diff --git a/.gitignore b/.gitignore
index 8bcf153..7374587 100644
--- a/.gitignore
+++ b/.gitignore
@@ -125,7 +125,6 @@
 /git-rebase--am
 /git-rebase--common
 /git-rebase--interactive
-/git-rebase--merge
 /git-rebase--preserve-merges
 /git-receive-pack
 /git-reflog
@@ -230,3 +229,4 @@
 *.pdb
 /Debug/
 /Release/
+*.dSYM
diff --git a/.mailmap b/.mailmap
index 247a3de..82cd056 100644
--- a/.mailmap
+++ b/.mailmap
@@ -40,6 +40,8 @@
 Christian Couder <chriscool@tuxfamily.org> <christian.couder@gmail.com>
 Christian Stimming <stimming@tuhh.de> <chs@ckiste.goetheallee>
 Christopher Díaz Riveros <chrisadr@gentoo.org> Christopher Diaz Riveros
+Clemens Buchacher <drizzd@gmx.net> <drizzd@aon.at>
+Clemens Buchacher <drizzd@gmx.net> <clemens.buchacher@intel.com>
 Csaba Henk <csaba@gluster.com> <csaba@lowlife.hu>
 Dan Johnson <computerdruid@gmail.com>
 Dana L. How <danahow@gmail.com> <how@deathvalley.cswitch.com>
diff --git a/.travis.yml b/.travis.yml
index 03c8e4c..36cbdea 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,6 +8,8 @@
   - linux
   - osx
 
+osx_image: xcode10.1
+
 compiler:
   - clang
   - gcc
diff --git a/Documentation/RelNotes/2.21.0.txt b/Documentation/RelNotes/2.21.0.txt
index 4596d9e..cf8298d 100644
--- a/Documentation/RelNotes/2.21.0.txt
+++ b/Documentation/RelNotes/2.21.0.txt
@@ -4,6 +4,14 @@
 Backward Compatibility Notes
 ----------------------------
 
+ * Historically, the "-m" (mainline) option can only be used for "git
+   cherry-pick" and "git revert" when working with a merge commit.
+   This version of Git no longer warns or errors out when working with
+   a single-parent commit, as long as the argument to the "-m" option
+   is 1 (i.e. it has only one parent, and the request is to pick or
+   revert relative to that first parent).  Scripts that relied on the
+   behaviour may get broken with this change.
+
 
 Updates since v2.20
 -------------------
@@ -11,11 +19,11 @@
 UI, Workflows & Features
 
  * The "http.version" configuration variable can be used with recent
-   enough cURL library to force the version of HTTP used to talk when
-   fetching and pushing.
+   enough versions of cURL library to force the version of HTTP used
+   to talk when fetching and pushing.
 
  * Small fixes and features for fast-export and fast-import, mostly on
-   the fast-export side.
+   the fast-export side has been made.
 
  * "git push $there $src:$dst" rejects when $dst is not a fully
    qualified refname and not clear what the end user meant.  The
@@ -59,13 +67,26 @@
  * Custom userformat "log --format" learned %S atom that stands for
    the tip the traversal reached the commit from, i.e. --source.
 
+ * "git instaweb" learned to drive http.server that comes with
+   "batteries included" Python installation (both Python2 & 3).
+
+ * A new encoding UTF-16LE-BOM has been invented to force encoding to
+   UTF-16 with BOM in little endian byte order, which cannot be directly
+   generated by using iconv.
+
+ * A new date format "--date=human" that morphs its output depending
+   on how far the time is from the current time has been introduced.
+   "--date=auto" can be used to use this new format when the output is
+   going to the pager or to the terminal and otherwise the default
+   format.
+
 
 Performance, Internal Implementation, Development Support etc.
 
  * Code clean-up with optimization for the codepath that checks
    (non-)existence of loose objects.
 
- * More codepaths become aware of working with in-core repository
+ * More codepaths have become aware of working with in-core repository
    instance other than the default "the_repository".
 
  * The "strncat()" function is now among the banned functions.
@@ -83,7 +104,6 @@
 
  * Flaky tests can now be repeatedly run under load with the
    "--stress" option.
-   (merge fb7d1e3ac8 sg/stress-test later to maint).
 
  * Documentation/Makefile is getting prepared for manpage
    localization.
@@ -101,6 +121,59 @@
  * The code to walk tree objects has been taught that we may be
    working with object names that are not computed with SHA-1.
 
+ * The in-core repository instances are passed through more codepaths.
+
+ * Update the protocol message specification to allow only the limited
+   use of scaled quantities.  This is ensure potential compatibility
+   issues will not go out of hand.
+
+ * Micro-optimize the code that prepares commit objects to be walked
+   by "git rev-list" when the commit-graph is available.
+
+ * "git fetch" and "git upload-pack" learned to send all exchange over
+   the sideband channel while talking the v2 protocol.
+
+ * The codepath to write out commit-graph has been optimized by
+   following the usual pattern of visiting objects in in-pack order.
+
+ * The codepath to show progress meter while writing out commit-graph
+   file has been improved.
+
+ * Cocci rules have been updated to encourage use of strbuf_addbuf().
+
+ * "git rebase --merge" has been reimplemented by reusing the internal
+   machinery used for "git rebase -i".
+
+ * More code in "git bisect" has been rewritten in C.
+
+ * Instead of going through "git-rebase--am" scriptlet to use the "am"
+   backend, the built-in version of "git rebase" learned to drive the
+   "am" backend directly.
+
+ * The assumption to work on the single "in-core index" instance has
+   been reduced from the library-ish part of the codebase.
+
+ * The test lint learned to catch non-portable "sed" options.
+
+ * "git pack-objects" learned another algorithm to compute the set of
+   objects to send, that trades the resulting packfile off to save
+   traversal cost to favor small pushes.
+
+ * The travis CI scripts have been corrected to build Git with the
+   compiler(s) of our choice.
+
+ * "git submodule update" learned to abort early when core.worktree
+   for the submodule is not set correctly to prevent spreading damage.
+
+ * Test suite has been adjusted to run on Azure Pipeline.
+
+ * Running "Documentation/doc-diff x" from anywhere other than the
+   top-level of the working tree did not show the usage string
+   correctly, which has been fixed.
+
+ * Use of the sparse tool got easier to customize from the command
+   line to help developers.
+
 
 Fixes since v2.20
 -----------------
@@ -221,6 +294,115 @@
    temporary file.
    (merge fa6f225e01 js/add-e-clear-patch-before-stating later to maint).
 
+ * "git p4" failed to update a shelved change when there were moved
+   files, which has been corrected.
+   (merge 7a10946ab9 ld/git-p4-shelve-update-fix later to maint).
+
+ * The codepath to read from the commit-graph file attempted to read
+   past the end of it when the file's table-of-contents was corrupt.
+
+ * The compat/obstack code had casts that -Wcast-function-type
+   compilation option found questionable.
+   (merge 764473d257 sg/obstack-cast-function-type-fix later to maint).
+
+ * An obvious typo in an assertion error message has been fixed.
+   (merge 3c27e2e059 cc/test-ref-store-typofix later to maint).
+
+ * In Git for Windows, "git clone \\server\share\path" etc. that uses
+   UNC paths from command line had bad interaction with its shell
+   emulation.
+
+ * "git add --ignore-errors" did not work as advertised and instead
+   worked as an unintended synonym for "git add --renormalize", which
+   has been fixed.
+   (merge e2c2a37545 jk/add-ignore-errors-bit-assignment-fix later to maint).
+
+ * On a case-insensitive filesystem, we failed to compare the part of
+   the path that is above the worktree directory in an absolute
+   pathname, which has been corrected.
+
+ * Asking "git check-attr" about a macro (e.g. "binary") on a specific
+   path did not work correctly, even though "git check-attr -a" listed
+   such a macro correctly.  This has been corrected.
+   (merge 7b95849be4 jk/attr-macro-fix later to maint).
+
+ * "git pack-objects" incorrectly used uninitialized mutex, which has
+   been corrected.
+   (merge edb673cf10 ph/pack-objects-mutex-fix later to maint).
+
+ * "git checkout -b <new> [HEAD]" to create a new branch from the
+   current commit and check it out ought to be a no-op in the index
+   and the working tree in normal cases, but there are corner cases
+   that do require updates to the index and the working tree.  Running
+   it immediately after "git clone --no-checkout" is one of these
+   cases that an earlier optimization kicked in incorrectly, which has
+   been fixed.
+   (merge 8424bfd45b bp/checkout-new-branch-optim later to maint).
+
+ * "git diff --color-moved --cc --stat -p" did not work well due to
+   funny interaction between a bug in color-moved and the rest, which
+   has been fixed.
+   (merge dac03b5518 jk/diff-cc-stat-fixes later to maint).
+
+ * When GIT_SEQUENCE_EDITOR is set, the command was incorrectly
+   started when modes of "git rebase" that implicitly uses the
+   machinery for the interactive rebase are run, which has been
+   corrected.
+   (merge 891d4a0313 pw/no-editor-in-rebase-i-implicit later to maint).
+
+ * The commit-graph facility did not work when in-core objects that
+   are promoted from unknown type to commit (e.g. a commit that is
+   accessed via a tag that refers to it) were involved, which has been
+   corrected.
+   (merge 4468d4435c sg/object-as-type-commit-graph-fix later to maint).
+
+ * "git fetch" output cleanup.
+   (merge dc40b24df4 nd/fetch-compact-update later to maint).
+
+ * "git cat-file --batch" reported a dangling symbolic link by
+   mistake, when it wanted to report that a given name is ambiguous.
+
+ * Documentation around core.crlf has been updated.
+   (merge c9446f0504 jk/autocrlf-overrides-eol-doc later to maint).
+
+ * The documentation of "git commit-tree" said that the command
+   understands "--gpg-sign" in addition to "-S", but the command line
+   parser did not know about the longhand, which has been corrected.
+
+ * "git rebase -x $cmd" did not reject multi-line command, even though
+   the command is incapable of handling such a command.  It now is
+   rejected upfront.
+   (merge c762aada1a pw/rebase-x-sanity-check later to maint).
+
+ * Output from "git help" was not correctly aligned, which has been
+   fixed.
+   (merge 6195a76da4 nd/help-align-command-desc later to maint).
+
+ * The "git submodule summary" subcommand showed shortened commit
+   object names by mechanically truncating them at 7-hexdigit, which
+   has been improved to let "rev-parse --short" scale the length of
+   the abbreviation with the size of the repository.
+   (merge 0586a438f6 sh/submodule-summary-abbrev-fix later to maint).
+
+ * The way the OSX build jobs updates its build environment used the
+   "--quiet" option to "brew update" command, but it wasn't all that
+   quiet to be useful.  The use of the option has been replaced with
+   an explicit redirection to the /dev/null (which incidentally would
+   have worked around a breakage by recent updates to homebrew, which
+   has fixed itself already).
+   (merge a1ccaedd62 sg/travis-osx-brew-breakage-workaround later to maint).
+
+ * "git --work-tree=$there --git-dir=$here describe --dirty" did not
+   work correctly as it did not pay attention to the location of the
+   worktree specified by the user by mistake, which has been
+   corrected.
+   (merge c801170b0c ss/describe-dirty-in-the-right-directory later to maint).
+
+ * "git fetch" over protocol v2 that needs to make a second connection
+   to backfill tags did not clear a variable that holds shallow
+   repository information correctly, leading to an access of freed
+   piece of memory.
+
  * Code cleanup, docfix, build fix, etc.
    (merge 89ba9a79ae hb/t0061-dot-in-path-fix later to maint).
    (merge d173e799ea sb/diff-color-moved-config-option-fixup later to maint).
@@ -237,6 +419,11 @@
    (merge 0650614982 cy/completion-typofix later to maint).
    (merge 6881925ef5 rs/sha1-file-close-mapped-file-on-error later to maint).
    (merge bd8d6f0def en/show-ref-doc-fix later to maint).
-   (merge 1747125e2c cc/parial-clone-doc-typofix later to maint).
+   (merge 1747125e2c cc/partial-clone-doc-typofix later to maint).
    (merge e01378753d cc/fetch-error-message-fix later to maint).
    (merge 54e8c11215 jk/remote-insteadof-cleanup later to maint).
+   (merge d609615f48 js/test-git-installed later to maint).
+   (merge ba170517be ja/doc-style-fix later to maint).
+   (merge 86fb1c4e77 km/init-doc-typofix later to maint).
+   (merge 5cfd4a9d10 nd/commit-doc later to maint).
+   (merge 9fce19a431 ab/diff-tree-doc-fix later to maint).
diff --git a/Documentation/config/core.txt b/Documentation/config/core.txt
index d0e6635..7e9b6c8 100644
--- a/Documentation/config/core.txt
+++ b/Documentation/config/core.txt
@@ -121,11 +121,14 @@
 
 core.eol::
 	Sets the line ending type to use in the working directory for
-	files that have the `text` property set when core.autocrlf is false.
+	files that are marked as text (either by having the `text`
+	attribute set, or by having `text=auto` and Git auto-detecting
+	the contents as text).
 	Alternatives are 'lf', 'crlf' and 'native', which uses the platform's
 	native line ending.  The default value is `native`.  See
 	linkgit:gitattributes[5] for more information on end-of-line
-	conversion.
+	conversion. Note that this value is ignored if `core.autocrlf`
+	is set to `true` or `input`.
 
 core.safecrlf::
 	If true, makes Git check if converting `CRLF` is reversible when
diff --git a/Documentation/config/pack.txt b/Documentation/config/pack.txt
index edac75c..425c73a 100644
--- a/Documentation/config/pack.txt
+++ b/Documentation/config/pack.txt
@@ -105,6 +105,15 @@
 	true. You should not generally need to turn this off unless
 	you are debugging pack bitmaps.
 
+pack.useSparse::
+	When true, git will default to using the '--sparse' option in
+	'git pack-objects' when the '--revs' option is present. This
+	algorithm only walks trees that appear in paths that introduce new
+	objects. This can have significant performance benefits when
+	computing a pack to send a small change. However, it is possible
+	that extra objects are added to the pack-file if the included
+	commits contain certain types of direct renames.
+
 pack.writeBitmaps (deprecated)::
 	This is a deprecated synonym for `repack.writeBitmaps`.
 
diff --git a/Documentation/doc-diff b/Documentation/doc-diff
index dfd9418..32c83dd 100755
--- a/Documentation/doc-diff
+++ b/Documentation/doc-diff
@@ -39,8 +39,7 @@
 	shift
 done
 
-cd_to_toplevel
-tmp=Documentation/tmp-doc-diff
+tmp="$(git rev-parse --show-toplevel)/Documentation/tmp-doc-diff" || exit 1
 
 if test -n "$clean"
 then
@@ -109,7 +108,7 @@
 		make -j$parallel -C "$tmp/worktree" \
 			GIT_VERSION=omitted \
 			SOURCE_DATE_EPOCH=0 \
-			DESTDIR="$PWD/$tmp/installed/$1+" \
+			DESTDIR="$tmp/installed/$1+" \
 			install-man &&
 		mv "$tmp/installed/$1+" "$tmp/installed/$1"
 	fi &&
diff --git a/Documentation/git-add.txt b/Documentation/git-add.txt
index 45652fe..37bcab9 100644
--- a/Documentation/git-add.txt
+++ b/Documentation/git-add.txt
@@ -58,9 +58,9 @@
 	specifying `dir` will record not just a file `dir/file1`
 	modified in the working tree, a file `dir/file2` added to
 	the working tree, but also a file `dir/file3` removed from
-	the working tree.  Note that older versions of Git used
+	the working tree). Note that older versions of Git used
 	to ignore removed files; use `--no-all` option if you want
-	to add modified or new files but ignore removed	ones.
+	to add modified or new files but ignore removed ones.
 +
 For more details about the <pathspec> syntax, see the 'pathspec' entry
 in linkgit:gitglossary[7].
@@ -124,7 +124,7 @@
 --no-ignore-removal::
 	Update the index not only where the working tree has a file
 	matching <pathspec> but also where the index already has an
-	entry.	This adds, modifies, and removes index entries to
+	entry. This adds, modifies, and removes index entries to
 	match the working tree.
 +
 If no <pathspec> is given when `-A` option is used, all
@@ -206,7 +206,7 @@
 --------
 
 * Adds content from all `*.txt` files under `Documentation` directory
-and its subdirectories:
+  and its subdirectories:
 +
 ------------
 $ git add Documentation/\*.txt
diff --git a/Documentation/git-branch.txt b/Documentation/git-branch.txt
index bf5316f..3bd83a7 100644
--- a/Documentation/git-branch.txt
+++ b/Documentation/git-branch.txt
@@ -297,7 +297,7 @@
 ------------
 +
 <1> This step and the next one could be combined into a single step with
-"checkout -b my2.6.14 v2.6.14".
+    "checkout -b my2.6.14 v2.6.14".
 
