>" around the address if necessary
-			if ($str_address ne "" && $str_phrase ne "") {
-				$str_address = qq[<$str_address>];
-			}
-
-			my $str_mailbox = "$str_phrase $str_address $str_comment";
-			$str_mailbox =~ s/^\s*|\s*$//g;
-			push @addr_list, $str_mailbox if ($str_mailbox);
-
-			@phrase = @address = @comment = @buffer = ();
-			$end_of_addr_seen = 0;
-		} elsif ($token =~ /^\(/) {
-			push @comment, $token;
-		} elsif ($token eq "<") {
-			push @phrase, (splice @address), (splice @buffer);
-		} elsif ($token eq ">") {
-			$end_of_addr_seen = 1;
-			push @address, (splice @buffer);
-		} elsif ($token eq "@" && !$end_of_addr_seen) {
-			push @address, (splice @buffer), "@";
-		} else {
-			push @buffer, $token;
-		}
-	}
-
-	return @addr_list;
-}
-
 =item hash_object ( TYPE, FILENAME )
 
 Compute the SHA1 object id of the given C<FILENAME> considering it is

diff --git a/perl/Git/Error.pm b/perl/Git/Error.pm
new file mode 100644
index 0000000..09bbc97
--- /dev/null
+++ b/perl/Git/Error.pm

@@ -0,0 +1,46 @@
+package Git::Error;
+use 5.008;
+use strict;
+use warnings;
+
+=head1 NAME
+
+Git::Error - Wrapper for the L<Error> module, in case it's not installed
+
+=head1 DESCRIPTION
+
+Wraps the import function for the L<Error> module.
+
+This module is only intended to be used for code shipping in the
+C<git.git> repository. Use it for anything else at your peril!
+
+=cut
+
+sub import {
+    shift;
+    my $caller = caller;
+
+    eval {
+	require Error;
+	1;
+    } or do {
+	my $error = $@ || "Zombie Error";
+
+	my $Git_Error_pm_path = $INC{"Git/Error.pm"} || die "BUG: Should have our own path from %INC!";
+
+	require File::Basename;
+	my $Git_Error_pm_root = File::Basename::dirname($Git_Error_pm_path) || die "BUG: Can't figure out lib/Git dirname from '$Git_Error_pm_path'!";
+
+	require File::Spec;
+	my $Git_pm_FromCPAN_root = File::Spec->catdir($Git_Error_pm_root, 'FromCPAN');
+	die "BUG: '$Git_pm_FromCPAN_root' should be a directory!" unless -d $Git_pm_FromCPAN_root;
+
+	local @INC = ($Git_pm_FromCPAN_root, @INC);
+	require Error;
+    };
+
+    unshift @_, $caller;
+    goto &Error::import;
+}
+
+1;

diff --git a/perl/private-Error.pm b/perl/Git/FromCPAN/Error.pm
similarity index 100%
rename from perl/private-Error.pm
rename to perl/Git/FromCPAN/Error.pm


diff --git a/perl/Git/FromCPAN/Mail/Address.pm b/perl/Git/FromCPAN/Mail/Address.pm
new file mode 100644
index 0000000..13b2ff7
--- /dev/null
+++ b/perl/Git/FromCPAN/Mail/Address.pm

@@ -0,0 +1,276 @@
+# Copyrights 1995-2017 by [Mark Overmeer <perl@overmeer.net>].
+#  For other contributors see ChangeLog.
+# See the manual pages for details on the licensing terms.
+# Pod stripped from pm file by OODoc 2.02.
+package Mail::Address;
+use vars '$VERSION';
+$VERSION = '2.19';
+
+use strict;
+
+use Carp;
+
+# use locale;   removed in version 1.78, because it causes taint problems
+
+sub Version { our $VERSION }
+
+
+
+# given a comment, attempt to extract a person's name
+sub _extract_name
+{   # This function can be called as method as well
+    my $self = @_ && ref $_[0] ? shift : undef;
+
+    local $_ = shift
+        or return '';
+
+    # Using encodings, too hard. See Mail::Message::Field::Full.
+    return '' if m/\=\?.*?\?\=/;
+
+    # trim whitespace
+    s/^\s+//;
+    s/\s+$//;
+    s/\s+/ /;
+
+    # Disregard numeric names (e.g. 123456.1234@compuserve.com)
+    return "" if /^[\d ]+$/;
+
+    s/^\((.*)\)$/$1/; # remove outermost parenthesis
+    s/^"(.*)"$/$1/;   # remove outer quotation marks
+    s/\(.*?\)//g;     # remove minimal embedded comments
+    s/\\//g;          # remove all escapes
+    s/^"(.*)"$/$1/;   # remove internal quotation marks
+    s/^([^\s]+) ?, ?(.*)$/$2 $1/; # reverse "Last, First M." if applicable
+    s/,.*//;
+
+    # Change casing only when the name contains only upper or only
+    # lower cased characters.
+    unless( m/[A-Z]/ && m/[a-z]/ )
+    {   # Set the case of the name to first char upper rest lower
+        s/\b(\w+)/\L\u$1/igo;  # Upcase first letter on name
+        s/\bMc(\w)/Mc\u$1/igo; # Scottish names such as 'McLeod'
+        s/\bo'(\w)/O'\u$1/igo; # Irish names such as 'O'Malley, O'Reilly'
+        s/\b(x*(ix)?v*(iv)?i*)\b/\U$1/igo; # Roman numerals, eg 'Level III Support'
+    }
+
+    # some cleanup
+    s/\[[^\]]*\]//g;
+    s/(^[\s'"]+|[\s'"]+$)//g;
+    s/\s{2,}/ /g;
+
+    $_;
+}
+
+sub _tokenise
+{   local $_ = join ',', @_;
+    my (@words,$snippet,$field);
+
+    s/\A\s+//;
+    s/[\r\n]+/ /g;
+
+    while ($_ ne '')
+    {   $field = '';
+        if(s/^\s*\(/(/ )    # (...)
+        {   my $depth = 0;
+
+     PAREN: while(s/^(\(([^\(\)\\]|\\.)*)//)
+            {   $field .= $1;
+                $depth++;
+                while(s/^(([^\(\)\\]|\\.)*\)\s*)//)
+                {   $field .= $1;
+                    last PAREN unless --$depth;
+	            $field .= $1 if s/^(([^\(\)\\]|\\.)+)//;
+                }
+            }
+
+            carp "Unmatched () '$field' '$_'"
+                if $depth;
+
+            $field =~ s/\s+\Z//;
+            push @words, $field;
+
+            next;
+        }
+
+        if( s/^("(?:[^"\\]+|\\.)*")\s*//       # "..."
+         || s/^(\[(?:[^\]\\]+|\\.)*\])\s*//    # [...]
+         || s/^([^\s()<>\@,;:\\".[\]]+)\s*//
+         || s/^([()<>\@,;:\\".[\]])\s*//
+          )
+        {   push @words, $1;
+            next;
+        }
+
+        croak "Unrecognised line: $_";
+    }
+
+    push @words, ",";
+    \@words;
+}
+
+sub _find_next
+{   my ($idx, $tokens, $len) = @_;
+
+    while($idx < $len)
+    {   my $c = $tokens->[$idx];
+        return $c if $c eq ',' || $c eq ';' || $c eq '<';
+        $idx++;
+    }
+
+    "";
+}
+
+sub _complete
+{   my ($class, $phrase, $address, $comment) = @_;
+
+    @$phrase || @$comment || @$address
+       or return undef;
+
+    my $o = $class->new(join(" ",@$phrase), join("",@$address), join(" ",@$comment));
+    @$phrase = @$address = @$comment = ();
+    $o;
+}
+
+#------------
+
+sub new(@)
+{   my $class = shift;
+    bless [@_], $class;
+}
+
+
+sub parse(@)
+{   my $class = shift;
+    my @line  = grep {defined} @_;
+    my $line  = join '', @line;
+
+    my (@phrase, @comment, @address, @objs);
+    my ($depth, $idx) = (0, 0);
+
+    my $tokens  = _tokenise @line;
+    my $len     = @$tokens;
+    my $next    = _find_next $idx, $tokens, $len;
+
+    local $_;
+    for(my $idx = 0; $idx < $len; $idx++)
+    {   $_ = $tokens->[$idx];
+
+        if(substr($_,0,1) eq '(') { push @comment, $_ }
+        elsif($_ eq '<')    { $depth++ }
+        elsif($_ eq '>')    { $depth-- if $depth }
+        elsif($_ eq ',' || $_ eq ';')
+        {   warn "Unmatched '<>' in $line" if $depth;
+            my $o = $class->_complete(\@phrase, \@address, \@comment);
+            push @objs, $o if defined $o;
+            $depth = 0;
+            $next = _find_next $idx+1, $tokens, $len;
+        }
+        elsif($depth)       { push @address, $_ }
+        elsif($next eq '<') { push @phrase,  $_ }
+        elsif( /^[.\@:;]$/ || !@address || $address[-1] =~ /^[.\@:;]$/ )
+        {   push @address, $_ }
+        else
+        {   warn "Unmatched '<>' in $line" if $depth;
+            my $o = $class->_complete(\@phrase, \@address, \@comment);
+            push @objs, $o if defined $o;
+            $depth = 0;
+            push @address, $_;
+        }
+    }
+    @objs;
+}
+
+#------------
+
+sub phrase  { shift->set_or_get(0, @_) }
+sub address { shift->set_or_get(1, @_) }
+sub comment { shift->set_or_get(2, @_) }
+
+sub set_or_get($)
+{   my ($self, $i) = (shift, shift);
+    @_ or return $self->[$i];
+
+    my $val = $self->[$i];
+    $self->[$i] = shift if @_;
+    $val;
+}
+
+
+my $atext = '[\-\w !#$%&\'*+/=?^`{|}~]';
+sub format
+{   my @addrs;
+
+    foreach (@_)
+    {   my ($phrase, $email, $comment) = @$_;
+        my @addr;
+
+        if(defined $phrase && length $phrase)
+        {   push @addr
+              , $phrase =~ /^(?:\s*$atext\s*)+$/o ? $phrase
+              : $phrase =~ /(?<!\\)"/             ? $phrase
+              :                                    qq("$phrase");
+
+            push @addr, "<$email>"
+                if defined $email && length $email;
+        }
+        elsif(defined $email && length $email)
+        {   push @addr, $email;
+        }
+
+        if(defined $comment && $comment =~ /\S/)
+        {   $comment =~ s/^\s*\(?/(/;
+            $comment =~ s/\)?\s*$/)/;
+        }
+
+        push @addr, $comment
+            if defined $comment && length $comment;
+
+        push @addrs, join(" ", @addr)
+            if @addr;
+    }
+
+    join ", ", @addrs;
+}
+
+#------------
+
+sub name
+{   my $self   = shift;
+    my $phrase = $self->phrase;
+    my $addr   = $self->address;
+
+    $phrase    = $self->comment
+        unless defined $phrase && length $phrase;
+
+    my $name   = $self->_extract_name($phrase);
+
+    # first.last@domain address
+    if($name eq '' && $addr =~ /([^\%\.\@_]+([\._][^\%\.\@_]+)+)[\@\%]/)
+    {   ($name  = $1) =~ s/[\._]+/ /g;
+	$name   = _extract_name $name;
+    }
+
+    if($name eq '' && $addr =~ m#/g=#i)    # X400 style address
+    {   my ($f) = $addr =~ m#g=([^/]*)#i;
+	my ($l) = $addr =~ m#s=([^/]*)#i;
+	$name   = _extract_name "$f $l";
+    }
+
+    length $name ? $name : undef;
+}
+
+
+sub host
+{   my $addr = shift->address || '';
+    my $i    = rindex $addr, '@';
+    $i >= 0 ? substr($addr, $i+1) : undef;
+}
+
+
+sub user
+{   my $addr = shift->address || '';
+    my $i    = rindex $addr, '@';
+    $i >= 0 ? substr($addr,0,$i) : $addr;
+}
+
+1;

diff --git a/perl/Git/I18N.pm b/perl/Git/I18N.pm
index 836a5c2..dba96ff 100644
--- a/perl/Git/I18N.pm
+++ b/perl/Git/I18N.pm

@@ -18,7 +18,7 @@
 
 sub __bootstrap_locale_messages {
 	our $TEXTDOMAIN = 'git';
-	our $TEXTDOMAINDIR = $ENV{GIT_TEXTDOMAINDIR} || '++LOCALEDIR++';
+	our $TEXTDOMAINDIR = $ENV{GIT_TEXTDOMAINDIR} || '@@LOCALEDIR@@';
 
 	require POSIX;
 	POSIX->import(qw(setlocale));

diff --git a/perl/Git/Mail/Address.pm b/perl/Git/Mail/Address.pm
new file mode 100755
index 0000000..2ce3e84
--- /dev/null
+++ b/perl/Git/Mail/Address.pm

@@ -0,0 +1,24 @@
+package Git::Mail::Address;
+use 5.008;
+use strict;
+use warnings;
+
+=head1 NAME
+
+Git::Mail::Address - Wrapper for the L<Mail::Address> module, in case it's not installed
+
+=head1 DESCRIPTION
+
+This module is only intended to be used for code shipping in the
+C<git.git> repository. Use it for anything else at your peril!
+
+=cut
+
+eval {
+    require Mail::Address;
+    1;
+} or do {
+    require Git::FromCPAN::Mail::Address;
+};
+
+1;

diff --git a/perl/Makefile b/perl/Makefile
deleted file mode 100644
index f657de2..0000000
--- a/perl/Makefile
+++ /dev/null

@@ -1,90 +0,0 @@
-#
-# Makefile for perl support modules and routine
-#
-makfile:=perl.mak
-modules =
-
-PERL_PATH_SQ = $(subst ','\'',$(PERL_PATH))
-prefix_SQ = $(subst ','\'',$(prefix))
-localedir_SQ = $(subst ','\'',$(localedir))
-
-ifndef V
-	QUIET = @
-endif
-
-all install instlibdir: $(makfile)
-	$(QUIET)$(MAKE) -f $(makfile) $@
-
-clean:
-	$(QUIET)test -f $(makfile) && $(MAKE) -f $(makfile) $@ || exit 0
-	$(RM) ppport.h
-	$(RM) $(makfile)
-	$(RM) $(makfile).old
-	$(RM) PM.stamp
-
-$(makfile): PM.stamp
-
-ifdef NO_PERL_MAKEMAKER
-instdir_SQ = $(subst ','\'',$(prefix)/lib)
-
-modules += Git
-modules += Git/I18N
-modules += Git/IndexInfo
-modules += Git/Packet
-modules += Git/SVN
-modules += Git/SVN/Memoize/YAML
-modules += Git/SVN/Fetcher
-modules += Git/SVN/Editor
-modules += Git/SVN/GlobSpec
-modules += Git/SVN/Log
-modules += Git/SVN/Migration
-modules += Git/SVN/Prompt
-modules += Git/SVN/Ra
-modules += Git/SVN/Utils
-
-$(makfile): ../GIT-CFLAGS Makefile
-	echo all: private-Error.pm Git.pm Git/I18N.pm > $@
-	set -e; \
-	for i in $(modules); \
-	do \
-		if test $$i = $${i%/*}; \
-		then \
-			subdir=; \
-		else \
-			subdir=/$${i%/*}; \
-		fi; \
-		echo '	$(RM) blib/lib/'$$i'.pm' >> $@; \
-		echo '	mkdir -p blib/lib'$$subdir >> $@; \
-		echo '	cp '$$i'.pm blib/lib/'$$i'.pm' >> $@; \
-	done
-	echo '	$(RM) blib/lib/Error.pm' >> $@
-	'$(PERL_PATH_SQ)' -MError -e 'exit($$Error::VERSION < 0.15009)' || \
-	echo '	cp private-Error.pm blib/lib/Error.pm' >> $@
-	echo install: >> $@
-	set -e; \
-	for i in $(modules); \
-	do \
-		if test $$i = $${i%/*}; \
-		then \
-			subdir=; \
-		else \
-			subdir=/$${i%/*}; \
-		fi; \
-		echo '	$(RM) "$$(DESTDIR)$(instdir_SQ)/'$$i'.pm"' >> $@; \
-		echo '	mkdir -p "$$(DESTDIR)$(instdir_SQ)'$$subdir'"' >> $@; \
-		echo '	cp '$$i'.pm "$$(DESTDIR)$(instdir_SQ)/'$$i'.pm"' >> $@; \
-	done
-	echo '	$(RM) "$$(DESTDIR)$(instdir_SQ)/Error.pm"' >> $@
-	'$(PERL_PATH_SQ)' -MError -e 'exit($$Error::VERSION < 0.15009)' || \
-	echo '	cp private-Error.pm "$$(DESTDIR)$(instdir_SQ)/Error.pm"' >> $@
-	echo instlibdir: >> $@
-	echo '	echo $(instdir_SQ)' >> $@
-else
-$(makfile): Makefile.PL ../GIT-CFLAGS
-	$(PERL_PATH) $< PREFIX='$(prefix_SQ)' INSTALL_BASE='' --localedir='$(localedir_SQ)'
-endif
-
-# this is just added comfort for calling make directly in perl dir
-# (even though GIT-CFLAGS aren't used yet. If ever)
-../GIT-CFLAGS:
-	$(MAKE) -C .. GIT-CFLAGS

diff --git a/perl/Makefile.PL b/perl/Makefile.PL
deleted file mode 100644
index 3f29ba9..0000000
--- a/perl/Makefile.PL
+++ /dev/null

@@ -1,62 +0,0 @@
-use strict;
-use warnings;
-use ExtUtils::MakeMaker;
-use Getopt::Long;
-use File::Find;
-
-# Don't forget to update the perl/Makefile, too.
-# Don't forget to test with NO_PERL_MAKEMAKER=YesPlease
-
-# Sanity: die at first unknown option
-Getopt::Long::Configure qw/ pass_through /;
-
-my $localedir = '';
-GetOptions("localedir=s" => \$localedir);
-
-sub MY::postamble {
-	return <<'MAKE_FRAG';
-instlibdir:
-	@echo '$(INSTALLSITELIB)'
-
-ifneq (,$(DESTDIR))
-ifeq (0,$(shell expr '$(MM_VERSION)' '>' 6.10))
-$(error ExtUtils::MakeMaker version "$(MM_VERSION)" is older than 6.11 and so \
-	is likely incompatible with the DESTDIR mechanism.  Try setting \
-	NO_PERL_MAKEMAKER=1 instead)
-endif
-endif
-
-MAKE_FRAG
-}
-
-# Find all the .pm files in "Git/" and Git.pm
-my %pm;
-find sub {
-	return unless /\.pm$/;
-
-	# sometimes File::Find prepends a ./  Strip it.
-	my $pm_path = $File::Find::name;
-	$pm_path =~ s{^\./}{};
-
-	$pm{$pm_path} = '$(INST_LIBDIR)/'.$pm_path;
-}, "Git", "Git.pm";
-
-
-# We come with our own bundled Error.pm. It's not in the set of default
-# Perl modules so install it if it's not available on the system yet.
-if ( !eval { require Error } || $Error::VERSION < 0.15009) {
-	$pm{'private-Error.pm'} = '$(INST_LIBDIR)/Error.pm';
-}
-
-# redirect stdout, otherwise the message "Writing perl.mak for Git"
-# disrupts the output for the target 'instlibdir'
-open STDOUT, ">&STDERR";
-
-WriteMakefile(
-	NAME            => 'Git',
-	VERSION_FROM    => 'Git.pm',
-	PM		=> \%pm,
-	PM_FILTER	=> qq[\$(PERL) -pe "s<\\Q++LOCALEDIR++\\E><$localedir>"],
-	MAKEFILE	=> 'perl.mak',
-	INSTALLSITEMAN3DIR => '$(SITEPREFIX)/share/man/man3'
-);

diff --git a/preload-index.c b/preload-index.c
index 2a83255..4d08d44 100644
--- a/preload-index.c
+++ b/preload-index.c

@@ -78,6 +78,7 @@ static void preload_index(struct index_state *index,
 {
 	int threads, i, work, offset;
 	struct thread_data data[MAX_PARALLEL];
+	uint64_t start = getnanotime();
 
 	if (!core_preload_index)
 		return;
@@ -108,6 +109,7 @@ static void preload_index(struct index_state *index,
 		if (pthread_join(p->pthread, NULL))
 			die("unable to join threaded lstat");
 	}
+	trace_performance_since(start, "preload index");
 }
 #endif
 

diff --git a/quote.c b/quote.c
index de2922d..37d2686 100644
--- a/quote.c
+++ b/quote.c

@@ -43,6 +43,22 @@ void sq_quote_buf(struct strbuf *dst, const char *src)
 	free(to_free);
 }
 
+void sq_quote_buf_pretty(struct strbuf *dst, const char *src)
+{
+	static const char ok_punct[] = "+,-./:=@_^";
+	const char *p;
+
+	for (p = src; *p; p++) {
+		if (!isalpha(*p) && !isdigit(*p) && !strchr(ok_punct, *p)) {
+			sq_quote_buf(dst, src);
+			return;
+		}
+	}
+
+	/* if we get here, we did not need quoting */
+	strbuf_addstr(dst, src);
+}
+
 void sq_quotef(struct strbuf *dst, const char *fmt, ...)
 {
 	struct strbuf src = STRBUF_INIT;
@@ -56,7 +72,7 @@ void sq_quotef(struct strbuf *dst, const char *fmt, ...)
 	strbuf_release(&src);
 }
 
-void sq_quote_argv(struct strbuf *dst, const char** argv, size_t maxlen)
+void sq_quote_argv(struct strbuf *dst, const char **argv)
 {
 	int i;
 
@@ -65,8 +81,16 @@ void sq_quote_argv(struct strbuf *dst, const char** argv, size_t maxlen)
 	for (i = 0; argv[i]; ++i) {
 		strbuf_addch(dst, ' ');
 		sq_quote_buf(dst, argv[i]);
-		if (maxlen && dst->len > maxlen)
-			die("Too many or long arguments");
+	}
+}
+
+void sq_quote_argv_pretty(struct strbuf *dst, const char **argv)
+{
+	int i;
+
+	for (i = 0; argv[i]; i++) {
+		strbuf_addch(dst, ' ');
+		sq_quote_buf_pretty(dst, argv[i]);
 	}
 }
 

diff --git a/quote.h b/quote.h
index 66f5644..ea992dc 100644
--- a/quote.h
+++ b/quote.h

@@ -30,9 +30,17 @@ struct strbuf;
  */
 
 extern void sq_quote_buf(struct strbuf *, const char *src);
-extern void sq_quote_argv(struct strbuf *, const char **argv, size_t maxlen);
+extern void sq_quote_argv(struct strbuf *, const char **argv);
 extern void sq_quotef(struct strbuf *, const char *fmt, ...);
 
+/*
+ * These match their non-pretty variants, except that they avoid
+ * quoting when there are no exotic characters. These should only be used for
+ * human-readable output, as sq_dequote() is not smart enough to dequote it.
+ */
+void sq_quote_buf_pretty(struct strbuf *, const char *src);
+void sq_quote_argv_pretty(struct strbuf *, const char **argv);
+
 /* This unwraps what sq_quote() produces in place, but returns
  * NULL if the input does not look like what sq_quote would have
  * produced.

diff --git a/read-cache.c b/read-cache.c
index 2eb81a6..28bf0db 100644
--- a/read-cache.c
+++ b/read-cache.c

@@ -631,10 +631,10 @@ static struct cache_entry *create_alias_ce(struct index_state *istate,
 
 void set_object_name_for_intent_to_add_entry(struct cache_entry *ce)
 {
-	unsigned char sha1[20];
-	if (write_sha1_file("", 0, blob_type, sha1))
+	struct object_id oid;
+	if (write_object_file("", 0, blob_type, &oid))
 		die("cannot create an empty blob in the object database");
-	hashcpy(ce->oid.hash, sha1);
+	oidcpy(&ce->oid, &oid);
 }
 
 int add_to_index(struct index_state *istate, const char *path, struct stat *st, int flags)
@@ -1217,9 +1217,8 @@ int add_index_entry(struct index_state *istate, struct cache_entry *ce, int opti
 	/* Add it in.. */
 	istate->cache_nr++;
 	if (istate->cache_nr > pos + 1)
-		memmove(istate->cache + pos + 1,
-			istate->cache + pos,
-			(istate->cache_nr - pos - 1) * sizeof(ce));
+		MOVE_ARRAY(istate->cache + pos + 1, istate->cache + pos,
+			   istate->cache_nr - pos - 1);
 	set_index_entry(istate, pos, ce);
 	istate->cache_changed |= CE_ENTRY_ADDED;
 	return 0;
@@ -1372,6 +1371,7 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 	const char *typechange_fmt;
 	const char *added_fmt;
 	const char *unmerged_fmt;
+	uint64_t start = getnanotime();
 
 	modified_fmt = (in_porcelain ? "M\t%s\n" : "%s: needs update\n");
 	deleted_fmt = (in_porcelain ? "D\t%s\n" : "%s: needs update\n");
@@ -1442,6 +1442,7 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 
 		replace_index_entry(istate, i, new);
 	}
+	trace_performance_since(start, "refresh index");
 	return has_errors;
 }
 
@@ -1545,8 +1546,8 @@ int verify_ce_order;
 
 static int verify_hdr(struct cache_header *hdr, unsigned long size)
 {
-	git_SHA_CTX c;
-	unsigned char sha1[20];
+	git_hash_ctx c;
+	unsigned char hash[GIT_MAX_RAWSZ];
 	int hdr_version;
 
 	if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
@@ -1558,10 +1559,10 @@ static int verify_hdr(struct cache_header *hdr, unsigned long size)
 	if (!verify_index_checksum)
 		return 0;
 
-	git_SHA1_Init(&c);
-	git_SHA1_Update(&c, hdr, size - 20);
-	git_SHA1_Final(sha1, &c);
-	if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
+	the_hash_algo->init_fn(&c);
+	the_hash_algo->update_fn(&c, hdr, size - the_hash_algo->rawsz);
+	the_hash_algo->final_fn(hash, &c);
+	if (hashcmp(hash, (unsigned char *)hdr + size - the_hash_algo->rawsz))
 		return error("bad index file sha1 signature");
 	return 0;
 }
@@ -1603,7 +1604,7 @@ int hold_locked_index(struct lock_file *lk, int lock_flags)
 
 int read_index(struct index_state *istate)
 {
-	return read_index_from(istate, get_index_file());
+	return read_index_from(istate, get_index_file(), get_git_dir());
 }
 
 static struct cache_entry *cache_entry_from_ondisk(struct ondisk_cache_entry *ondisk,
@@ -1791,7 +1792,7 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist)
 		die_errno("cannot stat the open index");
 
 	mmap_size = xsize_t(st.st_size);
-	if (mmap_size < sizeof(struct cache_header) + 20)
+	if (mmap_size < sizeof(struct cache_header) + the_hash_algo->rawsz)
 		die("index file smaller than expected");
 
 	mmap = xmmap(NULL, mmap_size, PROT_READ, MAP_PRIVATE, fd, 0);
@@ -1803,7 +1804,7 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist)
 	if (verify_hdr(hdr, mmap_size) < 0)
 		goto unmap;
 
-	hashcpy(istate->sha1, (const unsigned char *)hdr + mmap_size - 20);
+	hashcpy(istate->sha1, (const unsigned char *)hdr + mmap_size - the_hash_algo->rawsz);
 	istate->version = ntohl(hdr->hdr_version);
 	istate->cache_nr = ntohl(hdr->hdr_entries);
 	istate->cache_alloc = alloc_nr(istate->cache_nr);
@@ -1831,7 +1832,7 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist)
 	istate->timestamp.sec = st.st_mtime;
 	istate->timestamp.nsec = ST_MTIME_NSEC(st);
 
-	while (src_offset <= mmap_size - 20 - 8) {
+	while (src_offset <= mmap_size - the_hash_algo->rawsz - 8) {
 		/* After an array of active_nr index entries,
 		 * there can be arbitrary number of extended
 		 * sections, each of which is prefixed with
@@ -1863,26 +1864,27 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist)
  * This way, shared index can be removed if they have not been used
  * for some time.
  */
-static void freshen_shared_index(char *base_sha1_hex, int warn)
+static void freshen_shared_index(const char *shared_index, int warn)
 {
-	char *shared_index = git_pathdup("sharedindex.%s", base_sha1_hex);
 	if (!check_and_freshen_file(shared_index, 1) && warn)
 		warning("could not freshen shared index '%s'", shared_index);
-	free(shared_index);
 }
 
-int read_index_from(struct index_state *istate, const char *path)
+int read_index_from(struct index_state *istate, const char *path,
+		    const char *gitdir)
 {
+	uint64_t start = getnanotime();
 	struct split_index *split_index;
 	int ret;
 	char *base_sha1_hex;
-	const char *base_path;
+	char *base_path;
 
 	/* istate->initialized covers both .git/index and .git/sharedindex.xxx */
 	if (istate->initialized)
 		return istate->cache_nr;
 
 	ret = do_read_index(istate, path, 0);
+	trace_performance_since(start, "read cache %s", path);
 
 	split_index = istate->split_index;
 	if (!split_index || is_null_sha1(split_index->base_sha1)) {
@@ -1896,16 +1898,18 @@ int read_index_from(struct index_state *istate, const char *path)
 		split_index->base = xcalloc(1, sizeof(*split_index->base));
 
 	base_sha1_hex = sha1_to_hex(split_index->base_sha1);
-	base_path = git_path("sharedindex.%s", base_sha1_hex);
+	base_path = xstrfmt("%s/sharedindex.%s", gitdir, base_sha1_hex);
 	ret = do_read_index(split_index->base, base_path, 1);
 	if (hashcmp(split_index->base_sha1, split_index->base->sha1))
 		die("broken index, expect %s in %s, got %s",
 		    base_sha1_hex, base_path,
 		    sha1_to_hex(split_index->base->sha1));
 
-	freshen_shared_index(base_sha1_hex, 0);
+	freshen_shared_index(base_path, 0);
 	merge_base_index(istate);
 	post_read_index_from(istate);
+	trace_performance_since(start, "read cache %s", base_path);
+	free(base_path);
 	return ret;
 }
 
@@ -1957,11 +1961,11 @@ int unmerged_index(const struct index_state *istate)
 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
 static unsigned long write_buffer_len;
 
-static int ce_write_flush(git_SHA_CTX *context, int fd)
+static int ce_write_flush(git_hash_ctx *context, int fd)
 {
 	unsigned int buffered = write_buffer_len;
 	if (buffered) {
-		git_SHA1_Update(context, write_buffer, buffered);
+		the_hash_algo->update_fn(context, write_buffer, buffered);
 		if (write_in_full(fd, write_buffer, buffered) < 0)
 			return -1;
 		write_buffer_len = 0;
@@ -1969,7 +1973,7 @@ static int ce_write_flush(git_SHA_CTX *context, int fd)
 	return 0;
 }
 
-static int ce_write(git_SHA_CTX *context, int fd, void *data, unsigned int len)
+static int ce_write(git_hash_ctx *context, int fd, void *data, unsigned int len)
 {
 	while (len) {
 		unsigned int buffered = write_buffer_len;
@@ -1991,7 +1995,7 @@ static int ce_write(git_SHA_CTX *context, int fd, void *data, unsigned int len)
 	return 0;
 }
 
-static int write_index_ext_header(git_SHA_CTX *context, int fd,
+static int write_index_ext_header(git_hash_ctx *context, int fd,
 				  unsigned int ext, unsigned int sz)
 {
 	ext = htonl(ext);
@@ -2000,26 +2004,26 @@ static int write_index_ext_header(git_SHA_CTX *context, int fd,
 		(ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
 }
 
-static int ce_flush(git_SHA_CTX *context, int fd, unsigned char *sha1)
+static int ce_flush(git_hash_ctx *context, int fd, unsigned char *hash)
 {
 	unsigned int left = write_buffer_len;
 
 	if (left) {
 		write_buffer_len = 0;
-		git_SHA1_Update(context, write_buffer, left);
+		the_hash_algo->update_fn(context, write_buffer, left);
 	}
 
-	/* Flush first if not enough space for SHA1 signature */
-	if (left + 20 > WRITE_BUFFER_SIZE) {
+	/* Flush first if not enough space for hash signature */
+	if (left + the_hash_algo->rawsz > WRITE_BUFFER_SIZE) {
 		if (write_in_full(fd, write_buffer, left) < 0)
 			return -1;
 		left = 0;
 	}
 
-	/* Append the SHA1 signature at the end */
-	git_SHA1_Final(write_buffer + left, context);
-	hashcpy(sha1, write_buffer + left);
-	left += 20;
+	/* Append the hash signature at the end */
+	the_hash_algo->final_fn(write_buffer + left, context);
+	hashcpy(hash, write_buffer + left);
+	left += the_hash_algo->rawsz;
 	return (write_in_full(fd, write_buffer, left) < 0) ? -1 : 0;
 }
 
@@ -2100,7 +2104,7 @@ static void copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk,
 	}
 }
 
-static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce,
+static int ce_write_entry(git_hash_ctx *c, int fd, struct cache_entry *ce,
 			  struct strbuf *previous_name, struct ondisk_cache_entry *ondisk)
 {
 	int size;
@@ -2167,7 +2171,7 @@ static int verify_index_from(const struct index_state *istate, const char *path)
 	int fd;
 	ssize_t n;
 	struct stat st;
-	unsigned char sha1[20];
+	unsigned char hash[GIT_MAX_RAWSZ];
 
 	if (!istate->initialized)
 		return 0;
@@ -2179,14 +2183,14 @@ static int verify_index_from(const struct index_state *istate, const char *path)
 	if (fstat(fd, &st))
 		goto out;
 