 Delete an unneeded branch::
 +
@@ -309,10 +309,10 @@
 ------------
 +
 <1> Delete the remote-tracking branches "todo", "html" and "man". The next
-'fetch' or 'pull' will create them again unless you configure them not to.
-See linkgit:git-fetch[1].
+    'fetch' or 'pull' will create them again unless you configure them not to.
+    See linkgit:git-fetch[1].
 <2> Delete the "test" branch even if the "master" branch (or whichever branch
-is currently checked out) does not have all commits from the test branch.
+    is currently checked out) does not have all commits from the test branch.
 
 
 NOTES
diff --git a/Documentation/git-cat-file.txt b/Documentation/git-cat-file.txt
index 9a2e9cd..8eca671 100644
--- a/Documentation/git-cat-file.txt
+++ b/Documentation/git-cat-file.txt
@@ -252,6 +252,12 @@
 <object> SP missing LF
 ------------
 
+If a name is specified that might refer to more than one object (an ambiguous short sha), then `cat-file` will ignore any custom format and print:
+
+------------
+<object> SP ambiguous LF
+------------
+
 If --follow-symlinks is used, and a symlink in the repository points
 outside the repository, then `cat-file` will ignore any custom format
 and print:
diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index 6acc3d9..9a39649 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -424,14 +424,14 @@
 ------------
 
 <1> creates a new branch 'foo', which refers to commit 'f', and then
-updates HEAD to refer to branch 'foo'. In other words, we'll no longer
-be in detached HEAD state after this command.
+    updates HEAD to refer to branch 'foo'. In other words, we'll no longer
+    be in detached HEAD state after this command.
 
 <2> similarly creates a new branch 'foo', which refers to commit 'f',
-but leaves HEAD detached.
+    but leaves HEAD detached.
 
 <3> creates a new tag 'foo', which refers to commit 'f',
-leaving HEAD detached.
+    leaving HEAD detached.
 
 If we have moved away from commit 'f', then we must first recover its object
 name (typically by using git reflog), and then we can create a reference to
@@ -459,8 +459,8 @@
 --------
 
 . The following sequence checks out the `master` branch, reverts
-the `Makefile` to two revisions back, deletes hello.c by
-mistake, and gets it back from the index.
+  the `Makefile` to two revisions back, deletes hello.c by
+  mistake, and gets it back from the index.
 +
 ------------
 $ git checkout master             <1>
@@ -494,7 +494,7 @@
 ------------
 
 . After working in the wrong branch, switching to the correct
-branch would be done using:
+  branch would be done using:
 +
 ------------
 $ git checkout mytopic
@@ -522,7 +522,7 @@
 changes you made since the tip of the new branch.
 
 . When a merge conflict happens during switching branches with
-the `-m` option, you would see something like this:
+  the `-m` option, you would see something like this:
 +
 ------------
 $ git checkout -m mytopic
diff --git a/Documentation/git-cherry-pick.txt b/Documentation/git-cherry-pick.txt
index d35d771..b8cfeec 100644
--- a/Documentation/git-cherry-pick.txt
+++ b/Documentation/git-cherry-pick.txt
@@ -213,16 +213,16 @@
 $ git cherry-pick -Xpatience topic^  <4>
 ------------
 <1> apply the change that would be shown by `git show topic^`.
-In this example, the patch does not apply cleanly, so
-information about the conflict is written to the index and
-working tree and no new commit results.
+    In this example, the patch does not apply cleanly, so
+    information about the conflict is written to the index and
+    working tree and no new commit results.
 <2> summarize changes to be reconciled
 <3> cancel the cherry-pick.  In other words, return to the
-pre-cherry-pick state, preserving any local modifications you had in
-the working tree.
+    pre-cherry-pick state, preserving any local modifications
+    you had in the working tree.
 <4> try to apply the change introduced by `topic^` again,
-spending extra time to avoid mistakes based on incorrectly matching
-context lines.
+    spending extra time to avoid mistakes based on incorrectly
+    matching context lines.
 
 SEE ALSO
 --------
diff --git a/Documentation/git-commit.txt b/Documentation/git-commit.txt
index f970a43..a85c2c2 100644
--- a/Documentation/git-commit.txt
+++ b/Documentation/git-commit.txt
@@ -17,16 +17,20 @@
 
 DESCRIPTION
 -----------
-Stores the current contents of the index in a new commit along
-with a log message from the user describing the changes.
+Create a new commit containing the current contents of the index and
+the given log message describing the changes. The new commit is a
+direct child of HEAD, usually the tip of the current branch, and the
+branch is updated to point to it (unless no branch is associated with
+the working tree, in which case HEAD is "detached" as described in
+linkgit:git-checkout[1]).
 
-The content to be added can be specified in several ways:
+The content to be committed can be specified in several ways:
 
-1. by using 'git add' to incrementally "add" changes to the
-   index before using the 'commit' command (Note: even modified
-   files must be "added");
+1. by using linkgit:git-add[1] to incrementally "add" changes to the
+   index before using the 'commit' command (Note: even modified files
+   must be "added");
 
-2. by using 'git rm' to remove files from the working tree
+2. by using linkgit:git-rm[1] to remove files from the working tree
    and the index, again before using the 'commit' command;
 
 3. by listing files as arguments to the 'commit' command
diff --git a/Documentation/git-diff-tree.txt b/Documentation/git-diff-tree.txt
index 2319b2b..43daa7c 100644
--- a/Documentation/git-diff-tree.txt
+++ b/Documentation/git-diff-tree.txt
@@ -31,10 +31,7 @@
 
 <path>...::
 	If provided, the results are limited to a subset of files
-	matching one of these prefix strings.
-	i.e., file matches `/^<pattern1>|<pattern2>|.../`
-	Note that this parameter does not provide any wildcard or regexp
-	features.
+	matching one of the provided pathspecs.
 
 -r::
         recurse into sub-trees
@@ -114,52 +111,6 @@
 
 
 include::pretty-formats.txt[]
-
-
-LIMITING OUTPUT
----------------
-If you're only interested in differences in a subset of files, for
-example some architecture-specific files, you might do:
-
-	git diff-tree -r <tree-ish> <tree-ish> arch/ia64 include/asm-ia64
-
-and it will only show you what changed in those two directories.
-
-Or if you are searching for what changed in just `kernel/sched.c`, just do
-
-	git diff-tree -r <tree-ish> <tree-ish> kernel/sched.c
-
-and it will ignore all differences to other files.
-
-The pattern is always the prefix, and is matched exactly.  There are no
-wildcards.  Even stricter, it has to match a complete path component.
-I.e. "foo" does not pick up `foobar.h`.  "foo" does match `foo/bar.h`
-so it can be used to name subdirectories.
-
-An example of normal usage is:
-
-  torvalds@ppc970:~/git> git diff-tree --abbrev 5319e4
-  :100664 100664 ac348b... a01513...	git-fsck-objects.c
-
-which tells you that the last commit changed just one file (it's from
-this one:
-
------------------------------------------------------------------------------
-commit 3c6f7ca19ad4043e9e72fa94106f352897e651a8
-tree 5319e4d609cdd282069cc4dce33c1db559539b03
-parent b4e628ea30d5ab3606119d2ea5caeab141d38df7
-author Linus Torvalds <torvalds@ppc970.osdl.org> Sat Apr 9 12:02:30 2005
-committer Linus Torvalds <torvalds@ppc970.osdl.org> Sat Apr 9 12:02:30 2005
-
-Make "git-fsck-objects" print out all the root commits it finds.
-
-Once I do the reference tracking, I'll also make it print out all the
-HEAD commits it finds, which is even more interesting.
------------------------------------------------------------------------------
-
-in case you care).
-
-
 include::diff-format.txt[]
 
 GIT
diff --git a/Documentation/git-diff.txt b/Documentation/git-diff.txt
index 030f162..72179d9 100644
--- a/Documentation/git-diff.txt
+++ b/Documentation/git-diff.txt
@@ -132,9 +132,9 @@
 +
 <1> Changes in the working tree not yet staged for the next commit.
 <2> Changes between the index and your last commit; what you
-would be committing if you run "git commit" without "-a" option.
+    would be committing if you run "git commit" without "-a" option.
 <3> Changes in the working tree since your last commit; what you
-would be committing if you run "git commit -a"
+    would be committing if you run "git commit -a"
 
 Comparing with arbitrary commits::
 +
@@ -145,10 +145,10 @@
 ------------
 +
 <1> Instead of using the tip of the current branch, compare with the
-tip of "test" branch.
+    tip of "test" branch.
 <2> Instead of comparing with the tip of "test" branch, compare with
-the tip of the current branch, but limit the comparison to the
-file "test".
+    the tip of the current branch, but limit the comparison to the
+    file "test".
 <3> Compare the version before the last commit and the last commit.
 
 Comparing branches::
@@ -162,7 +162,7 @@
 <1> Changes between the tips of the topic and the master branches.
 <2> Same as above.
 <3> Changes that occurred on the master branch since when the topic
-branch was started off it.
+    branch was started off it.
 
 Limiting the diff output::
 +
@@ -173,9 +173,9 @@
 ------------
 +
 <1> Show only modification, rename, and copy, but not addition
-or deletion.
+    or deletion.
 <2> Show only names and the nature of change, but not actual
-diff output.
+    diff output.
 <3> Limit diff output to named subtrees.
 
 Munging the diff output::
@@ -186,7 +186,7 @@
 ------------
 +
 <1> Spend extra cycles to find renames, copies and complete
-rewrites (very expensive).
+    rewrites (very expensive).
 <2> Output diff in reverse.
 
 SEE ALSO
diff --git a/Documentation/git-fetch.txt b/Documentation/git-fetch.txt
index e319935..266d63c 100644
--- a/Documentation/git-fetch.txt
+++ b/Documentation/git-fetch.txt
@@ -266,7 +266,7 @@
 because it is prefixed with a plus sign; `tmp` will not be.
 
 * Peek at a remote's branch, without configuring the remote in your local
-repository:
+  repository:
 +
 ------------------------------------------------
 $ git fetch git://git.kernel.org/pub/scm/git/git.git maint
diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
index 2730442..1af85d4 100644
--- a/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@ -504,9 +504,9 @@
 "mailnews.wraplength" and set the value to 0.
 
 3. Disable the use of format=flowed:
-Edit..Preferences..Advanced..Config Editor.  Search for
-"mailnews.send_plaintext_flowed".
-Toggle it to make sure it is set to `false`.
+   Edit..Preferences..Advanced..Config Editor.  Search for
+   "mailnews.send_plaintext_flowed".
+   Toggle it to make sure it is set to `false`.
 
 After that is done, you should be able to compose email as you
 otherwise would (cut + paste, 'git format-patch' | 'git imap-send', etc),
@@ -629,14 +629,14 @@
 --------
 
 * Extract commits between revisions R1 and R2, and apply them on top of
-the current branch using 'git am' to cherry-pick them:
+  the current branch using 'git am' to cherry-pick them:
 +
 ------------
 $ git format-patch -k --stdout R1..R2 | git am -3 -k
 ------------
 
 * Extract all commits which are in the current branch but not in the
-origin branch:
+  origin branch:
 +
 ------------
 $ git format-patch origin
@@ -645,7 +645,7 @@
 For each commit a separate file is created in the current directory.
 
 * Extract all commits that lead to 'origin' since the inception of the
-project:
+  project:
 +
 ------------
 $ git format-patch --root origin
@@ -664,7 +664,7 @@
 use it only when you know the recipient uses Git to apply your patch.
 
 * Extract three topmost commits from the current branch and format them
-as e-mailable patches:
+  as e-mailable patches:
 +
 ------------
 $ git format-patch -3
diff --git a/Documentation/git-fsck.txt b/Documentation/git-fsck.txt
index ab9a93f..55950d9 100644
--- a/Documentation/git-fsck.txt
+++ b/Documentation/git-fsck.txt
@@ -140,9 +140,9 @@
 	The <type> object <object>, is present in the database but never
 	'directly' used. A dangling commit could be a root node.
 
-sha1 mismatch <object>::
-	The database has an object who's sha1 doesn't match the
-	database value.
+hash mismatch <object>::
+	The database has an object whose hash doesn't match the
+	object database value.
 	This indicates a serious data integrity problem.
 
 Environment Variables
diff --git a/Documentation/git-help.txt b/Documentation/git-help.txt
index aab5453..c318bf8 100644
--- a/Documentation/git-help.txt
+++ b/Documentation/git-help.txt
@@ -118,9 +118,9 @@
 
 * "man": use the 'man' program as usual,
 * "woman": use 'emacsclient' to launch the "woman" mode in emacs
-(this only works starting with emacsclient versions 22),
+  (this only works starting with emacsclient versions 22),
 * "konqueror": use 'kfmclient' to open the man page in a new konqueror
-tab (see 'Note about konqueror' below).
+  tab (see 'Note about konqueror' below).
 
 Values for other tools can be used if there is a corresponding
 `man.<tool>.cmd` configuration entry (see below).
diff --git a/Documentation/git-init.txt b/Documentation/git-init.txt
index 057076c..32880aa 100644
--- a/Documentation/git-init.txt
+++ b/Documentation/git-init.txt
@@ -128,7 +128,7 @@
 The default template directory includes some directory structure, suggested
 "exclude patterns" (see linkgit:gitignore[5]), and sample hook files.
 
-The sample hooks are all disabled by default, To enable one of the
+The sample hooks are all disabled by default. To enable one of the
 sample hooks rename it by removing its `.sample` suffix.
 