-	if (st.st_size < sizeof(struct cache_header) + 20)
+	if (st.st_size < sizeof(struct cache_header) + the_hash_algo->rawsz)
 		goto out;
 
-	n = pread_in_full(fd, sha1, 20, st.st_size - 20);
-	if (n != 20)
+	n = pread_in_full(fd, hash, the_hash_algo->rawsz, st.st_size - the_hash_algo->rawsz);
+	if (n != the_hash_algo->rawsz)
 		goto out;
 
-	if (hashcmp(istate->sha1, sha1))
+	if (hashcmp(istate->sha1, hash))
 		goto out;
 
 	close(fd);
@@ -2234,8 +2238,9 @@ void update_index_if_able(struct index_state *istate, struct lock_file *lockfile
 static int do_write_index(struct index_state *istate, struct tempfile *tempfile,
 			  int strip_extensions)
 {
+	uint64_t start = getnanotime();
 	int newfd = tempfile->fd;
-	git_SHA_CTX c;
+	git_hash_ctx c;
 	struct cache_header hdr;
 	int i, err = 0, removed, extended, hdr_version;
 	struct cache_entry **cache = istate->cache;
@@ -2243,7 +2248,7 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile,
 	struct stat st;
 	struct ondisk_cache_entry_extended ondisk;
 	struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
-	int drop_cache_tree = 0;
+	int drop_cache_tree = istate->drop_cache_tree;
 
 	for (i = removed = extended = 0; i < entries; i++) {
 		if (cache[i]->ce_flags & CE_REMOVE)
@@ -2273,7 +2278,7 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile,
 	hdr.hdr_version = htonl(hdr_version);
 	hdr.hdr_entries = htonl(entries - removed);
 
-	git_SHA1_Init(&c);
+	the_hash_algo->init_fn(&c);
 	if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
 		return -1;
 
@@ -2374,6 +2379,7 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile,
 		return -1;
 	istate->timestamp.sec = (unsigned int)st.st_mtime;
 	istate->timestamp.nsec = ST_MTIME_NSEC(st);
+	trace_performance_since(start, "write index, changed mask = %x", istate->cache_changed);
 	return 0;
 }
 
@@ -2472,32 +2478,21 @@ static int clean_shared_index_files(const char *current_hex)
 }
 
 static int write_shared_index(struct index_state *istate,
-			      struct lock_file *lock, unsigned flags)
+			      struct tempfile **temp)
 {
-	struct tempfile *temp;
 	struct split_index *si = istate->split_index;
 	int ret;
 
-	temp = mks_tempfile(git_path("sharedindex_XXXXXX"));
-	if (!temp) {
-		hashclr(si->base_sha1);
-		return do_write_locked_index(istate, lock, flags);
-	}
 	move_cache_to_base_index(istate);
-	ret = do_write_index(si->base, temp, 1);
+	ret = do_write_index(si->base, *temp, 1);
+	if (ret)
+		return ret;
+	ret = adjust_shared_perm(get_tempfile_path(*temp));
 	if (ret) {
-		delete_tempfile(&temp);
+		error("cannot fix permission bits on %s", get_tempfile_path(*temp));
 		return ret;
 	}
-	ret = adjust_shared_perm(get_tempfile_path(temp));
-	if (ret) {
-		int save_errno = errno;
-		error("cannot fix permission bits on %s", get_tempfile_path(temp));
-		delete_tempfile(&temp);
-		errno = save_errno;
-		return ret;
-	}
-	ret = rename_tempfile(&temp,
+	ret = rename_tempfile(temp,
 			      git_path("sharedindex.%s", sha1_to_hex(si->base->sha1)));
 	if (!ret) {
 		hashcpy(si->base_sha1, si->base->sha1);
@@ -2565,7 +2560,22 @@ int write_locked_index(struct index_state *istate, struct lock_file *lock,
 	new_shared_index = istate->cache_changed & SPLIT_INDEX_ORDERED;
 
 	if (new_shared_index) {
-		ret = write_shared_index(istate, lock, flags);
+		struct tempfile *temp;
+		int saved_errno;
+
+		temp = mks_tempfile(git_path("sharedindex_XXXXXX"));
+		if (!temp) {
+			hashclr(si->base_sha1);
+			ret = do_write_locked_index(istate, lock, flags);
+			goto out;
+		}
+		ret = write_shared_index(istate, &temp);
+
+		saved_errno = errno;
+		if (is_tempfile_active(temp))
+			delete_tempfile(&temp);
+		errno = saved_errno;
+
 		if (ret)
 			goto out;
 	}
@@ -2573,8 +2583,11 @@ int write_locked_index(struct index_state *istate, struct lock_file *lock,
 	ret = write_split_index(istate, lock, flags);
 
 	/* Freshen the shared index only if the split-index was written */
-	if (!ret && !new_shared_index)
-		freshen_shared_index(sha1_to_hex(si->base_sha1), 1);
+	if (!ret && !new_shared_index) {
+		const char *shared_index = git_path("sharedindex.%s",
+						    sha1_to_hex(si->base_sha1));
+		freshen_shared_index(shared_index, 1);
+	}
 
 out:
 	if (flags & COMMIT_LOCK)

diff --git a/ref-filter.c b/ref-filter.c
index 3f91617..f9e25ae 100644
--- a/ref-filter.c
+++ b/ref-filter.c

@@ -1995,8 +1995,7 @@ static void do_merge_filter(struct ref_filter_cbdata *ref_cbdata)
 			free_array_item(item);
 	}
 
-	for (i = 0; i < old_nr; i++)
-		clear_commit_marks(to_clear[i], ALL_REV_FLAGS);
+	clear_commit_marks_many(old_nr, to_clear, ALL_REV_FLAGS);
 	clear_commit_marks(filter->merge_commit, ALL_REV_FLAGS);
 	free(to_clear);
 }

diff --git a/refs/files-backend.c b/refs/files-backend.c
index f75d960..bec8e30 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c

@@ -2931,13 +2931,12 @@ static int files_initial_transaction_commit(struct ref_store *ref_store,
 
 	if (initial_ref_transaction_commit(packed_transaction, err)) {
 		ret = TRANSACTION_GENERIC_ERROR;
-		goto cleanup;
 	}
 
+	packed_refs_unlock(refs->packed_ref_store);
 cleanup:
 	if (packed_transaction)
 		ref_transaction_free(packed_transaction);
-	packed_refs_unlock(refs->packed_ref_store);
 	transaction->state = REF_TRANSACTION_CLOSED;
 	string_list_clear(&affected_refnames, 0);
 	return ret;

diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index 023243f..65288c6 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c

@@ -68,17 +68,21 @@ struct snapshot {
 	int mmapped;
 
 	/*
-	 * The contents of the `packed-refs` file. If the file was
-	 * already sorted, this points at the mmapped contents of the
-	 * file. If not, this points at heap-allocated memory
-	 * containing the contents, sorted. If there were no contents
-	 * (e.g., because the file didn't exist), `buf` and `eof` are
-	 * both NULL.
+	 * The contents of the `packed-refs` file:
+	 *
+	 * - buf -- a pointer to the start of the memory
+	 * - start -- a pointer to the first byte of actual references
+	 *   (i.e., after the header line, if one is present)
+	 * - eof -- a pointer just past the end of the reference
+	 *   contents
+	 *
+	 * If the `packed-refs` file was already sorted, `buf` points
+	 * at the mmapped contents of the file. If not, it points at
+	 * heap-allocated memory containing the contents, sorted. If
+	 * there were no contents (e.g., because the file didn't
+	 * exist), `buf`, `start`, and `eof` are all NULL.
 	 */
-	char *buf, *eof;
-
-	/* The size of the header line, if any; otherwise, 0: */
-	size_t header_len;
+	char *buf, *start, *eof;
 
 	/*
 	 * What is the peeled state of the `packed-refs` file that
@@ -169,8 +173,7 @@ static void clear_snapshot_buffer(struct snapshot *snapshot)
 	} else {
 		free(snapshot->buf);
 	}
-	snapshot->buf = snapshot->eof = NULL;
-	snapshot->header_len = 0;
+	snapshot->buf = snapshot->start = snapshot->eof = NULL;
 }
 
 /*
@@ -319,13 +322,14 @@ static void sort_snapshot(struct snapshot *snapshot)
 	size_t len, i;
 	char *new_buffer, *dst;
 
-	pos = snapshot->buf + snapshot->header_len;
+	pos = snapshot->start;
 	eof = snapshot->eof;
-	len = eof - pos;
 
-	if (!len)
+	if (pos == eof)
 		return;
 
+	len = eof - pos;
+
 	/*
 	 * Initialize records based on a crude estimate of the number
 	 * of references in the file (we'll grow it below if needed):
@@ -391,9 +395,8 @@ static void sort_snapshot(struct snapshot *snapshot)
 	 * place:
 	 */
 	clear_snapshot_buffer(snapshot);
-	snapshot->buf = new_buffer;
+	snapshot->buf = snapshot->start = new_buffer;
 	snapshot->eof = new_buffer + len;
-	snapshot->header_len = 0;
 
 cleanup:
 	free(records);
@@ -442,23 +445,26 @@ static const char *find_end_of_record(const char *p, const char *end)
  */
 static void verify_buffer_safe(struct snapshot *snapshot)
 {
-	const char *buf = snapshot->buf + snapshot->header_len;
+	const char *start = snapshot->start;
 	const char *eof = snapshot->eof;
 	const char *last_line;
 
-	if (buf == eof)
+	if (start == eof)
 		return;
 
-	last_line = find_start_of_record(buf, eof - 1);
+	last_line = find_start_of_record(start, eof - 1);
 	if (*(eof - 1) != '\n' || eof - last_line < GIT_SHA1_HEXSZ + 2)
 		die_invalid_line(snapshot->refs->path,
 				 last_line, eof - last_line);
 }
 
+#define SMALL_FILE_SIZE (32*1024)
+
 /*
  * Depending on `mmap_strategy`, either mmap or read the contents of
  * the `packed-refs` file into the snapshot. Return 1 if the file
- * existed and was read, or 0 if the file was absent. Die on errors.
+ * existed and was read, or 0 if the file was absent or empty. Die on
+ * errors.
  */
 static int load_contents(struct snapshot *snapshot)
 {
@@ -489,24 +495,23 @@ static int load_contents(struct snapshot *snapshot)
 		die_errno("couldn't stat %s", snapshot->refs->path);
 	size = xsize_t(st.st_size);
 
-	switch (mmap_strategy) {
-	case MMAP_NONE:
+	if (!size) {
+		return 0;
+	} else if (mmap_strategy == MMAP_NONE || size <= SMALL_FILE_SIZE) {
 		snapshot->buf = xmalloc(size);
 		bytes_read = read_in_full(fd, snapshot->buf, size);
 		if (bytes_read < 0 || bytes_read != size)
 			die_errno("couldn't read %s", snapshot->refs->path);
-		snapshot->eof = snapshot->buf + size;
 		snapshot->mmapped = 0;
-		break;
-	case MMAP_TEMPORARY:
-	case MMAP_OK:
+	} else {
 		snapshot->buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
-		snapshot->eof = snapshot->buf + size;
 		snapshot->mmapped = 1;
-		break;
 	}
 	close(fd);
 
+	snapshot->start = snapshot->buf;
+	snapshot->eof = snapshot->buf + size;
+
 	return 1;
 }
 
@@ -515,9 +520,11 @@ static int load_contents(struct snapshot *snapshot)
  * `refname` starts. If `mustexist` is true and the reference doesn't
  * exist, then return NULL. If `mustexist` is false and the reference
  * doesn't exist, then return the point where that reference would be
- * inserted. In the latter mode, `refname` doesn't have to be a proper
- * reference name; for example, one could search for "refs/replace/"
- * to find the start of any replace references.
+ * inserted, or `snapshot->eof` (which might be NULL) if it would be
+ * inserted at the end of the file. In the latter mode, `refname`
+ * doesn't have to be a proper reference name; for example, one could
+ * search for "refs/replace/" to find the start of any replace
+ * references.
  *
  * The record is sought using a binary search, so `snapshot->buf` must
  * be sorted.
@@ -539,7 +546,7 @@ static const char *find_reference_location(struct snapshot *snapshot,
 	 * preceding records all have reference names that come
 	 * *before* `refname`.
 	 */
-	const char *lo = snapshot->buf + snapshot->header_len;
+	const char *lo = snapshot->start;
 
 	/*
 	 * A pointer to a the first character of a record whose
@@ -547,7 +554,7 @@ static const char *find_reference_location(struct snapshot *snapshot,
 	 */
 	const char *hi = snapshot->eof;
 
-	while (lo < hi) {
+	while (lo != hi) {
 		const char *mid, *rec;
 		int cmp;
 
@@ -616,9 +623,7 @@ static struct snapshot *create_snapshot(struct packed_ref_store *refs)
 
 	/* If the file has a header line, process it: */
 	if (snapshot->buf < snapshot->eof && *snapshot->buf == '#') {
-		struct strbuf tmp = STRBUF_INIT;
-		char *p;
-		const char *eol;
+		char *tmp, *p, *eol;
 		struct string_list traits = STRING_LIST_INIT_NODUP;
 
 		eol = memchr(snapshot->buf, '\n',
@@ -628,9 +633,9 @@ static struct snapshot *create_snapshot(struct packed_ref_store *refs)
 					      snapshot->buf,
 					      snapshot->eof - snapshot->buf);
 
-		strbuf_add(&tmp, snapshot->buf, eol - snapshot->buf);
+		tmp = xmemdupz(snapshot->buf, eol - snapshot->buf);
 
-		if (!skip_prefix(tmp.buf, "# pack-refs with:", (const char **)&p))
+		if (!skip_prefix(tmp, "# pack-refs with:", (const char **)&p))
 			die_invalid_line(refs->path,
 					 snapshot->buf,
 					 snapshot->eof - snapshot->buf);
@@ -647,10 +652,10 @@ static struct snapshot *create_snapshot(struct packed_ref_store *refs)
 		/* perhaps other traits later as well */
 
 		/* The "+ 1" is for the LF character. */
-		snapshot->header_len = eol + 1 - snapshot->buf;
+		snapshot->start = eol + 1;
 
 		string_list_clear(&traits, 0);
-		strbuf_release(&tmp);
+		free(tmp);
 	}
 
 	verify_buffer_safe(snapshot);
@@ -671,13 +676,12 @@ static struct snapshot *create_snapshot(struct packed_ref_store *refs)
 		 * We don't want to leave the file mmapped, so we are
 		 * forced to make a copy now:
 		 */
-		size_t size = snapshot->eof -
-			(snapshot->buf + snapshot->header_len);
+		size_t size = snapshot->eof - snapshot->start;
 		char *buf_copy = xmalloc(size);
 
-		memcpy(buf_copy, snapshot->buf + snapshot->header_len, size);
+		memcpy(buf_copy, snapshot->start, size);
 		clear_snapshot_buffer(snapshot);
-		snapshot->buf = buf_copy;
+		snapshot->buf = snapshot->start = buf_copy;
 		snapshot->eof = buf_copy + size;
 	}
 
@@ -924,7 +928,12 @@ static struct ref_iterator *packed_ref_iterator_begin(
 	 */
 	snapshot = get_snapshot(refs);
 
-	if (!snapshot->buf)
+	if (prefix && *prefix)
+		start = find_reference_location(snapshot, prefix, 0);
+	else
+		start = snapshot->start;
+
+	if (start == snapshot->eof)
 		return empty_ref_iterator_begin();
 
 	iter = xcalloc(1, sizeof(*iter));
@@ -934,11 +943,6 @@ static struct ref_iterator *packed_ref_iterator_begin(
 	iter->snapshot = snapshot;
 	acquire_snapshot(snapshot);
 
-	if (prefix && *prefix)
-		start = find_reference_location(snapshot, prefix, 0);
-	else
-		start = snapshot->buf + snapshot->header_len;
-
 	iter->pos = start;
 	iter->eof = snapshot->eof;
 	strbuf_init(&iter->refname_buf, 0);

diff --git a/refs/ref-cache.c b/refs/ref-cache.c
index 82c1cf9..e90bd3e 100644
--- a/refs/ref-cache.c
+++ b/refs/ref-cache.c

@@ -238,10 +238,8 @@ int remove_entry_from_dir(struct ref_dir *dir, const char *refname)
 		return -1;
 	entry = dir->entries[entry_index];
 
-	memmove(&dir->entries[entry_index],
-		&dir->entries[entry_index + 1],
-		(dir->nr - entry_index - 1) * sizeof(*dir->entries)
-		);
+	MOVE_ARRAY(&dir->entries[entry_index],
+		   &dir->entries[entry_index + 1], dir->nr - entry_index - 1);
 	dir->nr--;
 	if (dir->sorted > entry_index)
 		dir->sorted--;

diff --git a/remote-curl.c b/remote-curl.c
index 0053b09..6ec5352 100644
--- a/remote-curl.c
+++ b/remote-curl.c

@@ -24,6 +24,7 @@ struct options {
 	char *deepen_since;
 	struct string_list deepen_not;
 	struct string_list push_options;
+	char *filter;
 	unsigned progress : 1,
 		check_self_contained_and_connected : 1,
 		cloning : 1,
@@ -33,7 +34,9 @@ struct options {
 		thin : 1,
 		/* One of the SEND_PACK_PUSH_CERT_* constants. */
 		push_cert : 2,
-		deepen_relative : 1;
+		deepen_relative : 1,
+		from_promisor : 1,
+		no_dependents : 1;
 };
 static struct options options;
 static struct string_list cas_options = STRING_LIST_INIT_DUP;
@@ -157,6 +160,15 @@ static int set_option(const char *name, const char *value)
 			return -1;
 		return 0;
 #endif /* LIBCURL_VERSION_NUM >= 0x070a08 */
+	} else if (!strcmp(name, "from-promisor")) {
+		options.from_promisor = 1;
+		return 0;
+	} else if (!strcmp(name, "no-dependents")) {
+		options.no_dependents = 1;
+		return 0;
+	} else if (!strcmp(name, "filter")) {
+		options.filter = xstrdup(value);;
+		return 0;
 	} else {
 		return 1 /* unsupported */;
 	}
@@ -822,6 +834,12 @@ static int fetch_git(struct discovery *heads,
 				 options.deepen_not.items[i].string);
 	if (options.deepen_relative && options.depth)
 		argv_array_push(&args, "--deepen-relative");
+	if (options.from_promisor)
+		argv_array_push(&args, "--from-promisor");
+	if (options.no_dependents)
+		argv_array_push(&args, "--no-dependents");
+	if (options.filter)
+		argv_array_pushf(&args, "--filter=%s", options.filter);
 	argv_array_push(&args, url.buf);
 
 	for (i = 0; i < nr_heads; i++) {

diff --git a/replace_object.c b/replace_object.c
index f0b39f0..3e49965 100644
--- a/replace_object.c
+++ b/replace_object.c

@@ -44,10 +44,8 @@ static int register_replace_object(struct replace_object *replace,
 	ALLOC_GROW(replace_object, replace_object_nr + 1, replace_object_alloc);
 	replace_object_nr++;
 	if (pos < replace_object_nr)
-		memmove(replace_object + pos + 1,
-			replace_object + pos,
-			(replace_object_nr - pos - 1) *
-			sizeof(*replace_object));
+		MOVE_ARRAY(replace_object + pos + 1, replace_object + pos,
+			   replace_object_nr - pos - 1);
 	replace_object[pos] = replace;
 	return 0;
 }

diff --git a/repository.c b/repository.c
index f66fcb1..4ffbe9b 100644
--- a/repository.c
+++ b/repository.c

@@ -236,5 +236,5 @@ int repo_read_index(struct repository *repo)
 	if (!repo->index)
 		repo->index = xcalloc(1, sizeof(*repo->index));
 
-	return read_index_from(repo->index, repo->index_file);
+	return read_index_from(repo->index, repo->index_file, repo->gitdir);
 }

diff --git a/rerere.c b/rerere.c
index 1ce440f..79203c6 100644
--- a/rerere.c
+++ b/rerere.c

@@ -159,8 +159,8 @@ static struct rerere_dir *find_rerere_dir(const char *hex)
 		ALLOC_GROW(rerere_dir, rerere_dir_nr + 1, rerere_dir_alloc);
 		/* ... and add it in. */
 		rerere_dir_nr++;
-		memmove(rerere_dir + pos + 1, rerere_dir + pos,
-			(rerere_dir_nr - pos - 1) * sizeof(*rerere_dir));
+		MOVE_ARRAY(rerere_dir + pos + 1, rerere_dir + pos,
+			   rerere_dir_nr - pos - 1);
 		rerere_dir[pos] = rr_dir;
 		scan_rerere_dir(rr_dir);
 	}

diff --git a/revision.c b/revision.c
index 72f2b45..5ce9b93 100644
--- a/revision.c
+++ b/revision.c

@@ -198,6 +198,8 @@ static struct object *get_reference(struct rev_info *revs, const char *name,
 	if (!object) {
 		if (revs->ignore_missing)
 			return object;
+		if (revs->exclude_promisor_objects && is_promisor_object(oid))
+			return NULL;
 		die("bad object %s", name);
 	}
 	object->flags |= flags;
@@ -799,9 +801,17 @@ static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 
 	for (parent = commit->parents; parent; parent = parent->next) {
 		struct commit *p = parent->item;
-
-		if (parse_commit_gently(p, revs->ignore_missing_links) < 0)
+		int gently = revs->ignore_missing_links ||
+			     revs->exclude_promisor_objects;
+		if (parse_commit_gently(p, gently) < 0) {
+			if (revs->exclude_promisor_objects &&
+			    is_promisor_object(&p->object.oid)) {
+				if (revs->first_parent_only)
+					break;
+				continue;
+			}
 			return -1;
+		}
 		if (revs->show_source && !p->util)
 			p->util = commit->util;
 		p->object.flags |= left_flag;
@@ -1352,7 +1362,8 @@ void add_index_objects_to_pending(struct rev_info *revs, unsigned int flags)
 			continue; /* current index already taken care of */
 
 		if (read_index_from(&istate,
-				    worktree_git_path(wt, "index")) > 0)
+				    worktree_git_path(wt, "index"),
+				    get_worktree_git_dir(wt)) > 0)
 			do_add_index_objects_to_pending(revs, &istate);
 		discard_index(&istate);
 	}
@@ -2078,7 +2089,7 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_ERE;
 	} else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
 		revs->grep_filter.ignore_case = 1;
-		revs->diffopt.flags.pickaxe_ignore_case = 1;
+		revs->diffopt.pickaxe_opts |= DIFF_PICKAXE_IGNORE_CASE;
 	} else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
 		revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_FIXED;
 	} else if (!strcmp(arg, "--perl-regexp") || !strcmp(arg, "-P")) {
@@ -2100,6 +2111,10 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		revs->limited = 1;
 	} else if (!strcmp(arg, "--ignore-missing")) {
 		revs->ignore_missing = 1;
+	} else if (!strcmp(arg, "--exclude-promisor-objects")) {
+		if (fetch_if_missing)
+			die("BUG: exclude_promisor_objects can only be used when fetch_if_missing is 0");
+		revs->exclude_promisor_objects = 1;
 	} else {
 		int opts = diff_opt_parse(&revs->diffopt, argv, argc, revs->prefix);
 		if (!opts)
@@ -2409,11 +2424,14 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
 		revs->diff = 1;
 
 	/* Pickaxe, diff-filter and rename following need diffs */
-	if (revs->diffopt.pickaxe ||
+	if ((revs->diffopt.pickaxe_opts & DIFF_PICKAXE_KINDS_MASK) ||
 	    revs->diffopt.filter ||
 	    revs->diffopt.flags.follow_renames)
 		revs->diff = 1;
 
+	if (revs->diffopt.objfind)
+		revs->simplify_history = 0;
+
 	if (revs->topo_order)
 		revs->limited = 1;
 
@@ -2842,6 +2860,16 @@ void reset_revision_walk(void)
 	clear_object_flags(SEEN | ADDED | SHOWN);
 }
 
+static int mark_uninteresting(const struct object_id *oid,
+			      struct packed_git *pack,
+			      uint32_t pos,
+			      void *unused)
+{
+	struct object *o = parse_object(oid);
+	o->flags |= UNINTERESTING | SEEN;
+	return 0;
+}
+
 int prepare_revision_walk(struct rev_info *revs)
 {
 	int i;
@@ -2862,14 +2890,18 @@ int prepare_revision_walk(struct rev_info *revs)
 			}
 		}
 	}
-	if (!revs->leak_pending)
-		object_array_clear(&old_pending);
+	object_array_clear(&old_pending);
 
 	/* Signal whether we need per-parent treesame decoration */
 	if (revs->simplify_merges ||
 	    (revs->limited && limiting_can_increase_treesame(revs)))
 		revs->treesame.name = "treesame";
 
+	if (revs->exclude_promisor_objects) {
+		for_each_packed_object(mark_uninteresting, NULL,
+				       FOR_EACH_OBJECT_PROMISOR_ONLY);
+	}
+
 	if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
 		commit_list_sort_by_date(&revs->commits);
 	if (revs->no_walk)

diff --git a/revision.h b/revision.h
index 19dc9bd..3dee97b 100644
--- a/revision.h
+++ b/revision.h

@@ -122,7 +122,10 @@ struct rev_info {
 			ancestry_path:1,
 			first_parent_only:1,
 			line_level_traverse:1,
-			tree_blobs_in_commit_order:1;
+			tree_blobs_in_commit_order:1,
+
+			/* for internal use only */
+			exclude_promisor_objects:1;
 
 	/* Diff flags */
 	unsigned int	diff:1,
@@ -151,18 +154,6 @@ struct rev_info {
 			date_mode_explicit:1,
 			preserve_subject:1;
 	unsigned int	disable_stdin:1;
-	/*
-	 * Set `leak_pending` to prevent `prepare_revision_walk()` from clearing
-	 * the array of pending objects (`pending`). It will still forget about
-	 * the array and its entries, so they really are leaked. This can be
-	 * useful if the `struct object_array` `pending` is copied before
-	 * calling `prepare_revision_walk()`. By setting `leak_pending`, you
-	 * effectively claim ownership of the old array, so you should most
-	 * likely call `object_array_clear(&pending_copy)` once you are done.
-	 * Observe that this is about ownership of the array and its entries,
-	 * not the commits referenced by those entries.
-	 */
-	unsigned int	leak_pending:1;
 	/* --show-linear-break */
 	unsigned int	track_linear:1,
 			track_first_time:1,

diff --git a/run-command.c b/run-command.c
index 31fc5ea..a483d59 100644
--- a/run-command.c
+++ b/run-command.c

@@ -6,6 +6,7 @@
 #include "thread-utils.h"
 #include "strbuf.h"
 #include "string-list.h"
+#include "quote.h"
 
 void child_process_init(struct child_process *child)
 {
@@ -556,6 +557,90 @@ static int wait_or_whine(pid_t pid, const char *argv0, int in_signal)
 	return code;
 }
 
+static void trace_add_env(struct strbuf *dst, const char *const *deltaenv)
+{
+	struct string_list envs = STRING_LIST_INIT_DUP;
+	const char *const *e;
+	int i;
+	int printed_unset = 0;
+
+	/* Last one wins, see run-command.c:prep_childenv() for context */
+	for (e = deltaenv; e && *e; e++) {
+		struct strbuf key = STRBUF_INIT;
+		char *equals = strchr(*e, '=');
+
+		if (equals) {
+			strbuf_add(&key, *e, equals - *e);
+			string_list_insert(&envs, key.buf)->util = equals + 1;
+		} else {
+			string_list_insert(&envs, *e)->util = NULL;
+		}
+		strbuf_release(&key);
+	}
+
+	/* "unset X Y...;" */
+	for (i = 0; i < envs.nr; i++) {
+		const char *var = envs.items[i].string;
+		const char *val = envs.items[i].util;
+
+		if (val || !getenv(var))
+			continue;
+
+		if (!printed_unset) {
+			strbuf_addstr(dst, " unset");
+			printed_unset = 1;
+		}
+		strbuf_addf(dst, " %s", var);
+	}
+	if (printed_unset)
+		strbuf_addch(dst, ';');
+
+	/* ... followed by "A=B C=D ..." */
+	for (i = 0; i < envs.nr; i++) {
+		const char *var = envs.items[i].string;
+		const char *val = envs.items[i].util;
+		const char *oldval;
+
+		if (!val)
+			continue;
+
+		oldval = getenv(var);
+		if (oldval && !strcmp(val, oldval))
+			continue;
+
+		strbuf_addf(dst, " %s=", var);
+		sq_quote_buf_pretty(dst, val);
+	}
+	string_list_clear(&envs, 0);
+}
+
+static void trace_run_command(const struct child_process *cp)
+{
+	struct strbuf buf = STRBUF_INIT;
+
+	if (!trace_want(&trace_default_key))
+		return;
+
+	strbuf_addf(&buf, "trace: run_command:");
+	if (cp->dir) {
+		strbuf_addstr(&buf, " cd ");
+		sq_quote_buf_pretty(&buf, cp->dir);
+		strbuf_addch(&buf, ';');
+	}
+	/*
+	 * The caller is responsible for initializing cp->env from
+	 * cp->env_array if needed. We only check one place.
+	 */
+	if (cp->env)
+		trace_add_env(&buf, cp->env);
+	if (cp->git_cmd)
+		strbuf_addstr(&buf, " git");
+	sq_quote_argv_pretty(&buf, cp->argv);
+
+	trace_printf("%s", buf.buf);
+	strbuf_release(&buf);
+}
+
 int start_command(struct child_process *cmd)
 {
 	int need_in, need_out, need_err;
@@ -624,7 +709,8 @@ int start_command(struct child_process *cmd)
 		cmd->err = fderr[0];
 	}
 
-	trace_argv_printf(cmd->argv, "trace: run_command:");
+	trace_run_command(cmd);
+
 	fflush(NULL);
 
 #ifndef GIT_WINDOWS_NATIVE

diff --git a/sequencer.c b/sequencer.c
index 4d3f605..e9baaf5 100644
--- a/sequencer.c
+++ b/sequencer.c

@@ -1,10 +1,10 @@
 #include "cache.h"
 #include "config.h"
 #include "lockfile.h"
-#include "sequencer.h"
 #include "dir.h"
 #include "object.h"
 #include "commit.h"
+#include "sequencer.h"
 #include "tag.h"
 #include "run-command.h"
 #include "exec_cmd.h"
@@ -21,12 +21,16 @@
 #include "log-tree.h"
 #include "wt-status.h"
 #include "hashmap.h"
+#include "notes-utils.h"
+#include "sigchain.h"
 
 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
 
 const char sign_off_header[] = "Signed-off-by: ";
 static const char cherry_picked_prefix[] = "(cherry picked from commit ";
 
+GIT_PATH_FUNC(git_path_commit_editmsg, "COMMIT_EDITMSG")
+
 GIT_PATH_FUNC(git_path_seq_dir, "sequencer")
 
 static GIT_PATH_FUNC(git_path_todo_file, "sequencer/todo")
@@ -130,6 +134,51 @@ static GIT_PATH_FUNC(rebase_path_strategy, "rebase-merge/strategy")
 static GIT_PATH_FUNC(rebase_path_strategy_opts, "rebase-merge/strategy_opts")
 static GIT_PATH_FUNC(rebase_path_allow_rerere_autoupdate, "rebase-merge/allow_rerere_autoupdate")
 
+static int git_sequencer_config(const char *k, const char *v, void *cb)
+{
+	struct replay_opts *opts = cb;
+	int status;
+
+	if (!strcmp(k, "commit.cleanup")) {
+		const char *s;
+
+		status = git_config_string(&s, k, v);
+		if (status)
+			return status;
+
+		if (!strcmp(s, "verbatim"))
+			opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_NONE;
+		else if (!strcmp(s, "whitespace"))
+			opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_SPACE;
+		else if (!strcmp(s, "strip"))
+			opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_ALL;
+		else if (!strcmp(s, "scissors"))
+			opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_SPACE;
+		else
+			warning(_("invalid commit message cleanup mode '%s'"),
+				  s);
+
+		return status;
+	}
+
+	if (!strcmp(k, "commit.gpgsign")) {
+		opts->gpg_sign = git_config_bool(k, v) ? xstrdup("") : NULL;
+		return 0;
+	}
+
+	status = git_gpg_config(k, v, NULL);
+	if (status)
+		return status;
+
+	return git_diff_basic_config(k, v, NULL);
+}
+
+void sequencer_init_config(struct replay_opts *opts)
+{
+	opts->default_msg_cleanup = COMMIT_MSG_CLEANUP_NONE;
+	git_config(git_sequencer_config, opts);
+}
+
 static inline int is_rebase_i(const struct replay_opts *opts)
 {
 	return opts->action == REPLAY_INTERACTIVE_REBASE;
@@ -478,9 +527,6 @@ static int do_recursive_merge(struct commit *base, struct commit *next,
 			_(action_name(opts)));
 	rollback_lock_file(&index_lock);
 
-	if (opts->signoff)
-		append_signoff(msgbuf, 0, 0);
-
 	if (!clean)
 		append_conflicts_hint(msgbuf);
 
@@ -596,6 +642,18 @@ static int read_env_script(struct argv_array *env)
 	return 0;
 }
 
+static char *get_author(const char *message)
+{
+	size_t len;
+	const char *a;
+
+	a = find_commit_header(message, "author", &len);
+	if (a)
+		return xmemdupz(a, len);
+
+	return NULL;
+}
+
 static const char staged_changes_advice[] =
 N_("you have staged changes in your working tree\n"
 "If these changes are meant to be squashed into the previous commit, run:\n"
@@ -658,8 +716,6 @@ static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 		argv_array_push(&cmd.args, "--amend");
 	if (opts->gpg_sign)
 		argv_array_pushf(&cmd.args, "-S%s", opts->gpg_sign);
-	if (opts->signoff)
-		argv_array_push(&cmd.args, "-s");
 	if (defmsg)
 		argv_array_pushl(&cmd.args, "-F", defmsg, NULL);
 	if ((flags & CLEANUP_MSG))
@@ -694,6 +750,461 @@ static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 	return run_command(&cmd);
 }
 
+static int rest_is_empty(const struct strbuf *sb, int start)
+{
+	int i, eol;
+	const char *nl;
+
+	/* Check if the rest is just whitespace and Signed-off-by's. */
+	for (i = start; i < sb->len; i++) {
+		nl = memchr(sb->buf + i, '\n', sb->len - i);
+		if (nl)
+			eol = nl - sb->buf;
+		else
+			eol = sb->len;
+
+		if (strlen(sign_off_header) <= eol - i &&
+		    starts_with(sb->buf + i, sign_off_header)) {
+			i = eol;
+			continue;
+		}
+		while (i < eol)
+			if (!isspace(sb->buf[i++]))
+				return 0;
+	}
+
+	return 1;
+}
+
+/*
+ * Find out if the message in the strbuf contains only whitespace and
+ * Signed-off-by lines.
+ */
+int message_is_empty(const struct strbuf *sb,
+		     enum commit_msg_cleanup_mode cleanup_mode)
+{
+	if (cleanup_mode == COMMIT_MSG_CLEANUP_NONE && sb->len)
+		return 0;
+	return rest_is_empty(sb, 0);
+}
+
+/*
+ * See if the user edited the message in the editor or left what
+ * was in the template intact
+ */
+int template_untouched(const struct strbuf *sb, const char *template_file,
+		       enum commit_msg_cleanup_mode cleanup_mode)
+{
+	struct strbuf tmpl = STRBUF_INIT;
+	const char *start;
+
+	if (cleanup_mode == COMMIT_MSG_CLEANUP_NONE && sb->len)
+		return 0;
+
+	if (!template_file || strbuf_read_file(&tmpl, template_file, 0) <= 0)
+		return 0;
+
+	strbuf_stripspace(&tmpl, cleanup_mode == COMMIT_MSG_CLEANUP_ALL);
+	if (!skip_prefix(sb->buf, tmpl.buf, &start))
+		start = sb->buf;
+	strbuf_release(&tmpl);
+	return rest_is_empty(sb, start - sb->buf);
+}
+
+int update_head_with_reflog(const struct commit *old_head,
+			    const struct object_id *new_head,
+			    const char *action, const struct strbuf *msg,
+			    struct strbuf *err)
+{
+	struct ref_transaction *transaction;
+	struct strbuf sb = STRBUF_INIT;
+	const char *nl;
+	int ret = 0;
+
+	if (action) {
+		strbuf_addstr(&sb, action);
+		strbuf_addstr(&sb, ": ");
+	}
+
+	nl = strchr(msg->buf, '\n');
+	if (nl) {
+		strbuf_add(&sb, msg->buf, nl + 1 - msg->buf);
+	} else {
+		strbuf_addbuf(&sb, msg);
+		strbuf_addch(&sb, '\n');
+	}
+
+	transaction = ref_transaction_begin(err);
+	if (!transaction ||
+	    ref_transaction_update(transaction, "HEAD", new_head,
+				   old_head ? &old_head->object.oid : &null_oid,
+				   0, sb.buf, err) ||
+	    ref_transaction_commit(transaction, err)) {
+		ret = -1;
+	}
+	ref_transaction_free(transaction);
+	strbuf_release(&sb);
+
+	return ret;
+}
+
+static int run_rewrite_hook(const struct object_id *oldoid,
+			    const struct object_id *newoid)
+{
+	struct child_process proc = CHILD_PROCESS_INIT;
+	const char *argv[3];
+	int code;
+	struct strbuf sb = STRBUF_INIT;
+
+	argv[0] = find_hook("post-rewrite");
+	if (!argv[0])
+		return 0;
+
+	argv[1] = "amend";
+	argv[2] = NULL;
+
+	proc.argv = argv;
+	proc.in = -1;
+	proc.stdout_to_stderr = 1;
+
+	code = start_command(&proc);
+	if (code)
+		return code;
+	strbuf_addf(&sb, "%s %s\n", oid_to_hex(oldoid), oid_to_hex(newoid));
+	sigchain_push(SIGPIPE, SIG_IGN);
+	write_in_full(proc.in, sb.buf, sb.len);
+	close(proc.in);
+	strbuf_release(&sb);
+	sigchain_pop(SIGPIPE);
+	return finish_command(&proc);
+}
+
+void commit_post_rewrite(const struct commit *old_head,
+			 const struct object_id *new_head)
+{
+	struct notes_rewrite_cfg *cfg;
+
+	cfg = init_copy_notes_for_rewrite("amend");
+	if (cfg) {
+		/* we are amending, so old_head is not NULL */
+		copy_note_for_rewrite(cfg, &old_head->object.oid, new_head);
+		finish_copy_notes_for_rewrite(cfg, "Notes added by 'git commit --amend'");
+	}
+	run_rewrite_hook(&old_head->object.oid, new_head);
+}
+
+static int run_prepare_commit_msg_hook(struct strbuf *msg, const char *commit)
+{
+	struct argv_array hook_env = ARGV_ARRAY_INIT;
+	int ret;
+	const char *name;
+
+	name = git_path_commit_editmsg();
+	if (write_message(msg->buf, msg->len, name, 0))
+		return -1;
+
+	argv_array_pushf(&hook_env, "GIT_INDEX_FILE=%s", get_index_file());
+	argv_array_push(&hook_env, "GIT_EDITOR=:");
+	if (commit)
+		ret = run_hook_le(hook_env.argv, "prepare-commit-msg", name,
+				  "commit", commit, NULL);
+	else
+		ret = run_hook_le(hook_env.argv, "prepare-commit-msg", name,
+				  "message", NULL);
+	if (ret)
+		ret = error(_("'prepare-commit-msg' hook failed"));
+	argv_array_clear(&hook_env);
+
+	return ret;
+}
+
+static const char implicit_ident_advice_noconfig[] =
+N_("Your name and email address were configured automatically based\n"
+"on your username and hostname. Please check that they are accurate.\n"
+"You can suppress this message by setting them explicitly. Run the\n"
+"following command and follow the instructions in your editor to edit\n"
+"your configuration file:\n"
+"\n"
+"    git config --global --edit\n"
+"\n"
+"After doing this, you may fix the identity used for this commit with:\n"
+"\n"
+"    git commit --amend --reset-author\n");
+
+static const char implicit_ident_advice_config[] =
+N_("Your name and email address were configured automatically based\n"
+"on your username and hostname. Please check that they are accurate.\n"
+"You can suppress this message by setting them explicitly:\n"
+"\n"
+"    git config --global user.name \"Your Name\"\n"
+"    git config --global user.email you@example.com\n"
+"\n"
+"After doing this, you may fix the identity used for this commit with:\n"
+"\n"
+"    git commit --amend --reset-author\n");
+
+static const char *implicit_ident_advice(void)
+{
+	char *user_config = expand_user_path("~/.gitconfig", 0);
+	char *xdg_config = xdg_config_home("config");
+	int config_exists = file_exists(user_config) || file_exists(xdg_config);
+
+	free(user_config);
+	free(xdg_config);
+
+	if (config_exists)
+		return _(implicit_ident_advice_config);
+	else
+		return _(implicit_ident_advice_noconfig);
+
+}
+
+void print_commit_summary(const char *prefix, const struct object_id *oid,
+			  unsigned int flags)
+{
+	struct rev_info rev;
+	struct commit *commit;
+	struct strbuf format = STRBUF_INIT;
+	const char *head;
+	struct pretty_print_context pctx = {0};
+	struct strbuf author_ident = STRBUF_INIT;
+	struct strbuf committer_ident = STRBUF_INIT;
+
+	commit = lookup_commit(oid);
+	if (!commit)
+		die(_("couldn't look up newly created commit"));
+	if (parse_commit(commit))
+		die(_("could not parse newly created commit"));
+
+	strbuf_addstr(&format, "format:%h] %s");
+
+	format_commit_message(commit, "%an <%ae>", &author_ident, &pctx);
+	format_commit_message(commit, "%cn <%ce>", &committer_ident, &pctx);
+	if (strbuf_cmp(&author_ident, &committer_ident)) {
+		strbuf_addstr(&format, "\n Author: ");
+		strbuf_addbuf_percentquote(&format, &author_ident);
+	}
+	if (flags & SUMMARY_SHOW_AUTHOR_DATE) {
+		struct strbuf date = STRBUF_INIT;
+
+		format_commit_message(commit, "%ad", &date, &pctx);
+		strbuf_addstr(&format, "\n Date: ");
+		strbuf_addbuf_percentquote(&format, &date);
+		strbuf_release(&date);
+	}
+	if (!committer_ident_sufficiently_given()) {
+		strbuf_addstr(&format, "\n Committer: ");
+		strbuf_addbuf_percentquote(&format, &committer_ident);
+		if (advice_implicit_identity) {
+			strbuf_addch(&format, '\n');
+			strbuf_addstr(&format, implicit_ident_advice());
+		}
+	}
+	strbuf_release(&author_ident);
+	strbuf_release(&committer_ident);
+
+	init_revisions(&rev, prefix);
+	setup_revisions(0, NULL, &rev, NULL);
+
+	rev.diff = 1;
+	rev.diffopt.output_format =
+		DIFF_FORMAT_SHORTSTAT | DIFF_FORMAT_SUMMARY;
+
+	rev.verbose_header = 1;
+	rev.show_root_diff = 1;
+	get_commit_format(format.buf, &rev);
+	rev.always_show_header = 0;
+	rev.diffopt.detect_rename = DIFF_DETECT_RENAME;
+	rev.diffopt.break_opt = 0;
+	diff_setup_done(&rev.diffopt);
+
+	head = resolve_ref_unsafe("HEAD", 0, NULL, NULL);
+	if (!head)
+		die_errno(_("unable to resolve HEAD after creating commit"));
+	if (!strcmp(head, "HEAD"))
+		head = _("detached HEAD");
+	else
+		skip_prefix(head, "refs/heads/", &head);
+	printf("[%s%s ", head, (flags & SUMMARY_INITIAL_COMMIT) ?
+						_(" (root-commit)") : "");
+
+	if (!log_tree_commit(&rev, commit)) {
+		rev.always_show_header = 1;
+		rev.use_terminator = 1;
+		log_tree_commit(&rev, commit);
+	}
+
+	strbuf_release(&format);
+}
+
+static int parse_head(struct commit **head)
+{
+	struct commit *current_head;
+	struct object_id oid;
+
+	if (get_oid("HEAD", &oid)) {
+		current_head = NULL;
+	} else {
+		current_head = lookup_commit_reference(&oid);
+		if (!current_head)
+			return error(_("could not parse HEAD"));
+		if (oidcmp(&oid, &current_head->object.oid)) {
+			warning(_("HEAD %s is not a commit!"),
+				oid_to_hex(&oid));
+		}
+		if (parse_commit(current_head))
+			return error(_("could not parse HEAD commit"));
+	}
+	*head = current_head;
+
+	return 0;
+}
+
+/*
+ * Try to commit without forking 'git commit'. In some cases we need
+ * to run 'git commit' to display an error message
+ *
+ * Returns:
+ *  -1 - error unable to commit
+ *   0 - success
+ *   1 - run 'git commit'
+ */
+static int try_to_commit(struct strbuf *msg, const char *author,
+			 struct replay_opts *opts, unsigned int flags,
+			 struct object_id *oid)
+{
+	struct object_id tree;
+	struct commit *current_head;
+	struct commit_list *parents = NULL;
+	struct commit_extra_header *extra = NULL;
+	struct strbuf err = STRBUF_INIT;
+	struct strbuf commit_msg = STRBUF_INIT;
+	char *amend_author = NULL;
+	const char *hook_commit = NULL;
+	enum commit_msg_cleanup_mode cleanup;
+	int res = 0;
+
+	if (parse_head(&current_head))
+		return -1;
+
+	if (flags & AMEND_MSG) {
+		const char *exclude_gpgsig[] = { "gpgsig", NULL };
+		const char *out_enc = get_commit_output_encoding();
+		const char *message = logmsg_reencode(current_head, NULL,
+						      out_enc);
+
+		if (!msg) {
+			const char *orig_message = NULL;
+
+			find_commit_subject(message, &orig_message);
+			msg = &commit_msg;
+			strbuf_addstr(msg, orig_message);
+			hook_commit = "HEAD";
+		}
+		author = amend_author = get_author(message);
+		unuse_commit_buffer(current_head, message);
+		if (!author) {
+			res = error(_("unable to parse commit author"));
+			goto out;
+		}
+		parents = copy_commit_list(current_head->parents);
+		extra = read_commit_extra_headers(current_head, exclude_gpgsig);
+	} else if (current_head) {
+		commit_list_insert(current_head, &parents);
+	}
+
+	if (write_cache_as_tree(tree.hash, 0, NULL)) {
+		res = error(_("git write-tree failed to write a tree"));
+		goto out;
+	}
+
+	if (!(flags & ALLOW_EMPTY) && !oidcmp(current_head ?
+					      &current_head->tree->object.oid :
+					      &empty_tree_oid, &tree)) {
+		res = 1; /* run 'git commit' to display error message */
+		goto out;
+	}
+
+	if (find_hook("prepare-commit-msg")) {
+		res = run_prepare_commit_msg_hook(msg, hook_commit);
+		if (res)
+			goto out;
+		if (strbuf_read_file(&commit_msg, git_path_commit_editmsg(),
+				     2048) < 0) {
+			res = error_errno(_("unable to read commit message "
+					      "from '%s'"),
+					    git_path_commit_editmsg());
+			goto out;
+		}
+		msg = &commit_msg;
+	}
+
+	cleanup = (flags & CLEANUP_MSG) ? COMMIT_MSG_CLEANUP_ALL :
+					  opts->default_msg_cleanup;
+
+	if (cleanup != COMMIT_MSG_CLEANUP_NONE)
+		strbuf_stripspace(msg, cleanup == COMMIT_MSG_CLEANUP_ALL);
+	if (!opts->allow_empty_message && message_is_empty(msg, cleanup)) {
+		res = 1; /* run 'git commit' to display error message */
+		goto out;
+	}
+
+	if (commit_tree_extended(msg->buf, msg->len, &tree, parents,
+				 oid, author, opts->gpg_sign, extra)) {
+		res = error(_("failed to write commit object"));
+		goto out;
+	}
+
+	if (update_head_with_reflog(current_head, oid,
+				    getenv("GIT_REFLOG_ACTION"), msg, &err)) {
+		res = error("%s", err.buf);
+		goto out;
+	}
+
+	if (flags & AMEND_MSG)
+		commit_post_rewrite(current_head, oid);
+
+out:
+	free_commit_extra_headers(extra);
+	strbuf_release(&err);
+	strbuf_release(&commit_msg);
+	free(amend_author);
+
+	return res;
+}
+
+static int do_commit(const char *msg_file, const char *author,
+		     struct replay_opts *opts, unsigned int flags)
+{
+	int res = 1;
+
+	if (!(flags & EDIT_MSG) && !(flags & VERIFY_MSG)) {
+		struct object_id oid;
+		struct strbuf sb = STRBUF_INIT;
+
+		if (msg_file && strbuf_read_file(&sb, msg_file, 2048) < 0)
+			return error_errno(_("unable to read commit message "
+					     "from '%s'"),
+					   msg_file);
+
+		res = try_to_commit(msg_file ? &sb : NULL, author, opts, flags,
+				    &oid);
+		strbuf_release(&sb);
+		if (!res) {
+			unlink(git_path_cherry_pick_head());
+			unlink(git_path_merge_msg());
+			if (!is_rebase_i(opts))
+				print_commit_summary(NULL, &oid,
+						SUMMARY_SHOW_AUTHOR_DATE);
+			return res;
+		}
+	}
+	if (res == 1)
+		return run_git_commit(msg_file, opts, flags);
+
+	return res;
+}
+
 static int is_original_commit_empty(struct commit *commit)
 {
 	const struct object_id *ptree_oid;
@@ -952,6 +1463,7 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
 	struct object_id head;
 	struct commit *base, *next, *parent;
 	const char *base_label, *next_label;
+	char *author = NULL;
 	struct commit_message msg = { NULL, NULL, NULL, NULL };
 	struct strbuf msgbuf = STRBUF_INIT;
 	int res, unborn = 0, allow;
@@ -1066,6 +1578,8 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
 			strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
 			strbuf_addstr(&msgbuf, ")\n");
 		}
+		if (!is_fixup(command))
+			author = get_author(msg.message);
 	}
 
 	if (command == TODO_REWORD)
@@ -1091,6 +1605,9 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
 		}
 	}
 
+	if (opts->signoff)
+		append_signoff(&msgbuf, 0, 0);
+
 	if (is_rebase_i(opts) && write_author_script(msg.message) < 0)
 		res = -1;
 	else if (!opts->strategy || !strcmp(opts->strategy, "recursive") || command == TODO_REVERT) {
@@ -1148,9 +1665,13 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
 		goto leave;
 	} else if (allow)
 		flags |= ALLOW_EMPTY;
-	if (!opts->no_commit)
+	if (!opts->no_commit) {
 fast_forward_edit:
-		res = run_git_commit(msg_file, opts, flags);
+		if (author || command == TODO_REVERT || (flags & AMEND_MSG))
+			res = do_commit(msg_file, author, opts, flags);
+		else
+			res = error(_("unable to parse commit author"));
+	}
 
 	if (!res && final_fixup) {
 		unlink(rebase_path_fixup_msg());
@@ -1159,6 +1680,7 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
 
 leave:
 	free_message(commit, &msg);
+	free(author);
 	update_abort_safety_file();
 
 	return res;

diff --git a/sequencer.h b/sequencer.h
index 81f6d7d..e45b178 100644
--- a/sequencer.h
+++ b/sequencer.h

@@ -1,6 +1,7 @@
 #ifndef SEQUENCER_H
 #define SEQUENCER_H
 
+const char *git_path_commit_editmsg(void);
 const char *git_path_seq_dir(void);
 
 #define APPEND_SIGNOFF_DEDUP (1u << 0)
@@ -11,6 +12,13 @@ enum replay_action {
 	REPLAY_INTERACTIVE_REBASE
 };
 
+enum commit_msg_cleanup_mode {
+	COMMIT_MSG_CLEANUP_SPACE,
+	COMMIT_MSG_CLEANUP_NONE,
+	COMMIT_MSG_CLEANUP_SCISSORS,
+	COMMIT_MSG_CLEANUP_ALL
+};
+
 struct replay_opts {
 	enum replay_action action;
 
@@ -29,6 +37,7 @@ struct replay_opts {
 	int mainline;
 
 	char *gpg_sign;
+	enum commit_msg_cleanup_mode default_msg_cleanup;
 
 	/* Merge strategy */
 	char *strategy;
@@ -40,6 +49,8 @@ struct replay_opts {
 };
 #define REPLAY_OPTS_INIT { -1 }
 
+/* Call this to setup defaults before parsing command line options */
+void sequencer_init_config(struct replay_opts *opts);
 int sequencer_pick_revisions(struct replay_opts *opts);
 int sequencer_continue(struct replay_opts *opts);
 int sequencer_rollback(struct replay_opts *opts);
@@ -61,5 +72,19 @@ extern const char sign_off_header[];
 
 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag);
 void append_conflicts_hint(struct strbuf *msgbuf);
+int message_is_empty(const struct strbuf *sb,
+		     enum commit_msg_cleanup_mode cleanup_mode);
+int template_untouched(const struct strbuf *sb, const char *template_file,
+		       enum commit_msg_cleanup_mode cleanup_mode);
+int update_head_with_reflog(const struct commit *old_head,
+			    const struct object_id *new_head,
+			    const char *action, const struct strbuf *msg,
+			    struct strbuf *err);
+void commit_post_rewrite(const struct commit *current_head,
+			 const struct object_id *new_head);
 
+#define SUMMARY_INITIAL_COMMIT   (1 << 0)
+#define SUMMARY_SHOW_AUTHOR_DATE (1 << 1)
+void print_commit_summary(const char *prefix, const struct object_id *oid,
+			  unsigned int flags);
 #endif

diff --git a/setup.c b/setup.c
index 8cc3418..c5d55dc 100644
--- a/setup.c
+++ b/setup.c

@@ -422,7 +422,11 @@ static int check_repo_format(const char *var, const char *value, void *vdata)
 			;
 		else if (!strcmp(ext, "preciousobjects"))
 			data->precious_objects = git_config_bool(var, value);
-		else
+		else if (!strcmp(ext, "partialclone")) {
+			if (!value)
+				return config_error_nonbool(var);
+			data->partial_clone = xstrdup(value);
+		} else
 			string_list_append(&data->unknown_extensions, ext);
 	} else if (strcmp(var, "core.bare") == 0) {
 		data->is_bare = git_config_bool(var, value);
@@ -464,6 +468,7 @@ static int check_repository_format_gently(const char *gitdir, struct repository_
 	}
 
 	repository_format_precious_objects = candidate->precious_objects;
+	repository_format_partial_clone = candidate->partial_clone;
 	string_list_clear(&candidate->unknown_extensions, 0);
 	if (!has_common) {
 		if (candidate->is_bare != -1) {

diff --git a/sha1_file.c b/sha1_file.c
index 3da70ac..826d7a0 100644
--- a/sha1_file.c
+++ b/sha1_file.c

@@ -24,11 +24,11 @@
 #include "bulk-checkin.h"
 #include "streaming.h"
 #include "dir.h"
-#include "mru.h"
 #include "list.h"
 #include "mergesort.h"
 #include "quote.h"
 #include "packfile.h"
+#include "fetch-object.h"
 
 const unsigned char null_sha1[GIT_MAX_RAWSZ];
 const struct object_id null_oid;
@@ -39,32 +39,32 @@ const struct object_id empty_blob_oid = {
 	EMPTY_BLOB_SHA1_BIN_LITERAL
 };
 
-static void git_hash_sha1_init(void *ctx)
+static void git_hash_sha1_init(git_hash_ctx *ctx)
 {
-	git_SHA1_Init((git_SHA_CTX *)ctx);
+	git_SHA1_Init(&ctx->sha1);
 }
 
-static void git_hash_sha1_update(void *ctx, const void *data, size_t len)
+static void git_hash_sha1_update(git_hash_ctx *ctx, const void *data, size_t len)
 {
-	git_SHA1_Update((git_SHA_CTX *)ctx, data, len);
+	git_SHA1_Update(&ctx->sha1, data, len);
 }
 
-static void git_hash_sha1_final(unsigned char *hash, void *ctx)
+static void git_hash_sha1_final(unsigned char *hash, git_hash_ctx *ctx)
 {
-	git_SHA1_Final(hash, (git_SHA_CTX *)ctx);
+	git_SHA1_Final(hash, &ctx->sha1);
 }
 
-static void git_hash_unknown_init(void *ctx)
+static void git_hash_unknown_init(git_hash_ctx *ctx)
 {
 	die("trying to init unknown hash");
 }
 
-static void git_hash_unknown_update(void *ctx, const void *data, size_t len)
+static void git_hash_unknown_update(git_hash_ctx *ctx, const void *data, size_t len)
 {
 	die("trying to update unknown hash");
 }
 
-static void git_hash_unknown_final(unsigned char *hash, void *ctx)
+static void git_hash_unknown_final(unsigned char *hash, git_hash_ctx *ctx)
 {
 	die("trying to finalize unknown hash");
 }
@@ -75,7 +75,6 @@ const struct git_hash_algo hash_algos[GIT_HASH_NALGOS] = {
 		0x00000000,
 		0,
 		0,
-		0,
 		git_hash_unknown_init,
 		git_hash_unknown_update,
 		git_hash_unknown_final,
@@ -86,7 +85,6 @@ const struct git_hash_algo hash_algos[GIT_HASH_NALGOS] = {
 		"sha-1",
 		/* "sha1", big-endian */
 		0x73686131,
-		sizeof(git_SHA_CTX),
 		GIT_SHA1_RAWSZ,
 		GIT_SHA1_HEXSZ,
 		git_hash_sha1_init,
@@ -133,14 +131,14 @@ static struct cached_object *find_cached_object(const unsigned char *sha1)
 }
 
 
-static enum safe_crlf get_safe_crlf(unsigned flags)
+static int get_conv_flags(unsigned flags)
 {
 	if (flags & HASH_RENORMALIZE)
-		return SAFE_CRLF_RENORMALIZE;
+		return CONV_EOL_RENORMALIZE;
 	else if (flags & HASH_WRITE_OBJECT)
-		return safe_crlf;
+	  return global_conv_flags_eol;
 	else
-		return SAFE_CRLF_FALSE;
+		return 0;
 }
 
 
@@ -321,15 +319,11 @@ static void fill_sha1_path(struct strbuf *buf, const unsigned char *sha1)
 	}
 }
 
-const char *sha1_file_name(const unsigned char *sha1)
+void sha1_file_name(struct strbuf *buf, const unsigned char *sha1)
 {
-	static struct strbuf buf = STRBUF_INIT;
-
-	strbuf_reset(&buf);
-	strbuf_addf(&buf, "%s/", get_object_directory());
-
-	fill_sha1_path(&buf, sha1);
-	return buf.buf;
+	strbuf_addstr(buf, get_object_directory());
+	strbuf_addch(buf, '/');
+	fill_sha1_path(buf, sha1);
 }
 
 struct strbuf *alt_scratch_buf(struct alternate_object_database *alt)
@@ -710,7 +704,12 @@ int check_and_freshen_file(const char *fn, int freshen)
 
 static int check_and_freshen_local(const unsigned char *sha1, int freshen)
 {
-	return check_and_freshen_file(sha1_file_name(sha1), freshen);
+	static struct strbuf buf = STRBUF_INIT;
+
+	strbuf_reset(&buf);
+	sha1_file_name(&buf, sha1);
+
+	return check_and_freshen_file(buf.buf, freshen);
 }
 
 static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
@@ -788,16 +787,16 @@ void *xmmap(void *start, size_t length,
 int check_sha1_signature(const unsigned char *sha1, void *map,
 			 unsigned long size, const char *type)
 {
-	unsigned char real_sha1[20];
+	struct object_id real_oid;
 	enum object_type obj_type;
 	struct git_istream *st;
-	git_SHA_CTX c;
+	git_hash_ctx c;
 	char hdr[32];
 	int hdrlen;
 
 	if (map) {
-		hash_sha1_file(map, size, type, real_sha1);
-		return hashcmp(sha1, real_sha1) ? -1 : 0;
+		hash_object_file(map, size, type, &real_oid);
+		return hashcmp(sha1, real_oid.hash) ? -1 : 0;
 	}
 
 	st = open_istream(sha1, &obj_type, &size, NULL);
@@ -808,8 +807,8 @@ int check_sha1_signature(const unsigned char *sha1, void *map,
 	hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(obj_type), size) + 1;
 
 	/* Sha1.. */
-	git_SHA1_Init(&c);
-	git_SHA1_Update(&c, hdr, hdrlen);
+	the_hash_algo->init_fn(&c);
+	the_hash_algo->update_fn(&c, hdr, hdrlen);
 	for (;;) {
 		char buf[1024 * 16];
 		ssize_t readlen = read_istream(st, buf, sizeof(buf));
@@ -820,11 +819,11 @@ int check_sha1_signature(const unsigned char *sha1, void *map,
 		}
 		if (!readlen)
 			break;
-		git_SHA1_Update(&c, buf, readlen);
+		the_hash_algo->update_fn(&c, buf, readlen);
 	}
-	git_SHA1_Final(real_sha1, &c);
+	the_hash_algo->final_fn(real_oid.hash, &c);
 	close_istream(st);
-	return hashcmp(sha1, real_sha1) ? -1 : 0;
+	return hashcmp(sha1, real_oid.hash) ? -1 : 0;
 }
 
 int git_open_cloexec(const char *name, int flags)
@@ -866,8 +865,12 @@ static int stat_sha1_file(const unsigned char *sha1, struct stat *st,
 			  const char **path)
 {
 	struct alternate_object_database *alt;
+	static struct strbuf buf = STRBUF_INIT;
 
-	*path = sha1_file_name(sha1);
+	strbuf_reset(&buf);
+	sha1_file_name(&buf, sha1);
+	*path = buf.buf;
+
 	if (!lstat(*path, st))
 		return 0;
 
@@ -891,8 +894,12 @@ static int open_sha1_file(const unsigned char *sha1, const char **path)
 	int fd;
 	struct alternate_object_database *alt;
 	int most_interesting_errno;
+	static struct strbuf buf = STRBUF_INIT;
 
-	*path = sha1_file_name(sha1);
+	strbuf_reset(&buf);
+	sha1_file_name(&buf, sha1);
+	*path = buf.buf;
+
 	fd = git_open(*path);
 	if (fd >= 0)
 		return fd;
@@ -1213,6 +1220,8 @@ static int sha1_loose_object_info(const unsigned char *sha1,
 	return (status < 0) ? status : 0;
 }
 
+int fetch_if_missing = 1;
+
 int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
 {
 	static struct object_info blank_oi = OBJECT_INFO_INIT;
@@ -1221,6 +1230,7 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi,
 	const unsigned char *real = (flags & OBJECT_INFO_LOOKUP_REPLACE) ?
 				    lookup_replace_object(sha1) :
 				    sha1;
+	int already_retried = 0;
 
 	if (is_null_sha1(real))
 		return -1;
@@ -1248,19 +1258,32 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi,
 		}
 	}
 
-	if (!find_pack_entry(real, &e)) {
+	while (1) {
+		if (find_pack_entry(real, &e))
+			break;
+
 		/* Most likely it's a loose object. */
 		if (!sha1_loose_object_info(real, oi, flags))
 			return 0;
 
 		/* Not a loose object; someone else may have just packed it. */
-		if (flags & OBJECT_INFO_QUICK) {
-			return -1;
-		} else {
-			reprepare_packed_git();
-			if (!find_pack_entry(real, &e))
-				return -1;
+		reprepare_packed_git();
+		if (find_pack_entry(real, &e))
+			break;
+
+		/* Check if it is a missing object */
+		if (fetch_if_missing && repository_format_partial_clone &&
+		    !already_retried) {
+			/*
+			 * TODO Investigate haveing fetch_object() return
+			 * TODO error/success and stopping the music here.
+			 */
+			fetch_object(repository_format_partial_clone, real);
+			already_retried = 1;
+			continue;
 		}
+
+		return -1;
 	}
 
 	if (oi == &blank_oi)
@@ -1269,7 +1292,6 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi,
 		 * information below, so return early.
 		 */
 		return 0;
-
 	rtype = packed_object_info(e.p, e.offset, oi);
 	if (rtype < 0) {
 		mark_bad_packed_object(e.p, real);
@@ -1312,13 +1334,13 @@ static void *read_object(const unsigned char *sha1, enum object_type *type,
 	return content;
 }
 
-int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
-		      unsigned char *sha1)
+int pretend_object_file(void *buf, unsigned long len, enum object_type type,
+			struct object_id *oid)
 {
 	struct cached_object *co;
 
-	hash_sha1_file(buf, len, typename(type), sha1);
-	if (has_sha1_file(sha1) || find_cached_object(sha1))
+	hash_object_file(buf, len, typename(type), oid);
+	if (has_sha1_file(oid->hash) || find_cached_object(oid->hash))
 		return 0;
 	ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
 	co = &cached_objects[cached_object_nr++];
@@ -1326,7 +1348,7 @@ int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
 	co->type = type;
 	co->buf = xmalloc(len);
 	memcpy(co->buf, buf, len);
-	hashcpy(co->sha1, sha1);
+	hashcpy(co->sha1, oid->hash);
 	return 0;
 }
 
@@ -1419,20 +1441,20 @@ void *read_object_with_reference(const unsigned char *sha1,
 	}
 }
 
-static void write_sha1_file_prepare(const void *buf, unsigned long len,
-                                    const char *type, unsigned char *sha1,
-                                    char *hdr, int *hdrlen)
+static void write_object_file_prepare(const void *buf, unsigned long len,
+				      const char *type, struct object_id *oid,
+				      char *hdr, int *hdrlen)
 {
-	git_SHA_CTX c;
+	git_hash_ctx c;
 
 	/* Generate the header */
 	*hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
 
 	/* Sha1.. */
-	git_SHA1_Init(&c);
-	git_SHA1_Update(&c, hdr, *hdrlen);
-	git_SHA1_Update(&c, buf, len);
-	git_SHA1_Final(sha1, &c);
+	the_hash_algo->init_fn(&c);
+	the_hash_algo->update_fn(&c, hdr, *hdrlen);
+	the_hash_algo->update_fn(&c, buf, len);
+	the_hash_algo->final_fn(oid->hash, &c);
 }
 
 /*
@@ -1485,12 +1507,12 @@ static int write_buffer(int fd, const void *buf, size_t len)
 	return 0;
 }
 