 See linkgit:githooks[5] for more general info on hook execution.
diff --git a/Documentation/git-instaweb.txt b/Documentation/git-instaweb.txt
index e8ecdbf..a54fe44 100644
--- a/Documentation/git-instaweb.txt
+++ b/Documentation/git-instaweb.txt
@@ -29,7 +29,8 @@
 	The HTTP daemon command-line that will be executed.
 	Command-line options may be specified here, and the
 	configuration file will be added at the end of the command-line.
-	Currently apache2, lighttpd, mongoose, plackup and webrick are supported.
+	Currently apache2, lighttpd, mongoose, plackup, python and
+	webrick are supported.
 	(Default: lighttpd)
 
 -m::
diff --git a/Documentation/git-log.txt b/Documentation/git-log.txt
index 90761f1..b02e922 100644
--- a/Documentation/git-log.txt
+++ b/Documentation/git-log.txt
@@ -192,6 +192,10 @@
 	Default format for human-readable dates.  (Compare the
 	`--date` option.)  Defaults to "default", which means to write
 	dates like `Sat May 8 19:35:34 2010 -0500`.
++
+If the format is set to "auto:foo" and the pager is in use, format
+"foo" will be the used for the date format. Otherwise "default" will
+be used.
 
 log.follow::
 	If `true`, `git log` will act as if the `--follow` option was used when
diff --git a/Documentation/git-p4.txt b/Documentation/git-p4.txt
index f0a0280..3494a1d 100644
--- a/Documentation/git-p4.txt
+++ b/Documentation/git-p4.txt
@@ -71,12 +71,12 @@
 ------------
 This:
 
-1.   Creates an empty Git repository in a subdirectory called 'project'.
+1. Creates an empty Git repository in a subdirectory called 'project'.
 +
-2.   Imports the full contents of the head revision from the given p4
-depot path into a single commit in the Git branch 'refs/remotes/p4/master'.
+2. Imports the full contents of the head revision from the given p4
+   depot path into a single commit in the Git branch 'refs/remotes/p4/master'.
 +
-3.   Creates a local branch, 'master' from this remote and checks it out.
+3. Creates a local branch, 'master' from this remote and checks it out.
 
 To reproduce the entire p4 history in Git, use the '@all' modifier on
 the depot path:
diff --git a/Documentation/git-pack-objects.txt b/Documentation/git-pack-objects.txt
index 40c825c..e45f3e6 100644
--- a/Documentation/git-pack-objects.txt
+++ b/Documentation/git-pack-objects.txt
@@ -14,7 +14,7 @@
 	[--local] [--incremental] [--window=<n>] [--depth=<n>]
 	[--revs [--unpacked | --all]] [--keep-pack=<pack-name>]
 	[--stdout [--filter=<filter-spec>] | base-name]
-	[--shallow] [--keep-true-parents] < object-list
+	[--shallow] [--keep-true-parents] [--sparse] < object-list
 
 
 DESCRIPTION
@@ -196,6 +196,15 @@
 	Add --no-reuse-object if you want to force a uniform compression
 	level on all data no matter the source.
 
+--sparse::
+	Use the "sparse" algorithm to determine which objects to include in
+	the pack, when combined with the "--revs" option. This algorithm
+	only walks trees that appear in paths that introduce new objects.
+	This can have significant performance benefits when computing
+	a pack to send a small change. However, it is possible that extra
+	objects are added to the pack-file if the included commits contain
+	certain types of direct renames.
+
 --thin::
 	Create a "thin" pack by omitting the common objects between a
 	sender and a receiver in order to reduce network transfer. This
diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index 4dd5853..7e695b3 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -515,15 +515,7 @@
 INCOMPATIBLE OPTIONS
 --------------------
 
-git-rebase has many flags that are incompatible with each other,
-predominantly due to the fact that it has three different underlying
-implementations:
-
- * one based on linkgit:git-am[1] (the default)
- * one based on git-merge-recursive (merge backend)
- * one based on linkgit:git-cherry-pick[1] (interactive backend)
-
-Flags only understood by the am backend:
+The following options:
 
  * --committer-date-is-author-date
  * --ignore-date
@@ -531,15 +523,12 @@
  * --ignore-whitespace
  * -C
 
-Flags understood by both merge and interactive backends:
+are incompatible with the following options:
 
  * --merge
  * --strategy
  * --strategy-option
  * --allow-empty-message
-
-Flags only understood by the interactive backend:
-
  * --[no-]autosquash
  * --rebase-merges
  * --preserve-merges
@@ -550,7 +539,7 @@
  * --edit-todo
  * --root when used in combination with --onto
 
-Other incompatible flag pairs:
+In addition, the following pairs of options are incompatible:
 
  * --preserve-merges and --interactive
  * --preserve-merges and --signoff
diff --git a/Documentation/git-reset.txt b/Documentation/git-reset.txt
index 9f69ae8..132f8e5 100644
--- a/Documentation/git-reset.txt
+++ b/Documentation/git-reset.txt
@@ -115,17 +115,17 @@
 ------------
 +
 <1> You are happily working on something, and find the changes
-in these files are in good order.  You do not want to see them
-when you run `git diff`, because you plan to work on other files
-and changes with these files are distracting.
+    in these files are in good order.  You do not want to see them
+    when you run `git diff`, because you plan to work on other files
+    and changes with these files are distracting.
 <2> Somebody asks you to pull, and the changes sound worthy of merging.
 <3> However, you already dirtied the index (i.e. your index does
-not match the `HEAD` commit).  But you know the pull you are going
-to make does not affect `frotz.c` or `filfre.c`, so you revert the
-index changes for these two files.  Your changes in working tree
-remain there.
+    not match the `HEAD` commit).  But you know the pull you are going
+    to make does not affect `frotz.c` or `filfre.c`, so you revert the
+    index changes for these two files.  Your changes in working tree
+    remain there.
 <4> Then you can pull and merge, leaving `frotz.c` and `filfre.c`
-changes still in the working tree.
+    changes still in the working tree.
 
 Undo a commit and redo::
 +
@@ -137,12 +137,12 @@
 ------------
 +
 <1> This is most often done when you remembered what you
-just committed is incomplete, or you misspelled your commit
-message, or both.  Leaves working tree as it was before "reset".
+    just committed is incomplete, or you misspelled your commit
+    message, or both.  Leaves working tree as it was before "reset".
 <2> Make corrections to working tree files.
 <3> "reset" copies the old head to `.git/ORIG_HEAD`; redo the
-commit by starting with its log message.  If you do not need to
-edit the message further, you can give `-C` option instead.
+    commit by starting with its log message.  If you do not need to
+    edit the message further, you can give `-C` option instead.
 +
 See also the `--amend` option to linkgit:git-commit[1].
 
@@ -155,9 +155,9 @@
 ------------
 +
 <1> You have made some commits, but realize they were premature
-to be in the `master` branch.  You want to continue polishing
-them in a topic branch, so create `topic/wip` branch off of the
-current `HEAD`.
+    to be in the `master` branch.  You want to continue polishing
+    them in a topic branch, so create `topic/wip` branch off of the
+    current `HEAD`.
 <2> Rewind the master branch to get rid of those three commits.
 <3> Switch to `topic/wip` branch and keep working.
 
@@ -169,10 +169,10 @@
 ------------
 +
 <1> The last three commits (`HEAD`, `HEAD^`, and `HEAD~2`) were bad
-and you do not want to ever see them again.  Do *not* do this if
-you have already given these commits to somebody else.  (See the
-"RECOVERING FROM UPSTREAM REBASE" section in linkgit:git-rebase[1] for
-the implications of doing so.)
+    and you do not want to ever see them again.  Do *not* do this if
+    you have already given these commits to somebody else.  (See the
+    "RECOVERING FROM UPSTREAM REBASE" section in linkgit:git-rebase[1]
+    for the implications of doing so.)
 
 Undo a merge or pull::
 +
@@ -189,18 +189,18 @@
 ------------
 +
 <1> Try to update from the upstream resulted in a lot of
-conflicts; you were not ready to spend a lot of time merging
-right now, so you decide to do that later.
+    conflicts; you were not ready to spend a lot of time merging
+    right now, so you decide to do that later.
 <2> "pull" has not made merge commit, so `git reset --hard`
-which is a synonym for `git reset --hard HEAD` clears the mess
-from the index file and the working tree.
+    which is a synonym for `git reset --hard HEAD` clears the mess
+    from the index file and the working tree.
 <3> Merge a topic branch into the current branch, which resulted
-in a fast-forward.
+    in a fast-forward.
 <4> But you decided that the topic branch is not ready for public
-consumption yet.  "pull" or "merge" always leaves the original
-tip of the current branch in `ORIG_HEAD`, so resetting hard to it
-brings your index file and the working tree back to that state,
-and resets the tip of the branch to that commit.
+    consumption yet.  "pull" or "merge" always leaves the original
+    tip of the current branch in `ORIG_HEAD`, so resetting hard to it
+    brings your index file and the working tree back to that state,
+    and resets the tip of the branch to that commit.
 
 Undo a merge or pull inside a dirty working tree::
 +
@@ -214,14 +214,14 @@
 ------------
 +
 <1> Even if you may have local modifications in your
-working tree, you can safely say `git pull` when you know
-that the change in the other branch does not overlap with
-them.
+    working tree, you can safely say `git pull` when you know
+    that the change in the other branch does not overlap with
+    them.
 <2> After inspecting the result of the merge, you may find
-that the change in the other branch is unsatisfactory.  Running
-`git reset --hard ORIG_HEAD` will let you go back to where you
-were, but it will discard your local changes, which you do not
-want.  `git reset --merge` keeps your local changes.
+    that the change in the other branch is unsatisfactory.  Running
+    `git reset --hard ORIG_HEAD` will let you go back to where you
+    were, but it will discard your local changes, which you do not
+    want.  `git reset --merge` keeps your local changes.
 
 
 Interrupted workflow::
diff --git a/Documentation/git-send-email.txt b/Documentation/git-send-email.txt
index 62c6c76..1afe9fc 100644
--- a/Documentation/git-send-email.txt
+++ b/Documentation/git-send-email.txt
@@ -33,7 +33,7 @@
 formatting are ignored.
 
 2. The original format used by Greg Kroah-Hartman's 'send_lots_of_email.pl'
-script
+   script
 +
 This format expects the first line of the file to contain the "Cc:" value
 and the "Subject:" of the message as the second line.
diff --git a/Documentation/git-tag.txt b/Documentation/git-tag.txt
index f2d644e..a74e7b9 100644
--- a/Documentation/git-tag.txt
+++ b/Documentation/git-tag.txt
@@ -237,16 +237,16 @@
 the old tag. In that case you can do one of two things:
 
 . The sane thing.
-Just admit you screwed up, and use a different name. Others have
-already seen one tag-name, and if you keep the same name, you
-may be in the situation that two people both have "version X",
-but they actually have 'different' "X"'s.  So just call it "X.1"
-and be done with it.
+  Just admit you screwed up, and use a different name. Others have
+  already seen one tag-name, and if you keep the same name, you
+  may be in the situation that two people both have "version X",
+  but they actually have 'different' "X"'s.  So just call it "X.1"
+  and be done with it.
 
 . The insane thing.
-You really want to call the new version "X" too, 'even though'
-others have already seen the old one. So just use 'git tag -f'
-again, as if you hadn't already published the old one.
+  You really want to call the new version "X" too, 'even though'
+  others have already seen the old one. So just use 'git tag -f'
+  again, as if you hadn't already published the old one.
 
 However, Git does *not* (and it should not) change tags behind
 users back. So if somebody already got the old tag, doing a
diff --git a/Documentation/git-upload-pack.txt b/Documentation/git-upload-pack.txt
index 998f52d..9822c1e 100644
--- a/Documentation/git-upload-pack.txt
+++ b/Documentation/git-upload-pack.txt
@@ -22,7 +22,6 @@
 program pair is meant to be used to pull updates from a remote
 repository.  For push operations, see 'git send-pack'.
 
-
 OPTIONS
 -------
 
diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt
index b8392fc..9b41f81 100644
--- a/Documentation/gitattributes.txt
+++ b/Documentation/gitattributes.txt
@@ -124,7 +124,9 @@
 repository.  To control what line ending style is used in the working
 directory, use the `eol` attribute for a single file and the
 `core.eol` configuration variable for all text files.
-Note that `core.autocrlf` overrides `core.eol`
+Note that setting `core.autocrlf` to `true` or `input` overrides
+`core.eol` (see the definitions of those options in
+linkgit:git-config[1]).
 
 Set::
 
@@ -344,7 +346,9 @@
 
 Use the following attributes if your '*.ps1' files are UTF-16 little
 endian encoded without BOM and you want Git to use Windows line endings
-in the working directory. Please note, it is highly recommended to
+in the working directory (use `UTF-16-LE-BOM` instead of `UTF-16LE` if
+you want UTF-16 little endian with BOM).
+Please note, it is highly recommended to
 explicitly define the line endings with `eol` if the `working-tree-encoding`
 attribute is used to avoid ambiguity.
 
diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt
index 91b3a72..cad711c 100644
--- a/Documentation/rev-list-options.txt
+++ b/Documentation/rev-list-options.txt
@@ -270,13 +270,13 @@
 +
 --
 1. If the starting point is specified as `ref@{Nth}`, show the index
-format.
+   format.
 +
 2. If the starting point was specified as `ref@{now}`, show the
-timestamp format.
+   timestamp format.
 +
 3. If neither was used, but `--date` was given on the command line, show
-the timestamp in the format requested by `--date`.
+   the timestamp in the format requested by `--date`.
 +
 4. Otherwise, show the index format.
 --
@@ -836,6 +836,13 @@
 value (which is always measured in UTC), but does switch the accompanying
 timezone value.
 +
+`--date=human` shows the timezone if the timezone does not match the
+current time-zone, and doesn't print the whole date if that matches
+(ie skip printing year for dates that are "this year", but also skip
+the whole date itself if it's in the last few days and we can just say
+what weekday it was).  For older dates the hour and minute is also
+omitted.
++
 `--date=unix` shows the date as a Unix epoch timestamp (seconds since
 1970).  As with `--raw`, this is always in UTC and therefore `-local`
 has no effect.
diff --git a/Documentation/technical/commit-graph-format.txt b/Documentation/technical/commit-graph-format.txt
index cc0474b..16452a0 100644
--- a/Documentation/technical/commit-graph-format.txt
+++ b/Documentation/technical/commit-graph-format.txt
@@ -76,7 +76,7 @@
       of the ith commit. Stores value 0x7000000 if no parent in that
       position. If there are more than two parents, the second value
       has its most-significant bit on and the other bits store an array
-      position into the Large Edge List chunk.
+      position into the Extra Edge List chunk.
     * The next 8 bytes store the generation number of the commit and
       the commit time in seconds since EPOCH. The generation number
       uses the higher 30 bits of the first 4 bytes, while the commit
@@ -84,7 +84,7 @@
       2 bits of the lowest byte, storing the 33rd and 34th bit of the
       commit time.
 
-  Large Edge List (ID: {'E', 'D', 'G', 'E'}) [Optional]
+  Extra Edge List (ID: {'E', 'D', 'G', 'E'}) [Optional]
       This list of 4-byte values store the second through nth parents for
       all octopus merges. The second parent value in the commit data stores
       an array position within this list along with the most-significant bit
diff --git a/GIT-VERSION-GEN b/GIT-VERSION-GEN
index 0a3ccac..1d4886b 100755
--- a/GIT-VERSION-GEN
+++ b/GIT-VERSION-GEN
@@ -1,7 +1,7 @@
 #!/bin/sh
 
 GVF=GIT-VERSION-FILE
-DEF_VER=v2.20.GIT
+DEF_VER=v2.21.0-rc0
 
 LF='
 '
diff --git a/Makefile b/Makefile
index 28ee179..0e13a5b 100644
--- a/Makefile
+++ b/Makefile
@@ -574,7 +574,11 @@
 
 export TCL_PATH TCLTK_PATH
 
-SPARSE_FLAGS =
+# user customisation variable for 'sparse' target
+SPARSE_FLAGS ?=
+# internal/platform customisation variable for 'sparse'
+SP_EXTRA_FLAGS =
+
 SPATCH_FLAGS = --all-includes --patch .
 