-int hash_sha1_file(const void *buf, unsigned long len, const char *type,
-                   unsigned char *sha1)
+int hash_object_file(const void *buf, unsigned long len, const char *type,
+		     struct object_id *oid)
 {
 	char hdr[32];
 	int hdrlen = sizeof(hdr);
-	write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
+	write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
 	return 0;
 }
 
@@ -1548,18 +1570,22 @@ static int create_tmpfile(struct strbuf *tmp, const char *filename)
 	return fd;
 }
 
-static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
-			      const void *buf, unsigned long len, time_t mtime)
+static int write_loose_object(const struct object_id *oid, char *hdr,
+			      int hdrlen, const void *buf, unsigned long len,
+			      time_t mtime)
 {
 	int fd, ret;
 	unsigned char compressed[4096];
 	git_zstream stream;
-	git_SHA_CTX c;
-	unsigned char parano_sha1[20];
+	git_hash_ctx c;
+	struct object_id parano_oid;
 	static struct strbuf tmp_file = STRBUF_INIT;
-	const char *filename = sha1_file_name(sha1);
+	static struct strbuf filename = STRBUF_INIT;
 
-	fd = create_tmpfile(&tmp_file, filename);
+	strbuf_reset(&filename);
+	sha1_file_name(&filename, oid->hash);
+
+	fd = create_tmpfile(&tmp_file, filename.buf);
 	if (fd < 0) {
 		if (errno == EACCES)
 			return error("insufficient permission for adding an object to repository database %s", get_object_directory());
@@ -1571,14 +1597,14 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
 	git_deflate_init(&stream, zlib_compression_level);
 	stream.next_out = compressed;
 	stream.avail_out = sizeof(compressed);
-	git_SHA1_Init(&c);
+	the_hash_algo->init_fn(&c);
 
 	/* First header.. */
 	stream.next_in = (unsigned char *)hdr;
 	stream.avail_in = hdrlen;
 	while (git_deflate(&stream, 0) == Z_OK)
 		; /* nothing */
-	git_SHA1_Update(&c, hdr, hdrlen);
+	the_hash_algo->update_fn(&c, hdr, hdrlen);
 
 	/* Then the data itself.. */
 	stream.next_in = (void *)buf;
@@ -1586,7 +1612,7 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
 	do {
 		unsigned char *in0 = stream.next_in;
 		ret = git_deflate(&stream, Z_FINISH);
-		git_SHA1_Update(&c, in0, stream.next_in - in0);
+		the_hash_algo->update_fn(&c, in0, stream.next_in - in0);
 		if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
 			die("unable to write sha1 file");
 		stream.next_out = compressed;
@@ -1594,13 +1620,16 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
 	} while (ret == Z_OK);
 
 	if (ret != Z_STREAM_END)
-		die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
+		die("unable to deflate new object %s (%d)", oid_to_hex(oid),
+		    ret);
 	ret = git_deflate_end_gently(&stream);
 	if (ret != Z_OK)
-		die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
-	git_SHA1_Final(parano_sha1, &c);
-	if (hashcmp(sha1, parano_sha1) != 0)
-		die("confused by unstable object source data for %s", sha1_to_hex(sha1));
+		die("deflateEnd on object %s failed (%d)", oid_to_hex(oid),
+		    ret);
+	the_hash_algo->final_fn(parano_oid.hash, &c);
+	if (oidcmp(oid, &parano_oid) != 0)
+		die("confused by unstable object source data for %s",
+		    oid_to_hex(oid));
 
 	close_sha1_file(fd);
 
@@ -1612,7 +1641,7 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
 			warning_errno("failed utime() on %s", tmp_file.buf);
 	}
 
-	return finalize_object_file(tmp_file.buf, filename);
+	return finalize_object_file(tmp_file.buf, filename.buf);
 }
 
 static int freshen_loose_object(const unsigned char *sha1)
@@ -1633,7 +1662,8 @@ static int freshen_packed_object(const unsigned char *sha1)
 	return 1;
 }
 
-int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1)
+int write_object_file(const void *buf, unsigned long len, const char *type,
+		      struct object_id *oid)
 {
 	char hdr[32];
 	int hdrlen = sizeof(hdr);
@@ -1641,14 +1671,15 @@ int write_sha1_file(const void *buf, unsigned long len, const char *type, unsign
 	/* Normally if we have it in the pack then we do not bother writing
 	 * it out into .git/objects/??/?{38} file.
 	 */
-	write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
-	if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
+	write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
+	if (freshen_packed_object(oid->hash) || freshen_loose_object(oid->hash))
 		return 0;
-	return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
+	return write_loose_object(oid, hdr, hdrlen, buf, len, 0);
 }
 
-int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type,
-			     struct object_id *oid, unsigned flags)
+int hash_object_file_literally(const void *buf, unsigned long len,
+			       const char *type, struct object_id *oid,
+			       unsigned flags)
 {
 	char *header;
 	int hdrlen, status = 0;
@@ -1656,20 +1687,20 @@ int hash_sha1_file_literally(const void *buf, unsigned long len, const char *typ
 	/* type string, SP, %lu of the length plus NUL must fit this */
 	hdrlen = strlen(type) + 32;
 	header = xmalloc(hdrlen);
-	write_sha1_file_prepare(buf, len, type, oid->hash, header, &hdrlen);
+	write_object_file_prepare(buf, len, type, oid, header, &hdrlen);
 
 	if (!(flags & HASH_WRITE_OBJECT))
 		goto cleanup;
 	if (freshen_packed_object(oid->hash) || freshen_loose_object(oid->hash))
 		goto cleanup;
-	status = write_loose_object(oid->hash, header, hdrlen, buf, len, 0);
+	status = write_loose_object(oid, header, hdrlen, buf, len, 0);
 
 cleanup:
 	free(header);
 	return status;
 }
 
-int force_object_loose(const unsigned char *sha1, time_t mtime)
+int force_object_loose(const struct object_id *oid, time_t mtime)
 {
 	void *buf;
 	unsigned long len;
@@ -1678,13 +1709,13 @@ int force_object_loose(const unsigned char *sha1, time_t mtime)
 	int hdrlen;
 	int ret;
 
-	if (has_loose_object(sha1))
+	if (has_loose_object(oid->hash))
 		return 0;
-	buf = read_object(sha1, &type, &len);
+	buf = read_object(oid->hash, &type, &len);
 	if (!buf)
-		return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
+		return error("cannot read sha1_file for %s", oid_to_hex(oid));
 	hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(type), len) + 1;
-	ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
+	ret = write_loose_object(oid, hdr, hdrlen, buf, len, mtime);
 	free(buf);
 
 	return ret;
@@ -1752,7 +1783,7 @@ static int index_mem(struct object_id *oid, void *buf, size_t size,
 	if ((type == OBJ_BLOB) && path) {
 		struct strbuf nbuf = STRBUF_INIT;
 		if (convert_to_git(&the_index, path, buf, size, &nbuf,
-				   get_safe_crlf(flags))) {
+				   get_conv_flags(flags))) {
 			buf = strbuf_detach(&nbuf, &size);
 			re_allocated = 1;
 		}
@@ -1767,9 +1798,9 @@ static int index_mem(struct object_id *oid, void *buf, size_t size,
 	}
 
 	if (write_object)
-		ret = write_sha1_file(buf, size, typename(type), oid->hash);
+		ret = write_object_file(buf, size, typename(type), oid);
 	else
-		ret = hash_sha1_file(buf, size, typename(type), oid->hash);
+		ret = hash_object_file(buf, size, typename(type), oid);
 	if (re_allocated)
 		free(buf);
 	return ret;
@@ -1786,14 +1817,14 @@ static int index_stream_convert_blob(struct object_id *oid, int fd,
 	assert(would_convert_to_git_filter_fd(path));
 
 	convert_to_git_filter_fd(&the_index, path, fd, &sbuf,
-				 get_safe_crlf(flags));
+				 get_conv_flags(flags));
 
 	if (write_object)
-		ret = write_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
-				      oid->hash);
+		ret = write_object_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
+					oid);
 	else
-		ret = hash_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
-				     oid->hash);
+		ret = hash_object_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
+				       oid);
 	strbuf_release(&sbuf);
 	return ret;
 }
@@ -1907,8 +1938,8 @@ int index_path(struct object_id *oid, const char *path, struct stat *st, unsigne
 		if (strbuf_readlink(&sb, path, st->st_size))
 			return error_errno("readlink(\"%s\")", path);
 		if (!(flags & HASH_WRITE_OBJECT))
-			hash_sha1_file(sb.buf, sb.len, blob_type, oid->hash);
-		else if (write_sha1_file(sb.buf, sb.len, blob_type, oid->hash))
+			hash_object_file(sb.buf, sb.len, blob_type, oid);
+		else if (write_object_file(sb.buf, sb.len, blob_type, oid))
 			rc = error("%s: failed to insert into database", path);
 		strbuf_release(&sb);
 		break;
@@ -2093,14 +2124,14 @@ static int check_stream_sha1(git_zstream *stream,
 			     const char *path,
 			     const unsigned char *expected_sha1)
 {
-	git_SHA_CTX c;
+	git_hash_ctx c;
 	unsigned char real_sha1[GIT_MAX_RAWSZ];
 	unsigned char buf[4096];
 	unsigned long total_read;
 	int status = Z_OK;
 
-	git_SHA1_Init(&c);
-	git_SHA1_Update(&c, hdr, stream->total_out);
+	the_hash_algo->init_fn(&c);
+	the_hash_algo->update_fn(&c, hdr, stream->total_out);
 
 	/*
 	 * We already read some bytes into hdr, but the ones up to the NUL
@@ -2119,7 +2150,7 @@ static int check_stream_sha1(git_zstream *stream,
 		if (size - total_read < stream->avail_out)
 			stream->avail_out = size - total_read;
 		status = git_inflate(stream, Z_FINISH);
-		git_SHA1_Update(&c, buf, stream->next_out - buf);
+		the_hash_algo->update_fn(&c, buf, stream->next_out - buf);
 		total_read += stream->next_out - buf;
 	}
 	git_inflate_end(stream);
@@ -2134,7 +2165,7 @@ static int check_stream_sha1(git_zstream *stream,
 		return -1;
 	}
 
-	git_SHA1_Final(real_sha1, &c);
+	the_hash_algo->final_fn(real_sha1, &c);
 	if (hashcmp(expected_sha1, real_sha1)) {
 		error("sha1 mismatch for %s (expected %s)", path,
 		      sha1_to_hex(expected_sha1));

diff --git a/sha1dc_git.h b/sha1dc_git.h
index a8c2729..41e1c3f 100644
--- a/sha1dc_git.h
+++ b/sha1dc_git.h

@@ -1,9 +1,9 @@
 /* Plumbing with collition-detecting SHA1 code */
 
-#ifdef DC_SHA1_SUBMODULE
-#include "sha1collisiondetection/lib/sha1.h"
-#elif defined(DC_SHA1_EXTERNAL)
+#ifdef DC_SHA1_EXTERNAL
 #include <sha1dc/sha1.h>
+#elif defined(DC_SHA1_SUBMODULE)
+#include "sha1collisiondetection/lib/sha1.h"
 #else
 #include "sha1dc/sha1.h"
 #endif

diff --git a/split-index.c b/split-index.c
index 83e39ec..284d04d 100644
--- a/split-index.c
+++ b/split-index.c

@@ -238,6 +238,8 @@ void prepare_to_write_split_index(struct index_state *istate)
 				ALLOC_GROW(entries, nr_entries+1, nr_alloc);
 				entries[nr_entries++] = ce;
 			}
+			if (is_null_oid(&ce->oid))
+				istate->drop_cache_tree = 1;
 		}
 	}
 

diff --git a/sub-process.h b/sub-process.h
index 4970199..71b18ad 100644
--- a/sub-process.h
+++ b/sub-process.h

@@ -73,8 +73,8 @@ static inline struct child_process *subprocess_get_child_process(
 }
 
 /*
- * Perform the version and capability negotiation as described in the "Long
- * Running Filter Process" section of the gitattributes documentation using the
+ * Perform the version and capability negotiation as described in the
+ * "Handshake" section of long-running-process-protocol.txt using the
  * given requested versions and capabilities. The "versions" and "capabilities"
  * parameters are arrays terminated by a 0 or blank struct.
  *

diff --git a/submodule.c b/submodule.c
index 2967704..47ddc9b 100644
--- a/submodule.c
+++ b/submodule.c

@@ -1657,7 +1657,9 @@ int submodule_move_head(const char *path,
 	else
 		argv_array_push(&cp.args, "-m");
 
-	argv_array_push(&cp.args, old ? old : EMPTY_TREE_SHA1_HEX);
+	if (!(flags & SUBMODULE_MOVE_HEAD_FORCE))
+		argv_array_push(&cp.args, old ? old : EMPTY_TREE_SHA1_HEX);
+
 	argv_array_push(&cp.args, new ? new : EMPTY_TREE_SHA1_HEX);
 
 	if (run_command(&cp)) {

diff --git a/t/helper/test-dump-untracked-cache.c b/t/helper/test-dump-untracked-cache.c
index f752532..d7c55c2 100644
--- a/t/helper/test-dump-untracked-cache.c
+++ b/t/helper/test-dump-untracked-cache.c

@@ -54,8 +54,8 @@ int cmd_main(int ac, const char **av)
 		printf("no untracked cache\n");
 		return 0;
 	}
-	printf("info/exclude %s\n", sha1_to_hex(uc->ss_info_exclude.sha1));
-	printf("core.excludesfile %s\n", sha1_to_hex(uc->ss_excludes_file.sha1));
+	printf("info/exclude %s\n", oid_to_hex(&uc->ss_info_exclude.oid));
+	printf("core.excludesfile %s\n", oid_to_hex(&uc->ss_excludes_file.oid));
 	printf("exclude_per_dir %s\n", uc->exclude_per_dir);
 	printf("flags %08x\n", uc->dir_flags);
 	if (uc->root)

diff --git a/t/helper/test-run-command.c b/t/helper/test-run-command.c
index d24d157..153342e 100644
--- a/t/helper/test-run-command.c
+++ b/t/helper/test-run-command.c

@@ -56,6 +56,15 @@ int cmd_main(int argc, const char **argv)
 
 	if (argc < 3)
 		return 1;
+	while (!strcmp(argv[1], "env")) {
+		if (!argv[2])
+			die("env specifier without a value");
+		argv_array_push(&proc.env_array, argv[2]);
+		argv += 2;
+		argc -= 2;
+	}
+	if (argc < 3)
+		return 1;
 	proc.argv = (const char **)argv + 2;
 
 	if (!strcmp(argv[1], "start-command-ENOENT")) {

diff --git a/t/helper/test-wildmatch.c b/t/helper/test-wildmatch.c
index 921d7b3..66d33df 100644
--- a/t/helper/test-wildmatch.c
+++ b/t/helper/test-wildmatch.c

@@ -16,6 +16,8 @@ int cmd_main(int argc, const char **argv)
 		return !!wildmatch(argv[3], argv[2], WM_PATHNAME | WM_CASEFOLD);
 	else if (!strcmp(argv[1], "pathmatch"))
 		return !!wildmatch(argv[3], argv[2], 0);
+	else if (!strcmp(argv[1], "ipathmatch"))
+		return !!wildmatch(argv[3], argv[2], WM_CASEFOLD);
 	else
 		return 1;
 }

diff --git a/t/lib-git-daemon.sh b/t/lib-git-daemon.sh
index 987d406..edbea2d 100644
--- a/t/lib-git-daemon.sh
+++ b/t/lib-git-daemon.sh

@@ -32,7 +32,8 @@
 
 GIT_DAEMON_PID=
 GIT_DAEMON_DOCUMENT_ROOT_PATH="$PWD"/repo
-GIT_DAEMON_URL=git://127.0.0.1:$LIB_GIT_DAEMON_PORT
+GIT_DAEMON_HOST_PORT=127.0.0.1:$LIB_GIT_DAEMON_PORT
+GIT_DAEMON_URL=git://$GIT_DAEMON_HOST_PORT
 
 start_git_daemon() {
 	if test -n "$GIT_DAEMON_PID"
@@ -53,11 +54,19 @@
 		"$@" "$GIT_DAEMON_DOCUMENT_ROOT_PATH" \
 		>&3 2>git_daemon_output &
 	GIT_DAEMON_PID=$!
+	>daemon.log
 	{
-		read line <&7
-		echo >&4 "$line"
-		cat <&7 >&4 &
-	} 7<git_daemon_output &&
+		read -r line <&7
+		printf "%s\n" "$line"
+		printf >&4 "%s\n" "$line"
+		(
+			while read -r line <&7
+			do
+				printf "%s\n" "$line"
+				printf >&4 "%s\n" "$line"
+			done
+		) &
+	} 7<git_daemon_output >>"$TRASH_DIRECTORY/daemon.log" &&
 
 	# Check expected output
 	if test x"$(expr "$line" : "\[[0-9]*\] \(.*\)")" != x"Ready to rumble"
@@ -90,3 +99,25 @@
 	GIT_DAEMON_PID=
 	rm -f git_daemon_output
 }
+
+# A stripped-down version of a netcat client, that connects to a "host:port"
+# given in $1, sends its stdin followed by EOF, then dumps the response (until
+# EOF) to stdout.
+fake_nc() {
+	if ! test_declared_prereq FAKENC
+	then
+		echo >&4 "fake_nc: need to declare FAKENC prerequisite"
+		return 127
+	fi
+	perl -Mstrict -MIO::Socket::INET -e '
+		my $s = IO::Socket::INET->new(shift)
+			or die "unable to open socket: $!";
+		print $s <STDIN>;
+		$s->shutdown(1);
+		print <$s>;
+	' "$@"
+}
+
+test_lazy_prereq FAKENC '
+	perl -MIO::Socket::INET -e "exit 0"
+'

diff --git a/t/lib-submodule-update.sh b/t/lib-submodule-update.sh
index 38dadd2..1f38a85 100755
--- a/t/lib-submodule-update.sh
+++ b/t/lib-submodule-update.sh

@@ -664,8 +664,8 @@
 			cd submodule_update &&
 			git -C sub1 checkout -b keep_branch &&
 			git -C sub1 rev-parse HEAD >expect &&
-			git branch -t check-keep origin/modify_sub1 &&
-			$command check-keep &&
+			git branch -t modify_sub1 origin/modify_sub1 &&
+			$command modify_sub1 &&
 			test_superproject_content origin/modify_sub1 &&
 			test_submodule_content sub1 origin/modify_sub1 &&
 			git -C sub1 rev-parse keep_branch >actual &&
@@ -885,6 +885,7 @@
 		(
 			cd submodule_update &&
 			git branch -t replace_sub1_with_file origin/replace_sub1_with_file &&
+			echo ignored >.git/modules/sub1/info/exclude &&
 			: >sub1/ignored &&
 			$command replace_sub1_with_file &&
 			test_superproject_content origin/replace_sub1_with_file &&
@@ -1014,4 +1015,18 @@
 			test_submodule_content sub1 origin/modify_sub1
 		)
 	'
+
+	test_expect_success "$command: changed submodule worktree is reset" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			rm sub1/file1 &&
+			: >sub1/new_file &&
+			git -C sub1 add new_file &&
+			$command HEAD &&
+			test_path_is_file sub1/file1 &&
+			test_path_is_missing sub1/new_file
+		)
+	'
 }

diff --git a/t/perf/aggregate.perl b/t/perf/aggregate.perl
index e401208..821cf14 100755
--- a/t/perf/aggregate.perl
+++ b/t/perf/aggregate.perl

@@ -1,8 +1,9 @@
 #!/usr/bin/perl
 
-use lib '../../perl/blib/lib';
+use lib '../../perl/build/lib';
 use strict;
 use warnings;
+use JSON;
 use Git;
 
 sub get_times {
@@ -35,10 +36,34 @@
 	return $out;
 }
 
-my (@dirs, %dirnames, %dirabbrevs, %prefixes, @tests);
+my (@dirs, %dirnames, %dirabbrevs, %prefixes, @tests,
+    $codespeed, $subsection, $reponame);
 while (scalar @ARGV) {
 	my $arg = $ARGV[0];
 	my $dir;
+	if ($arg eq "--codespeed") {
+		$codespeed = 1;
+		shift @ARGV;
+		next;
+	}
+	if ($arg eq "--subsection") {
+		shift @ARGV;
+		$subsection = $ARGV[0];
+		shift @ARGV;
+		if (! $subsection) {
+			die "empty subsection";
+		}
+		next;
+	}
+	if ($arg eq "--reponame") {
+		shift @ARGV;
+		$reponame = $ARGV[0];
+		shift @ARGV;
+		if (! $reponame) {
+			die "empty reponame";
+		}
+		next;
+	}
 	last if -f $arg or $arg eq "--";
 	if (! -d $arg) {
 		my $rev = Git::command_oneline(qw(rev-parse --verify), $arg);
@@ -70,8 +95,15 @@
 }
 
 my $resultsdir = "test-results";
-if ($ENV{GIT_PERF_SUBSECTION} ne "") {
-	$resultsdir .= "/" . $ENV{GIT_PERF_SUBSECTION};
+
+if (! $subsection and
+    exists $ENV{GIT_PERF_SUBSECTION} and
+    $ENV{GIT_PERF_SUBSECTION} ne "") {
+	$subsection = $ENV{GIT_PERF_SUBSECTION};
+}
+
+if ($subsection) {
+	$resultsdir .= "/" . $subsection;
 }
 
 my @subtests;
@@ -100,13 +132,6 @@
 	return $line;
 }
 
-my %descrs;
-my $descrlen = 4; # "Test"
-for my $t (@subtests) {
-	$descrs{$t} = $shorttests{$t}.": ".read_descr("$resultsdir/$t.descr");
-	$descrlen = length $descrs{$t} if length $descrs{$t}>$descrlen;
-}
-
 sub have_duplicate {
 	my %seen;
 	for (@_) {
@@ -122,54 +147,119 @@
 	return 0;
 }
 
-my %newdirabbrevs = %dirabbrevs;
-while (!have_duplicate(values %newdirabbrevs)) {
-	%dirabbrevs = %newdirabbrevs;
-	last if !have_slash(values %dirabbrevs);
-	%newdirabbrevs = %dirabbrevs;
-	for (values %newdirabbrevs) {
-		s{^[^/]*/}{};
+sub print_default_results {
+	my %descrs;
+	my $descrlen = 4; # "Test"
+	for my $t (@subtests) {
+		$descrs{$t} = $shorttests{$t}.": ".read_descr("$resultsdir/$t.descr");
+		$descrlen = length $descrs{$t} if length $descrs{$t}>$descrlen;
+	}
+
+	my %newdirabbrevs = %dirabbrevs;
+	while (!have_duplicate(values %newdirabbrevs)) {
+		%dirabbrevs = %newdirabbrevs;
+		last if !have_slash(values %dirabbrevs);
+		%newdirabbrevs = %dirabbrevs;
+		for (values %newdirabbrevs) {
+			s{^[^/]*/}{};
+		}
+	}
+
+	my %times;
+	my @colwidth = ((0)x@dirs);
+	for my $i (0..$#dirs) {
+		my $d = $dirs[$i];
+		my $w = length (exists $dirabbrevs{$d} ? $dirabbrevs{$d} : $dirnames{$d});
+		$colwidth[$i] = $w if $w > $colwidth[$i];
+	}
+	for my $t (@subtests) {
+		my $firstr;
+		for my $i (0..$#dirs) {
+			my $d = $dirs[$i];
+			$times{$prefixes{$d}.$t} = [get_times("$resultsdir/$prefixes{$d}$t.times")];
+			my ($r,$u,$s) = @{$times{$prefixes{$d}.$t}};
+			my $w = length format_times($r,$u,$s,$firstr);
+			$colwidth[$i] = $w if $w > $colwidth[$i];
+			$firstr = $r unless defined $firstr;
+		}
+	}
+	my $totalwidth = 3*@dirs+$descrlen;
+	$totalwidth += $_ for (@colwidth);
+
+	printf "%-${descrlen}s", "Test";
+	for my $i (0..$#dirs) {
+		my $d = $dirs[$i];
+		printf "   %-$colwidth[$i]s", (exists $dirabbrevs{$d} ? $dirabbrevs{$d} : $dirnames{$d});
+	}
+	print "\n";
+	print "-"x$totalwidth, "\n";
+	for my $t (@subtests) {
+		printf "%-${descrlen}s", $descrs{$t};
+		my $firstr;
+		for my $i (0..$#dirs) {
+			my $d = $dirs[$i];
+			my ($r,$u,$s) = @{$times{$prefixes{$d}.$t}};
+			printf "   %-$colwidth[$i]s", format_times($r,$u,$s,$firstr);
+			$firstr = $r unless defined $firstr;
+		}
+		print "\n";
 	}
 }
 
-my %times;
-my @colwidth = ((0)x@dirs);
-for my $i (0..$#dirs) {
-	my $d = $dirs[$i];
-	my $w = length (exists $dirabbrevs{$d} ? $dirabbrevs{$d} : $dirnames{$d});
-	$colwidth[$i] = $w if $w > $colwidth[$i];
-}
-for my $t (@subtests) {
-	my $firstr;
-	for my $i (0..$#dirs) {
-		my $d = $dirs[$i];
-		$times{$prefixes{$d}.$t} = [get_times("$resultsdir/$prefixes{$d}$t.times")];
-		my ($r,$u,$s) = @{$times{$prefixes{$d}.$t}};
-		my $w = length format_times($r,$u,$s,$firstr);
-		$colwidth[$i] = $w if $w > $colwidth[$i];
-		$firstr = $r unless defined $firstr;
+sub print_codespeed_results {
+	my ($subsection) = @_;
+
+	my $project = "Git";
+
+	my $executable = `uname -s -m`;
+	chomp $executable;
+
+	if ($subsection) {
+		$executable .= ", " . $subsection;
 	}
+
+	my $environment;
+	if ($reponame) {
+		$environment = $reponame;
+	} elsif (exists $ENV{GIT_PERF_REPO_NAME} and $ENV{GIT_PERF_REPO_NAME} ne "") {
+		$environment = $ENV{GIT_PERF_REPO_NAME};
+	} elsif (exists $ENV{GIT_TEST_INSTALLED} and $ENV{GIT_TEST_INSTALLED} ne "") {
+		$environment = $ENV{GIT_TEST_INSTALLED};
+		$environment =~ s|/bin-wrappers$||;
+	} else {
+		$environment = `uname -r`;
+		chomp $environment;
+	}
+
+	my @data;
+
+	for my $t (@subtests) {
+		for my $d (@dirs) {
+			my $commitid = $prefixes{$d};
+			$commitid =~ s/^build_//;
+			$commitid =~ s/\.$//;
+			my ($result_value, $u, $s) = get_times("$resultsdir/$prefixes{$d}$t.times");
+
+			my %vals = (
+				"commitid" => $commitid,
+				"project" => $project,
+				"branch" => $dirnames{$d},
+				"executable" => $executable,
+				"benchmark" => $shorttests{$t} . " " . read_descr("$resultsdir/$t.descr"),
+				"environment" => $environment,
+				"result_value" => $result_value,
+			    );
+			push @data, \%vals;
+		}
+	}
+
+	print to_json(\@data, {utf8 => 1, pretty => 1, canonical => 1}), "\n";
 }
-my $totalwidth = 3*@dirs+$descrlen;
-$totalwidth += $_ for (@colwidth);
 
 binmode STDOUT, ":utf8" or die "PANIC on binmode: $!";
 
-printf "%-${descrlen}s", "Test";
-for my $i (0..$#dirs) {
-	my $d = $dirs[$i];
-	printf "   %-$colwidth[$i]s", (exists $dirabbrevs{$d} ? $dirabbrevs{$d} : $dirnames{$d});
-}
-print "\n";
-print "-"x$totalwidth, "\n";
-for my $t (@subtests) {
-	printf "%-${descrlen}s", $descrs{$t};
-	my $firstr;
-	for my $i (0..$#dirs) {
-		my $d = $dirs[$i];
-		my ($r,$u,$s) = @{$times{$prefixes{$d}.$t}};
-		printf "   %-$colwidth[$i]s", format_times($r,$u,$s,$firstr);
-		$firstr = $r unless defined $firstr;
-	}
-	print "\n";
+if ($codespeed) {
+	print_codespeed_results($subsection);
+} else {
+	print_default_results();
 }

diff --git a/t/perf/p7820-grep-engines.sh b/t/perf/p7820-grep-engines.sh
index 62aba19..8b09c5b 100755
--- a/t/perf/p7820-grep-engines.sh
+++ b/t/perf/p7820-grep-engines.sh

@@ -12,6 +12,9 @@
 	-vi
 	-vw
 	-viw
+
+If GIT_PERF_GREP_THREADS is set to a list of threads (e.g. '1 4 8'
+etc.) we will test the patterns under those numbers of threads.
 "
 
 . ./perf-lib.sh
@@ -19,6 +22,11 @@
 test_perf_large_repo
 test_checkout_worktree
 
+if test -n "$GIT_PERF_GREP_THREADS"
+then
+	test_set_prereq PERF_GREP_ENGINES_THREADS
+fi
+
 for pattern in \
 	'how.to' \
 	'^how to' \
@@ -39,18 +47,42 @@
 		else
 			prereq=""
 		fi
-		test_perf $prereq "$engine grep$GIT_PERF_7820_GREP_OPTS '$pattern'" "
-			git -c grep.patternType=$engine grep$GIT_PERF_7820_GREP_OPTS -- '$pattern' >'out.$engine' || :
-		"
+		if ! test_have_prereq PERF_GREP_ENGINES_THREADS
+		then
+			test_perf $prereq "$engine grep$GIT_PERF_7820_GREP_OPTS '$pattern'" "
+				git -c grep.patternType=$engine grep$GIT_PERF_7820_GREP_OPTS -- '$pattern' >'out.$engine' || :
+			"
+		else
+			for threads in $GIT_PERF_GREP_THREADS
+			do
+				test_perf PTHREADS,$prereq "$engine grep$GIT_PERF_7820_GREP_OPTS '$pattern' with $threads threads" "
+					git -c grep.patternType=$engine -c grep.threads=$threads grep$GIT_PERF_7820_GREP_OPTS -- '$pattern' >'out.$engine.$threads' || :
+				"
+			done
+		fi
 	done
 
-	test_expect_success "assert that all engines found the same for$GIT_PERF_7820_GREP_OPTS '$pattern'" '
-		test_cmp out.basic out.extended &&
-		if test_have_prereq PCRE
-		then
-			test_cmp out.basic out.perl
-		fi
-	'
+	if ! test_have_prereq PERF_GREP_ENGINES_THREADS
+	then
+		test_expect_success "assert that all engines found the same for$GIT_PERF_7820_GREP_OPTS '$pattern'" '
+			test_cmp out.basic out.extended &&
+			if test_have_prereq PCRE
+			then
+				test_cmp out.basic out.perl
+			fi
+		'
+	else
+		for threads in $GIT_PERF_GREP_THREADS
+		do
+			test_expect_success PTHREADS "assert that all engines found the same for$GIT_PERF_7820_GREP_OPTS '$pattern' under threading" "
+				test_cmp out.basic.$threads out.extended.$threads &&
+				if test_have_prereq PCRE
+				then
+					test_cmp out.basic.$threads out.perl.$threads
+				fi
+			"
+		done
+	fi
 done
 
 test_done

diff --git a/t/perf/p7821-grep-engines-fixed.sh b/t/perf/p7821-grep-engines-fixed.sh
index c7ef1e1..61e41b8 100755
--- a/t/perf/p7821-grep-engines-fixed.sh
+++ b/t/perf/p7821-grep-engines-fixed.sh

@@ -6,6 +6,9 @@
 git-grep. Make sure to include a leading space,
 e.g. GIT_PERF_7821_GREP_OPTS=' -w'. See p7820-grep-engines.sh for more
 options to try.
+
+If GIT_PERF_7821_THREADS is set to a list of threads (e.g. '1 4 8'
+etc.) we will test the patterns under those numbers of threads.
 "
 
 . ./perf-lib.sh
@@ -13,6 +16,11 @@
 test_perf_large_repo
 test_checkout_worktree
 
+if test -n "$GIT_PERF_GREP_THREADS"
+then
+	test_set_prereq PERF_GREP_ENGINES_THREADS
+fi
+
 for pattern in 'int' 'uncommon' 'æ'
 do
 	for engine in fixed basic extended perl
@@ -23,19 +31,44 @@
 		else
 			prereq=""
 		fi
-		test_perf $prereq "$engine grep$GIT_PERF_7821_GREP_OPTS $pattern" "
-			git -c grep.patternType=$engine grep$GIT_PERF_7821_GREP_OPTS $pattern >'out.$engine' || :
-		"
+		if ! test_have_prereq PERF_GREP_ENGINES_THREADS
+		then
+			test_perf $prereq "$engine grep$GIT_PERF_7821_GREP_OPTS $pattern" "
+				git -c grep.patternType=$engine grep$GIT_PERF_7821_GREP_OPTS $pattern >'out.$engine' || :
+			"
+		else
+			for threads in $GIT_PERF_GREP_THREADS
+			do
+				test_perf PTHREADS,$prereq "$engine grep$GIT_PERF_7821_GREP_OPTS $pattern with $threads threads" "
+					git -c grep.patternType=$engine -c grep.threads=$threads grep$GIT_PERF_7821_GREP_OPTS $pattern >'out.$engine.$threads' || :
+				"
+			done
+		fi
 	done
 
-	test_expect_success "assert that all engines found the same for$GIT_PERF_7821_GREP_OPTS $pattern" '
-		test_cmp out.fixed out.basic &&
-		test_cmp out.fixed out.extended &&
-		if test_have_prereq PCRE
-		then
-			test_cmp out.fixed out.perl
-		fi
-	'
+	if ! test_have_prereq PERF_GREP_ENGINES_THREADS
+	then
+		test_expect_success "assert that all engines found the same for$GIT_PERF_7821_GREP_OPTS $pattern" '
+			test_cmp out.fixed out.basic &&
+			test_cmp out.fixed out.extended &&
+			if test_have_prereq PCRE
+			then
+				test_cmp out.fixed out.perl
+			fi
+		'
+	else
+		for threads in $GIT_PERF_GREP_THREADS
+		do
+			test_expect_success PTHREADS "assert that all engines found the same for$GIT_PERF_7821_GREP_OPTS $pattern under threading" "
+				test_cmp out.fixed.$threads out.basic.$threads &&
+				test_cmp out.fixed.$threads out.extended.$threads &&
+				if test_have_prereq PCRE
+				then
+					test_cmp out.fixed.$threads out.perl.$threads
+				fi
+			"
+		done
+	fi
 done
 
 test_done

diff --git a/t/perf/run b/t/perf/run
index 43e4de4..1a100d6 100755
--- a/t/perf/run
+++ b/t/perf/run

@@ -105,7 +105,8 @@
 	env_var="$1"
 	conf_sec="$2"
 	conf_var="$3"
-	# $4 can be set to a default value
+	conf_opts="$4" # optional
+	# $5 can be set to a default value
 
 	# Do nothing if the env variable is already set
 	eval "test -z \"\${$env_var+x}\"" || return
@@ -116,18 +117,18 @@
 	if test -n "$GIT_PERF_SUBSECTION"
 	then
 		var="$conf_sec.$GIT_PERF_SUBSECTION.$conf_var"
-		conf_value=$(git config -f "$GIT_PERF_CONFIG_FILE" "$var") &&
+		conf_value=$(git config $conf_opts -f "$GIT_PERF_CONFIG_FILE" "$var") &&
 		eval "$env_var=\"$conf_value\"" && return
 	fi
 	var="$conf_sec.$conf_var"
-	conf_value=$(git config -f "$GIT_PERF_CONFIG_FILE" "$var") &&
+	conf_value=$(git config $conf_opts -f "$GIT_PERF_CONFIG_FILE" "$var") &&
 	eval "$env_var=\"$conf_value\"" && return
 
-	test -n "${4+x}" && eval "$env_var=\"$4\""
+	test -n "${5+x}" && eval "$env_var=\"$5\""
 }
 
 run_subsection () {
-	get_var_from_env_or_config "GIT_PERF_REPEAT_COUNT" "perf" "repeatCount" 3
+	get_var_from_env_or_config "GIT_PERF_REPEAT_COUNT" "perf" "repeatCount" "--int" 3
 	export GIT_PERF_REPEAT_COUNT
 
 	get_var_from_env_or_config "GIT_PERF_DIRS_OR_REVS" "perf" "dirsOrRevs"
@@ -136,6 +137,9 @@
 	get_var_from_env_or_config "GIT_PERF_MAKE_COMMAND" "perf" "makeCommand"
 	get_var_from_env_or_config "GIT_PERF_MAKE_OPTS" "perf" "makeOpts"
 
+	get_var_from_env_or_config "GIT_PERF_REPO_NAME" "perf" "repoName"
+	export GIT_PERF_REPO_NAME
+
 	GIT_PERF_AGGREGATING_LATER=t
 	export GIT_PERF_AGGREGATING_LATER
 
@@ -143,10 +147,25 @@
 		set -- . "$@"
 	fi
 
+	codespeed_opt=
+	test "$GIT_PERF_CODESPEED_OUTPUT" = "true" && codespeed_opt="--codespeed"
+
 	run_dirs "$@"
-	./aggregate.perl "$@"
+
+	if test -z "$GIT_PERF_SEND_TO_CODESPEED"
+	then
+		./aggregate.perl $codespeed_opt "$@"
+	else
+		json_res_file="test-results/$GIT_PERF_SUBSECTION/aggregate.json"
+		./aggregate.perl --codespeed "$@" | tee "$json_res_file"
+		send_data_url="$GIT_PERF_SEND_TO_CODESPEED/result/add/json/"
+		curl -v --request POST --data-urlencode "json=$(cat "$json_res_file")" "$send_data_url"
+	fi
 }
 
+get_var_from_env_or_config "GIT_PERF_CODESPEED_OUTPUT" "perf" "codespeedOutput" "--bool"
+get_var_from_env_or_config "GIT_PERF_SEND_TO_CODESPEED" "perf" "sendToCodespeed"
+
 cd "$(dirname $0)"
 . ../../GIT-BUILD-OPTIONS
 

diff --git a/t/t0061-run-command.sh b/t/t0061-run-command.sh
index e473917..24c92b6 100755
--- a/t/t0061-run-command.sh
+++ b/t/t0061-run-command.sh

@@ -141,4 +141,41 @@
 	test_cmp expect actual
 '
 
+test_trace () {
+	expect="$1"
+	shift
+	GIT_TRACE=1 test-run-command "$@" run-command true 2>&1 >/dev/null | \
+		sed 's/.* run_command: //' >actual &&
+	echo "$expect true" >expect &&
+	test_cmp expect actual
+}
+
+test_expect_success 'GIT_TRACE with environment variables' '
+	test_trace "abc=1 def=2" env abc=1 env def=2 &&
+	test_trace "abc=2" env abc env abc=1 env abc=2 &&
+	test_trace "abc=2" env abc env abc=2 &&
+	(
+		abc=1 && export abc &&
+		test_trace "def=1" env abc=1 env def=1
+	) &&
+	(
+		abc=1 && export abc &&
+		test_trace "def=1" env abc env abc=1 env def=1
+	) &&
+	test_trace "def=1" env non-exist env def=1 &&
+	test_trace "abc=2" env abc=1 env abc env abc=2 &&
+	(
+		abc=1 def=2 && export abc def &&
+		test_trace "unset abc def;" env abc env def
+	) &&
+	(
+		abc=1 def=2 && export abc def &&
+		test_trace "unset def; abc=3" env abc env def env abc=3
+	) &&
+	(
+		abc=1 && export abc &&
+		test_trace "unset abc;" env abc=2 env abc
+	)
+'
+
 test_done

diff --git a/t/t0410-partial-clone.sh b/t/t0410-partial-clone.sh
new file mode 100755
index 0000000..cc18b75
--- /dev/null
+++ b/t/t0410-partial-clone.sh

@@ -0,0 +1,343 @@
+#!/bin/sh
+
+test_description='partial clone'
+
+. ./test-lib.sh
+
+delete_object () {
+	rm $1/.git/objects/$(echo $2 | sed -e 's|^..|&/|')
+}
+
+pack_as_from_promisor () {
+	HASH=$(git -C repo pack-objects .git/objects/pack/pack) &&
+	>repo/.git/objects/pack/pack-$HASH.promisor &&
+	echo $HASH
+}
+
+promise_and_delete () {
+	HASH=$(git -C repo rev-parse "$1") &&
+	git -C repo tag -a -m message my_annotated_tag "$HASH" &&
+	git -C repo rev-parse my_annotated_tag | pack_as_from_promisor &&
+	# tag -d prints a message to stdout, so redirect it
+	git -C repo tag -d my_annotated_tag >/dev/null &&
+	delete_object repo "$HASH"
+}
+
+test_expect_success 'missing reflog object, but promised by a commit, passes fsck' '
+	test_create_repo repo &&
+	test_commit -C repo my_commit &&
+
+	A=$(git -C repo commit-tree -m a HEAD^{tree}) &&
+	C=$(git -C repo commit-tree -m c -p $A HEAD^{tree}) &&
+
+	# Reference $A only from reflog, and delete it
+	git -C repo branch my_branch "$A" &&
+	git -C repo branch -f my_branch my_commit &&
+	delete_object repo "$A" &&
+
+	# State that we got $C, which refers to $A, from promisor
+	printf "$C\n" | pack_as_from_promisor &&
+
+	# Normally, it fails
+	test_must_fail git -C repo fsck &&
+
+	# But with the extension, it succeeds
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo fsck
+'
+
+test_expect_success 'missing reflog object, but promised by a tag, passes fsck' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo my_commit &&
+
+	A=$(git -C repo commit-tree -m a HEAD^{tree}) &&
+	git -C repo tag -a -m d my_tag_name $A &&
+	T=$(git -C repo rev-parse my_tag_name) &&
+	git -C repo tag -d my_tag_name &&
+
+	# Reference $A only from reflog, and delete it
+	git -C repo branch my_branch "$A" &&
+	git -C repo branch -f my_branch my_commit &&
+	delete_object repo "$A" &&
+
+	# State that we got $T, which refers to $A, from promisor
+	printf "$T\n" | pack_as_from_promisor &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo fsck
+'
+
+test_expect_success 'missing reflog object alone fails fsck, even with extension set' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo my_commit &&
+
+	A=$(git -C repo commit-tree -m a HEAD^{tree}) &&
+	B=$(git -C repo commit-tree -m b HEAD^{tree}) &&
+
+	# Reference $A only from reflog, and delete it
+	git -C repo branch my_branch "$A" &&
+	git -C repo branch -f my_branch my_commit &&
+	delete_object repo "$A" &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	test_must_fail git -C repo fsck
+'
+
+test_expect_success 'missing ref object, but promised, passes fsck' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo my_commit &&
+
+	A=$(git -C repo commit-tree -m a HEAD^{tree}) &&
+
+	# Reference $A only from ref
+	git -C repo branch my_branch "$A" &&
+	promise_and_delete "$A" &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo fsck
+'
+
+test_expect_success 'missing object, but promised, passes fsck' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo 1 &&
+	test_commit -C repo 2 &&
+	test_commit -C repo 3 &&
+	git -C repo tag -a annotated_tag -m "annotated tag" &&
+
+	C=$(git -C repo rev-parse 1) &&
+	T=$(git -C repo rev-parse 2^{tree}) &&
+	B=$(git hash-object repo/3.t) &&
+	AT=$(git -C repo rev-parse annotated_tag) &&
+
+	promise_and_delete "$C" &&
+	promise_and_delete "$T" &&
+	promise_and_delete "$B" &&
+	promise_and_delete "$AT" &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo fsck
+'
+
+test_expect_success 'missing CLI object, but promised, passes fsck' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo my_commit &&
+
+	A=$(git -C repo commit-tree -m a HEAD^{tree}) &&
+	promise_and_delete "$A" &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo fsck "$A"
+'
+
+test_expect_success 'fetching of missing objects' '
+	rm -rf repo &&
+	test_create_repo server &&
+	test_commit -C server foo &&
+	git -C server repack -a -d --write-bitmap-index &&
+
+	git clone "file://$(pwd)/server" repo &&
+	HASH=$(git -C repo rev-parse foo) &&
+	rm -rf repo/.git/objects/* &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "origin" &&
+	git -C repo cat-file -p "$HASH" &&
+
+	# Ensure that the .promisor file is written, and check that its
+	# associated packfile contains the object
+	ls repo/.git/objects/pack/pack-*.promisor >promisorlist &&
+	test_line_count = 1 promisorlist &&
+	IDX=$(cat promisorlist | sed "s/promisor$/idx/") &&
+	git verify-pack --verbose "$IDX" | grep "$HASH"
+'
+
+test_expect_success 'rev-list stops traversal at missing and promised commit' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo foo &&
+	test_commit -C repo bar &&
+
+	FOO=$(git -C repo rev-parse foo) &&
+	promise_and_delete "$FOO" &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo rev-list --exclude-promisor-objects --objects bar >out &&
+	grep $(git -C repo rev-parse bar) out &&
+	! grep $FOO out
+'
+
+test_expect_success 'rev-list stops traversal at missing and promised tree' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo foo &&
+	mkdir repo/a_dir &&
+	echo something >repo/a_dir/something &&
+	git -C repo add a_dir/something &&
+	git -C repo commit -m bar &&
+
+	# foo^{tree} (tree referenced from commit)
+	TREE=$(git -C repo rev-parse foo^{tree}) &&
+
+	# a tree referenced by HEAD^{tree} (tree referenced from tree)
+	TREE2=$(git -C repo ls-tree HEAD^{tree} | grep " tree " | head -1 | cut -b13-52) &&
+
+	promise_and_delete "$TREE" &&
+	promise_and_delete "$TREE2" &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo rev-list --exclude-promisor-objects --objects HEAD >out &&
+	grep $(git -C repo rev-parse foo) out &&
+	! grep $TREE out &&
+	grep $(git -C repo rev-parse HEAD) out &&
+	! grep $TREE2 out
+'
+
+test_expect_success 'rev-list stops traversal at missing and promised blob' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	echo something >repo/something &&
+	git -C repo add something &&
+	git -C repo commit -m foo &&
+
+	BLOB=$(git -C repo hash-object -w something) &&
+	promise_and_delete "$BLOB" &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo rev-list --exclude-promisor-objects --objects HEAD >out &&
+	grep $(git -C repo rev-parse HEAD) out &&
+	! grep $BLOB out
+'
+
+test_expect_success 'rev-list stops traversal at promisor commit, tree, and blob' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo foo &&
+	test_commit -C repo bar &&
+	test_commit -C repo baz &&
+
+	COMMIT=$(git -C repo rev-parse foo) &&
+	TREE=$(git -C repo rev-parse bar^{tree}) &&
+	BLOB=$(git hash-object repo/baz.t) &&
+	printf "%s\n%s\n%s\n" $COMMIT $TREE $BLOB | pack_as_from_promisor &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo rev-list --exclude-promisor-objects --objects HEAD >out &&
+	! grep $COMMIT out &&
+	! grep $TREE out &&
+	! grep $BLOB out &&
+	grep $(git -C repo rev-parse bar) out  # sanity check that some walking was done
+'
+
+test_expect_success 'rev-list accepts missing and promised objects on command line' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo foo &&
+	test_commit -C repo bar &&
+	test_commit -C repo baz &&
+
+	COMMIT=$(git -C repo rev-parse foo) &&
+	TREE=$(git -C repo rev-parse bar^{tree}) &&
+	BLOB=$(git hash-object repo/baz.t) &&
+
+	promise_and_delete $COMMIT &&
+	promise_and_delete $TREE &&
+	promise_and_delete $BLOB &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo rev-list --exclude-promisor-objects --objects "$COMMIT" "$TREE" "$BLOB"
+'
+
+test_expect_success 'gc does not repack promisor objects' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo my_commit &&
+
+	TREE_HASH=$(git -C repo rev-parse HEAD^{tree}) &&
+	HASH=$(printf "$TREE_HASH\n" | pack_as_from_promisor) &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo gc &&
+
+	# Ensure that the promisor packfile still exists, and remove it
+	test -e repo/.git/objects/pack/pack-$HASH.pack &&
+	rm repo/.git/objects/pack/pack-$HASH.* &&
+
+	# Ensure that the single other pack contains the commit, but not the tree
+	ls repo/.git/objects/pack/pack-*.pack >packlist &&
+	test_line_count = 1 packlist &&
+	git verify-pack repo/.git/objects/pack/pack-*.pack -v >out &&
+	grep "$(git -C repo rev-parse HEAD)" out &&
+	! grep "$TREE_HASH" out
+'
+
+test_expect_success 'gc stops traversal when a missing but promised object is reached' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo my_commit &&
+
+	TREE_HASH=$(git -C repo rev-parse HEAD^{tree}) &&
+	HASH=$(promise_and_delete $TREE_HASH) &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo gc &&
+
+	# Ensure that the promisor packfile still exists, and remove it
+	test -e repo/.git/objects/pack/pack-$HASH.pack &&
+	rm repo/.git/objects/pack/pack-$HASH.* &&
+
+	# Ensure that the single other pack contains the commit, but not the tree
+	ls repo/.git/objects/pack/pack-*.pack >packlist &&
+	test_line_count = 1 packlist &&
+	git verify-pack repo/.git/objects/pack/pack-*.pack -v >out &&
+	grep "$(git -C repo rev-parse HEAD)" out &&
+	! grep "$TREE_HASH" out
+'
+
+LIB_HTTPD_PORT=12345  # default port, 410, cannot be used as non-root
+. "$TEST_DIRECTORY"/lib-httpd.sh
+start_httpd
+
+test_expect_success 'fetching of missing objects from an HTTP server' '
+	rm -rf repo &&
+	SERVER="$HTTPD_DOCUMENT_ROOT_PATH/server" &&
+	test_create_repo "$SERVER" &&
+	test_commit -C "$SERVER" foo &&
+	git -C "$SERVER" repack -a -d --write-bitmap-index &&
+
+	git clone $HTTPD_URL/smart/server repo &&
+	HASH=$(git -C repo rev-parse foo) &&
+	rm -rf repo/.git/objects/* &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "origin" &&
+	git -C repo cat-file -p "$HASH" &&
+
+	# Ensure that the .promisor file is written, and check that its
+	# associated packfile contains the object
+	ls repo/.git/objects/pack/pack-*.promisor >promisorlist &&
+	test_line_count = 1 promisorlist &&
+	IDX=$(cat promisorlist | sed "s/promisor$/idx/") &&
+	git verify-pack --verbose "$IDX" | grep "$HASH"
+'
+
+stop_httpd
+
+test_done

diff --git a/t/t1700-split-index.sh b/t/t1700-split-index.sh
index af9b847..a66936f 100755
--- a/t/t1700-split-index.sh
+++ b/t/t1700-split-index.sh

@@ -401,4 +401,42 @@
 0642 -rw-r---w-
 EOF
 
+test_expect_success POSIXPERM,SANITY 'graceful handling when splitting index is not allowed' '
+	test_create_repo ro &&
+	(
+		cd ro &&
+		test_commit initial &&
+		git update-index --split-index &&
+		test -f .git/sharedindex.*
+	) &&
+	cp ro/.git/index new-index &&
+	test_when_finished "chmod u+w ro/.git" &&
+	chmod u-w ro/.git &&
+	GIT_INDEX_FILE="$(pwd)/new-index" git -C ro update-index --split-index &&
+	chmod u+w ro/.git &&
+	rm ro/.git/sharedindex.* &&
+	GIT_INDEX_FILE=new-index git ls-files >actual &&
+	echo initial.t >expected &&
+	test_cmp expected actual
+'
+
+test_expect_success 'writing split index with null sha1 does not write cache tree' '
+	git config core.splitIndex true &&
+	git config splitIndex.maxPercentChange 0 &&
+	git commit -m "commit" &&
+	{
+		git ls-tree HEAD &&
+		printf "160000 commit $_z40\\tbroken\\n"
+	} >broken-tree &&
+	echo "add broken entry" >msg &&
+
+	tree=$(git mktree <broken-tree) &&
+	test_tick &&
+	commit=$(git commit-tree $tree -p HEAD <msg) &&
+	git update-ref HEAD "$commit" &&
+	GIT_ALLOW_NULL_SHA1=1 git reset --hard &&
+	(test-dump-cache-tree >cache-tree.out || true) &&
+	test_line_count = 0 cache-tree.out
+'
+
 test_done

diff --git a/t/t2203-add-intent.sh b/t/t2203-add-intent.sh
index 1bdf38e..78236dc 100755
--- a/t/t2203-add-intent.sh
+++ b/t/t2203-add-intent.sh

@@ -25,6 +25,18 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'git status with porcelain v2' '
+	git status --porcelain=v2 | grep -v "^?" >actual &&
+	nam1=d00491fd7e5bb6fa28c517a0bb32b8b506539d4d &&
+	nam2=ce013625030ba8dba906f756967f9e9ca394464a &&
+	cat >expect <<-EOF &&
+	1 DA N... 100644 000000 100644 $nam1 $_z40 1.t
+	1 A. N... 000000 100644 100644 $_z40 $nam2 elif
+	1 .A N... 000000 000000 100644 $_z40 $_z40 file
+	EOF
+	test_cmp expect actual
+'
+
 test_expect_success 'check result of "add -N"' '
 	git ls-files -s file >actual &&
 	empty=$(git hash-object --stdin </dev/null) &&
@@ -150,5 +162,65 @@
 	)
 '
 
+test_expect_success 'rename detection finds the right names' '
+	git init rename-detection &&
+	(
+		cd rename-detection &&
+		echo contents >first &&
+		git add first &&
+		git commit -m first &&
+		mv first third &&
+		git add -N third &&
+
+		git status | grep -v "^?" >actual.1 &&
+		test_i18ngrep "renamed: *first -> third" actual.1 &&
+
+		git status --porcelain | grep -v "^?" >actual.2 &&
+		cat >expected.2 <<-\EOF &&
+		 R first -> third
+		EOF
+		test_cmp expected.2 actual.2 &&
+
+		hash=12f00e90b6ef79117ce6e650416b8cf517099b78 &&
+		git status --porcelain=v2 | grep -v "^?" >actual.3 &&
+		cat >expected.3 <<-EOF &&
+		2 .R N... 100644 100644 100644 $hash $hash R100 third	first
+		EOF
+		test_cmp expected.3 actual.3
+	)
+'
+
+test_expect_success 'double rename detection in status' '
+	git init rename-detection-2 &&
+	(
+		cd rename-detection-2 &&
+		echo contents >first &&
+		git add first &&
+		git commit -m first &&
+		git mv first second &&
+		mv second third &&
+		git add -N third &&
+
+		git status | grep -v "^?" >actual.1 &&
+		test_i18ngrep "renamed: *first -> second" actual.1 &&
+		test_i18ngrep "renamed: *second -> third" actual.1 &&
+
+		git status --porcelain | grep -v "^?" >actual.2 &&
+		cat >expected.2 <<-\EOF &&
+		R  first -> second
+		 R second -> third
+		EOF
+		test_cmp expected.2 actual.2 &&
+
+		hash=12f00e90b6ef79117ce6e650416b8cf517099b78 &&
+		git status --porcelain=v2 | grep -v "^?" >actual.3 &&
+		cat >expected.3 <<-EOF &&
+		2 R. N... 100644 100644 100644 $hash $hash R100 second	first
+		2 .R N... 100644 100644 100644 $hash $hash R100 third	second
+		EOF
+		test_cmp expected.3 actual.3
+	)
+'
+
 test_done
 

diff --git a/t/t3070-wildmatch.sh b/t/t3070-wildmatch.sh
index 163a14a..c1fc6ca 100755
--- a/t/t3070-wildmatch.sh
+++ b/t/t3070-wildmatch.sh

@@ -4,266 +4,431 @@
 
 . ./test-lib.sh
 
+should_create_test_file() {
+	file=$1
+
+	case $file in
+	# `touch .` will succeed but obviously not do what we intend
+	# here.
+	".")
+		return 1
+		;;
+	# We cannot create a file with an empty filename.
+	"")
+		return 1
+		;;
+	# The tests that are testing that e.g. foo//bar is matched by
+	# foo/*/bar can't be tested on filesystems since there's no
+	# way we're getting a double slash.
+	*//*)
+		return 1
+		;;
+	# When testing the difference between foo/bar and foo/bar/ we
+	# can't test the latter.
+	*/)
+		return 1
+		;;
+	# On Windows, \ in paths is silently converted to /, which
+	# would result in the "touch" below working, but the test
+	# itself failing. See 6fd1106aa4 ("t3700: Skip a test with
+	# backslashes in pathspec", 2009-03-13) for prior art and
+	# details.
+	*\\*)
+		if ! test_have_prereq BSLASHPSPEC
+		then
+			return 1
+		fi
+		# NOTE: The ;;& bash extension is not portable, so
+		# this test needs to be at the end of the pattern
+		# list.
+		#
+		# If we want to add more conditional returns we either
+		# need a new case statement, or turn this whole thing
+		# into a series of "if" tests.
+		;;
+	esac
+
+
+	# On Windows proper (i.e. not Cygwin) many file names which
+	# under Cygwin would be emulated don't work.
+	if test_have_prereq MINGW
+	then
+		case $file in
+		" ")
+			# Files called " " are forbidden on Windows
+			return 1
+			;;
+		*\<*|*\>*|*:*|*\"*|*\|*|*\?*|*\**)
+			# Files with various special characters aren't
+			# allowed on Windows. Sourced from
+			# https://stackoverflow.com/a/31976060
+			return 1
+			;;
+		esac
+	fi
+
+	return 0
+}
+
+match_with_function() {
+	text=$1
+	pattern=$2
+	match_expect=$3
+	match_function=$4
+
+	if test "$match_expect" = 1
+	then
+		test_expect_success "$match_function: match '$text' '$pattern'" "
+			test-wildmatch $match_function '$text' '$pattern'
+		"
+	elif test "$match_expect" = 0
+	then
+		test_expect_success "$match_function: no match '$text' '$pattern'" "
+			test_must_fail test-wildmatch $match_function '$text' '$pattern'
+		"
+	else
+		test_expect_success "PANIC: Test framework error. Unknown matches value $match_expect" 'false'
+	fi
+
+}
+
+match_with_ls_files() {
+	text=$1
+	pattern=$2
+	match_expect=$3
+	match_function=$4
+	ls_files_args=$5
+
+	match_stdout_stderr_cmp="
+		tr -d '\0' <actual.raw >actual &&
+		>expect.err &&
+		test_cmp expect.err actual.err &&
+		test_cmp expect actual"
+
+	if test "$match_expect" = 'E'
+	then
+		if test -e .git/created_test_file
+		then
+			test_expect_success EXPENSIVE_ON_WINDOWS "$match_function (via ls-files): match dies on '$pattern' '$text'" "
+				printf '%s' '$text' >expect &&
+				test_must_fail git$ls_files_args ls-files -z -- '$pattern'
+			"
+		else
+			test_expect_failure EXPENSIVE_ON_WINDOWS "$match_function (via ls-files): match skip '$pattern' '$text'" 'false'
+		fi
+	elif test "$match_expect" = 1
+	then
+		if test -e .git/created_test_file
+		then
+			test_expect_success EXPENSIVE_ON_WINDOWS "$match_function (via ls-files): match '$pattern' '$text'" "
+				printf '%s' '$text' >expect &&
+				git$ls_files_args ls-files -z -- '$pattern' >actual.raw 2>actual.err &&
+				$match_stdout_stderr_cmp
+			"
+		else
+			test_expect_failure EXPENSIVE_ON_WINDOWS "$match_function (via ls-files): match skip '$pattern' '$text'" 'false'
+		fi
+	elif test "$match_expect" = 0
+	then
+		if test -e .git/created_test_file
+		then
+			test_expect_success EXPENSIVE_ON_WINDOWS "$match_function (via ls-files): no match '$pattern' '$text'" "
+				>expect &&
+				git$ls_files_args ls-files -z -- '$pattern' >actual.raw 2>actual.err &&
+				$match_stdout_stderr_cmp
+			"
+		else
+			test_expect_failure EXPENSIVE_ON_WINDOWS "$match_function (via ls-files): no match skip '$pattern' '$text'" 'false'
+		fi
+	else
+		test_expect_success "PANIC: Test framework error. Unknown matches value $match_expect" 'false'
+	fi
+}
+
 match() {
-    if [ $1 = 1 ]; then
-	test_expect_success "wildmatch:     match '$3' '$4'" "
-	    test-wildmatch wildmatch '$3' '$4'
-	"
-    else
-	test_expect_success "wildmatch:  no match '$3' '$4'" "
-	    ! test-wildmatch wildmatch '$3' '$4'
-	"
-    fi
+	if test "$#" = 6
+	then
+		# When test-wildmatch and git ls-files produce the same
+		# result.
+		match_glob=$1
+		match_file_glob=$match_glob
+		match_iglob=$2
+		match_file_iglob=$match_iglob
+		match_pathmatch=$3
+		match_file_pathmatch=$match_pathmatch
+		match_pathmatchi=$4
+		match_file_pathmatchi=$match_pathmatchi
+		text=$5
+		pattern=$6
+	elif test "$#" = 10
+	then
+		match_glob=$1
+		match_iglob=$2
+		match_pathmatch=$3
+		match_pathmatchi=$4
+		match_file_glob=$5
+		match_file_iglob=$6
+		match_file_pathmatch=$7
+		match_file_pathmatchi=$8
+		text=$9
+		pattern=${10}
+	fi
+
+	test_expect_success EXPENSIVE_ON_WINDOWS 'cleanup after previous file test' '
+		if test -e .git/created_test_file
+		then
+			git reset &&
+			git clean -df
+		fi
+	'
+
+	printf '%s' "$text" >.git/expected_test_file
+
+	test_expect_success EXPENSIVE_ON_WINDOWS "setup match file test for $text" '
+		file=$(cat .git/expected_test_file) &&
+		if should_create_test_file "$file"
+		then
+			dirs=${file%/*}
+			if test "$file" != "$dirs"
+			then
+				mkdir -p -- "$dirs" &&
+				touch -- "./$text"
+			else
+				touch -- "./$file"
+			fi &&
+			git add -A &&
+			printf "%s" "$file" >.git/created_test_file
+		elif test -e .git/created_test_file
+		then
+			rm .git/created_test_file
+		fi
+	'
+
+	# $1: Case sensitive glob match: test-wildmatch & ls-files
+	match_with_function "$text" "$pattern" $match_glob "wildmatch"
+	match_with_ls_files "$text" "$pattern" $match_file_glob "wildmatch" " --glob-pathspecs"
+
+	# $2: Case insensitive glob match: test-wildmatch & ls-files
+	match_with_function "$text" "$pattern" $match_iglob "iwildmatch"
+	match_with_ls_files "$text" "$pattern" $match_file_iglob "iwildmatch" " --glob-pathspecs --icase-pathspecs"
+
+	# $3: Case sensitive path match: test-wildmatch & ls-files
+	match_with_function "$text" "$pattern" $match_pathmatch "pathmatch"
+	match_with_ls_files "$text" "$pattern" $match_file_pathmatch "pathmatch" ""
+
+	# $4: Case insensitive path match: test-wildmatch & ls-files
+	match_with_function "$text" "$pattern" $match_pathmatchi "ipathmatch"
+	match_with_ls_files "$text" "$pattern" $match_file_pathmatchi "ipathmatch" " --icase-pathspecs"
 }
 
-imatch() {
-    if [ $1 = 1 ]; then
-	test_expect_success "iwildmatch:    match '$2' '$3'" "
-	    test-wildmatch iwildmatch '$2' '$3'
-	"
-    else
-	test_expect_success "iwildmatch: no match '$2' '$3'" "
-	    ! test-wildmatch iwildmatch '$2' '$3'
-	"
-    fi
-}
-
-pathmatch() {
-    if [ $1 = 1 ]; then
-	test_expect_success "pathmatch:     match '$2' '$3'" "
-	    test-wildmatch pathmatch '$2' '$3'
-	"
-    else
-	test_expect_success "pathmatch:  no match '$2' '$3'" "
-	    ! test-wildmatch pathmatch '$2' '$3'
-	"
-    fi
-}
-
-# Basic wildmat features
-match 1 1 foo foo
-match 0 0 foo bar
-match 1 1 '' ""
-match 1 1 foo '???'
-match 0 0 foo '??'
-match 1 1 foo '*'
-match 1 1 foo 'f*'
-match 0 0 foo '*f'
-match 1 1 foo '*foo*'
-match 1 1 foobar '*ob*a*r*'
-match 1 1 aaaaaaabababab '*ab'
-match 1 1 'foo*' 'foo\*'
-match 0 0 foobar 'foo\*bar'
-match 1 1 'f\oo' 'f\\oo'
-match 1 1 ball '*[al]?'
-match 0 0 ten '[ten]'
-match 0 1 ten '**[!te]'
-match 0 0 ten '**[!ten]'
-match 1 1 ten 't[a-g]n'
-match 0 0 ten 't[!a-g]n'
-match 1 1 ton 't[!a-g]n'
-match 1 1 ton 't[^a-g]n'
-match 1 x 'a]b' 'a[]]b'
-match 1 x a-b 'a[]-]b'
-match 1 x 'a]b' 'a[]-]b'
-match 0 x aab 'a[]-]b'
-match 1 x aab 'a[]a-]b'
-match 1 1 ']' ']'
+# Basic wildmatch features
+match 1 1 1 1 foo foo
+match 0 0 0 0 foo bar
+match 1 1 1 1 '' ""
+match 1 1 1 1 foo '???'
+match 0 0 0 0 foo '??'
+match 1 1 1 1 foo '*'
+match 1 1 1 1 foo 'f*'
+match 0 0 0 0 foo '*f'
+match 1 1 1 1 foo '*foo*'
+match 1 1 1 1 foobar '*ob*a*r*'
+match 1 1 1 1 aaaaaaabababab '*ab'
+match 1 1 1 1 'foo*' 'foo\*'
+match 0 0 0 0 foobar 'foo\*bar'
+match 1 1 1 1 'f\oo' 'f\\oo'
+match 1 1 1 1 ball '*[al]?'
+match 0 0 0 0 ten '[ten]'
+match 0 0 1 1 ten '**[!te]'
+match 0 0 0 0 ten '**[!ten]'
+match 1 1 1 1 ten 't[a-g]n'
+match 0 0 0 0 ten 't[!a-g]n'
+match 1 1 1 1 ton 't[!a-g]n'
+match 1 1 1 1 ton 't[^a-g]n'
+match 1 1 1 1 'a]b' 'a[]]b'
+match 1 1 1 1 a-b 'a[]-]b'
+match 1 1 1 1 'a]b' 'a[]-]b'
+match 0 0 0 0 aab 'a[]-]b'
+match 1 1 1 1 aab 'a[]a-]b'
+match 1 1 1 1 ']' ']'
 