 
@@ -634,7 +638,6 @@
 SCRIPT_LIB += git-rebase--am
 SCRIPT_LIB += git-rebase--common
 SCRIPT_LIB += git-rebase--preserve-merges
-SCRIPT_LIB += git-rebase--merge
 SCRIPT_LIB += git-sh-setup
 SCRIPT_LIB += git-sh-i18n
 
@@ -764,6 +767,7 @@
 TEST_BUILTINS_OBJS += test-submodule-nested-repo-config.o
 TEST_BUILTINS_OBJS += test-subprocess.o
 TEST_BUILTINS_OBJS += test-urlmatch-normalization.o
+TEST_BUILTINS_OBJS += test-xml-encode.o
 TEST_BUILTINS_OBJS += test-wildmatch.o
 TEST_BUILTINS_OBJS += test-windows-named-pipe.o
 TEST_BUILTINS_OBJS += test-write-cache.o
@@ -2370,10 +2374,10 @@
 gettext.sp gettext.s gettext.o: EXTRA_CPPFLAGS = \
 	-DGIT_LOCALE_PATH='"$(localedir_relative_SQ)"'
 
-http-push.sp http.sp http-walker.sp remote-curl.sp imap-send.sp: SPARSE_FLAGS += \
+http-push.sp http.sp http-walker.sp remote-curl.sp imap-send.sp: SP_EXTRA_FLAGS += \
 	-DCURL_DISABLE_TYPECHECK
 
-pack-revindex.sp: SPARSE_FLAGS += -Wno-memcpy-max-count
+pack-revindex.sp: SP_EXTRA_FLAGS += -Wno-memcpy-max-count
 
 ifdef NO_EXPAT
 http-walker.sp http-walker.s http-walker.o: EXTRA_CPPFLAGS = -DNO_EXPAT
@@ -2387,7 +2391,7 @@
 ifdef USE_NED_ALLOCATOR
 compat/nedmalloc/nedmalloc.sp compat/nedmalloc/nedmalloc.o: EXTRA_CPPFLAGS = \
 	-DNDEBUG -DREPLACE_SYSTEM_ALLOCATOR
-compat/nedmalloc/nedmalloc.sp: SPARSE_FLAGS += -Wno-non-pointer-null
+compat/nedmalloc/nedmalloc.sp: SP_EXTRA_FLAGS += -Wno-non-pointer-null
 endif
 
 git-%$X: %.o GIT-LDFLAGS $(GITLIBS)
@@ -2711,7 +2715,7 @@
 
 $(SP_OBJ): %.sp: %.c GIT-CFLAGS FORCE
 	$(QUIET_SP)cgcc -no-compile $(ALL_CFLAGS) $(EXTRA_CPPFLAGS) \
-		$(SPARSE_FLAGS) $<
+		$(SPARSE_FLAGS) $(SP_EXTRA_FLAGS) $<
 
 .PHONY: sparse $(SP_OBJ)
 sparse: $(SP_OBJ)
@@ -2949,6 +2953,16 @@
 	@false
 .PHONY: rpm
 
+artifacts-tar:: $(ALL_PROGRAMS) $(SCRIPT_LIB) $(BUILT_INS) $(OTHER_PROGRAMS) \
+		GIT-BUILD-OPTIONS $(TEST_PROGRAMS) $(test_bindir_programs) \
+		$(NO_INSTALL) $(MOFILES)
+	$(QUIET_SUBDIR0)templates $(QUIET_SUBDIR1) \
+		SHELL_PATH='$(SHELL_PATH_SQ)' PERL_PATH='$(PERL_PATH_SQ)'
+	test -n "$(ARTIFACTS_DIRECTORY)"
+	mkdir -p "$(ARTIFACTS_DIRECTORY)"
+	$(TAR) czf "$(ARTIFACTS_DIRECTORY)/artifacts.tar.gz" $^ templates/blt/
+.PHONY: artifacts-tar
+
 htmldocs = git-htmldocs-$(GIT_VERSION)
 manpages = git-manpages-$(GIT_VERSION)
 .PHONY: dist-doc distclean
@@ -3100,6 +3114,11 @@
 	$(MAKE) CFLAGS="$(COVERAGE_CFLAGS)" LDFLAGS="$(COVERAGE_LDFLAGS)" \
 		DEFAULT_TEST_TARGET=test -j1 test
 
+coverage-prove: coverage-clean-results coverage-compile
+	$(MAKE) CFLAGS="$(COVERAGE_CFLAGS)" LDFLAGS="$(COVERAGE_LDFLAGS)" \
+		DEFAULT_TEST_TARGET=prove GIT_PROVE_OPTS="$(GIT_PROVE_OPTS) -j1" \
+		-j1 test
+
 coverage-report:
 	$(QUIET_GCOV)for dir in $(object_dirs); do \
 		$(GCOV) $(GCOVFLAGS) --object-directory=$$dir $$dir*.c || exit; \
diff --git a/README.md b/README.md
index f920a42..764c480 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,5 @@
+[![Build Status](https://dev.azure.com/git/git/_apis/build/status/test-git.git)](https://dev.azure.com/git/git/_build/latest?definitionId=2)
+
 Git - fast, scalable, distributed revision control system
 =========================================================
 
diff --git a/alloc.c b/alloc.c
index e7aa81b..1c64c4d 100644
--- a/alloc.c
+++ b/alloc.c
@@ -99,18 +99,23 @@
 	return obj;
 }
 
-unsigned int alloc_commit_index(struct repository *r)
+static unsigned int alloc_commit_index(struct repository *r)
 {
 	return r->parsed_objects->commit_count++;
 }
 
+void init_commit_node(struct repository *r, struct commit *c)
+{
+	c->object.type = OBJ_COMMIT;
+	c->index = alloc_commit_index(r);
+	c->graph_pos = COMMIT_NOT_FROM_GRAPH;
+	c->generation = GENERATION_NUMBER_INFINITY;
+}
+
 void *alloc_commit_node(struct repository *r)
 {
 	struct commit *c = alloc_node(r->parsed_objects->commit_state, sizeof(struct commit));
-	c->object.type = OBJ_COMMIT;
-	c->index = alloc_commit_index(r);
-	c->graph_pos = COMMIT_NOT_FROM_GRAPH;
-	c->generation = GENERATION_NUMBER_INFINITY;
+	init_commit_node(r, c);
 	return c;
 }
 
diff --git a/alloc.h b/alloc.h
index ba356ed..ed1071c 100644
--- a/alloc.h
+++ b/alloc.h
@@ -9,11 +9,11 @@
 
 void *alloc_blob_node(struct repository *r);
 void *alloc_tree_node(struct repository *r);
+void init_commit_node(struct repository *r, struct commit *c);
 void *alloc_commit_node(struct repository *r);
 void *alloc_tag_node(struct repository *r);
 void *alloc_object_node(struct repository *r);
 void alloc_report(struct repository *r);
-unsigned int alloc_commit_index(struct repository *r);
 
 struct alloc_state *allocate_alloc_state(void);
 void clear_alloc_state(struct alloc_state *s);
diff --git a/apply.c b/apply.c
index 3703bfc..892ede5 100644
--- a/apply.c
+++ b/apply.c
@@ -467,7 +467,6 @@
 
 static char *find_name_gnu(struct apply_state *state,
 			   const char *line,
-			   const char *def,
 			   int p_value)
 {
 	struct strbuf name = STRBUF_INIT;
@@ -714,7 +713,7 @@
 		       int terminate)
 {
 	if (*line == '"') {
-		char *name = find_name_gnu(state, line, def, p_value);
+		char *name = find_name_gnu(state, line, p_value);
 		if (name)
 			return name;
 	}
@@ -731,7 +730,7 @@
 	size_t date_len;
 
 	if (*line == '"') {
-		char *name = find_name_gnu(state, line, def, p_value);
+		char *name = find_name_gnu(state, line, p_value);
 		if (name)
 			return name;
 	}
@@ -3183,7 +3182,7 @@
 		return 0; /* deletion patch */
 	}
 
-	if (has_sha1_file(oid.hash)) {
+	if (has_object_file(&oid)) {
 		/* We already have the postimage */
 		enum object_type type;
 		unsigned long size;
@@ -4020,7 +4019,7 @@
 		return read_index_from(state->repo->index, state->index_file,
 				       get_git_dir());
 	else
-		return read_index(state->repo->index);
+		return repo_read_index(state->repo);
 }
 
 /* This function tries to read the object name from the current index */
@@ -4713,7 +4712,8 @@
 						  state->index_file,
 						  LOCK_DIE_ON_ERROR);
 		else
-			hold_locked_index(&state->lock_file, LOCK_DIE_ON_ERROR);
+			repo_hold_locked_index(state->repo, &state->lock_file,
+					       LOCK_DIE_ON_ERROR);
 	}
 
 	if (state->check_index && read_apply_cache(state) < 0) {
diff --git a/attr.c b/attr.c
index b63fe0f..fdd110b 100644
--- a/attr.c
+++ b/attr.c
@@ -7,7 +7,6 @@
  * an insanely large number of attributes.
  */
 
-#define NO_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "exec-cmd.h"
@@ -1092,7 +1091,7 @@
 			       const char *path,
 			       struct attr_check *check)
 {
-	int i, pathlen, rem, dirlen;
+	int pathlen, rem, dirlen;
 	const char *cp, *last_slash = NULL;
 	int basename_offset;
 
@@ -1113,20 +1112,6 @@
 	all_attrs_init(&g_attr_hashmap, check);
 	determine_macros(check->all_attrs, check->stack);
 
-	if (check->nr) {
-		rem = 0;
-		for (i = 0; i < check->nr; i++) {
-			int n = check->items[i].attr->attr_nr;
-			struct all_attrs_item *item = &check->all_attrs[n];
-			if (item->macro) {
-				item->value = ATTR__UNSET;
-				rem++;
-			}
-		}
-		if (rem == check->nr)
-			return;
-	}
-
 	rem = check->all_attrs_nr;
 	fill(path, pathlen, basename_offset, check->stack, check->all_attrs, rem);
 }
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
new file mode 100644
index 0000000..c329b72
--- /dev/null
+++ b/azure-pipelines.yml
@@ -0,0 +1,387 @@
+resources:
+- repo: self
+  fetchDepth: 1
+
+jobs:
+- job: windows_build
+  displayName: Windows Build
+  condition: succeeded()
+  pool: Hosted
+  timeoutInMinutes: 240
+  steps:
+  - powershell: |
+      if ("$GITFILESHAREPWD" -ne "" -and "$GITFILESHAREPWD" -ne "`$`(gitfileshare.pwd)") {
+        net use s: \\gitfileshare.file.core.windows.net\test-cache "$GITFILESHAREPWD" /user:AZURE\gitfileshare /persistent:no
+        cmd /c mklink /d "$(Build.SourcesDirectory)\test-cache" S:\
+      }
+    displayName: 'Mount test-cache'
+    env:
+      GITFILESHAREPWD: $(gitfileshare.pwd)
+  - powershell: |
+      $urlbase = "https://dev.azure.com/git-for-windows/git/_apis/build/builds"
+      $id = ((Invoke-WebRequest -UseBasicParsing "${urlbase}?definitions=22&statusFilter=completed&resultFilter=succeeded&`$top=1").content | ConvertFrom-JSON).value[0].id
+      $downloadUrl = ((Invoke-WebRequest -UseBasicParsing "${urlbase}/$id/artifacts").content | ConvertFrom-JSON).value[1].resource.downloadUrl
+      (New-Object Net.WebClient).DownloadFile($downloadUrl,"git-sdk-64-minimal.zip")
+      Expand-Archive git-sdk-64-minimal.zip -DestinationPath . -Force
+      Remove-Item git-sdk-64-minimal.zip
+
+      # Let Git ignore the SDK and the test-cache
+      "/git-sdk-64-minimal/`n/test-cache/`n" | Out-File -NoNewLine -Encoding ascii -Append "$(Build.SourcesDirectory)\.git\info\exclude"
+    displayName: 'Download git-sdk-64-minimal'
+  - powershell: |
+      & git-sdk-64-minimal\usr\bin\bash.exe -lc @"
+        ci/make-test-artifacts.sh artifacts
+      "@
+      if (!$?) { exit(1) }
+    displayName: Build
+    env:
+      HOME: $(Build.SourcesDirectory)
+      MSYSTEM: MINGW64
+      DEVELOPER: 1
+      NO_PERL: 1
+  - task: PublishPipelineArtifact@0
+    displayName: 'Publish Pipeline Artifact: test artifacts'
+    inputs:
+      artifactName: 'windows-artifacts'
+      targetPath: '$(Build.SourcesDirectory)\artifacts'
+  - task: PublishPipelineArtifact@0
+    displayName: 'Publish Pipeline Artifact: git-sdk-64-minimal'
+    inputs:
+      artifactName: 'git-sdk-64-minimal'
+      targetPath: '$(Build.SourcesDirectory)\git-sdk-64-minimal'
+  - powershell: |
+      if ("$GITFILESHAREPWD" -ne "" -and "$GITFILESHAREPWD" -ne "`$`(gitfileshare.pwd)") {
+        cmd /c rmdir "$(Build.SourcesDirectory)\test-cache"
+      }
+    displayName: 'Unmount test-cache'
+    condition: true
+    env:
+      GITFILESHAREPWD: $(gitfileshare.pwd)
+
+- job: windows_test
+  displayName: Windows Test
+  dependsOn: windows_build
+  condition: succeeded()
+  pool: Hosted
+  timeoutInMinutes: 240
+  strategy:
+    parallel: 10
+  steps:
+  - powershell: |
+      if ("$GITFILESHAREPWD" -ne "" -and "$GITFILESHAREPWD" -ne "`$`(gitfileshare.pwd)") {
+        net use s: \\gitfileshare.file.core.windows.net\test-cache "$GITFILESHAREPWD" /user:AZURE\gitfileshare /persistent:no
+        cmd /c mklink /d "$(Build.SourcesDirectory)\test-cache" S:\
+      }
+    displayName: 'Mount test-cache'
+    env:
+      GITFILESHAREPWD: $(gitfileshare.pwd)
+  - task: DownloadPipelineArtifact@0
+    displayName: 'Download Pipeline Artifact: test artifacts'
+    inputs:
+      artifactName: 'windows-artifacts'
+      targetPath: '$(Build.SourcesDirectory)'
+  - task: DownloadPipelineArtifact@0
+    displayName: 'Download Pipeline Artifact: git-sdk-64-minimal'
+    inputs:
+      artifactName: 'git-sdk-64-minimal'
+      targetPath: '$(Build.SourcesDirectory)\git-sdk-64-minimal'
+  - powershell: |
+      & git-sdk-64-minimal\usr\bin\bash.exe -lc @"
+        test -f artifacts.tar.gz || {
+          echo No test artifacts found\; skipping >&2
+          exit 0
+        }
+        tar xf artifacts.tar.gz || exit 1
+
+        # Let Git ignore the SDK and the test-cache
+        printf '%s\n' /git-sdk-64-minimal/ /test-cache/ >>.git/info/exclude
+
+        ci/run-test-slice.sh `$SYSTEM_JOBPOSITIONINPHASE `$SYSTEM_TOTALJOBSINPHASE || {
+          ci/print-test-failures.sh
+          exit 1
+        }
+      "@
+      if (!$?) { exit(1) }
+    displayName: 'Test (parallel)'
+    env:
+      HOME: $(Build.SourcesDirectory)
+      MSYSTEM: MINGW64
+      NO_SVN_TESTS: 1
+      GIT_TEST_SKIP_REBASE_P: 1
+  - powershell: |
+      if ("$GITFILESHAREPWD" -ne "" -and "$GITFILESHAREPWD" -ne "`$`(gitfileshare.pwd)") {
+        cmd /c rmdir "$(Build.SourcesDirectory)\test-cache"
+      }
+    displayName: 'Unmount test-cache'
+    condition: true
+    env:
+      GITFILESHAREPWD: $(gitfileshare.pwd)
+  - task: PublishTestResults@2
+    displayName: 'Publish Test Results **/TEST-*.xml'
+    inputs:
+      mergeTestResults: true
+      testRunTitle: 'windows'
+      platform: Windows
+      publishRunAttachments: false
+    condition: succeededOrFailed()
+  - task: PublishBuildArtifacts@1
+    displayName: 'Publish trash directories of failed tests'
+    condition: failed()
+    inputs:
+      PathtoPublish: t/failed-test-artifacts
+      ArtifactName: failed-test-artifacts
+
+- job: linux_clang
+  displayName: linux-clang
+  condition: succeeded()
+  pool: Hosted Ubuntu 1604
+  steps:
+  - bash: |
+       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || ci/mount-fileshare.sh //gitfileshare.file.core.windows.net/test-cache gitfileshare "$GITFILESHAREPWD" "$HOME/test-cache" || exit 1
+
+       sudo apt-get update &&
+       sudo apt-get -y install git gcc make libssl-dev libcurl4-openssl-dev libexpat-dev tcl tk gettext git-email zlib1g-dev apache2-bin &&
+
+       export CC=clang || exit 1
+
+       ci/install-dependencies.sh || exit 1
+       ci/run-build-and-tests.sh || {
+           ci/print-test-failures.sh
+           exit 1
+       }
+
+       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || sudo umount "$HOME/test-cache" || exit 1
+    displayName: 'ci/run-build-and-tests.sh'
+    env:
+      GITFILESHAREPWD: $(gitfileshare.pwd)
+  - task: PublishTestResults@2
+    displayName: 'Publish Test Results **/TEST-*.xml'
+    inputs:
+      mergeTestResults: true
+      testRunTitle: 'linux-clang'
+      platform: Linux
+      publishRunAttachments: false
+    condition: succeededOrFailed()
+  - task: PublishBuildArtifacts@1
+    displayName: 'Publish trash directories of failed tests'
+    condition: failed()
+    inputs:
+      PathtoPublish: t/failed-test-artifacts
+      ArtifactName: failed-test-artifacts
+
+- job: linux_gcc
+  displayName: linux-gcc
+  condition: succeeded()
+  pool: Hosted Ubuntu 1604
+  steps:
+  - bash: |
+       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || ci/mount-fileshare.sh //gitfileshare.file.core.windows.net/test-cache gitfileshare "$GITFILESHAREPWD" "$HOME/test-cache" || exit 1
+
+       sudo add-apt-repository ppa:ubuntu-toolchain-r/test &&
+       sudo apt-get update &&
+       sudo apt-get -y install git gcc make libssl-dev libcurl4-openssl-dev libexpat-dev tcl tk gettext git-email zlib1g-dev apache2 language-pack-is git-svn gcc-8 || exit 1
+
+       ci/install-dependencies.sh || exit 1
+       ci/run-build-and-tests.sh || {
+           ci/print-test-failures.sh
+           exit 1
+       }
+
+       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || sudo umount "$HOME/test-cache" || exit 1
+    displayName: 'ci/run-build-and-tests.sh'
+    env:
+      GITFILESHAREPWD: $(gitfileshare.pwd)
+  - task: PublishTestResults@2
+    displayName: 'Publish Test Results **/TEST-*.xml'
+    inputs:
+      mergeTestResults: true
+      testRunTitle: 'linux-gcc'
+      platform: Linux
+      publishRunAttachments: false
+    condition: succeededOrFailed()
+  - task: PublishBuildArtifacts@1
+    displayName: 'Publish trash directories of failed tests'
+    condition: failed()
+    inputs:
+      PathtoPublish: t/failed-test-artifacts
+      ArtifactName: failed-test-artifacts
+
+- job: osx_clang
+  displayName: osx-clang
+  condition: succeeded()
+  pool: Hosted macOS
+  steps:
+  - bash: |
+       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || ci/mount-fileshare.sh //gitfileshare.file.core.windows.net/test-cache gitfileshare "$GITFILESHAREPWD" "$HOME/test-cache" || exit 1
+
+       export CC=clang
+
+       ci/install-dependencies.sh || exit 1
+       ci/run-build-and-tests.sh || {
+           ci/print-test-failures.sh
+           exit 1
+       }
+
+       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || umount "$HOME/test-cache" || exit 1
+    displayName: 'ci/run-build-and-tests.sh'
+    env:
+      GITFILESHAREPWD: $(gitfileshare.pwd)
+  - task: PublishTestResults@2
+    displayName: 'Publish Test Results **/TEST-*.xml'
+    inputs:
+      mergeTestResults: true
+      testRunTitle: 'osx-clang'
+      platform: macOS
+      publishRunAttachments: false
+    condition: succeededOrFailed()
+  - task: PublishBuildArtifacts@1
+    displayName: 'Publish trash directories of failed tests'
+    condition: failed()
+    inputs:
+      PathtoPublish: t/failed-test-artifacts
+      ArtifactName: failed-test-artifacts
+
+- job: osx_gcc
+  displayName: osx-gcc
+  condition: succeeded()
+  pool: Hosted macOS
+  steps:
+  - bash: |
+       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || ci/mount-fileshare.sh //gitfileshare.file.core.windows.net/test-cache gitfileshare "$GITFILESHAREPWD" "$HOME/test-cache" || exit 1
+
+       ci/install-dependencies.sh || exit 1
+       ci/run-build-and-tests.sh || {
+           ci/print-test-failures.sh
+           exit 1
+       }
+
+       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || umount "$HOME/test-cache" || exit 1
+    displayName: 'ci/run-build-and-tests.sh'
+    env:
+      GITFILESHAREPWD: $(gitfileshare.pwd)
+  - task: PublishTestResults@2
+    displayName: 'Publish Test Results **/TEST-*.xml'
+    inputs:
+      mergeTestResults: true
+      testRunTitle: 'osx-gcc'
+      platform: macOS
+      publishRunAttachments: false
+    condition: succeededOrFailed()
+  - task: PublishBuildArtifacts@1
+    displayName: 'Publish trash directories of failed tests'
+    condition: failed()
+    inputs:
+      PathtoPublish: t/failed-test-artifacts
+      ArtifactName: failed-test-artifacts
+
+- job: gettext_poison
+  displayName: GETTEXT_POISON
+  condition: succeeded()
+  pool: Hosted Ubuntu 1604
+  steps:
+  - bash: |
+       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || ci/mount-fileshare.sh //gitfileshare.file.core.windows.net/test-cache gitfileshare "$GITFILESHAREPWD" "$HOME/test-cache" || exit 1
+
+       sudo apt-get update &&
+       sudo apt-get -y install git gcc make libssl-dev libcurl4-openssl-dev libexpat-dev tcl tk gettext git-email zlib1g-dev &&
+
+       export jobname=GETTEXT_POISON || exit 1
+
+       ci/run-build-and-tests.sh || {
+           ci/print-test-failures.sh
+           exit 1
+       }
+
+       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || sudo umount "$HOME/test-cache" || exit 1
+    displayName: 'ci/run-build-and-tests.sh'
+    env:
+      GITFILESHAREPWD: $(gitfileshare.pwd)
+  - task: PublishTestResults@2
+    displayName: 'Publish Test Results **/TEST-*.xml'
+    inputs:
+      mergeTestResults: true
+      testRunTitle: 'gettext-poison'
+      platform: Linux
+      publishRunAttachments: false
+    condition: succeededOrFailed()
+  - task: PublishBuildArtifacts@1
+    displayName: 'Publish trash directories of failed tests'
+    condition: failed()
+    inputs:
+      PathtoPublish: t/failed-test-artifacts
+      ArtifactName: failed-test-artifacts
+
+- job: linux32
+  displayName: Linux32
+  condition: succeeded()
+  pool: Hosted Ubuntu 1604
+  steps:
+  - bash: |
+       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || ci/mount-fileshare.sh //gitfileshare.file.core.windows.net/test-cache gitfileshare "$GITFILESHAREPWD" "$HOME/test-cache" || exit 1
+
+       res=0
+       sudo AGENT_OS="$AGENT_OS" BUILD_BUILDNUMBER="$BUILD_BUILDNUMBER" BUILD_REPOSITORY_URI="$BUILD_REPOSITORY_URI" BUILD_SOURCEBRANCH="$BUILD_SOURCEBRANCH" BUILD_SOURCEVERSION="$BUILD_SOURCEVERSION" SYSTEM_PHASENAME="$SYSTEM_PHASENAME" SYSTEM_TASKDEFINITIONSURI="$SYSTEM_TASKDEFINITIONSURI" SYSTEM_TEAMPROJECT="$SYSTEM_TEAMPROJECT" CC=$CC MAKEFLAGS="$MAKEFLAGS" bash -lxc ci/run-linux32-docker.sh || res=1
+
+       sudo chmod a+r t/out/TEST-*.xml
+       test ! -d t/failed-test-artifacts || sudo chmod a+r t/failed-test-artifacts
+
+       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || sudo umount "$HOME/test-cache" || res=1
+       exit $res
+    displayName: 'ci/run-linux32-docker.sh'
+    env:
+      GITFILESHAREPWD: $(gitfileshare.pwd)
+  - task: PublishTestResults@2
+    displayName: 'Publish Test Results **/TEST-*.xml'
+    inputs:
+      mergeTestResults: true
+      testRunTitle: 'linux32'
+      platform: Linux
+      publishRunAttachments: false
+    condition: succeededOrFailed()
+  - task: PublishBuildArtifacts@1
+    displayName: 'Publish trash directories of failed tests'
+    condition: failed()
+    inputs:
+      PathtoPublish: t/failed-test-artifacts
+      ArtifactName: failed-test-artifacts
+
+- job: static_analysis
+  displayName: StaticAnalysis
+  condition: succeeded()
+  pool: Hosted Ubuntu 1604
+  steps:
+  - bash: |
+       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || ci/mount-fileshare.sh //gitfileshare.file.core.windows.net/test-cache gitfileshare "$GITFILESHAREPWD" "$HOME/test-cache" || exit 1
+
+       sudo apt-get update &&
+       sudo apt-get install -y coccinelle &&
+
+       export jobname=StaticAnalysis &&
+
+       ci/run-static-analysis.sh || exit 1
+
+       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || sudo umount "$HOME/test-cache" || exit 1
+    displayName: 'ci/run-static-analysis.sh'
+    env:
+      GITFILESHAREPWD: $(gitfileshare.pwd)
+
+- job: documentation
+  displayName: Documentation
+  condition: succeeded()
+  pool: Hosted Ubuntu 1604
+  steps:
+  - bash: |
+       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || ci/mount-fileshare.sh //gitfileshare.file.core.windows.net/test-cache gitfileshare "$GITFILESHAREPWD" "$HOME/test-cache" || exit 1
+
+       sudo apt-get update &&
+       sudo apt-get install -y asciidoc xmlto asciidoctor &&
+
+       export ALREADY_HAVE_ASCIIDOCTOR=yes. &&
+       export jobname=Documentation &&
+
+       ci/test-documentation.sh || exit 1
+
+       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || sudo umount "$HOME/test-cache" || exit 1
+    displayName: 'ci/test-documentation.sh'
+    env:
+      GITFILESHAREPWD: $(gitfileshare.pwd)
diff --git a/bisect.c b/bisect.c
index 6bf5211..3af955c 100644
--- a/bisect.c
+++ b/bisect.c
@@ -658,7 +658,7 @@
 	if (prepare_revision_walk(revs))
 		die("revision walk setup failed");
 	if (revs->tree_objects)
-		mark_edges_uninteresting(revs, NULL);
+		mark_edges_uninteresting(revs, NULL, 0);
 }
 
 static void exit_if_skipped_commits(struct commit_list *tried,
diff --git a/blame.c b/blame.c
index 4386143..da57233 100644
--- a/blame.c
+++ b/blame.c
@@ -188,7 +188,7 @@
 	unsigned mode;
 	struct strbuf msg = STRBUF_INIT;
 
-	read_index(r->index);
+	repo_read_index(r);
 	time(&now);
 	commit = alloc_commit_node(r);
 	commit->object.parsed = 1;
@@ -270,7 +270,7 @@
 	 * want to run "diff-index --cached".
 	 */
 	discard_index(r->index);
-	read_index(r->index);
+	repo_read_index(r);
 
 	len = strlen(path);
 	if (!mode) {
diff --git a/builtin/add.c b/builtin/add.c
index d461ba0..db2dfa4 100644
--- a/builtin/add.c
+++ b/builtin/add.c
@@ -3,6 +3,7 @@
  *
  * Copyright (C) 2006 Linus Torvalds
  */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "builtin.h"
@@ -137,7 +138,7 @@
 			continue; /* do not touch non blobs */
 		if (pathspec && !ce_path_match(&the_index, ce, pathspec, NULL))
 			continue;
-		retval |= add_file_to_cache(ce->name, flags | HASH_RENORMALIZE);
+		retval |= add_file_to_cache(ce->name, flags | ADD_CACHE_RENORMALIZE);
 	}
 
 	return retval;
diff --git a/builtin/am.c b/builtin/am.c
index 9537031..58a2aef 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -3,6 +3,7 @@
  *
  * Based on git-am.sh by Junio C Hamano.
  */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "builtin.h"
@@ -35,22 +36,6 @@
 #include "repository.h"
 
 /**
- * Returns 1 if the file is empty or does not exist, 0 otherwise.
- */
-static int is_empty_file(const char *filename)
-{
-	struct stat st;
-
-	if (stat(filename, &st) < 0) {
-		if (errno == ENOENT)
-			return 1;
-		die_errno(_("could not stat %s"), filename);
-	}
-
-	return !st.st_size;
-}
-
-/**
  * Returns the length of the first line of msg.
  */
 static int linelen(const char *msg)
@@ -527,7 +512,7 @@
 	}
 
 finish:
-	finish_copy_notes_for_rewrite(c, msg);
+	finish_copy_notes_for_rewrite(the_repository, c, msg);
 	fclose(fp);
 	strbuf_release(&sb);
 	return ret;
@@ -1220,7 +1205,7 @@
 		goto finish;
 	}
 
-	if (is_empty_file(am_path(state, "patch"))) {
+	if (is_empty_or_missing_file(am_path(state, "patch"))) {
 		printf_ln(_("Patch is empty."));
 		die_user_resolve(state);
 	}
@@ -1545,7 +1530,7 @@
 	 * changes.
 	 */
 
-	init_merge_options(&o);
+	init_merge_options(&o, the_repository);
 
 	o.branch1 = "HEAD";
 	their_tree_name = xstrfmt("%.*s", linelen(state->msg), state->msg);
@@ -1719,7 +1704,7 @@
 
 	refresh_and_write_cache();
 