 # Extended slash-matching features
-match 0 0 'foo/baz/bar' 'foo*bar'
-match 0 0 'foo/baz/bar' 'foo**bar'
-match 0 1 'foobazbar' 'foo**bar'
-match 1 1 'foo/baz/bar' 'foo/**/bar'
-match 1 0 'foo/baz/bar' 'foo/**/**/bar'
-match 1 0 'foo/b/a/z/bar' 'foo/**/bar'
-match 1 0 'foo/b/a/z/bar' 'foo/**/**/bar'
-match 1 0 'foo/bar' 'foo/**/bar'
-match 1 0 'foo/bar' 'foo/**/**/bar'
-match 0 0 'foo/bar' 'foo?bar'
-match 0 0 'foo/bar' 'foo[/]bar'
-match 0 0 'foo/bar' 'foo[^a-z]bar'
-match 0 0 'foo/bar' 'f[^eiu][^eiu][^eiu][^eiu][^eiu]r'
-match 1 1 'foo-bar' 'f[^eiu][^eiu][^eiu][^eiu][^eiu]r'
-match 1 0 'foo' '**/foo'
-match 1 x 'XXX/foo' '**/foo'
-match 1 0 'bar/baz/foo' '**/foo'
-match 0 0 'bar/baz/foo' '*/foo'
-match 0 0 'foo/bar/baz' '**/bar*'
-match 1 0 'deep/foo/bar/baz' '**/bar/*'
-match 0 0 'deep/foo/bar/baz/' '**/bar/*'
-match 1 0 'deep/foo/bar/baz/' '**/bar/**'
-match 0 0 'deep/foo/bar' '**/bar/*'
-match 1 0 'deep/foo/bar/' '**/bar/**'
-match 0 0 'foo/bar/baz' '**/bar**'
-match 1 0 'foo/bar/baz/x' '*/bar/**'
-match 0 0 'deep/foo/bar/baz/x' '*/bar/**'
-match 1 0 'deep/foo/bar/baz/x' '**/bar/*/*'
+match 0 0 1 1 'foo/baz/bar' 'foo*bar'
+match 0 0 1 1 'foo/baz/bar' 'foo**bar'
+match 0 0 1 1 'foobazbar' 'foo**bar'
+match 1 1 1 1 'foo/baz/bar' 'foo/**/bar'
+match 1 1 0 0 'foo/baz/bar' 'foo/**/**/bar'
+match 1 1 1 1 'foo/b/a/z/bar' 'foo/**/bar'
+match 1 1 1 1 'foo/b/a/z/bar' 'foo/**/**/bar'
+match 1 1 0 0 'foo/bar' 'foo/**/bar'
+match 1 1 0 0 'foo/bar' 'foo/**/**/bar'
+match 0 0 1 1 'foo/bar' 'foo?bar'
+match 0 0 1 1 'foo/bar' 'foo[/]bar'
+match 0 0 1 1 'foo/bar' 'foo[^a-z]bar'
+match 0 0 1 1 'foo/bar' 'f[^eiu][^eiu][^eiu][^eiu][^eiu]r'
+match 1 1 1 1 'foo-bar' 'f[^eiu][^eiu][^eiu][^eiu][^eiu]r'
+match 1 1 0 0 'foo' '**/foo'
+match 1 1 1 1 'XXX/foo' '**/foo'
+match 1 1 1 1 'bar/baz/foo' '**/foo'
+match 0 0 1 1 'bar/baz/foo' '*/foo'
+match 0 0 1 1 'foo/bar/baz' '**/bar*'
+match 1 1 1 1 'deep/foo/bar/baz' '**/bar/*'
+match 0 0 1 1 'deep/foo/bar/baz/' '**/bar/*'
+match 1 1 1 1 'deep/foo/bar/baz/' '**/bar/**'
+match 0 0 0 0 'deep/foo/bar' '**/bar/*'
+match 1 1 1 1 'deep/foo/bar/' '**/bar/**'
+match 0 0 1 1 'foo/bar/baz' '**/bar**'
+match 1 1 1 1 'foo/bar/baz/x' '*/bar/**'
+match 0 0 1 1 'deep/foo/bar/baz/x' '*/bar/**'
+match 1 1 1 1 'deep/foo/bar/baz/x' '**/bar/*/*'
 
 # Various additional tests
-match 0 0 'acrt' 'a[c-c]st'
-match 1 1 'acrt' 'a[c-c]rt'
-match 0 0 ']' '[!]-]'
-match 1 x 'a' '[!]-]'
-match 0 0 '' '\'
-match 0 x '\' '\'
-match 0 x 'XXX/\' '*/\'
-match 1 x 'XXX/\' '*/\\'
-match 1 1 'foo' 'foo'
-match 1 1 '@foo' '@foo'
-match 0 0 'foo' '@foo'
-match 1 1 '[ab]' '\[ab]'
-match 1 1 '[ab]' '[[]ab]'
-match 1 x '[ab]' '[[:]ab]'
-match 0 x '[ab]' '[[::]ab]'
-match 1 x '[ab]' '[[:digit]ab]'
-match 1 x '[ab]' '[\[:]ab]'
-match 1 1 '?a?b' '\??\?b'
-match 1 1 'abc' '\a\b\c'
-match 0 0 'foo' ''
-match 1 0 'foo/bar/baz/to' '**/t[o]'
+match 0 0 0 0 'acrt' 'a[c-c]st'
+match 1 1 1 1 'acrt' 'a[c-c]rt'
+match 0 0 0 0 ']' '[!]-]'
+match 1 1 1 1 'a' '[!]-]'
+match 0 0 0 0 '' '\'
+match 0 0 0 0 \
+      1 1 1 1 '\' '\'
+match 0 0 0 0 'XXX/\' '*/\'
+match 1 1 1 1 'XXX/\' '*/\\'
+match 1 1 1 1 'foo' 'foo'
+match 1 1 1 1 '@foo' '@foo'
+match 0 0 0 0 'foo' '@foo'
+match 1 1 1 1 '[ab]' '\[ab]'
+match 1 1 1 1 '[ab]' '[[]ab]'
+match 1 1 1 1 '[ab]' '[[:]ab]'
+match 0 0 0 0 '[ab]' '[[::]ab]'
+match 1 1 1 1 '[ab]' '[[:digit]ab]'
+match 1 1 1 1 '[ab]' '[\[:]ab]'
+match 1 1 1 1 '?a?b' '\??\?b'
+match 1 1 1 1 'abc' '\a\b\c'
+match 0 0 0 0 \
+      E E E E 'foo' ''
+match 1 1 1 1 'foo/bar/baz/to' '**/t[o]'
 
 # Character class tests
-match 1 x 'a1B' '[[:alpha:]][[:digit:]][[:upper:]]'
-match 0 x 'a' '[[:digit:][:upper:][:space:]]'
-match 1 x 'A' '[[:digit:][:upper:][:space:]]'
-match 1 x '1' '[[:digit:][:upper:][:space:]]'
-match 0 x '1' '[[:digit:][:upper:][:spaci:]]'
-match 1 x ' ' '[[:digit:][:upper:][:space:]]'
-match 0 x '.' '[[:digit:][:upper:][:space:]]'
-match 1 x '.' '[[:digit:][:punct:][:space:]]'
-match 1 x '5' '[[:xdigit:]]'
-match 1 x 'f' '[[:xdigit:]]'
-match 1 x 'D' '[[:xdigit:]]'
-match 1 x '_' '[[:alnum:][:alpha:][:blank:][:cntrl:][:digit:][:graph:][:lower:][:print:][:punct:][:space:][:upper:][:xdigit:]]'
-match 1 x '.' '[^[:alnum:][:alpha:][:blank:][:cntrl:][:digit:][:lower:][:space:][:upper:][:xdigit:]]'
-match 1 x '5' '[a-c[:digit:]x-z]'
-match 1 x 'b' '[a-c[:digit:]x-z]'
-match 1 x 'y' '[a-c[:digit:]x-z]'
-match 0 x 'q' '[a-c[:digit:]x-z]'
+match 1 1 1 1 'a1B' '[[:alpha:]][[:digit:]][[:upper:]]'
+match 0 1 0 1 'a' '[[:digit:][:upper:][:space:]]'
+match 1 1 1 1 'A' '[[:digit:][:upper:][:space:]]'
+match 1 1 1 1 '1' '[[:digit:][:upper:][:space:]]'
+match 0 0 0 0 '1' '[[:digit:][:upper:][:spaci:]]'
+match 1 1 1 1 ' ' '[[:digit:][:upper:][:space:]]'
+match 0 0 0 0 '.' '[[:digit:][:upper:][:space:]]'
+match 1 1 1 1 '.' '[[:digit:][:punct:][:space:]]'
+match 1 1 1 1 '5' '[[:xdigit:]]'
+match 1 1 1 1 'f' '[[:xdigit:]]'
+match 1 1 1 1 'D' '[[:xdigit:]]'
+match 1 1 1 1 '_' '[[:alnum:][:alpha:][:blank:][:cntrl:][:digit:][:graph:][:lower:][:print:][:punct:][:space:][:upper:][:xdigit:]]'
+match 1 1 1 1 '.' '[^[:alnum:][:alpha:][:blank:][:cntrl:][:digit:][:lower:][:space:][:upper:][:xdigit:]]'
+match 1 1 1 1 '5' '[a-c[:digit:]x-z]'
+match 1 1 1 1 'b' '[a-c[:digit:]x-z]'
+match 1 1 1 1 'y' '[a-c[:digit:]x-z]'
+match 0 0 0 0 'q' '[a-c[:digit:]x-z]'
 
-# Additional tests, including some malformed wildmats
-match 1 x ']' '[\\-^]'
-match 0 0 '[' '[\\-^]'
-match 1 x '-' '[\-_]'
-match 1 x ']' '[\]]'
-match 0 0 '\]' '[\]]'
-match 0 0 '\' '[\]]'
-match 0 0 'ab' 'a[]b'
-match 0 x 'a[]b' 'a[]b'
-match 0 x 'ab[' 'ab['
-match 0 0 'ab' '[!'
-match 0 0 'ab' '[-'
-match 1 1 '-' '[-]'
-match 0 0 '-' '[a-'
-match 0 0 '-' '[!a-'
-match 1 x '-' '[--A]'
-match 1 x '5' '[--A]'
-match 1 1 ' ' '[ --]'
-match 1 1 '$' '[ --]'
-match 1 1 '-' '[ --]'
-match 0 0 '0' '[ --]'
-match 1 x '-' '[---]'
-match 1 x '-' '[------]'
-match 0 0 'j' '[a-e-n]'
-match 1 x '-' '[a-e-n]'
-match 1 x 'a' '[!------]'
-match 0 0 '[' '[]-a]'
-match 1 x '^' '[]-a]'
-match 0 0 '^' '[!]-a]'
-match 1 x '[' '[!]-a]'
-match 1 1 '^' '[a^bc]'
-match 1 x '-b]' '[a-]b]'
-match 0 0 '\' '[\]'
-match 1 1 '\' '[\\]'
-match 0 0 '\' '[!\\]'
-match 1 1 'G' '[A-\\]'
-match 0 0 'aaabbb' 'b*a'
-match 0 0 'aabcaa' '*ba*'
-match 1 1 ',' '[,]'
-match 1 1 ',' '[\\,]'
-match 1 1 '\' '[\\,]'
-match 1 1 '-' '[,-.]'
-match 0 0 '+' '[,-.]'
-match 0 0 '-.]' '[,-.]'
-match 1 1 '2' '[\1-\3]'
-match 1 1 '3' '[\1-\3]'
-match 0 0 '4' '[\1-\3]'
-match 1 1 '\' '[[-\]]'
-match 1 1 '[' '[[-\]]'
-match 1 1 ']' '[[-\]]'
-match 0 0 '-' '[[-\]]'
+# Additional tests, including some malformed wildmatch patterns
+match 1 1 1 1 ']' '[\\-^]'
+match 0 0 0 0 '[' '[\\-^]'
+match 1 1 1 1 '-' '[\-_]'
+match 1 1 1 1 ']' '[\]]'
+match 0 0 0 0 '\]' '[\]]'
+match 0 0 0 0 '\' '[\]]'
+match 0 0 0 0 'ab' 'a[]b'
+match 0 0 0 0 \
+      1 1 1 1 'a[]b' 'a[]b'
+match 0 0 0 0 \
+      1 1 1 1 'ab[' 'ab['
+match 0 0 0 0 'ab' '[!'
+match 0 0 0 0 'ab' '[-'
+match 1 1 1 1 '-' '[-]'
+match 0 0 0 0 '-' '[a-'
+match 0 0 0 0 '-' '[!a-'
+match 1 1 1 1 '-' '[--A]'
+match 1 1 1 1 '5' '[--A]'
+match 1 1 1 1 ' ' '[ --]'
+match 1 1 1 1 '$' '[ --]'
+match 1 1 1 1 '-' '[ --]'
+match 0 0 0 0 '0' '[ --]'
+match 1 1 1 1 '-' '[---]'
+match 1 1 1 1 '-' '[------]'
+match 0 0 0 0 'j' '[a-e-n]'
+match 1 1 1 1 '-' '[a-e-n]'
+match 1 1 1 1 'a' '[!------]'
+match 0 0 0 0 '[' '[]-a]'
+match 1 1 1 1 '^' '[]-a]'
+match 0 0 0 0 '^' '[!]-a]'
+match 1 1 1 1 '[' '[!]-a]'
+match 1 1 1 1 '^' '[a^bc]'
+match 1 1 1 1 '-b]' '[a-]b]'
+match 0 0 0 0 '\' '[\]'
+match 1 1 1 1 '\' '[\\]'
+match 0 0 0 0 '\' '[!\\]'
+match 1 1 1 1 'G' '[A-\\]'
+match 0 0 0 0 'aaabbb' 'b*a'
+match 0 0 0 0 'aabcaa' '*ba*'
+match 1 1 1 1 ',' '[,]'
+match 1 1 1 1 ',' '[\\,]'
+match 1 1 1 1 '\' '[\\,]'
+match 1 1 1 1 '-' '[,-.]'
+match 0 0 0 0 '+' '[,-.]'
+match 0 0 0 0 '-.]' '[,-.]'
+match 1 1 1 1 '2' '[\1-\3]'
+match 1 1 1 1 '3' '[\1-\3]'
+match 0 0 0 0 '4' '[\1-\3]'
+match 1 1 1 1 '\' '[[-\]]'
+match 1 1 1 1 '[' '[[-\]]'
+match 1 1 1 1 ']' '[[-\]]'
+match 0 0 0 0 '-' '[[-\]]'
 
-# Test recursion and the abort code (use "wildtest -i" to see iteration counts)
-match 1 1 '-adobe-courier-bold-o-normal--12-120-75-75-m-70-iso8859-1' '-*-*-*-*-*-*-12-*-*-*-m-*-*-*'
-match 0 0 '-adobe-courier-bold-o-normal--12-120-75-75-X-70-iso8859-1' '-*-*-*-*-*-*-12-*-*-*-m-*-*-*'
-match 0 0 '-adobe-courier-bold-o-normal--12-120-75-75-/-70-iso8859-1' '-*-*-*-*-*-*-12-*-*-*-m-*-*-*'
-match 1 1 'XXX/adobe/courier/bold/o/normal//12/120/75/75/m/70/iso8859/1' 'XXX/*/*/*/*/*/*/12/*/*/*/m/*/*/*'
-match 0 0 'XXX/adobe/courier/bold/o/normal//12/120/75/75/X/70/iso8859/1' 'XXX/*/*/*/*/*/*/12/*/*/*/m/*/*/*'
-match 1 0 'abcd/abcdefg/abcdefghijk/abcdefghijklmnop.txt' '**/*a*b*g*n*t'
-match 0 0 'abcd/abcdefg/abcdefghijk/abcdefghijklmnop.txtz' '**/*a*b*g*n*t'
-match 0 x foo '*/*/*'
-match 0 x foo/bar '*/*/*'
-match 1 x foo/bba/arr '*/*/*'
-match 0 x foo/bb/aa/rr '*/*/*'
-match 1 x foo/bb/aa/rr '**/**/**'
-match 1 x abcXdefXghi '*X*i'
-match 0 x ab/cXd/efXg/hi '*X*i'
-match 1 x ab/cXd/efXg/hi '*/*X*/*/*i'
-match 1 x ab/cXd/efXg/hi '**/*X*/**/*i'
+# Test recursion
+match 1 1 1 1 '-adobe-courier-bold-o-normal--12-120-75-75-m-70-iso8859-1' '-*-*-*-*-*-*-12-*-*-*-m-*-*-*'
+match 0 0 0 0 '-adobe-courier-bold-o-normal--12-120-75-75-X-70-iso8859-1' '-*-*-*-*-*-*-12-*-*-*-m-*-*-*'
+match 0 0 0 0 '-adobe-courier-bold-o-normal--12-120-75-75-/-70-iso8859-1' '-*-*-*-*-*-*-12-*-*-*-m-*-*-*'
+match 1 1 1 1 'XXX/adobe/courier/bold/o/normal//12/120/75/75/m/70/iso8859/1' 'XXX/*/*/*/*/*/*/12/*/*/*/m/*/*/*'
+match 0 0 0 0 'XXX/adobe/courier/bold/o/normal//12/120/75/75/X/70/iso8859/1' 'XXX/*/*/*/*/*/*/12/*/*/*/m/*/*/*'
+match 1 1 1 1 'abcd/abcdefg/abcdefghijk/abcdefghijklmnop.txt' '**/*a*b*g*n*t'
+match 0 0 0 0 'abcd/abcdefg/abcdefghijk/abcdefghijklmnop.txtz' '**/*a*b*g*n*t'
+match 0 0 0 0 foo '*/*/*'
+match 0 0 0 0 foo/bar '*/*/*'
+match 1 1 1 1 foo/bba/arr '*/*/*'
+match 0 0 1 1 foo/bb/aa/rr '*/*/*'
+match 1 1 1 1 foo/bb/aa/rr '**/**/**'
+match 1 1 1 1 abcXdefXghi '*X*i'
+match 0 0 1 1 ab/cXd/efXg/hi '*X*i'
+match 1 1 1 1 ab/cXd/efXg/hi '*/*X*/*/*i'
+match 1 1 1 1 ab/cXd/efXg/hi '**/*X*/**/*i'
 
-pathmatch 1 foo foo
-pathmatch 0 foo fo
-pathmatch 1 foo/bar foo/bar
-pathmatch 1 foo/bar 'foo/*'
-pathmatch 1 foo/bba/arr 'foo/*'
-pathmatch 1 foo/bba/arr 'foo/**'
-pathmatch 1 foo/bba/arr 'foo*'
-pathmatch 1 foo/bba/arr 'foo**'
-pathmatch 1 foo/bba/arr 'foo/*arr'
-pathmatch 1 foo/bba/arr 'foo/**arr'
-pathmatch 0 foo/bba/arr 'foo/*z'
-pathmatch 0 foo/bba/arr 'foo/**z'
-pathmatch 1 foo/bar 'foo?bar'
-pathmatch 1 foo/bar 'foo[/]bar'
-pathmatch 1 foo/bar 'foo[^a-z]bar'
-pathmatch 0 foo '*/*/*'
-pathmatch 0 foo/bar '*/*/*'
-pathmatch 1 foo/bba/arr '*/*/*'
-pathmatch 1 foo/bb/aa/rr '*/*/*'
-pathmatch 1 abcXdefXghi '*X*i'
-pathmatch 1 ab/cXd/efXg/hi '*/*X*/*/*i'
-pathmatch 1 ab/cXd/efXg/hi '*Xg*i'
+# Extra pathmatch tests
+match 0 0 0 0 foo fo
+match 1 1 1 1 foo/bar foo/bar
+match 1 1 1 1 foo/bar 'foo/*'
+match 0 0 1 1 foo/bba/arr 'foo/*'
+match 1 1 1 1 foo/bba/arr 'foo/**'
+match 0 0 1 1 foo/bba/arr 'foo*'
+match 0 0 1 1 \
+      1 1 1 1 foo/bba/arr 'foo**'
+match 0 0 1 1 foo/bba/arr 'foo/*arr'
+match 0 0 1 1 foo/bba/arr 'foo/**arr'
+match 0 0 0 0 foo/bba/arr 'foo/*z'
+match 0 0 0 0 foo/bba/arr 'foo/**z'
+match 0 0 1 1 foo/bar 'foo?bar'
+match 0 0 1 1 foo/bar 'foo[/]bar'
+match 0 0 1 1 foo/bar 'foo[^a-z]bar'
+match 0 0 1 1 ab/cXd/efXg/hi '*Xg*i'
 
-# Case-sensitivity features
-match 0 x 'a' '[A-Z]'
-match 1 x 'A' '[A-Z]'
-match 0 x 'A' '[a-z]'
-match 1 x 'a' '[a-z]'
-match 0 x 'a' '[[:upper:]]'
-match 1 x 'A' '[[:upper:]]'
-match 0 x 'A' '[[:lower:]]'
-match 1 x 'a' '[[:lower:]]'
-match 0 x 'A' '[B-Za]'
-match 1 x 'a' '[B-Za]'
-match 0 x 'A' '[B-a]'
-match 1 x 'a' '[B-a]'
-match 0 x 'z' '[Z-y]'
-match 1 x 'Z' '[Z-y]'
-
-imatch 1 'a' '[A-Z]'
-imatch 1 'A' '[A-Z]'
-imatch 1 'A' '[a-z]'
-imatch 1 'a' '[a-z]'
-imatch 1 'a' '[[:upper:]]'
-imatch 1 'A' '[[:upper:]]'
-imatch 1 'A' '[[:lower:]]'
-imatch 1 'a' '[[:lower:]]'
-imatch 1 'A' '[B-Za]'
-imatch 1 'a' '[B-Za]'
-imatch 1 'A' '[B-a]'
-imatch 1 'a' '[B-a]'
-imatch 1 'z' '[Z-y]'
-imatch 1 'Z' '[Z-y]'
+# Extra case-sensitivity tests
+match 0 1 0 1 'a' '[A-Z]'
+match 1 1 1 1 'A' '[A-Z]'
+match 0 1 0 1 'A' '[a-z]'
+match 1 1 1 1 'a' '[a-z]'
+match 0 1 0 1 'a' '[[:upper:]]'
+match 1 1 1 1 'A' '[[:upper:]]'
+match 0 1 0 1 'A' '[[:lower:]]'
+match 1 1 1 1 'a' '[[:lower:]]'
+match 0 1 0 1 'A' '[B-Za]'
+match 1 1 1 1 'a' '[B-Za]'
+match 0 1 0 1 'A' '[B-a]'
+match 1 1 1 1 'a' '[B-a]'
+match 0 1 0 1 'z' '[Z-y]'
+match 1 1 1 1 'Z' '[Z-y]'
 
 test_done

diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 481a350..ef2887b 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh

@@ -453,6 +453,10 @@
 		git rebase -i $base &&
 	git cat-file commit HEAD | sed -e 1,/^\$/d > actual-squash-fixup &&
 	test_cmp expect-squash-fixup actual-squash-fixup &&
+	git cat-file commit HEAD@{2} |
+		grep "^# This is a combination of 3 commits\."  &&
+	git cat-file commit HEAD@{3} |
+		grep "^# This is a combination of 2 commits\."  &&
 	git checkout to-be-rebased &&
 	git branch -D squash-fixup
 '
@@ -1336,6 +1340,16 @@
 
 SQ="'"
 test_expect_success 'rebase -i --gpg-sign=<key-id>' '
+	test_when_finished "test_might_fail git rebase --abort" &&
+	set_fake_editor &&
+	FAKE_LINES="edit 1" git rebase -i --gpg-sign="\"S I Gner\"" HEAD^ \
+		>out 2>err &&
+	test_i18ngrep "$SQ-S\"S I Gner\"$SQ" err
+'
+
+test_expect_success 'rebase -i --gpg-sign=<key-id> overrides commit.gpgSign' '
+	test_when_finished "test_might_fail git rebase --abort" &&
+	test_config commit.gpgsign true &&
 	set_fake_editor &&
 	FAKE_LINES="edit 1" git rebase -i --gpg-sign="\"S I Gner\"" HEAD^ \
 		>out 2>err &&

diff --git a/t/t3405-rebase-malformed.sh b/t/t3405-rebase-malformed.sh
index ff8c360..cb7c6de 100755
--- a/t/t3405-rebase-malformed.sh
+++ b/t/t3405-rebase-malformed.sh

@@ -3,6 +3,7 @@
 test_description='rebase should handle arbitrary git message'
 
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-rebase.sh
 
 cat >F <<\EOF
 This is an example of a commit log message
@@ -25,6 +26,7 @@
 	test_tick &&
 	git commit -m "Initial commit" &&
 	git branch diff-in-message &&
+	git branch empty-message-merge &&
 
 	git checkout -b multi-line-subject &&
 	cat F >file2 &&
@@ -45,6 +47,11 @@
 
 	git cat-file commit HEAD | sed -e "1,/^\$/d" >G0 &&
 
+	git checkout empty-message-merge &&
+	echo file3 >file3 &&
+	git add file3 &&
+	git commit --allow-empty-message -m "" &&
+
 	git checkout master &&
 
 	echo One >file1 &&
@@ -69,4 +76,20 @@
 	test_cmp G G0
 '
 
+test_expect_success 'rebase -m commit with empty message' '
+	test_must_fail git rebase -m master empty-message-merge &&
+	git rebase --abort &&
+	git rebase -m --allow-empty-message master empty-message-merge
+'
+
+test_expect_success 'rebase -i commit with empty message' '
+	git checkout diff-in-message &&
+	set_fake_editor &&
+	test_must_fail env FAKE_COMMIT_MESSAGE=" " FAKE_LINES="reword 1" \
+		git rebase -i HEAD^ &&
+	git rebase --abort &&
+	FAKE_COMMIT_MESSAGE=" " FAKE_LINES="reword 1" \
+		git rebase -i --allow-empty-message HEAD^
+'
+
 test_done

diff --git a/t/t3501-revert-cherry-pick.sh b/t/t3501-revert-cherry-pick.sh
index 4f2a263..783bdbf 100755
--- a/t/t3501-revert-cherry-pick.sh
+++ b/t/t3501-revert-cherry-pick.sh

@@ -141,7 +141,7 @@
 	test_cmp expect actual
 '
 
-test_expect_success 'cherry-pick works with dirty renamed file' '
+test_expect_failure 'cherry-pick works with dirty renamed file' '
 	test_commit to-rename &&
 	git checkout -b unrelated &&
 	test_commit unrelated &&
@@ -150,7 +150,10 @@
 	test_tick &&
 	git commit -m renamed &&
 	echo modified >renamed &&
-	git cherry-pick refs/heads/unrelated
+	test_must_fail git cherry-pick refs/heads/unrelated >out &&
+	test_i18ngrep "Refusing to lose dirty file at renamed" out &&
+	test $(git rev-parse :0:renamed) = $(git rev-parse HEAD^:to-rename.t) &&
+	grep -q "^modified$" renamed
 '
 
 test_done

diff --git a/t/t3512-cherry-pick-submodule.sh b/t/t3512-cherry-pick-submodule.sh
index ce48c4f..bd78287 100755
--- a/t/t3512-cherry-pick-submodule.sh
+++ b/t/t3512-cherry-pick-submodule.sh

@@ -5,7 +5,6 @@
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-submodule-update.sh
 
-KNOWN_FAILURE_CHERRY_PICK_SEES_EMPTY_COMMIT=1
 KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR=1
 KNOWN_FAILURE_NOFF_MERGE_ATTEMPTS_TO_MERGE_REMOVED_SUBMODULE_FILES=1
 test_submodule_switch "git cherry-pick"

diff --git a/t/t3513-revert-submodule.sh b/t/t3513-revert-submodule.sh
index db93781..5e39fcd 100755
--- a/t/t3513-revert-submodule.sh
+++ b/t/t3513-revert-submodule.sh

@@ -25,7 +25,6 @@
 	git revert HEAD
 }
 
-KNOWN_FAILURE_CHERRY_PICK_SEES_EMPTY_COMMIT=1
 KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR=1
 test_submodule_switch "git_revert"
 

diff --git a/t/t3701-add-interactive.sh b/t/t3701-add-interactive.sh
index a49c12c..058698d 100755
--- a/t/t3701-add-interactive.sh
+++ b/t/t3701-add-interactive.sh

@@ -493,4 +493,52 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'setup different kinds of dirty submodules' '
+	test_create_repo for-submodules &&
+	(
+		cd for-submodules &&
+		test_commit initial &&
+		test_create_repo dirty-head &&
+		(
+			cd dirty-head &&
+			test_commit initial
+		) &&
+		cp -R dirty-head dirty-otherwise &&
+		cp -R dirty-head dirty-both-ways &&
+		git add dirty-head &&
+		git add dirty-otherwise dirty-both-ways &&
+		git commit -m initial &&
+
+		cd dirty-head &&
+		test_commit updated &&
+		cd ../dirty-both-ways &&
+		test_commit updated &&
+		echo dirty >>initial &&
+		: >untracked &&
+		cd ../dirty-otherwise &&
+		echo dirty >>initial &&
+		: >untracked
+	) &&
+	git -C for-submodules diff-files --name-only >actual &&
+	cat >expected <<-\EOF &&
+	dirty-both-ways
+	dirty-head
+	dirty-otherwise
+	EOF
+	test_cmp expected actual &&
+	git -C for-submodules diff-files --name-only --ignore-submodules=dirty >actual &&
+	cat >expected <<-\EOF &&
+	dirty-both-ways
+	dirty-head
+	EOF
+	test_cmp expected actual
+'
+
+test_expect_success 'status ignores dirty submodules (except HEAD)' '
+	git -C for-submodules add -i </dev/null >output &&
+	grep dirty-head output &&
+	grep dirty-both-ways output &&
+	! grep dirty-otherwise output
+'
+
 test_done

diff --git a/t/t3903-stash.sh b/t/t3903-stash.sh
index 39c7f2e..aefde7b 100755
--- a/t/t3903-stash.sh
+++ b/t/t3903-stash.sh

@@ -1064,4 +1064,36 @@
 	test foo,bar = $(cat foo),$(cat bar)
 '
 
+test_expect_success 'stash -- <subdir> leaves untracked files in subdir intact' '
+	git reset &&
+	>subdir/untracked &&
+	>subdir/tracked1 &&
+	>subdir/tracked2 &&
+	git add subdir/tracked* &&
+	git stash -- subdir/ &&
+	test_path_is_missing subdir/tracked1 &&
+	test_path_is_missing subdir/tracked2 &&
+	test_path_is_file subdir/untracked &&
+	git stash pop &&
+	test_path_is_file subdir/tracked1 &&
+	test_path_is_file subdir/tracked2 &&
+	test_path_is_file subdir/untracked
+'
+
+test_expect_success 'stash -- <subdir> works with binary files' '
+	git reset &&
+	>subdir/untracked &&
+	>subdir/tracked &&
+	cp "$TEST_DIRECTORY"/test-binary-1.png subdir/tracked-binary &&
+	git add subdir/tracked* &&
+	git stash -- subdir/ &&
+	test_path_is_missing subdir/tracked &&
+	test_path_is_missing subdir/tracked-binary &&
+	test_path_is_file subdir/untracked &&
+	git stash pop &&
+	test_path_is_file subdir/tracked &&
+	test_path_is_file subdir/tracked-binary &&
+	test_path_is_file subdir/untracked
+'
+
 test_done

diff --git a/t/t4052-stat-output.sh b/t/t4052-stat-output.sh
index 9f563db..6e2cf93 100755
--- a/t/t4052-stat-output.sh
+++ b/t/t4052-stat-output.sh

@@ -19,17 +19,33 @@
 	git commit -m message "$name"
 '
 
+cat >expect72 <<-'EOF'
+ ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1 +
+EOF
+test_expect_success "format-patch: small change with long name gives more space to the name" '
+	git format-patch -1 --stdout >output &&
+	grep " | " output >actual &&
+	test_cmp expect72 actual
+'
+
 while read cmd args
 do
-	cat >expect <<-'EOF'
+	cat >expect80 <<-'EOF'
 	 ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1 +
 	EOF
 	test_expect_success "$cmd: small change with long name gives more space to the name" '
 		git $cmd $args >output &&
 		grep " | " output >actual &&
-		test_cmp expect actual
+		test_cmp expect80 actual
 	'
+done <<\EOF
+diff HEAD^ HEAD --stat
+show --stat
+log -1 --stat
+EOF
 
+while read cmd args
+do
 	cat >expect <<-'EOF'
 	 ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1 +
 	EOF
@@ -79,11 +95,11 @@
 	git commit -m message abcd
 '
 
-cat >expect80 <<'EOF'
- abcd | 1000 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+cat >expect72 <<'EOF'
+ abcd | 1000 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 EOF
-cat >expect80-graph <<'EOF'
-|  abcd | 1000 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+cat >expect72-graph <<'EOF'
+|  abcd | 1000 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 EOF
 cat >expect200 <<'EOF'
  abcd | 1000 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
@@ -107,7 +123,7 @@
 		test_cmp "$expect-graph" actual
 	'
 done <<\EOF
-ignores expect80 format-patch -1 --stdout
+ignores expect72 format-patch -1 --stdout
 respects expect200 diff HEAD^ HEAD --stat
 respects expect200 show --stat
 respects expect200 log -1 --stat
@@ -135,7 +151,7 @@
 		test_cmp "$expect-graph" actual
 	'
 done <<\EOF
-ignores expect80 format-patch -1 --stdout
+ignores expect72 format-patch -1 --stdout
 respects expect40 diff HEAD^ HEAD --stat
 respects expect40 show --stat
 respects expect40 log -1 --stat
@@ -163,7 +179,7 @@
 		test_cmp "$expect-graph" actual
 	'
 done <<\EOF
-ignores expect80 format-patch -1 --stdout
+ignores expect72 format-patch -1 --stdout
 respects expect40 diff HEAD^ HEAD --stat
 respects expect40 show --stat
 respects expect40 log -1 --stat
@@ -250,11 +266,11 @@
 log -1 --stat
 EOF
 
-cat >expect80 <<'EOF'
- ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1000 ++++++++++++++++++++
+cat >expect72 <<'EOF'
+ ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1000 +++++++++++++++++
 EOF
-cat >expect80-graph <<'EOF'
-|  ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1000 ++++++++++++++++++++
+cat >expect72-graph <<'EOF'
+|  ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1000 +++++++++++++++++
 EOF
 cat >expect200 <<'EOF'
  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1000 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
@@ -278,7 +294,7 @@
 		test_cmp "$expect-graph" actual
 	'
 done <<\EOF
-ignores expect80 format-patch -1 --stdout
+ignores expect72 format-patch -1 --stdout
 respects expect200 diff HEAD^ HEAD --stat
 respects expect200 show --stat
 respects expect200 log -1 --stat
@@ -308,7 +324,7 @@
 		test_cmp "$expect-graph" actual
 	'
 done <<\EOF
-ignores expect80 format-patch -1 --stdout
+ignores expect72 format-patch -1 --stdout
 respects expect1 diff HEAD^ HEAD --stat
 respects expect1 show --stat
 respects expect1 log -1 --stat

diff --git a/t/t4064-diff-oidfind.sh b/t/t4064-diff-oidfind.sh
new file mode 100755
index 0000000..3bdf317
--- /dev/null
+++ b/t/t4064-diff-oidfind.sh

@@ -0,0 +1,68 @@
+#!/bin/sh
+
+test_description='test finding specific blobs in the revision walking'
+. ./test-lib.sh
+
+test_expect_success 'setup ' '
+	git commit --allow-empty -m "empty initial commit" &&
+
+	echo "Hello, world!" >greeting &&
+	git add greeting &&
+	git commit -m "add the greeting blob" && # borrowed from Git from the Bottom Up
+	git tag -m "the blob" greeting $(git rev-parse HEAD:greeting) &&
+
+	echo asdf >unrelated &&
+	git add unrelated &&
+	git commit -m "unrelated history" &&
+
+	git revert HEAD^ &&
+
+	git commit --allow-empty -m "another unrelated commit"
+'
+
+test_expect_success 'find the greeting blob' '
+	cat >expect <<-EOF &&
+	Revert "add the greeting blob"
+	add the greeting blob
+	EOF
+
+	git log --format=%s --find-object=greeting^{blob} >actual &&
+
+	test_cmp expect actual
+'
+
+test_expect_success 'setup a tree' '
+	mkdir a &&
+	echo asdf >a/file &&
+	git add a/file &&
+	git commit -m "add a file in a subdirectory"
+'
+
+test_expect_success 'find a tree' '
+	cat >expect <<-EOF &&
+	add a file in a subdirectory
+	EOF
+
+	git log --format=%s -t --find-object=HEAD:a >actual &&
+
+	test_cmp expect actual
+'
+
+test_expect_success 'setup a submodule' '
+	test_create_repo sub &&
+	test_commit -C sub sub &&
+	git submodule add ./sub sub &&
+	git commit -a -m "add sub"
+'
+
+test_expect_success 'find a submodule' '
+	cat >expect <<-EOF &&
+	add sub
+	EOF
+
+	git log --format=%s --find-object=HEAD:sub >actual &&
+
+	test_cmp expect actual
+'
+
+test_done

diff --git a/t/t5500-fetch-pack.sh b/t/t5500-fetch-pack.sh
index 80a1a32..ec9ba9b 100755
--- a/t/t5500-fetch-pack.sh
+++ b/t/t5500-fetch-pack.sh

@@ -755,4 +755,67 @@
 	)
 '
 
+test_expect_success 'filtering by size' '
+	rm -rf server client &&
+	test_create_repo server &&
+	test_commit -C server one &&
+	test_config -C server uploadpack.allowfilter 1 &&
+
+	test_create_repo client &&
+	git -C client fetch-pack --filter=blob:limit=0 ../server HEAD &&
+
+	# Ensure that object is not inadvertently fetched
+	test_must_fail git -C client cat-file -e $(git hash-object server/one.t)
+'
+
+test_expect_success 'filtering by size has no effect if support for it is not advertised' '
+	rm -rf server client &&
+	test_create_repo server &&
+	test_commit -C server one &&
+
+	test_create_repo client &&
+	git -C client fetch-pack --filter=blob:limit=0 ../server HEAD 2> err &&
+
+	# Ensure that object is fetched
+	git -C client cat-file -e $(git hash-object server/one.t) &&
+
+	test_i18ngrep "filtering not recognized by server" err
+'
+
+fetch_filter_blob_limit_zero () {
+	SERVER="$1"
+	URL="$2"
+
+	rm -rf "$SERVER" client &&
+	test_create_repo "$SERVER" &&
+	test_commit -C "$SERVER" one &&
+	test_config -C "$SERVER" uploadpack.allowfilter 1 &&
+
+	git clone "$URL" client &&
+	test_config -C client extensions.partialclone origin &&
+
+	test_commit -C "$SERVER" two &&
+
+	git -C client fetch --filter=blob:limit=0 origin HEAD:somewhere &&
+
+	# Ensure that commit is fetched, but blob is not
+	test_config -C client extensions.partialclone "arbitrary string" &&
+	git -C client cat-file -e $(git -C "$SERVER" rev-parse two) &&
+	test_must_fail git -C client cat-file -e $(git hash-object "$SERVER/two.t")
+}
+
+test_expect_success 'fetch with --filter=blob:limit=0' '
+	fetch_filter_blob_limit_zero server server
+'
+
+. "$TEST_DIRECTORY"/lib-httpd.sh
+start_httpd
+
+test_expect_success 'fetch with --filter=blob:limit=0 and HTTP' '
+	fetch_filter_blob_limit_zero "$HTTPD_DOCUMENT_ROOT_PATH/server" "$HTTPD_URL/smart/server"
+'
+
+stop_httpd
+
+
 test_done

diff --git a/t/t5551-http-fetch-smart.sh b/t/t5551-http-fetch-smart.sh
index a51b7e2..f5721b4 100755
--- a/t/t5551-http-fetch-smart.sh
+++ b/t/t5551-http-fetch-smart.sh

@@ -364,5 +364,38 @@
 		submodule update sub
 '
 
+test_expect_success 'GIT_REDACT_COOKIES redacts cookies' '
+	rm -rf clone &&
+	echo "Set-Cookie: Foo=1" >cookies &&
+	echo "Set-Cookie: Bar=2" >>cookies &&
+	GIT_TRACE_CURL=true GIT_REDACT_COOKIES=Bar,Baz \
+		git -c "http.cookieFile=$(pwd)/cookies" clone \
+		$HTTPD_URL/smart/repo.git clone 2>err &&
+	grep "Cookie:.*Foo=1" err &&
+	grep "Cookie:.*Bar=<redacted>" err &&
+	! grep "Cookie:.*Bar=2" err
+'
+
+test_expect_success 'GIT_REDACT_COOKIES handles empty values' '
+	rm -rf clone &&
+	echo "Set-Cookie: Foo=" >cookies &&
+	GIT_TRACE_CURL=true GIT_REDACT_COOKIES=Foo \
+		git -c "http.cookieFile=$(pwd)/cookies" clone \
+		$HTTPD_URL/smart/repo.git clone 2>err &&
+	grep "Cookie:.*Foo=<redacted>" err
+'
+
+test_expect_success 'GIT_TRACE_CURL_NO_DATA prevents data from being traced' '
+	rm -rf clone &&
+	GIT_TRACE_CURL=true \
+		git clone $HTTPD_URL/smart/repo.git clone 2>err &&
+	grep "=> Send data" err &&
+
+	rm -rf clone &&
+	GIT_TRACE_CURL=true GIT_TRACE_CURL_NO_DATA=1 \
+		git clone $HTTPD_URL/smart/repo.git clone 2>err &&
+	! grep "=> Send data" err
+'
+
 stop_httpd
 test_done

diff --git a/t/t5570-git-daemon.sh b/t/t5570-git-daemon.sh
index 225a022..755b05a 100755
--- a/t/t5570-git-daemon.sh
+++ b/t/t5570-git-daemon.sh

@@ -167,23 +167,48 @@
 	git init --bare "$repo" &&
 	git push "$repo" HEAD &&
 	>"$repo"/git-daemon-export-ok &&
-	rm -rf tmp.git &&
 	GIT_OVERRIDE_VIRTUAL_HOST=localhost \
-		git clone --bare "$GIT_DAEMON_URL/interp.git" tmp.git &&
-	rm -rf tmp.git &&
+		git ls-remote "$GIT_DAEMON_URL/interp.git" &&
 	GIT_OVERRIDE_VIRTUAL_HOST=LOCALHOST \
-		git clone --bare "$GIT_DAEMON_URL/interp.git" tmp.git
+		git ls-remote "$GIT_DAEMON_URL/interp.git"
 '
 
 test_expect_success 'hostname cannot break out of directory' '
-	rm -rf tmp.git &&
 	repo="$GIT_DAEMON_DOCUMENT_ROOT_PATH/../escape.git" &&
 	git init --bare "$repo" &&
 	git push "$repo" HEAD &&
 	>"$repo"/git-daemon-export-ok &&
 	test_must_fail \
 		env GIT_OVERRIDE_VIRTUAL_HOST=.. \
-		git clone --bare "$GIT_DAEMON_URL/escape.git" tmp.git
+		git ls-remote "$GIT_DAEMON_URL/escape.git"
+'
+
+test_expect_success 'daemon log records all attributes' '
+	cat >expect <<-\EOF &&
+	Extended attribute "host": localhost
+	Extended attribute "protocol": version=1
+	EOF
+	>daemon.log &&
+	GIT_OVERRIDE_VIRTUAL_HOST=localhost \
+		git -c protocol.version=1 \
+			ls-remote "$GIT_DAEMON_URL/interp.git" &&
+	grep -i extended.attribute daemon.log | cut -d" " -f2- >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success FAKENC 'hostname interpolation works after LF-stripping' '
+	{
+		printf "git-upload-pack /interp.git\n\0host=localhost" | packetize
+		printf "0000"
+	} >input &&
+	fake_nc "$GIT_DAEMON_HOST_PORT" <input >output &&
+	depacketize <output >output.raw &&
+
+	# just pick out the value of master, which avoids any protocol
+	# particulars
+	perl -lne "print \$1 if m{^(\\S+) refs/heads/master}" <output.raw >actual &&
+	git -C "$repo" rev-parse master >expect &&
+	test_cmp expect actual
 '
 
 stop_git_daemon

diff --git a/t/t5600-clone-fail-cleanup.sh b/t/t5600-clone-fail-cleanup.sh
index 4435693..4a1a912 100755
--- a/t/t5600-clone-fail-cleanup.sh
+++ b/t/t5600-clone-fail-cleanup.sh

@@ -7,46 +7,94 @@
 
 This test covers the fact that if git clone fails, it should remove
 the directory it created, to avoid the user having to manually
-remove the directory before attempting a clone again.'
+remove the directory before attempting a clone again.
+
+Unless the directory already exists, in which case we clean up only what we
+wrote.
+'
 
 . ./test-lib.sh
 
-test_expect_success \
-    'clone of non-existent source should fail' \
-    'test_must_fail git clone foo bar'
+corrupt_repo () {
+	test_when_finished "rmdir foo/.git/objects.bak" &&
+	mkdir foo/.git/objects.bak/ &&
+	test_when_finished "mv foo/.git/objects.bak/* foo/.git/objects/" &&
+	mv foo/.git/objects/* foo/.git/objects.bak/
+}
 
-test_expect_success \
-    'failed clone should not leave a directory' \
-    '! test -d bar'
+test_expect_success 'clone of non-existent source should fail' '
+	test_must_fail git clone foo bar
+'
 
-# Need a repo to clone
-test_create_repo foo
+test_expect_success 'failed clone should not leave a directory' '
+	test_path_is_missing bar
+'
 
-# clone doesn't like it if there is no HEAD. Is that a bug?
-(cd foo && touch file && git add file && git commit -m 'add file' >/dev/null 2>&1)
+test_expect_success 'create a repo to clone' '
+	test_create_repo foo
+'
+
+test_expect_success 'create objects in repo for later corruption' '
+	test_commit -C foo file
+'
 
 # source repository given to git clone should be relative to the
 # current path not to the target dir
-test_expect_success \
-    'clone of non-existent (relative to $PWD) source should fail' \
-    'test_must_fail git clone ../foo baz'
+test_expect_success 'clone of non-existent (relative to $PWD) source should fail' '
+	test_must_fail git clone ../foo baz
+'
 
-test_expect_success \
-    'clone should work now that source exists' \
-    'git clone foo bar'
+test_expect_success 'clone should work now that source exists' '
+	git clone foo bar
+'
 
-test_expect_success \
-    'successful clone must leave the directory' \
-    'test -d bar'
+test_expect_success 'successful clone must leave the directory' '
+	test_path_is_dir bar
+'
 
 test_expect_success 'failed clone --separate-git-dir should not leave any directories' '
-	mkdir foo/.git/objects.bak/ &&
-	mv foo/.git/objects/* foo/.git/objects.bak/ &&
+	corrupt_repo &&
 	test_must_fail git clone --separate-git-dir gitdir foo worktree &&
-	test_must_fail test -e gitdir &&
-	test_must_fail test -e worktree &&
-	mv foo/.git/objects.bak/* foo/.git/objects/ &&
-	rmdir foo/.git/objects.bak
+	test_path_is_missing gitdir &&
+	test_path_is_missing worktree
+'
+
+test_expect_success 'failed clone into empty leaves directory (vanilla)' '
+	mkdir -p empty &&
+	corrupt_repo &&
+	test_must_fail git clone foo empty &&
+	test_dir_is_empty empty
+'
+
+test_expect_success 'failed clone into empty leaves directory (bare)' '
+	mkdir -p empty &&
+	corrupt_repo &&
+	test_must_fail git clone --bare foo empty &&
+	test_dir_is_empty empty
+'
+
+test_expect_success 'failed clone into empty leaves directory (separate)' '
+	mkdir -p empty-git empty-wt &&
+	corrupt_repo &&
+	test_must_fail git clone --separate-git-dir empty-git foo empty-wt &&
+	test_dir_is_empty empty-git &&
+	test_dir_is_empty empty-wt
+'
+
+test_expect_success 'failed clone into empty leaves directory (separate, git)' '
+	mkdir -p empty-git &&
+	corrupt_repo &&
+	test_must_fail git clone --separate-git-dir empty-git foo no-wt &&
+	test_dir_is_empty empty-git &&
+	test_path_is_missing no-wt
+'
+
+test_expect_success 'failed clone into empty leaves directory (separate, wt)' '
+	mkdir -p empty-wt &&
+	corrupt_repo &&
+	test_must_fail git clone --separate-git-dir no-git foo empty-wt &&
+	test_path_is_missing no-git &&
+	test_dir_is_empty empty-wt
 '
 
 test_done

diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index 8c437bf..0b62037 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh

@@ -628,4 +628,105 @@
 	)
 '
 
+partial_clone () {
+	       SERVER="$1" &&
+	       URL="$2" &&
+
+	rm -rf "$SERVER" client &&
+	test_create_repo "$SERVER" &&
+	test_commit -C "$SERVER" one &&
+	HASH1=$(git hash-object "$SERVER/one.t") &&
+	git -C "$SERVER" revert HEAD &&
+	test_commit -C "$SERVER" two &&
+	HASH2=$(git hash-object "$SERVER/two.t") &&
+	test_config -C "$SERVER" uploadpack.allowfilter 1 &&
+	test_config -C "$SERVER" uploadpack.allowanysha1inwant 1 &&
+
+	git clone --filter=blob:limit=0 "$URL" client &&
+
+	git -C client fsck &&
+
+	# Ensure that unneeded blobs are not inadvertently fetched.
+	test_config -C client extensions.partialclone "not a remote" &&
+	test_must_fail git -C client cat-file -e "$HASH1" &&
+
+	# But this blob was fetched, because clone performs an initial checkout
+	git -C client cat-file -e "$HASH2"
+}
+
+test_expect_success 'partial clone' '
+	partial_clone server "file://$(pwd)/server"
+'
+
+test_expect_success 'partial clone: warn if server does not support object filtering' '
+	rm -rf server client &&
+	test_create_repo server &&
+	test_commit -C server one &&
+
+	git clone --filter=blob:limit=0 "file://$(pwd)/server" client 2> err &&
+
+	test_i18ngrep "filtering not recognized by server" err
+'
+
+test_expect_success 'batch missing blob request during checkout' '
+	rm -rf server client &&
+
+	test_create_repo server &&
+	echo a >server/a &&
+	echo b >server/b &&
+	git -C server add a b &&
+
+	git -C server commit -m x &&
+	echo aa >server/a &&
+	echo bb >server/b &&
+	git -C server add a b &&
+	git -C server commit -m x &&
+
+	test_config -C server uploadpack.allowfilter 1 &&
+	test_config -C server uploadpack.allowanysha1inwant 1 &&
+
+	git clone --filter=blob:limit=0 "file://$(pwd)/server" client &&
+
+	# Ensure that there is only one negotiation by checking that there is
+	# only "done" line sent. ("done" marks the end of negotiation.)
+	GIT_TRACE_PACKET="$(pwd)/trace" git -C client checkout HEAD^ &&
+	grep "git> done" trace >done_lines &&
+	test_line_count = 1 done_lines
+'
+
+test_expect_success 'batch missing blob request does not inadvertently try to fetch gitlinks' '
+	rm -rf server client &&
+
+	test_create_repo repo_for_submodule &&
+	test_commit -C repo_for_submodule x &&
+
+	test_create_repo server &&
+	echo a >server/a &&
+	echo b >server/b &&
+	git -C server add a b &&
+	git -C server commit -m x &&
+
+	echo aa >server/a &&
+	echo bb >server/b &&
+	# Also add a gitlink pointing to an arbitrary repository
+	git -C server submodule add "$(pwd)/repo_for_submodule" c &&
+	git -C server add a b c &&
+	git -C server commit -m x &&
+
+	test_config -C server uploadpack.allowfilter 1 &&
+	test_config -C server uploadpack.allowanysha1inwant 1 &&
+
+	# Make sure that it succeeds
+	git clone --filter=blob:limit=0 "file://$(pwd)/server" client
+'
+
+. "$TEST_DIRECTORY"/lib-httpd.sh
+start_httpd
+
+test_expect_success 'partial clone using HTTP' '
+	partial_clone "$HTTPD_DOCUMENT_ROOT_PATH/server" "$HTTPD_URL/smart/server"
+'
+
+stop_httpd
+
 test_done

diff --git a/t/t5616-partial-clone.sh b/t/t5616-partial-clone.sh
new file mode 100755
index 0000000..29d8631
--- /dev/null
+++ b/t/t5616-partial-clone.sh

@@ -0,0 +1,146 @@
+#!/bin/sh
+
+test_description='git partial clone'
+
+. ./test-lib.sh
+
+# create a normal "src" repo where we can later create new commits.
+# expect_1.oids will contain a list of the OIDs of all blobs.
+test_expect_success 'setup normal src repo' '
+	echo "{print \$1}" >print_1.awk &&
+	echo "{print \$2}" >print_2.awk &&
+
+	git init src &&
+	for n in 1 2 3 4
+	do
+		echo "This is file: $n" > src/file.$n.txt
+		git -C src add file.$n.txt
+		git -C src commit -m "file $n"
+		git -C src ls-files -s file.$n.txt >>temp
+	done &&
+	awk -f print_2.awk <temp | sort >expect_1.oids &&
+	test_line_count = 4 expect_1.oids
+'
+
+# bare clone "src" giving "srv.bare" for use as our server.
+test_expect_success 'setup bare clone for server' '
+	git clone --bare "file://$(pwd)/src" srv.bare &&
+	git -C srv.bare config --local uploadpack.allowfilter 1 &&
+	git -C srv.bare config --local uploadpack.allowanysha1inwant 1
+'
+
+# do basic partial clone from "srv.bare"
+# confirm we are missing all of the known blobs.
+# confirm partial clone was registered in the local config.
+test_expect_success 'do partial clone 1' '
+	git clone --no-checkout --filter=blob:none "file://$(pwd)/srv.bare" pc1 &&
+	git -C pc1 rev-list HEAD --quiet --objects --missing=print \
+		| awk -f print_1.awk \
+		| sed "s/?//" \
+		| sort >observed.oids &&
+	test_cmp expect_1.oids observed.oids &&
+	test "$(git -C pc1 config --local core.repositoryformatversion)" = "1" &&
+	test "$(git -C pc1 config --local extensions.partialclone)" = "origin" &&
+	test "$(git -C pc1 config --local core.partialclonefilter)" = "blob:none"
+'
+
+# checkout master to force dynamic object fetch of blobs at HEAD.
+test_expect_success 'verify checkout with dynamic object fetch' '
+	git -C pc1 rev-list HEAD --quiet --objects --missing=print >observed &&
+	test_line_count = 4 observed &&
+	git -C pc1 checkout master &&
+	git -C pc1 rev-list HEAD --quiet --objects --missing=print >observed &&
+	test_line_count = 0 observed
+'
+
+# create new commits in "src" repo to establish a blame history on file.1.txt
+# and push to "srv.bare".
+test_expect_success 'push new commits to server' '
+	git -C src remote add srv "file://$(pwd)/srv.bare" &&
+	for x in a b c d e
+	do
+		echo "Mod file.1.txt $x" >>src/file.1.txt
+		git -C src add file.1.txt
+		git -C src commit -m "mod $x"
+	done &&
+	git -C src blame master -- file.1.txt >expect.blame &&
+	git -C src push -u srv master
+'
+
+# (partial) fetch in the partial clone repo from the promisor remote.
+# verify that fetch inherited the filter-spec from the config and DOES NOT
+# have the new blobs.
+test_expect_success 'partial fetch inherits filter settings' '
+	git -C pc1 fetch origin &&
+	git -C pc1 rev-list master..origin/master --quiet --objects --missing=print >observed &&
+	test_line_count = 5 observed
+'
+
+# force dynamic object fetch using diff.
+# we should only get 1 new blob (for the file in origin/master).
+test_expect_success 'verify diff causes dynamic object fetch' '
+	git -C pc1 diff master..origin/master -- file.1.txt &&
+	git -C pc1 rev-list master..origin/master --quiet --objects --missing=print >observed &&
+	test_line_count = 4 observed
+'
+
+# force full dynamic object fetch of the file's history using blame.
+# we should get the intermediate blobs for the file.
+test_expect_success 'verify blame causes dynamic object fetch' '
+	git -C pc1 blame origin/master -- file.1.txt >observed.blame &&
+	test_cmp expect.blame observed.blame &&
+	git -C pc1 rev-list master..origin/master --quiet --objects --missing=print >observed &&
+	test_line_count = 0 observed
+'
+
+# create new commits in "src" repo to establish a history on file.2.txt
+# and push to "srv.bare".
+test_expect_success 'push new commits to server for file.2.txt' '
+	for x in a b c d e f
+	do
+		echo "Mod file.2.txt $x" >>src/file.2.txt
+		git -C src add file.2.txt
+		git -C src commit -m "mod $x"
+	done &&
+	git -C src push -u srv master
+'
+
+# Do FULL fetch by disabling inherited filter-spec using --no-filter.
+# Verify we have all the new blobs.
+test_expect_success 'override inherited filter-spec using --no-filter' '
+	git -C pc1 fetch --no-filter origin &&
+	git -C pc1 rev-list master..origin/master --quiet --objects --missing=print >observed &&
+	test_line_count = 0 observed
+'
+
+# create new commits in "src" repo to establish a history on file.3.txt
+# and push to "srv.bare".
+test_expect_success 'push new commits to server for file.3.txt' '
+	for x in a b c d e f
+	do
+		echo "Mod file.3.txt $x" >>src/file.3.txt
+		git -C src add file.3.txt
+		git -C src commit -m "mod $x"
+	done &&
+	git -C src push -u srv master
+'
+
+# Do a partial fetch and then try to manually fetch the missing objects.
+# This can be used as the basis of a pre-command hook to bulk fetch objects
+# perhaps combined with a command in dry-run mode.
+test_expect_success 'manual prefetch of missing objects' '
+	git -C pc1 fetch --filter=blob:none origin &&
+	git -C pc1 rev-list master..origin/master --quiet --objects --missing=print \
+		| awk -f print_1.awk \
+		| sed "s/?//" \
+		| sort >observed.oids &&
+	test_line_count = 6 observed.oids &&
+	git -C pc1 fetch-pack --stdin "file://$(pwd)/srv.bare" <observed.oids &&
+	git -C pc1 rev-list master..origin/master --quiet --objects --missing=print \
+		| awk -f print_1.awk \
+		| sed "s/?//" \
+		| sort >observed.oids &&
+	test_line_count = 0 observed.oids
+'
+
+test_done

diff --git a/t/t6037-merge-ours-theirs.sh b/t/t6037-merge-ours-theirs.sh
index 3889eca..0aebc6c 100755
--- a/t/t6037-merge-ours-theirs.sh
+++ b/t/t6037-merge-ours-theirs.sh

@@ -73,4 +73,36 @@
 	git reset --hard master && test_must_fail git pull -s recursive -X bork . side
 '
 
+test_expect_success SYMLINKS 'symlink with -Xours/-Xtheirs' '
+	git reset --hard master &&
+	git checkout -b two master &&
+	ln -s target-zero link &&
+	git add link &&
+	git commit -m "add link pointing to zero" &&
+
+	ln -f -s target-two link &&
+	git commit -m "add link pointing to two" link &&
+
+	git checkout -b one HEAD^ &&
+	ln -f -s target-one link &&
+	git commit -m "add link pointing to one" link &&
+
+	# we expect symbolic links not to resolve automatically, of course
+	git checkout one^0 &&
+	test_must_fail git merge -s recursive two &&
+
+	# favor theirs to resolve to target-two?
+	git reset --hard &&
+	git checkout one^0 &&
+	git merge -s recursive -X theirs two &&
+	git diff --exit-code two HEAD link &&
+
+	# favor ours to resolve to target-one?
+	git reset --hard &&
+	git checkout one^0 &&
+	git merge -s recursive -X ours two &&
+	git diff --exit-code one HEAD link
+
+'
+
 test_done

diff --git a/t/t6120-describe.sh b/t/t6120-describe.sh
index 3e3fb46..a5d9015 100755
--- a/t/t6120-describe.sh
+++ b/t/t6120-describe.sh

@@ -122,7 +122,7 @@
 '
 
 : >err.expect
-check_describe A --all A^0
+check_describe tags/A --all A^0
 test_expect_success 'no warning was displayed for A' '
 	test_cmp err.expect err.actual
 '
@@ -374,4 +374,8 @@
 	test_cmp expect actual
 '
 
+check_describe tags/A --all A
+check_describe tags/c --all c
+check_describe heads/branch_A --all --match='branch_*' branch_A
+
 test_done

diff --git a/t/t7500-commit.sh b/t/t7500-commit.sh
index 1d33c5f..170b481 100755
--- a/t/t7500-commit.sh
+++ b/t/t7500-commit.sh

@@ -272,6 +272,14 @@
 	commit_msg_is "fixup! target message subject line"
 '
 
+test_expect_success 'commit --fixup -m"something" -m"extra"' '
+	commit_for_rebase_autosquash_setup &&
+	git commit --fixup HEAD~1 -m"something" -m"extra" &&
+	commit_msg_is "fixup! target message subject linesomething
+
+extra"
+'
+
 test_expect_success 'commit --squash works with -F' '
 	commit_for_rebase_autosquash_setup &&
 	echo "log message from file" >msgfile &&
@@ -325,7 +333,6 @@
 	test_must_fail git commit --fixup HEAD~1 --squash HEAD~2 &&
 	test_must_fail git commit --fixup HEAD~1 -C HEAD~2 &&
 	test_must_fail git commit --fixup HEAD~1 -c HEAD~2 &&
-	test_must_fail git commit --fixup HEAD~1 -m "cmdline message" &&
 	test_must_fail git commit --fixup HEAD~1 -F log
 '
 

diff --git a/t/t7505-prepare-commit-msg-hook.sh b/t/t7505-prepare-commit-msg-hook.sh
index b13f729..1f43b3c 100755
--- a/t/t7505-prepare-commit-msg-hook.sh
+++ b/t/t7505-prepare-commit-msg-hook.sh

@@ -4,6 +4,38 @@
 
 . ./test-lib.sh
 
+test_expect_success 'set up commits for rebasing' '
+	test_commit root &&
+	test_commit a a a &&
+	test_commit b b b &&
+	git checkout -b rebase-me root &&
+	test_commit rebase-a a aa &&
+	test_commit rebase-b b bb &&
+	for i in $(test_seq 1 13)
+	do
+		test_commit rebase-$i c $i
+	done &&
+	git checkout master &&
+
+	cat >rebase-todo <<-EOF
+	pick $(git rev-parse rebase-a)
+	pick $(git rev-parse rebase-b)
+	fixup $(git rev-parse rebase-1)
+	fixup $(git rev-parse rebase-2)
+	pick $(git rev-parse rebase-3)
+	fixup $(git rev-parse rebase-4)
+	squash $(git rev-parse rebase-5)
+	reword $(git rev-parse rebase-6)
+	squash $(git rev-parse rebase-7)
+	fixup $(git rev-parse rebase-8)
+	fixup $(git rev-parse rebase-9)
+	edit $(git rev-parse rebase-10)
+	squash $(git rev-parse rebase-11)
+	squash $(git rev-parse rebase-12)
+	edit $(git rev-parse rebase-13)
+	EOF
+'
+
 test_expect_success 'with no hook' '
 
 	echo "foo" > file &&
@@ -31,17 +63,41 @@
 echo "#!$SHELL_PATH" > "$HOOK"
 cat >> "$HOOK" <<'EOF'
 
-if test "$2" = commit; then
-  source=$(git rev-parse "$3")
+GIT_DIR=$(git rev-parse --git-dir)
+if test -d "$GIT_DIR/rebase-merge"
+then
+	rebasing=1
 else
-  source=${2-default}
+	rebasing=0
 fi
-if test "$GIT_EDITOR" = :; then
-  sed -e "1s/.*/$source (no editor)/" "$1" > msg.tmp
+
+get_last_cmd () {
+	tail -n1 "$GIT_DIR/rebase-merge/done" | {
+		read cmd id _
+		git log --pretty="[$cmd %s]" -n1 $id
+	}
+}
+
+if test "$2" = commit
+then
+	if test $rebasing = 1
+	then
+		source="$3"
+	else
+		source=$(git rev-parse "$3")
+	fi
 else
-  sed -e "1s/.*/$source/" "$1" > msg.tmp
+	source=${2-default}
 fi
-mv msg.tmp "$1"
+test "$GIT_EDITOR" = : && source="$source (no editor)"
+
+if test $rebasing = 1
+then
+	echo "$source $(get_last_cmd)" >"$1"
+else
+	sed -e "1s/.*/$source/" "$1" >msg.tmp
+	mv msg.tmp "$1"
+fi
 exit 0
 EOF
 chmod +x "$HOOK"
@@ -156,6 +212,63 @@
 	test "$(git log -1 --pretty=format:%s)" = "merge"
 '
 
+test_rebase () {
+	expect=$1 &&
+	mode=$2 &&
+	test_expect_$expect C_LOCALE_OUTPUT "with hook (rebase $mode)" '
+		test_when_finished "\
+			git rebase --abort
+			git checkout -f master
+			git branch -D tmp" &&
+		git checkout -b tmp rebase-me &&
+		GIT_SEQUENCE_EDITOR="cp rebase-todo" &&
+		GIT_EDITOR="\"$FAKE_EDITOR\"" &&
+		(
+			export GIT_SEQUENCE_EDITOR GIT_EDITOR &&
+			test_must_fail git rebase $mode b &&
+			echo x >a &&
+			git add a &&
+			test_must_fail git rebase --continue &&
+			echo x >b &&
+			git add b &&
+			git commit &&
+			git rebase --continue &&
+			echo y >a &&
+			git add a &&
+			git commit &&
+			git rebase --continue &&
+			echo y >b &&
+			git add b &&
+			git rebase --continue
+		) &&
+		if test $mode = -p # reword amended after pick
+		then
+			n=18
+		else
+			n=17
+		fi &&
+		git log --pretty=%s -g -n$n HEAD@{1} >actual &&
+		test_cmp "$TEST_DIRECTORY/t7505/expected-rebase$mode" actual
+	'
+}
+
+test_rebase success -i
+test_rebase success -p
+
+test_expect_success 'with hook (cherry-pick)' '
+	test_when_finished "git checkout -f master" &&
+	git checkout -B other b &&
+	git cherry-pick rebase-1 &&
+	test "$(git log -1 --pretty=format:%s)" = "message (no editor)"
+'
+
+test_expect_success 'with hook and editor (cherry-pick)' '
+	test_when_finished "git checkout -f master" &&
+	git checkout -B other b &&
+	git cherry-pick -e rebase-1 &&
+	test "$(git log -1 --pretty=format:%s)" = merge
+'
+
 cat > "$HOOK" <<'EOF'
 #!/bin/sh
 exit 1
@@ -197,4 +310,11 @@
 