-	if (index_has_changes(&the_index, NULL, &sb)) {
+	if (repo_index_has_changes(the_repository, NULL, &sb)) {
 		write_state_bool(state, "dirtyindex", 1);
 		die(_("Dirty index: cannot apply patches (dirty: %s)"), sb.buf);
 	}
@@ -1777,7 +1762,7 @@
 			 * the result may have produced the same tree as ours.
 			 */
 			if (!apply_status &&
-			    !index_has_changes(&the_index, NULL, NULL)) {
+			    !repo_index_has_changes(the_repository, NULL, NULL)) {
 				say(state, stdout, _("No changes -- Patch already applied."));
 				goto next;
 			}
@@ -1803,7 +1788,7 @@
 		resume = 0;
 	}
 
-	if (!is_empty_file(am_path(state, "rewritten"))) {
+	if (!is_empty_or_missing_file(am_path(state, "rewritten"))) {
 		assert(state->rebasing);
 		copy_notes_for_rebase(state);
 		run_post_rewrite_hook(state);
@@ -1831,7 +1816,7 @@
 
 	say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
 
-	if (!index_has_changes(&the_index, NULL, NULL)) {
+	if (!repo_index_has_changes(the_repository, NULL, NULL)) {
 		printf_ln(_("No changes - did you forget to use 'git add'?\n"
 			"If there is nothing left to stage, chances are that something else\n"
 			"already introduced the same changes; you might want to skip this patch."));
@@ -2000,6 +1985,15 @@
 	if (clean_index(&head, &head))
 		die(_("failed to clean index"));
 
+	if (state->rebasing) {
+		FILE *fp = xfopen(am_path(state, "rewritten"), "a");
+
+		assert(!is_null_oid(&state->orig_commit));
+		fprintf(fp, "%s ", oid_to_hex(&state->orig_commit));
+		fprintf(fp, "%s\n", oid_to_hex(&head));
+		fclose(fp);
+	}
+
 	am_next(state);
 	am_load(state);
 	am_run(state, 0);
@@ -2278,7 +2272,7 @@
 	/* Ensure a valid committer ident can be constructed */
 	git_committer_info(IDENT_STRICT);
 
-	if (read_index_preload(&the_index, NULL, 0) < 0)
+	if (repo_read_index_preload(the_repository, NULL, 0) < 0)
 		die(_("failed to read the index"));
 
 	if (in_progress) {
diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index 417d141..c1cff32 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -3,18 +3,58 @@
 #include "parse-options.h"
 #include "bisect.h"
 #include "refs.h"
+#include "dir.h"
+#include "argv-array.h"
+#include "run-command.h"
+#include "prompt.h"
+#include "quote.h"
 
 static GIT_PATH_FUNC(git_path_bisect_terms, "BISECT_TERMS")
 static GIT_PATH_FUNC(git_path_bisect_expected_rev, "BISECT_EXPECTED_REV")
 static GIT_PATH_FUNC(git_path_bisect_ancestors_ok, "BISECT_ANCESTORS_OK")
+static GIT_PATH_FUNC(git_path_bisect_start, "BISECT_START")
+static GIT_PATH_FUNC(git_path_bisect_head, "BISECT_HEAD")
+static GIT_PATH_FUNC(git_path_bisect_log, "BISECT_LOG")
+static GIT_PATH_FUNC(git_path_head_name, "head-name")
+static GIT_PATH_FUNC(git_path_bisect_names, "BISECT_NAMES")
 
 static const char * const git_bisect_helper_usage[] = {
 	N_("git bisect--helper --next-all [--no-checkout]"),
 	N_("git bisect--helper --write-terms <bad_term> <good_term>"),
 	N_("git bisect--helper --bisect-clean-state"),
+	N_("git bisect--helper --bisect-reset [<commit>]"),
+	N_("git bisect--helper --bisect-write [--no-log] <state> <revision> <good_term> <bad_term>"),
+	N_("git bisect--helper --bisect-check-and-set-terms <command> <good_term> <bad_term>"),
+	N_("git bisect--helper --bisect-next-check <good_term> <bad_term> [<term>]"),
+	N_("git bisect--helper --bisect-terms [--term-good | --term-old | --term-bad | --term-new]"),
+	N_("git bisect--helper --bisect-start [--term-{old,good}=<term> --term-{new,bad}=<term>]"
+					     "[--no-checkout] [<bad> [<good>...]] [--] [<paths>...]"),
 	NULL
 };
 
+struct bisect_terms {
+	char *term_good;
+	char *term_bad;
+};
+
+static void free_terms(struct bisect_terms *terms)
+{
+	FREE_AND_NULL(terms->term_good);
+	FREE_AND_NULL(terms->term_bad);
+}
+
+static void set_terms(struct bisect_terms *terms, const char *bad,
+		      const char *good)
+{
+	free((void *)terms->term_good);
+	terms->term_good = xstrdup(good);
+	free((void *)terms->term_bad);
+	terms->term_bad = xstrdup(bad);
+}
+
+static const char *vocab_bad = "bad|new";
+static const char *vocab_good = "good|old";
+
 /*
  * Check whether the string `term` belongs to the set of strings
  * included in the variable arguments.
@@ -106,15 +146,482 @@
 	}
 }
 
+static int bisect_reset(const char *commit)
+{
+	struct strbuf branch = STRBUF_INIT;
+
+	if (!commit) {
+		if (strbuf_read_file(&branch, git_path_bisect_start(), 0) < 1) {
+			printf(_("We are not bisecting.\n"));
+			return 0;
+		}
+		strbuf_rtrim(&branch);
+	} else {
+		struct object_id oid;
+
+		if (get_oid_commit(commit, &oid))
+			return error(_("'%s' is not a valid commit"), commit);
+		strbuf_addstr(&branch, commit);
+	}
+
+	if (!file_exists(git_path_bisect_head())) {
+		struct argv_array argv = ARGV_ARRAY_INIT;
+
+		argv_array_pushl(&argv, "checkout", branch.buf, "--", NULL);
+		if (run_command_v_opt(argv.argv, RUN_GIT_CMD)) {
+			strbuf_release(&branch);
+			argv_array_clear(&argv);
+			return error(_("could not check out original"
+				       " HEAD '%s'. Try 'git bisect"
+				       "reset <commit>'."), branch.buf);
+		}
+		argv_array_clear(&argv);
+	}
+
+	strbuf_release(&branch);
+	return bisect_clean_state();
+}
+
+static void log_commit(FILE *fp, char *fmt, const char *state,
+		       struct commit *commit)
+{
+	struct pretty_print_context pp = {0};
+	struct strbuf commit_msg = STRBUF_INIT;
+	char *label = xstrfmt(fmt, state);
+
+	format_commit_message(commit, "%s", &commit_msg, &pp);
+
+	fprintf(fp, "# %s: [%s] %s\n", label, oid_to_hex(&commit->object.oid),
+		commit_msg.buf);
+
+	strbuf_release(&commit_msg);
+	free(label);
+}
+
+static int bisect_write(const char *state, const char *rev,
+			const struct bisect_terms *terms, int nolog)
+{
+	struct strbuf tag = STRBUF_INIT;
+	struct object_id oid;
+	struct commit *commit;
+	FILE *fp = NULL;
+	int retval = 0;
+
+	if (!strcmp(state, terms->term_bad)) {
+		strbuf_addf(&tag, "refs/bisect/%s", state);
+	} else if (one_of(state, terms->term_good, "skip", NULL)) {
+		strbuf_addf(&tag, "refs/bisect/%s-%s", state, rev);
+	} else {
+		retval = error(_("Bad bisect_write argument: %s"), state);
+		goto finish;
+	}
+
+	if (get_oid(rev, &oid)) {
+		retval = error(_("couldn't get the oid of the rev '%s'"), rev);
+		goto finish;
+	}
+
+	if (update_ref(NULL, tag.buf, &oid, NULL, 0,
+		       UPDATE_REFS_MSG_ON_ERR)) {
+		retval = -1;
+		goto finish;
+	}
+
+	fp = fopen(git_path_bisect_log(), "a");
+	if (!fp) {
+		retval = error_errno(_("couldn't open the file '%s'"), git_path_bisect_log());
+		goto finish;
+	}
+
+	commit = lookup_commit_reference(the_repository, &oid);
+	log_commit(fp, "%s", state, commit);
+
+	if (!nolog)
+		fprintf(fp, "git bisect %s %s\n", state, rev);
+
+finish:
+	if (fp)
+		fclose(fp);
+	strbuf_release(&tag);
+	return retval;
+}
+
+static int check_and_set_terms(struct bisect_terms *terms, const char *cmd)
+{
+	int has_term_file = !is_empty_or_missing_file(git_path_bisect_terms());
+
+	if (one_of(cmd, "skip", "start", "terms", NULL))
+		return 0;
+
+	if (has_term_file && strcmp(cmd, terms->term_bad) &&
+	    strcmp(cmd, terms->term_good))
+		return error(_("Invalid command: you're currently in a "
+				"%s/%s bisect"), terms->term_bad,
+				terms->term_good);
+
+	if (!has_term_file) {
+		if (one_of(cmd, "bad", "good", NULL)) {
+			set_terms(terms, "bad", "good");
+			return write_terms(terms->term_bad, terms->term_good);
+		}
+		if (one_of(cmd, "new", "old", NULL)) {
+			set_terms(terms, "new", "old");
+			return write_terms(terms->term_bad, terms->term_good);
+		}
+	}
+
+	return 0;
+}
+
+static int mark_good(const char *refname, const struct object_id *oid,
+		     int flag, void *cb_data)
+{
+	int *m_good = (int *)cb_data;
+	*m_good = 0;
+	return 1;
+}
+
+static const char *need_bad_and_good_revision_warning =
+	N_("You need to give me at least one %s and %s revision.\n"
+	   "You can use \"git bisect %s\" and \"git bisect %s\" for that.");
+
+static const char *need_bisect_start_warning =
+	N_("You need to start by \"git bisect start\".\n"
+	   "You then need to give me at least one %s and %s revision.\n"
+	   "You can use \"git bisect %s\" and \"git bisect %s\" for that.");
+
+static int bisect_next_check(const struct bisect_terms *terms,
+			     const char *current_term)
+{
+	int missing_good = 1, missing_bad = 1, retval = 0;
+	const char *bad_ref = xstrfmt("refs/bisect/%s", terms->term_bad);
+	const char *good_glob = xstrfmt("%s-*", terms->term_good);
+
+	if (ref_exists(bad_ref))
+		missing_bad = 0;
+
+	for_each_glob_ref_in(mark_good, good_glob, "refs/bisect/",
+			     (void *) &missing_good);
+
+	if (!missing_good && !missing_bad)
+		goto finish;
+
+	if (!current_term) {
+		retval = -1;
+		goto finish;
+	}
+
+	if (missing_good && !missing_bad &&
+	    !strcmp(current_term, terms->term_good)) {
+		char *yesno;
+		/*
+		 * have bad (or new) but not good (or old). We could bisect
+		 * although this is less optimum.
+		 */
+		warning(_("bisecting only with a %s commit"), terms->term_bad);
+		if (!isatty(0))
+			goto finish;
+		/*
+		 * TRANSLATORS: Make sure to include [Y] and [n] in your
+		 * translation. The program will only accept English input
+		 * at this point.
+		 */
+		yesno = git_prompt(_("Are you sure [Y/n]? "), PROMPT_ECHO);
+		if (starts_with(yesno, "N") || starts_with(yesno, "n"))
+			retval = -1;
+		goto finish;
+	}
+	if (!is_empty_or_missing_file(git_path_bisect_start())) {
+		retval = error(_(need_bad_and_good_revision_warning),
+			       vocab_bad, vocab_good, vocab_bad, vocab_good);
+	} else {
+		retval = error(_(need_bisect_start_warning),
+			       vocab_good, vocab_bad, vocab_good, vocab_bad);
+	}
+
+finish:
+	free((void *) good_glob);
+	free((void *) bad_ref);
+	return retval;
+}
+
+static int get_terms(struct bisect_terms *terms)
+{
+	struct strbuf str = STRBUF_INIT;
+	FILE *fp = NULL;
+	int res = 0;
+
+	fp = fopen(git_path_bisect_terms(), "r");
+	if (!fp) {
+		res = -1;
+		goto finish;
+	}
+
+	free_terms(terms);
+	strbuf_getline_lf(&str, fp);
+	terms->term_bad = strbuf_detach(&str, NULL);
+	strbuf_getline_lf(&str, fp);
+	terms->term_good = strbuf_detach(&str, NULL);
+
+finish:
+	if (fp)
+		fclose(fp);
+	strbuf_release(&str);
+	return res;
+}
+
+static int bisect_terms(struct bisect_terms *terms, const char *option)
+{
+	if (get_terms(terms))
+		return error(_("no terms defined"));
+
+	if (option == NULL) {
+		printf(_("Your current terms are %s for the old state\n"
+			 "and %s for the new state.\n"),
+		       terms->term_good, terms->term_bad);
+		return 0;
+	}
+	if (one_of(option, "--term-good", "--term-old", NULL))
+		printf("%s\n", terms->term_good);
+	else if (one_of(option, "--term-bad", "--term-new", NULL))
+		printf("%s\n", terms->term_bad);
+	else
+		return error(_("invalid argument %s for 'git bisect terms'.\n"
+			       "Supported options are: "
+			       "--term-good|--term-old and "
+			       "--term-bad|--term-new."), option);
+
+	return 0;
+}
+
+static int bisect_append_log_quoted(const char **argv)
+{
+	int retval = 0;
+	FILE *fp = fopen(git_path_bisect_log(), "a");
+	struct strbuf orig_args = STRBUF_INIT;
+
+	if (!fp)
+		return -1;
+
+	if (fprintf(fp, "git bisect start") < 1) {
+		retval = -1;
+		goto finish;
+	}
+
+	sq_quote_argv(&orig_args, argv);
+	if (fprintf(fp, "%s\n", orig_args.buf) < 1)
+		retval = -1;
+
+finish:
+	fclose(fp);
+	strbuf_release(&orig_args);
+	return retval;
+}
+
+static int bisect_start(struct bisect_terms *terms, int no_checkout,
+			const char **argv, int argc)
+{
+	int i, has_double_dash = 0, must_write_terms = 0, bad_seen = 0;
+	int flags, pathspec_pos, retval = 0;
+	struct string_list revs = STRING_LIST_INIT_DUP;
+	struct string_list states = STRING_LIST_INIT_DUP;
+	struct strbuf start_head = STRBUF_INIT;
+	struct strbuf bisect_names = STRBUF_INIT;
+	struct object_id head_oid;
+	struct object_id oid;
+	const char *head;
+
+	if (is_bare_repository())
+		no_checkout = 1;
+
+	/*
+	 * Check for one bad and then some good revisions
+	 */
+	for (i = 0; i < argc; i++) {
+		if (!strcmp(argv[i], "--")) {
+			has_double_dash = 1;
+			break;
+		}
+	}
+
+	for (i = 0; i < argc; i++) {
+		const char *arg = argv[i];
+		if (!strcmp(argv[i], "--")) {
+			break;
+		} else if (!strcmp(arg, "--no-checkout")) {
+			no_checkout = 1;
+		} else if (!strcmp(arg, "--term-good") ||
+			 !strcmp(arg, "--term-old")) {
+			must_write_terms = 1;
+			free((void *) terms->term_good);
+			terms->term_good = xstrdup(argv[++i]);
+		} else if (skip_prefix(arg, "--term-good=", &arg) ||
+			   skip_prefix(arg, "--term-old=", &arg)) {
+			must_write_terms = 1;
+			free((void *) terms->term_good);
+			terms->term_good = xstrdup(arg);
+		} else if (!strcmp(arg, "--term-bad") ||
+			 !strcmp(arg, "--term-new")) {
+			must_write_terms = 1;
+			free((void *) terms->term_bad);
+			terms->term_bad = xstrdup(argv[++i]);
+		} else if (skip_prefix(arg, "--term-bad=", &arg) ||
+			   skip_prefix(arg, "--term-new=", &arg)) {
+			must_write_terms = 1;
+			free((void *) terms->term_bad);
+			terms->term_bad = xstrdup(arg);
+		} else if (starts_with(arg, "--") &&
+			 !one_of(arg, "--term-good", "--term-bad", NULL)) {
+			return error(_("unrecognized option: '%s'"), arg);
+		} else {
+			char *commit_id = xstrfmt("%s^{commit}", arg);
+			if (get_oid(commit_id, &oid) && has_double_dash)
+				die(_("'%s' does not appear to be a valid "
+				      "revision"), arg);
+
+			string_list_append(&revs, oid_to_hex(&oid));
+			free(commit_id);
+		}
+	}
+	pathspec_pos = i;
+
+	/*
+	 * The user ran "git bisect start <sha1> <sha1>", hence did not
+	 * explicitly specify the terms, but we are already starting to
+	 * set references named with the default terms, and won't be able
+	 * to change afterwards.
+	 */
+	if (revs.nr)
+		must_write_terms = 1;
+	for (i = 0; i < revs.nr; i++) {
+		if (bad_seen) {
+			string_list_append(&states, terms->term_good);
+		} else {
+			bad_seen = 1;
+			string_list_append(&states, terms->term_bad);
+		}
+	}
+
+	/*
+	 * Verify HEAD
+	 */
+	head = resolve_ref_unsafe("HEAD", 0, &head_oid, &flags);
+	if (!head)
+		if (get_oid("HEAD", &head_oid))
+			return error(_("bad HEAD - I need a HEAD"));
+
+	/*
+	 * Check if we are bisecting
+	 */
+	if (!is_empty_or_missing_file(git_path_bisect_start())) {
+		/* Reset to the rev from where we started */
+		strbuf_read_file(&start_head, git_path_bisect_start(), 0);
+		strbuf_trim(&start_head);
+		if (!no_checkout) {
+			struct argv_array argv = ARGV_ARRAY_INIT;
+
+			argv_array_pushl(&argv, "checkout", start_head.buf,
+					 "--", NULL);
+			if (run_command_v_opt(argv.argv, RUN_GIT_CMD)) {
+				retval = error(_("checking out '%s' failed."
+						 " Try 'git bisect start "
+						 "<valid-branch>'."),
+					       start_head.buf);
+				goto finish;
+			}
+		}
+	} else {
+		/* Get the rev from where we start. */
+		if (!get_oid(head, &head_oid) &&
+		    !starts_with(head, "refs/heads/")) {
+			strbuf_reset(&start_head);
+			strbuf_addstr(&start_head, oid_to_hex(&head_oid));
+		} else if (!get_oid(head, &head_oid) &&
+			   skip_prefix(head, "refs/heads/", &head)) {
+			/*
+			 * This error message should only be triggered by
+			 * cogito usage, and cogito users should understand
+			 * it relates to cg-seek.
+			 */
+			if (!is_empty_or_missing_file(git_path_head_name()))
+				return error(_("won't bisect on cg-seek'ed tree"));
+			strbuf_addstr(&start_head, head);
+		} else {
+			return error(_("bad HEAD - strange symbolic ref"));
+		}
+	}
+
+	/*
+	 * Get rid of any old bisect state.
+	 */
+	if (bisect_clean_state())
+		return -1;
+
+	/*
+	 * In case of mistaken revs or checkout error, or signals received,
+	 * "bisect_auto_next" below may exit or misbehave.
+	 * We have to trap this to be able to clean up using
+	 * "bisect_clean_state".
+	 */
+
+	/*
+	 * Write new start state
+	 */
+	write_file(git_path_bisect_start(), "%s\n", start_head.buf);
+
+	if (no_checkout) {
+		get_oid(start_head.buf, &oid);
+		if (update_ref(NULL, "BISECT_HEAD", &oid, NULL, 0,
+			       UPDATE_REFS_MSG_ON_ERR)) {
+			retval = -1;
+			goto finish;
+		}
+	}
+
+	if (pathspec_pos < argc - 1)
+		sq_quote_argv(&bisect_names, argv + pathspec_pos);
+	write_file(git_path_bisect_names(), "%s\n", bisect_names.buf);
+
+	for (i = 0; i < states.nr; i++)
+		if (bisect_write(states.items[i].string,
+				 revs.items[i].string, terms, 1)) {
+			retval = -1;
+			goto finish;
+		}
+
+	if (must_write_terms && write_terms(terms->term_bad,
+					    terms->term_good)) {
+		retval = -1;
+		goto finish;
+	}
+
+	retval = bisect_append_log_quoted(argv);
+	if (retval)
+		retval = -1;
+
+finish:
+	string_list_clear(&revs, 0);
+	string_list_clear(&states, 0);
+	strbuf_release(&start_head);
+	strbuf_release(&bisect_names);
+	return retval;
+}
+
 int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 {
 	enum {
 		NEXT_ALL = 1,
 		WRITE_TERMS,
 		BISECT_CLEAN_STATE,
-		CHECK_EXPECTED_REVS
+		CHECK_EXPECTED_REVS,
+		BISECT_RESET,
+		BISECT_WRITE,
+		CHECK_AND_SET_TERMS,
+		BISECT_NEXT_CHECK,
+		BISECT_TERMS,
+		BISECT_START
 	} cmdmode = 0;
-	int no_checkout = 0;
+	int no_checkout = 0, res = 0, nolog = 0;
 	struct option options[] = {
 		OPT_CMDMODE(0, "next-all", &cmdmode,
 			 N_("perform 'git bisect next'"), NEXT_ALL),
@@ -124,13 +631,29 @@
 			 N_("cleanup the bisection state"), BISECT_CLEAN_STATE),
 		OPT_CMDMODE(0, "check-expected-revs", &cmdmode,
 			 N_("check for expected revs"), CHECK_EXPECTED_REVS),
+		OPT_CMDMODE(0, "bisect-reset", &cmdmode,
+			 N_("reset the bisection state"), BISECT_RESET),
+		OPT_CMDMODE(0, "bisect-write", &cmdmode,
+			 N_("write out the bisection state in BISECT_LOG"), BISECT_WRITE),
+		OPT_CMDMODE(0, "check-and-set-terms", &cmdmode,
+			 N_("check and set terms in a bisection state"), CHECK_AND_SET_TERMS),
+		OPT_CMDMODE(0, "bisect-next-check", &cmdmode,
+			 N_("check whether bad or good terms exist"), BISECT_NEXT_CHECK),
+		OPT_CMDMODE(0, "bisect-terms", &cmdmode,
+			 N_("print out the bisect terms"), BISECT_TERMS),
+		OPT_CMDMODE(0, "bisect-start", &cmdmode,
+			 N_("start the bisect session"), BISECT_START),
 		OPT_BOOL(0, "no-checkout", &no_checkout,
 			 N_("update BISECT_HEAD instead of checking out the current commit")),
+		OPT_BOOL(0, "no-log", &nolog,
+			 N_("no log for BISECT_WRITE ")),
 		OPT_END()
 	};
+	struct bisect_terms terms = { .term_good = NULL, .term_bad = NULL };
 
 	argc = parse_options(argc, argv, prefix, options,
-			     git_bisect_helper_usage, 0);
+			     git_bisect_helper_usage,
+			     PARSE_OPT_KEEP_DASHDASH | PARSE_OPT_KEEP_UNKNOWN);
 
 	if (!cmdmode)
 		usage_with_options(git_bisect_helper_usage, options);
@@ -149,8 +672,40 @@
 	case CHECK_EXPECTED_REVS:
 		check_expected_revs(argv, argc);
 		return 0;
+	case BISECT_RESET:
+		if (argc > 1)
+			return error(_("--bisect-reset requires either no argument or a commit"));
+		return !!bisect_reset(argc ? argv[0] : NULL);
+	case BISECT_WRITE:
+		if (argc != 4 && argc != 5)
+			return error(_("--bisect-write requires either 4 or 5 arguments"));
+		set_terms(&terms, argv[3], argv[2]);
+		res = bisect_write(argv[0], argv[1], &terms, nolog);
+		break;
+	case CHECK_AND_SET_TERMS:
+		if (argc != 3)
+			return error(_("--check-and-set-terms requires 3 arguments"));
+		set_terms(&terms, argv[2], argv[1]);
+		res = check_and_set_terms(&terms, argv[0]);
+		break;
+	case BISECT_NEXT_CHECK:
+		if (argc != 2 && argc != 3)
+			return error(_("--bisect-next-check requires 2 or 3 arguments"));
+		set_terms(&terms, argv[1], argv[0]);
+		res = bisect_next_check(&terms, argc == 3 ? argv[2] : NULL);
+		break;
+	case BISECT_TERMS:
+		if (argc > 1)
+			return error(_("--bisect-terms requires 0 or 1 argument"));
+		res = bisect_terms(&terms, argc == 1 ? argv[0] : NULL);
+		break;
+	case BISECT_START:
+		set_terms(&terms, "bad", "good");
+		res = bisect_start(&terms, no_checkout, argv, argc);
+		break;
 	default:
 		return error("BUG: unknown subcommand '%d'", cmdmode);
 	}
-	return 0;
+	free_terms(&terms);
+	return !!res;
 }
diff --git a/builtin/blame.c b/builtin/blame.c
index 6d798f9..581de0d 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -925,6 +925,10 @@
 		 */
 		blame_date_width = utf8_strwidth(_("4 years, 11 months ago")) + 1; /* add the null */
 		break;
+	case DATE_HUMAN:
+		/* If the year is shown, no time is shown */
+		blame_date_width = sizeof("Thu Oct 19 16:00");
+		break;
 	case DATE_NORMAL:
 		blame_date_width = sizeof("Thu Oct 19 16:00:04 2006 -0700");
 		break;
@@ -1007,7 +1011,8 @@
 		long bottom, top;
 		if (parse_range_arg(range_list.items[range_i].string,
 				    nth_line_cb, &sb, lno, anchor,
-				    &bottom, &top, sb.path, &the_index))
+				    &bottom, &top, sb.path,
+				    the_repository->index))
 			usage(blame_usage);
 		if ((!lno && (top || bottom)) || lno < bottom)
 			die(Q_("file %s has only %lu line",
diff --git a/builtin/bundle.c b/builtin/bundle.c
index 9e9c65d..1ea4bfd 100644
--- a/builtin/bundle.c
+++ b/builtin/bundle.c
@@ -56,8 +56,7 @@
 		}
 		if (!startup_info->have_repository)
 			die(_("Need a repository to create a bundle."));
-		return !!create_bundle(the_repository, &header,
-				       bundle_file, argc, argv);
+		return !!create_bundle(the_repository, bundle_file, argc, argv);
 	} else if (!strcmp(cmd, "unbundle")) {
 		if (!startup_info->have_repository)
 			die(_("Need a repository to unbundle."));
diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 2ca56fd..0f09238 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -3,6 +3,7 @@
  *
  * Copyright (C) Linus Torvalds, 2005
  */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "builtin.h"
@@ -73,7 +74,8 @@
 	if (unknown_type)
 		flags |= OBJECT_INFO_ALLOW_UNKNOWN_TYPE;
 
-	if (get_oid_with_context(obj_name, GET_OID_RECORD_PATH,
+	if (get_oid_with_context(the_repository, obj_name,
+				 GET_OID_RECORD_PATH,
 				 &oid, &obj_context))
 		die("Not a valid object name %s", obj_name);
 
@@ -209,14 +211,14 @@
 
 	/*
 	 * After a mark_query run, this object_info is set up to be
-	 * passed to sha1_object_info_extended. It will point to the data
+	 * passed to oid_object_info_extended. It will point to the data
 	 * elements above, so you can retrieve the response from there.
 	 */
 	struct object_info info;
 
 	/*
 	 * This flag will be true if the requested batch format and options
-	 * don't require us to call sha1_object_info, which can then be
+	 * don't require us to call oid_object_info, which can then be
 	 * optimized out.
 	 */
 	unsigned skip_object_info : 1;
@@ -380,14 +382,18 @@
 {
 	struct object_context ctx;
 	int flags = opt->follow_symlinks ? GET_OID_FOLLOW_SYMLINKS : 0;
-	enum follow_symlinks_result result;
+	enum get_oid_result result;
 
-	result = get_oid_with_context(obj_name, flags, &data->oid, &ctx);
+	result = get_oid_with_context(the_repository, obj_name,
+				      flags, &data->oid, &ctx);
 	if (result != FOUND) {
 		switch (result) {
 		case MISSING_OBJECT:
 			printf("%s missing\n", obj_name);
 			break;
+		case SHORT_NAME_AMBIGUOUS:
+			printf("%s ambiguous\n", obj_name);
+			break;
 		case DANGLING_SYMLINK:
 			printf("dangling %"PRIuMAX"\n%s\n",
 			       (uintmax_t)strlen(obj_name), obj_name);
@@ -490,7 +496,7 @@
 
 	/*
 	 * Expand once with our special mark_query flag, which will prime the
-	 * object_info to be handed to sha1_object_info_extended for each
+	 * object_info to be handed to oid_object_info_extended for each
 	 * object.
 	 */
 	memset(&data, 0, sizeof(data));
diff --git a/builtin/check-attr.c b/builtin/check-attr.c
index 30a2f84..dd83397 100644
--- a/builtin/check-attr.c
+++ b/builtin/check-attr.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "cache.h"
 #include "config.h"
diff --git a/builtin/check-ignore.c b/builtin/check-ignore.c
index ec9a959..5990973 100644
--- a/builtin/check-ignore.c
+++ b/builtin/check-ignore.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "cache.h"
 #include "config.h"
diff --git a/builtin/checkout-index.c b/builtin/checkout-index.c
index a2a726a..1ac1cc2 100644
--- a/builtin/checkout-index.c
+++ b/builtin/checkout-index.c
@@ -4,6 +4,7 @@
  * Copyright (C) 2005 Linus Torvalds
  *
  */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "config.h"
 #include "lockfile.h"
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 6fadf41..ece4eb1 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "config.h"
 #include "checkout.h"
@@ -288,7 +289,7 @@
 		return run_add_interactive(revision, "--patch=checkout",
 					   &opts->pathspec);
 
-	hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
+	repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
 	if (read_cache_preload(&opts->pathspec) < 0)
 		return error(_("index file corrupt"));
 
@@ -592,6 +593,14 @@
 	 * Remaining variables are not checkout options but used to track state
 	 */
 
+	 /*
+	  * Do the merge if this is the initial checkout. We cannot use
+	  * is_cache_unborn() here because the index hasn't been loaded yet
+	  * so cache_nr and timestamp.sec are always zero.
+	  */
+	if (!file_exists(get_index_file()))
+		return 0;
+
 	return 1;
 }
 
@@ -693,7 +702,7 @@
 			 * a pain; plumb in an option to set
 			 * o.renormalize?
 			 */
-			init_merge_options(&o);
+			init_merge_options(&o, the_repository);
 			o.verbosity = 0;
 			work = write_tree_from_memory(&o);
 
diff --git a/builtin/clean.c b/builtin/clean.c
index bbcdeb2..aaba4af 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -6,6 +6,7 @@
  * Based on git-clean.sh by Pavel Roskin
  */
 