 '
 
+test_expect_success C_LOCALE_OUTPUT 'with failing hook (cherry-pick)' '
+	test_when_finished "git checkout -f master" &&
+	git checkout -B other b &&
+	test_must_fail git cherry-pick rebase-1 2>actual &&
+	test $(grep -c prepare-commit-msg actual) = 1
+'
+
 test_done

diff --git a/t/t7505/expected-rebase-i b/t/t7505/expected-rebase-i
new file mode 100644
index 0000000..c514bdb
--- /dev/null
+++ b/t/t7505/expected-rebase-i

@@ -0,0 +1,17 @@
+message [edit rebase-13]
+message (no editor) [edit rebase-13]
+message [squash rebase-12]
+message (no editor) [squash rebase-11]
+default [edit rebase-10]
+message (no editor) [edit rebase-10]
+message [fixup rebase-9]
+message (no editor) [fixup rebase-8]
+message (no editor) [squash rebase-7]
+message [reword rebase-6]
+message [squash rebase-5]
+message (no editor) [fixup rebase-4]
+message (no editor) [pick rebase-3]
+message (no editor) [fixup rebase-2]
+message (no editor) [fixup rebase-1]
+merge [pick rebase-b]
+message [pick rebase-a]

diff --git a/t/t7505/expected-rebase-p b/t/t7505/expected-rebase-p
new file mode 100644
index 0000000..93bada5
--- /dev/null
+++ b/t/t7505/expected-rebase-p

@@ -0,0 +1,18 @@
+message [edit rebase-13]
+message (no editor) [edit rebase-13]
+message [squash rebase-12]
+message (no editor) [squash rebase-11]
+default [edit rebase-10]
+message (no editor) [edit rebase-10]
+message [fixup rebase-9]
+message (no editor) [fixup rebase-8]
+message (no editor) [squash rebase-7]
+HEAD [reword rebase-6]
+message (no editor) [reword rebase-6]
+message [squash rebase-5]
+message (no editor) [fixup rebase-4]
+message (no editor) [pick rebase-3]
+message (no editor) [fixup rebase-2]
+message (no editor) [fixup rebase-1]
+merge [pick rebase-b]
+message [pick rebase-a]

diff --git a/t/t7607-merge-overwrite.sh b/t/t7607-merge-overwrite.sh
index 9444d6a..9c422bc 100755
--- a/t/t7607-merge-overwrite.sh
+++ b/t/t7607-merge-overwrite.sh

@@ -97,7 +97,10 @@
 	git mv c1.c other.c &&
 	git commit -m rename &&
 	cp important other.c &&
-	git merge c1a &&
+	test_must_fail git merge c1a >out &&
+	test_i18ngrep "Refusing to lose dirty file at other.c" out &&
+	test_path_is_file other.c~HEAD &&
+	test $(git hash-object other.c~HEAD) = $(git rev-parse c1a:c1.c) &&
 	test_cmp important other.c
 '
 

diff --git a/t/t9000-addresses.sh b/t/t9000-addresses.sh
deleted file mode 100755
index a1ebef6..0000000
--- a/t/t9000-addresses.sh
+++ /dev/null

@@ -1,27 +0,0 @@
-#!/bin/sh
-
-test_description='compare address parsing with and without Mail::Address'
-. ./test-lib.sh
-
-if ! test_have_prereq PERL; then
-	skip_all='skipping perl interface tests, perl not available'
-	test_done
-fi
-
-perl -MTest::More -e 0 2>/dev/null || {
-	skip_all="Perl Test::More unavailable, skipping test"
-	test_done
-}
-
-perl -MMail::Address -e 0 2>/dev/null || {
-	skip_all="Perl Mail::Address unavailable, skipping test"
-	test_done
-}
-
-test_external_has_tap=1
-
-test_external_without_stderr \
-	'Perl address parsing function' \
-	perl "$TEST_DIRECTORY"/t9000/test.pl
-
-test_done

diff --git a/t/t9000/test.pl b/t/t9000/test.pl
deleted file mode 100755
index dfeaa9c..0000000
--- a/t/t9000/test.pl
+++ /dev/null

@@ -1,67 +0,0 @@
-#!/usr/bin/perl
-use lib (split(/:/, $ENV{GITPERLLIB}));
-
-use 5.008;
-use warnings;
-use strict;
-
-use Test::More qw(no_plan);
-use Mail::Address;
-
-BEGIN { use_ok('Git') }
-
-my @success_list = (q[Jane],
-	q[jdoe@example.com],
-	q[<jdoe@example.com>],
-	q[Jane <jdoe@example.com>],
-	q[Jane Doe <jdoe@example.com>],
-	q["Jane" <jdoe@example.com>],
-	q["Doe, Jane" <jdoe@example.com>],
-	q["Jane@:;\>.,()<Doe" <jdoe@example.com>],
-	q[Jane!#$%&'*+-/=?^_{|}~Doe' <jdoe@example.com>],
-	q["<jdoe@example.com>"],
-	q["Jane jdoe@example.com"],
-	q[Jane Doe <jdoe    @   example.com  >],
-	q[Jane       Doe <  jdoe@example.com  >],
-	q[Jane @ Doe @ Jane @ Doe],
-	q["Jane, 'Doe'" <jdoe@example.com>],
-	q['Doe, "Jane' <jdoe@example.com>],
-	q["Jane" "Do"e <jdoe@example.com>],
-	q["Jane' Doe" <jdoe@example.com>],
-	q["Jane Doe <jdoe@example.com>" <jdoe@example.com>],
-	q["Jane\" Doe" <jdoe@example.com>],
-	q[Doe, jane <jdoe@example.com>],
-	q["Jane Doe <jdoe@example.com>],
-	q['Jane 'Doe' <jdoe@example.com>],
-	q[Jane@:;\.,()<>Doe <jdoe@example.com>],
-	q[Jane <jdoe@example.com> Doe],
-	q[<jdoe@example.com> Jane Doe]);
-
-my @known_failure_list = (q[Jane\ Doe <jdoe@example.com>],
-	q["Doe, Ja"ne <jdoe@example.com>],
-	q["Doe, Katarina" Jane <jdoe@example.com>],
-	q[Jane jdoe@example.com],
-	q["Jane "Kat"a" ri"na" ",Doe" <jdoe@example.com>],
-	q[Jane Doe],
-	q[Jane "Doe <jdoe@example.com>"],
-	q[\"Jane Doe <jdoe@example.com>],
-	q[Jane\"\" Doe <jdoe@example.com>],
-	q['Jane "Katarina\" \' Doe' <jdoe@example.com>]);
-
-foreach my $str (@success_list) {
-	my @expected = map { $_->format } Mail::Address->parse("$str");
-	my @actual = Git::parse_mailboxes("$str");
-	is_deeply(\@expected, \@actual, qq[same output : $str]);
-}
-
-TODO: {
-	local $TODO = "known breakage";
-	foreach my $str (@known_failure_list) {
-		my @expected = map { $_->format } Mail::Address->parse("$str");
-		my @actual = Git::parse_mailboxes("$str");
-		is_deeply(\@expected, \@actual, qq[same output : $str]);
-	}
-}
-
-my $is_passing = eval { Test::More->is_passing };
-exit($is_passing ? 0 : 1) unless $@ =~ /Can't locate object method/;

diff --git a/t/t9001-send-email.sh b/t/t9001-send-email.sh
index 4d261c2..19601fb 100755
--- a/t/t9001-send-email.sh
+++ b/t/t9001-send-email.sh

@@ -6,6 +6,12 @@
 # May be altered later in the test
 PREREQ="PERL"
 
+replace_variable_fields () {
+	sed	-e "s/^\(Date:\).*/\1 DATE-STRING/" \
+		-e "s/^\(Message-Id:\).*/\1 MESSAGE-ID-STRING/" \
+		-e "s/^\(X-Mailer:\).*/\1 X-MAILER-STRING/"
+}
+
 test_expect_success $PREREQ 'prepare reference tree' '
 	echo "1A quick brown fox jumps over the" >file &&
 	echo "lazy dog" >>file &&
@@ -172,6 +178,25 @@
 	test_cmp expected-cc commandline1
 '
 
+test_expect_success $PREREQ 'setup fake get_maintainer.pl script for cc trailer' "
+	write_script expected-cc-script.sh <<-EOF
+	echo 'One Person <one@example.com> (supporter:THIS (FOO/bar))'
+	echo 'Two Person <two@example.com> (maintainer:THIS THING)'
+	echo 'Third List <three@example.com> (moderated list:THIS THING (FOO/bar))'
+	echo '<four@example.com> (moderated list:FOR THING)'
+	echo 'five@example.com (open list:FOR THING (FOO/bar))'
+	echo 'six@example.com (open list)'
+	EOF
+"
+
+test_expect_success $PREREQ 'cc trailer with get_maintainer.pl output' '
+	clean_fake_sendmail &&
+	git send-email -1 --to=recipient@example.com \
+		--cc-cmd=./expected-cc-script.sh \
+		--smtp-server="$(pwd)/fake.sendmail" &&
+	test_cmp expected-cc commandline1
+'
+
 test_expect_success $PREREQ 'setup expect' "
 cat >expected-show-all-headers <<\EOF
 0001-Second.patch
@@ -296,10 +321,7 @@
 		--bcc=bcc@example.com \
 		--in-reply-to="<unique-message-id@example.com>" \
 		--smtp-server relay.example.com \
-		$patches |
-	sed	-e "s/^\(Date:\).*/\1 DATE-STRING/" \
-		-e "s/^\(Message-Id:\).*/\1 MESSAGE-ID-STRING/" \
-		-e "s/^\(X-Mailer:\).*/\1 X-MAILER-STRING/" \
+		$patches | replace_variable_fields \
 		>actual-show-all-headers &&
 	test_cmp expected-show-all-headers actual-show-all-headers
 '
@@ -554,12 +576,6 @@
 EOF
 "
 
-replace_variable_fields () {
-	sed	-e "s/^\(Date:\).*/\1 DATE-STRING/" \
-		-e "s/^\(Message-Id:\).*/\1 MESSAGE-ID-STRING/" \
-		-e "s/^\(X-Mailer:\).*/\1 X-MAILER-STRING/"
-}
-
 test_suppression () {
 	git send-email \
 		--dry-run \

diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 1de31fa..67b5994 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh

@@ -1074,3 +1074,37 @@
 		"$@"
 	)
 }
+
+# convert stdin to pktline representation; note that empty input becomes an
+# empty packet, not a flush packet (for that you can just print 0000 yourself).
+packetize() {
+	cat >packetize.tmp &&
+	len=$(wc -c <packetize.tmp) &&
+	printf '%04x%s' "$(($len + 4))" &&
+	cat packetize.tmp &&
+	rm -f packetize.tmp
+}
+
+# Parse the input as a series of pktlines, writing the result to stdout.
+# Sideband markers are removed automatically, and the output is routed to
+# stderr if appropriate.
+#
+# NUL bytes are converted to "\\0" for ease of parsing with text tools.
+depacketize () {
+	perl -e '
+		while (read(STDIN, $len, 4) == 4) {
+			if ($len eq "0000") {
+				print "FLUSH\n";
+			} else {
+				read(STDIN, $buf, hex($len) - 4);
+				$buf =~ s/\0/\\0/g;
+				if ($buf =~ s/^[\x2\x3]//) {
+					print STDERR $buf;
+				} else {
+					$buf =~ s/^\x1//;
+					print $buf;
+				}
+			}
+		}
+	'
+}

diff --git a/t/test-lib.sh b/t/test-lib.sh
index 852b22c..33f6ce2 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh

@@ -939,7 +939,7 @@
 	fi
 fi
 
-GITPERLLIB="$GIT_BUILD_DIR"/perl/blib/lib:"$GIT_BUILD_DIR"/perl/blib/arch/auto/Git
+GITPERLLIB="$GIT_BUILD_DIR"/perl/build/lib
 export GITPERLLIB
 test -d "$GIT_BUILD_DIR"/templates/blt || {
 	error "You haven't built things yet, have you?"
@@ -1106,6 +1106,10 @@
 	test -n "$GIT_TEST_LONG"
 '
 
+test_lazy_prereq EXPENSIVE_ON_WINDOWS '
+	test_have_prereq EXPENSIVE || test_have_prereq !MINGW,!CYGWIN
+'
+
 test_lazy_prereq USR_BIN_TIME '
 	test -x /usr/bin/time
 '

diff --git a/trace.c b/trace.c
index b7530b5..7f3b08e 100644
--- a/trace.c
+++ b/trace.c

@@ -131,7 +131,6 @@ static void print_trace_line(struct trace_key *key, struct strbuf *buf)
 {
 	strbuf_complete_line(buf);
 	trace_write(key, buf->buf, buf->len);
-	strbuf_release(buf);
 }
 
 static void trace_vprintf_fl(const char *file, int line, struct trace_key *key,
@@ -144,6 +143,7 @@ static void trace_vprintf_fl(const char *file, int line, struct trace_key *key,
 
 	strbuf_vaddf(&buf, format, ap);
 	print_trace_line(key, &buf);
+	strbuf_release(&buf);
 }
 
 static void trace_argv_vprintf_fl(const char *file, int line,
@@ -157,8 +157,9 @@ static void trace_argv_vprintf_fl(const char *file, int line,
 
 	strbuf_vaddf(&buf, format, ap);
 
-	sq_quote_argv(&buf, argv, 0);
+	sq_quote_argv_pretty(&buf, argv);
 	print_trace_line(&trace_default_key, &buf);
+	strbuf_release(&buf);
 }
 
 void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
@@ -171,6 +172,7 @@ void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
 
 	strbuf_addbuf(&buf, data);
 	print_trace_line(key, &buf);
+	strbuf_release(&buf);
 }
 
 static void trace_performance_vprintf_fl(const char *file, int line,
@@ -190,6 +192,7 @@ static void trace_performance_vprintf_fl(const char *file, int line,
 	}
 
 	print_trace_line(&trace_perf_key, &buf);
+	strbuf_release(&buf);
 }
 
 #ifndef HAVE_VARIADIC_MACROS
@@ -426,6 +429,6 @@ void trace_command_performance(const char **argv)
 		atexit(print_command_performance_atexit);
 
 	strbuf_reset(&command_line);
-	sq_quote_argv(&command_line, argv, 0);
+	sq_quote_argv_pretty(&command_line, argv);
 	command_start_time = getnanotime();
 }

diff --git a/transport-helper.c b/transport-helper.c
index 5080150..3f380d8 100644
--- a/transport-helper.c
+++ b/transport-helper.c

@@ -672,6 +672,11 @@ static int fetch(struct transport *transport,
 	if (data->transport_options.update_shallow)
 		set_helper_option(transport, "update-shallow", "true");
 
+	if (data->transport_options.filter_options.choice)
+		set_helper_option(
+			transport, "filter",
+			data->transport_options.filter_options.filter_spec);
+
 	if (data->fetch)
 		return fetch_with_fetch(transport, nr_heads, to_fetch);
 

diff --git a/transport.c b/transport.c
index fc80226..00d48b5 100644
--- a/transport.c
+++ b/transport.c

@@ -161,6 +161,15 @@ static int set_git_option(struct git_transport_options *opts,
 	} else if (!strcmp(name, TRANS_OPT_DEEPEN_RELATIVE)) {
 		opts->deepen_relative = !!value;
 		return 0;
+	} else if (!strcmp(name, TRANS_OPT_FROM_PROMISOR)) {
+		opts->from_promisor = !!value;
+		return 0;
+	} else if (!strcmp(name, TRANS_OPT_NO_DEPENDENTS)) {
+		opts->no_dependents = !!value;
+		return 0;
+	} else if (!strcmp(name, TRANS_OPT_LIST_OBJECTS_FILTER)) {
+		parse_list_objects_filter(&opts->filter_options, value);
+		return 0;
 	}
 	return 1;
 }
@@ -229,6 +238,9 @@ static int fetch_refs_via_pack(struct transport *transport,
 		data->options.check_self_contained_and_connected;
 	args.cloning = transport->cloning;
 	args.update_shallow = data->options.update_shallow;
+	args.from_promisor = data->options.from_promisor;
+	args.no_dependents = data->options.no_dependents;
+	args.filter_options = data->options.filter_options;
 
 	if (!data->got_remote_heads) {
 		connect_setup(transport, 0);

diff --git a/transport.h b/transport.h
index 731c78b..3c68d73 100644
--- a/transport.h
+++ b/transport.h

@@ -4,6 +4,7 @@
 #include "cache.h"
 #include "run-command.h"
 #include "remote.h"
+#include "list-objects-filter-options.h"
 
 struct string_list;
 
@@ -15,12 +16,15 @@ struct git_transport_options {
 	unsigned self_contained_and_connected : 1;
 	unsigned update_shallow : 1;
 	unsigned deepen_relative : 1;
+	unsigned from_promisor : 1;
+	unsigned no_dependents : 1;
 	int depth;
 	const char *deepen_since;
 	const struct string_list *deepen_not;
 	const char *uploadpack;
 	const char *receivepack;
 	struct push_cas_option *cas;
+	struct list_objects_filter_options filter_options;
 };
 
 enum transport_family {
@@ -159,6 +163,18 @@ void transport_check_allowed(const char *type);
 /* Send push certificates */
 #define TRANS_OPT_PUSH_CERT "pushcert"
 
+/* Indicate that these objects are being fetched by a promisor */
+#define TRANS_OPT_FROM_PROMISOR "from-promisor"
+
+/*
+ * Indicate that only the objects wanted need to be fetched, not their
+ * dependents
+ */
+#define TRANS_OPT_NO_DEPENDENTS "no-dependents"
+
+/* Filter objects for partial clone and fetch */
+#define TRANS_OPT_LIST_OBJECTS_FILTER "filter"
+
 /**
  * Returns 0 if the option was used, non-zero otherwise. Prints a
  * message to stderr if the option is not used.

diff --git a/unpack-trees.c b/unpack-trees.c
index bf8b602..e6a15bb 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c

@@ -15,6 +15,7 @@
 #include "submodule.h"
 #include "submodule-config.h"
 #include "fsmonitor.h"
+#include "fetch-object.h"
 
 /*
  * Error messages expected by scripts out of plumbing commands such as
@@ -370,6 +371,27 @@ static int check_updates(struct unpack_trees_options *o)
 		load_gitmodules_file(index, &state);
 
 	enable_delayed_checkout(&state);
+	if (repository_format_partial_clone && o->update && !o->dry_run) {
+		/*
+		 * Prefetch the objects that are to be checked out in the loop
+		 * below.
+		 */
+		struct oid_array to_fetch = OID_ARRAY_INIT;
+		int fetch_if_missing_store = fetch_if_missing;
+		fetch_if_missing = 0;
+		for (i = 0; i < index->cache_nr; i++) {
+			struct cache_entry *ce = index->cache[i];
+			if ((ce->ce_flags & CE_UPDATE) &&
+			    !S_ISGITLINK(ce->ce_mode)) {
+				if (!has_object_file(&ce->oid))
+					oid_array_append(&to_fetch, &ce->oid);
+			}
+		}
+		if (to_fetch.nr)
+			fetch_objects(repository_format_partial_clone,
+				      &to_fetch);
+		fetch_if_missing = fetch_if_missing_store;
+	}
 	for (i = 0; i < index->cache_nr; i++) {
 		struct cache_entry *ce = index->cache[i];
 
@@ -2139,6 +2161,9 @@ int oneway_merge(const struct cache_entry * const *src,
 			    ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE))
 				update |= CE_UPDATE;
 		}
+		if (o->update && S_ISGITLINK(old->ce_mode) &&
+		    should_update_submodules() && !verify_uptodate(old, o))
+			update |= CE_UPDATE;
 		add_entry(o, old, update, 0);
 		return 0;
 	}

diff --git a/upload-pack.c b/upload-pack.c
index d5de181..f51b6cf 100644
--- a/upload-pack.c
+++ b/upload-pack.c

@@ -10,6 +10,8 @@
 #include "diff.h"
 #include "revision.h"
 #include "list-objects.h"
+#include "list-objects-filter.h"
+#include "list-objects-filter-options.h"
 #include "run-command.h"
 #include "connect.h"
 #include "sigchain.h"
@@ -19,6 +21,7 @@
 #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>"),
@@ -65,6 +68,10 @@ static int advertise_refs;
 static int stateless_rpc;
 static const char *pack_objects_hook;
 
+static int filter_capability_requested;
+static int filter_advertise;
+static struct list_objects_filter_options filter_options;
+
 static void reset_timeout(void)
 {
 	alarm(timeout);
@@ -132,6 +139,17 @@ static void create_pack_file(void)
 		argv_array_push(&pack_objects.args, "--delta-base-offset");
 	if (use_include_tag)
 		argv_array_push(&pack_objects.args, "--include-tag");
+	if (filter_options.filter_spec) {
+		if (pack_objects.use_shell) {
+			struct strbuf buf = STRBUF_INIT;
+			sq_quote_buf(&buf, filter_options.filter_spec);
+			argv_array_pushf(&pack_objects.args, "--filter=%s", buf.buf);
+			strbuf_release(&buf);
+		} else {
+			argv_array_pushf(&pack_objects.args, "--filter=%s",
+					 filter_options.filter_spec);
+		}
+	}
 
 	pack_objects.in = -1;
 	pack_objects.out = -1;
@@ -795,6 +813,12 @@ static void receive_needs(void)
 			deepen_rev_list = 1;
 			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, "
@@ -822,6 +846,8 @@ static void receive_needs(void)
 			no_progress = 1;
 		if (parse_feature_request(features, "include-tag"))
 			use_include_tag = 1;
+		if (parse_feature_request(features, "filter"))
+			filter_capability_requested = 1;
 
 		o = parse_object(&oid_buf);
 		if (!o) {
@@ -941,7 +967,7 @@ static int send_ref(const char *refname, const struct object_id *oid,
 		struct strbuf symref_info = STRBUF_INIT;
 
 		format_symref_info(&symref_info, cb_data);
-		packet_write_fmt(1, "%s %s%c%s%s%s%s%s agent=%s\n",
+		packet_write_fmt(1, "%s %s%c%s%s%s%s%s%s agent=%s\n",
 			     oid_to_hex(oid), refname_nons,
 			     0, capabilities,
 			     (allow_unadvertised_object_request & ALLOW_TIP_SHA1) ?
@@ -950,6 +976,7 @@ static int send_ref(const char *refname, const struct object_id *oid,
 				     " allow-reachable-sha1-in-want" : "",
 			     stateless_rpc ? " no-done" : "",
 			     symref_info.buf,
+			     filter_advertise ? " filter" : "",
 			     git_user_agent_sanitized());
 		strbuf_release(&symref_info);
 	} else {
@@ -1028,6 +1055,8 @@ static int upload_pack_config(const char *var, const char *value, void *unused)
 	} else if (current_config_scope() != CONFIG_SCOPE_REPO) {
 		if (!strcmp("uploadpack.packobjectshook", var))
 			return git_config_string(&pack_objects_hook, var, value);
+	} else if (!strcmp("uploadpack.allowfilter", var)) {
+		filter_advertise = git_config_bool(var, value);
 	}
 	return parse_hide_refs_config(var, value, "uploadpack");
 }

diff --git a/wrap-for-bin.sh b/wrap-for-bin.sh
index 22b6e49..5842408 100644
--- a/wrap-for-bin.sh
+++ b/wrap-for-bin.sh

@@ -14,7 +14,7 @@
 	GIT_TEMPLATE_DIR='@@BUILD_DIR@@/templates/blt'
 	export GIT_TEMPLATE_DIR
 fi
-GITPERLLIB='@@BUILD_DIR@@/perl/blib/lib'"${GITPERLLIB:+:$GITPERLLIB}"
+GITPERLLIB='@@BUILD_DIR@@/perl/build/lib'"${GITPERLLIB:+:$GITPERLLIB}"
 GIT_TEXTDOMAINDIR='@@BUILD_DIR@@/po/build/locale'
 PATH='@@BUILD_DIR@@/bin-wrappers:'"$PATH"
 

diff --git a/wt-status.c b/wt-status.c
index ef26f07..f5debcd 100644
--- a/wt-status.c
+++ b/wt-status.c

@@ -360,8 +360,6 @@ static void wt_longstatus_print_change_data(struct wt_status *s,
 	switch (change_type) {
 	case WT_STATUS_UPDATED:
 		status = d->index_status;
-		if (d->head_path)
-			one_name = d->head_path;
 		break;
 	case WT_STATUS_CHANGED:
 		if (d->new_submodule_commits || d->dirty_submodule) {
@@ -382,6 +380,14 @@ static void wt_longstatus_print_change_data(struct wt_status *s,
 		    change_type);
 	}
 
+	/*
+	 * Only pick up the rename it's relevant. If the rename is for
+	 * the changed section and we're printing the updated section,
+	 * ignore it.
+	 */
+	if (d->rename_status == status)
+		one_name = d->rename_source;
+
 	one = quote_path(one_name, s->prefix, &onebuf);
 	two = quote_path(two_name, s->prefix, &twobuf);
 
@@ -391,7 +397,7 @@ static void wt_longstatus_print_change_data(struct wt_status *s,
 		die("BUG: unhandled diff status %c", status);
 	len = label_width - utf8_strwidth(what);
 	assert(len >= 0);
-	if (status == DIFF_STATUS_COPIED || status == DIFF_STATUS_RENAMED)
+	if (one_name != two_name)
 		status_printf_more(s, c, "%s%.*s%s -> %s",
 				   what, len, padding, one, two);
 	else
@@ -406,7 +412,8 @@ static void wt_longstatus_print_change_data(struct wt_status *s,
 	strbuf_release(&twobuf);
 }
 
-static char short_submodule_status(struct wt_status_change_data *d) {
+static char short_submodule_status(struct wt_status_change_data *d)
+{
 	if (d->new_submodule_commits)
 		return 'M';
 	if (d->dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
@@ -432,7 +439,7 @@ static void wt_status_collect_changed_cb(struct diff_queue_struct *q,
 		struct wt_status_change_data *d;
 
 		p = q->queue[i];
-		it = string_list_insert(&s->change, p->one->path);
+		it = string_list_insert(&s->change, p->two->path);
 		d = it->util;
 		if (!d) {
 			d = xcalloc(1, sizeof(*d));
@@ -459,6 +466,14 @@ static void wt_status_collect_changed_cb(struct diff_queue_struct *q,
 			/* mode_worktree is zero for a delete. */
 			break;
 
+		case DIFF_STATUS_COPIED:
+		case DIFF_STATUS_RENAMED:
+			if (d->rename_status)
+				die("BUG: multiple renames on the same target? how?");
+			d->rename_source = xstrdup(p->one->path);
+			d->rename_score = p->score * 100 / MAX_SCORE;
+			d->rename_status = p->status;
+			/* fallthru */
 		case DIFF_STATUS_MODIFIED:
 		case DIFF_STATUS_TYPE_CHANGED:
 		case DIFF_STATUS_UNMERGED:
@@ -467,8 +482,8 @@ static void wt_status_collect_changed_cb(struct diff_queue_struct *q,
 			oidcpy(&d->oid_index, &p->one->oid);
 			break;
 
-		case DIFF_STATUS_UNKNOWN:
-			die("BUG: worktree status unknown???");
+		default:
+			die("BUG: unhandled diff-files status '%c'", p->status);
 			break;
 		}
 
@@ -530,8 +545,11 @@ static void wt_status_collect_updated_cb(struct diff_queue_struct *q,
 
 		case DIFF_STATUS_COPIED:
 		case DIFF_STATUS_RENAMED:
-			d->head_path = xstrdup(p->one->path);
-			d->score = p->score * 100 / MAX_SCORE;
+			if (d->rename_status)
+				die("BUG: multiple renames on the same target? how?");
+			d->rename_source = xstrdup(p->one->path);
+			d->rename_score = p->score * 100 / MAX_SCORE;
+			d->rename_status = p->status;
 			/* fallthru */
 		case DIFF_STATUS_MODIFIED:
 		case DIFF_STATUS_TYPE_CHANGED:
@@ -548,6 +566,10 @@ static void wt_status_collect_updated_cb(struct diff_queue_struct *q,
 			 * values in these fields.
 			 */
 			break;
+
+		default:
+			die("BUG: unhandled diff-index status '%c'", p->status);
+			break;
 		}
 	}
 }
@@ -602,7 +624,7 @@ static void wt_status_collect_changes_index(struct wt_status *s)
 	rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 	rev.diffopt.format_callback = wt_status_collect_updated_cb;
 	rev.diffopt.format_callback_data = s;
-	rev.diffopt.detect_rename = 1;
+	rev.diffopt.detect_rename = DIFF_DETECT_RENAME;
 	rev.diffopt.rename_limit = 200;
 	rev.diffopt.break_opt = 0;
 	copy_pathspec(&rev.prune_data, &s->pathspec);
@@ -962,7 +984,7 @@ static void wt_longstatus_print_verbose(struct wt_status *s)
 	setup_revisions(0, NULL, &rev, &opt);
 
 	rev.diffopt.output_format |= DIFF_FORMAT_PATCH;
-	rev.diffopt.detect_rename = 1;
+	rev.diffopt.detect_rename = DIFF_DETECT_RENAME;
 	rev.diffopt.file = s->fp;
 	rev.diffopt.close_file = 0;
 	/*
@@ -1719,13 +1741,14 @@ static void wt_shortstatus_status(struct string_list_item *it,
 	putchar(' ');
 	if (s->null_termination) {
 		fprintf(stdout, "%s%c", it->string, 0);
-		if (d->head_path)
-			fprintf(stdout, "%s%c", d->head_path, 0);
+		if (d->rename_source)
+			fprintf(stdout, "%s%c", d->rename_source, 0);
 	} else {
 		struct strbuf onebuf = STRBUF_INIT;
 		const char *one;
-		if (d->head_path) {
-			one = quote_path(d->head_path, s->prefix, &onebuf);
+
+		if (d->rename_source) {
+			one = quote_path(d->rename_source, s->prefix, &onebuf);
 			if (*one != '"' && strchr(one, ' ') != NULL) {
 				putchar('"');
 				strbuf_addch(&onebuf, '"');
@@ -2030,10 +2053,10 @@ static void wt_porcelain_v2_print_changed_entry(
 	struct wt_status *s)
 {
 	struct wt_status_change_data *d = it->util;
-	struct strbuf buf_index = STRBUF_INIT;
-	struct strbuf buf_head = STRBUF_INIT;
-	const char *path_index = NULL;
-	const char *path_head = NULL;
+	struct strbuf buf = STRBUF_INIT;
+	struct strbuf buf_from = STRBUF_INIT;
+	const char *path = NULL;
+	const char *path_from = NULL;
 	char key[3];
 	char submodule_token[5];
 	char sep_char, eol_char;
@@ -2052,8 +2075,8 @@ static void wt_porcelain_v2_print_changed_entry(
 		 */
 		sep_char = '\0';
 		eol_char = '\0';
-		path_index = it->string;
-		path_head = d->head_path;
+		path = it->string;
+		path_from = d->rename_source;
 	} else {
 		/*
 		 * Path(s) are C-quoted if necessary. Current path is ALWAYS first.
@@ -2063,27 +2086,27 @@ static void wt_porcelain_v2_print_changed_entry(
 		 */
 		sep_char = '\t';
 		eol_char = '\n';
-		path_index = quote_path(it->string, s->prefix, &buf_index);
-		if (d->head_path)
-			path_head = quote_path(d->head_path, s->prefix, &buf_head);
+		path = quote_path(it->string, s->prefix, &buf);
+		if (d->rename_source)
+			path_from = quote_path(d->rename_source, s->prefix, &buf_from);
 	}
 
-	if (path_head)
+	if (path_from)
 		fprintf(s->fp, "2 %s %s %06o %06o %06o %s %s %c%d %s%c%s%c",
 				key, submodule_token,
 				d->mode_head, d->mode_index, d->mode_worktree,
 				oid_to_hex(&d->oid_head), oid_to_hex(&d->oid_index),
-				key[0], d->score,
-				path_index, sep_char, path_head, eol_char);
+				d->rename_status, d->rename_score,
+				path, sep_char, path_from, eol_char);
 	else
 		fprintf(s->fp, "1 %s %s %06o %06o %06o %s %s %s%c",
 				key, submodule_token,
 				d->mode_head, d->mode_index, d->mode_worktree,
 				oid_to_hex(&d->oid_head), oid_to_hex(&d->oid_index),
-				path_index, eol_char);
+				path, eol_char);
 
-	strbuf_release(&buf_index);
-	strbuf_release(&buf_head);
+	strbuf_release(&buf);
+	strbuf_release(&buf_from);
 }
 
 /*

diff --git a/wt-status.h b/wt-status.h
index fe27b46..3f84d5c 100644
--- a/wt-status.h
+++ b/wt-status.h

@@ -44,10 +44,11 @@ struct wt_status_change_data {
 	int worktree_status;
 	int index_status;
 	int stagemask;
-	int score;
 	int mode_head, mode_index, mode_worktree;
 	struct object_id oid_head, oid_index;
-	char *head_path;
+	int rename_status;
+	int rename_score;
+	char *rename_source;
 	unsigned dirty_submodule       : 2;
 	unsigned new_submodule_commits : 1;
 };