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "cache.h"
 #include "config.h"
diff --git a/builtin/clone.c b/builtin/clone.c
index 739de68..50bde99 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -8,6 +8,7 @@
  * Clone a repository into a different directory that does not yet exist.
  */
 
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "config.h"
 #include "lockfile.h"
diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
index c02a3f1..4ae5027 100644
--- a/builtin/commit-graph.c
+++ b/builtin/commit-graph.c
@@ -110,8 +110,8 @@
 		printf(" oid_lookup");
 	if (graph->chunk_commit_data)
 		printf(" commit_metadata");
-	if (graph->chunk_large_edges)
-		printf(" large_edges");
+	if (graph->chunk_extra_edges)
+		printf(" extra_edges");
 	printf("\n");
 
 	UNLEAK(graph);
diff --git a/builtin/commit-tree.c b/builtin/commit-tree.c
index 9ec36a8..12cc403 100644
--- a/builtin/commit-tree.c
+++ b/builtin/commit-tree.c
@@ -66,7 +66,13 @@
 			continue;
 		}
 
-		if (skip_prefix(arg, "-S", &sign_commit))
+		if (!strcmp(arg, "--gpg-sign")) {
+		    sign_commit = "";
+		    continue;
+		}
+
+		if (skip_prefix(arg, "-S", &sign_commit) ||
+			skip_prefix(arg, "--gpg-sign=", &sign_commit))
 			continue;
 
 		if (!strcmp(arg, "--no-gpg-sign")) {
diff --git a/builtin/commit.c b/builtin/commit.c
index 7d2e0b6..2986553 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -5,6 +5,7 @@
  * Based on git-commit.sh by Junio C Hamano and Linus Torvalds
  */
 
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "lockfile.h"
@@ -1368,7 +1369,7 @@
 	if (status_format != STATUS_FORMAT_PORCELAIN &&
 	    status_format != STATUS_FORMAT_PORCELAIN_V2)
 		progress_flag = REFRESH_PROGRESS;
-	read_index(&the_index);
+	repo_read_index(the_repository);
 	refresh_index(&the_index,
 		      REFRESH_QUIET|REFRESH_UNMERGED|progress_flag,
 		      &s.pathspec, NULL, NULL);
@@ -1397,7 +1398,7 @@
 	wt_status_collect(&s);
 
 	if (0 <= fd)
-		update_index_if_able(&the_index, &index_lock);
+		repo_update_index_if_able(the_repository, &index_lock);
 
 	if (s.relative_paths)
 		s.prefix = prefix;
@@ -1675,7 +1676,7 @@
 	run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 	run_commit_hook(use_editor, get_index_file(), "post-commit", NULL);
 	if (amend && !no_post_rewrite) {
-		commit_post_rewrite(current_head, &oid);
+		commit_post_rewrite(the_repository, current_head, &oid);
 	}
 	if (!quiet) {
 		unsigned int flags = 0;
diff --git a/builtin/describe.c b/builtin/describe.c
index cc11844..1409ced 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "lockfile.h"
@@ -629,12 +630,13 @@
 			struct argv_array args = ARGV_ARRAY_INIT;
 			int fd, result;
 
+			setup_work_tree();
 			read_cache();
 			refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 				      NULL, NULL, NULL);
 			fd = hold_locked_index(&index_lock, 0);
 			if (0 <= fd)
-				update_index_if_able(&the_index, &index_lock);
+				repo_update_index_if_able(the_repository, &index_lock);
 
 			repo_init_revisions(the_repository, &revs, prefix);
 			argv_array_pushv(&args, diff_index_args);
diff --git a/builtin/diff-files.c b/builtin/diff-files.c
index 48cfcb9..86ae474 100644
--- a/builtin/diff-files.c
+++ b/builtin/diff-files.c
@@ -3,6 +3,7 @@
  *
  * Copyright (C) Linus Torvalds, 2005
  */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "diff.h"
diff --git a/builtin/diff-index.c b/builtin/diff-index.c
index fcccd1f..93ec642 100644
--- a/builtin/diff-index.c
+++ b/builtin/diff-index.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "diff.h"
diff --git a/builtin/diff-tree.c b/builtin/diff-tree.c
index ef99612..a90681b 100644
--- a/builtin/diff-tree.c
+++ b/builtin/diff-tree.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "diff.h"
@@ -165,7 +166,7 @@
 
 		if (opt->diffopt.detect_rename) {
 			if (!the_index.cache)
-				read_index(&the_index);
+				repo_read_index(the_repository);
 			opt->diffopt.setup |= DIFF_SETUP_USE_SIZE_CACHE;
 		}
 		while (fgets(line, sizeof(line), stdin)) {
diff --git a/builtin/diff.c b/builtin/diff.c
index f0393bb..9f61092 100644
--- a/builtin/diff.c
+++ b/builtin/diff.c
@@ -3,6 +3,7 @@
  *
  * Copyright (c) 2006 Junio C Hamano
  */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "lockfile.h"
@@ -102,7 +103,7 @@
 			      int argc, const char **argv,
 			      struct object_array_entry **blob)
 {
-	unsigned mode = canon_mode(S_IFREG | 0644);
+	const unsigned mode = canon_mode(S_IFREG | 0644);
 
 	if (argc > 1)
 		usage(builtin_diff_usage);
@@ -212,7 +213,7 @@
 	discard_cache();
 	read_cache();
 	refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
-	update_index_if_able(&the_index, &lock_file);
+	repo_update_index_if_able(the_repository, &lock_file);
 }
 
 static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
diff --git a/builtin/difftool.c b/builtin/difftool.c
index 71318c2..a3ea60e 100644
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -11,6 +11,7 @@
  *
  * Copyright (C) 2016 Johannes Schindelin
  */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "builtin.h"
diff --git a/builtin/fetch.c b/builtin/fetch.c
index 61a4430..5a09fe2 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -317,8 +317,7 @@
 			    !has_object_file_with_flags(&ref->old_oid,
 							OBJECT_INFO_QUICK) &&
 			    !will_fetch(head, ref->old_oid.hash) &&
-			    !has_sha1_file_with_flags(item->oid.hash,
-						      OBJECT_INFO_QUICK) &&
+			    !has_object_file_with_flags(&item->oid, OBJECT_INFO_QUICK) &&
 			    !will_fetch(head, item->oid.hash))
 				oidclr(&item->oid);
 			item = NULL;
@@ -332,7 +331,7 @@
 		 * fetch.
 		 */
 		if (item &&
-		    !has_sha1_file_with_flags(item->oid.hash, OBJECT_INFO_QUICK) &&
+		    !has_object_file_with_flags(&item->oid, OBJECT_INFO_QUICK) &&
 		    !will_fetch(head, item->oid.hash))
 			oidclr(&item->oid);
 
@@ -353,7 +352,7 @@
 	 * checked to see if it needs fetching.
 	 */
 	if (item &&
-	    !has_sha1_file_with_flags(item->oid.hash, OBJECT_INFO_QUICK) &&
+	    !has_object_file_with_flags(&item->oid, OBJECT_INFO_QUICK) &&
 	    !will_fetch(head, item->oid.hash))
 		oidclr(&item->oid);
 
@@ -629,9 +628,14 @@
 			    const char *needle,
 			    const char *placeholder)
 {
-	const char *p = strstr(haystack->buf, needle);
+	const char *p = NULL;
 	int plen, nlen;
 
+	nlen = strlen(needle);
+	if (ends_with(haystack->buf, needle))
+		p = haystack->buf + haystack->len - nlen;
+	else
+		p = strstr(haystack->buf, needle);
 	if (!p)
 		return 0;
 
@@ -639,7 +643,6 @@
 		return 0;
 
 	plen = strlen(p);
-	nlen = strlen(needle);
 	if (plen > nlen && p[nlen] != '/')
 		return 0;
 
diff --git a/builtin/fsck.c b/builtin/fsck.c
index 9c4c11d..bb4227b 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "cache.h"
 #include "repository.h"
diff --git a/builtin/grep.c b/builtin/grep.c
index dd52ea9..580fd38 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -3,6 +3,7 @@
  *
  * Copyright (c) 2006 Junio C Hamano
  */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "repository.h"
 #include "config.h"
@@ -393,21 +394,22 @@
 		exit(status);
 }
 
-static int grep_cache(struct grep_opt *opt, struct repository *repo,
+static int grep_cache(struct grep_opt *opt,
 		      const struct pathspec *pathspec, int cached);
 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 		     struct tree_desc *tree, struct strbuf *base, int tn_len,
-		     int check_attr, struct repository *repo);
+		     int check_attr);
 
-static int grep_submodule(struct grep_opt *opt, struct repository *superproject,
+static int grep_submodule(struct grep_opt *opt,
 			  const struct pathspec *pathspec,
 			  const struct object_id *oid,
 			  const char *filename, const char *path)
 {
 	struct repository subrepo;
+	struct repository *superproject = opt->repo;
 	const struct submodule *sub = submodule_from_path(superproject,
 							  &null_oid, path);
-
+	struct grep_opt subopt;
 	int hit;
 
 	/*
@@ -443,6 +445,9 @@
 	add_to_alternates_memory(subrepo.objects->odb->path);
 	grep_read_unlock();
 
+	memcpy(&subopt, opt, sizeof(subopt));
+	subopt.repo = &subrepo;
+
 	if (oid) {
 		struct object *object;
 		struct tree_desc tree;
@@ -464,21 +469,22 @@
 		strbuf_addch(&base, '/');
 
 		init_tree_desc(&tree, data, size);
-		hit = grep_tree(opt, pathspec, &tree, &base, base.len,
-				object->type == OBJ_COMMIT, &subrepo);
+		hit = grep_tree(&subopt, pathspec, &tree, &base, base.len,
+				object->type == OBJ_COMMIT);
 		strbuf_release(&base);
 		free(data);
 	} else {
-		hit = grep_cache(opt, &subrepo, pathspec, 1);
+		hit = grep_cache(&subopt, pathspec, 1);
 	}
 
 	repo_clear(&subrepo);
 	return hit;
 }
 
-static int grep_cache(struct grep_opt *opt, struct repository *repo,
+static int grep_cache(struct grep_opt *opt,
 		      const struct pathspec *pathspec, int cached)
 {
+	struct repository *repo = opt->repo;
 	int hit = 0;
 	int nr;
 	struct strbuf name = STRBUF_INIT;
@@ -516,7 +522,7 @@
 			}
 		} else if (recurse_submodules && S_ISGITLINK(ce->ce_mode) &&
 			   submodule_path_match(repo->index, pathspec, name.buf, NULL)) {
-			hit |= grep_submodule(opt, repo, pathspec, NULL, ce->name, ce->name);
+			hit |= grep_submodule(opt, pathspec, NULL, ce->name, ce->name);
 		} else {
 			continue;
 		}
@@ -538,8 +544,9 @@
 
 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 		     struct tree_desc *tree, struct strbuf *base, int tn_len,
-		     int check_attr, struct repository *repo)
+		     int check_attr)
 {
+	struct repository *repo = opt->repo;
 	int hit = 0;
 	enum interesting match = entry_not_interesting;
 	struct name_entry entry;
@@ -586,10 +593,10 @@
 			strbuf_addch(base, '/');
 			init_tree_desc(&sub, data, size);
 			hit |= grep_tree(opt, pathspec, &sub, base, tn_len,
-					 check_attr, repo);
+					 check_attr);
 			free(data);
 		} else if (recurse_submodules && S_ISGITLINK(entry.mode)) {
-			hit |= grep_submodule(opt, repo, pathspec, &entry.oid,
+			hit |= grep_submodule(opt, pathspec, &entry.oid,
 					      base->buf, base->buf + tn_len);
 		}
 
@@ -631,7 +638,7 @@
 		}
 		init_tree_desc(&tree, data, size);
 		hit = grep_tree(opt, pathspec, &tree, &base, base.len,
-				obj->type == OBJ_COMMIT, the_repository);
+				obj->type == OBJ_COMMIT);
 		strbuf_release(&base);
 		free(data);
 		return hit;
@@ -648,12 +655,12 @@
 
 	for (i = 0; i < nr; i++) {
 		struct object *real_obj;
-		real_obj = deref_tag(the_repository, list->objects[i].item,
+		real_obj = deref_tag(opt->repo, list->objects[i].item,
 				     NULL, 0);
 
 		/* load the gitmodules file for this rev */
 		if (recurse_submodules) {
-			submodule_free(the_repository);
+			submodule_free(opt->repo);
 			gitmodules_config_oid(&real_obj->oid);
 		}
 		if (grep_object(opt, pathspec, real_obj, list->objects[i].name,
@@ -678,9 +685,9 @@
 	if (exc_std)
 		setup_standard_excludes(&dir);
 
-	fill_directory(&dir, &the_index, pathspec);
+	fill_directory(&dir, opt->repo->index, pathspec);
 	for (i = 0; i < dir.nr; i++) {
-		if (!dir_path_match(&the_index, dir.entries[i], pathspec, 0, NULL))
+		if (!dir_path_match(opt->repo->index, dir.entries[i], pathspec, 0, NULL))
 			continue;
 		hit |= grep_file(opt, dir.entries[i]->name);
 		if (hit && opt->status_only)
@@ -1018,7 +1025,8 @@
 			break;
 		}
 
-		if (get_oid_with_context(arg, GET_OID_RECORD_PATH,
+		if (get_oid_with_context(the_repository, arg,
+					 GET_OID_RECORD_PATH,
 					 &oid, &oc)) {
 			if (seen_dashdash)
 				die(_("unable to resolve revision: %s"), arg);
@@ -1121,7 +1129,7 @@
 		if (!cached)
 			setup_work_tree();
 
-		hit = grep_cache(&opt, the_repository, &pathspec, cached);
+		hit = grep_cache(&opt, &pathspec, cached);
 	} else {
 		if (cached)
 			die(_("both --cached and trees are given"));
diff --git a/builtin/hash-object.c b/builtin/hash-object.c
index d6f06ea..e055c11 100644
--- a/builtin/hash-object.c
+++ b/builtin/hash-object.c
@@ -40,7 +40,8 @@
 	if (fstat(fd, &st) < 0 ||
 	    (literally
 	     ? hash_literally(&oid, fd, type, flags)
-	     : index_fd(&the_index, &oid, fd, &st, type_from_string(type), path, flags)))
+	     : index_fd(the_repository->index, &oid, fd, &st,
+			type_from_string(type), path, flags)))
 		die((flags & HASH_WRITE_OBJECT)
 		    ? "Unable to add %s to database"
 		    : "Unable to hash %s", path);
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index ac1f4ea..31046c7 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -772,7 +772,7 @@
 	if (startup_info->have_repository) {
 		read_lock();
 		collision_test_needed =
-			has_sha1_file_with_flags(oid->hash, OBJECT_INFO_QUICK);
+			has_object_file_with_flags(oid, OBJECT_INFO_QUICK);
 		read_unlock();
 	}
 
diff --git a/builtin/log.c b/builtin/log.c
index c91a59d..5786926 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -4,6 +4,7 @@
  * (C) Copyright 2006 Linus Torvalds
  *		 2006 Junio Hamano
  */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "refs.h"
@@ -509,7 +510,8 @@
 	    !rev->diffopt.flags.allow_textconv)
 		return stream_blob_to_fd(1, oid, NULL, 0);
 
-	if (get_oid_with_context(obj_name, GET_OID_RECORD_PATH,
+	if (get_oid_with_context(the_repository, obj_name,
+				 GET_OID_RECORD_PATH,
 				 &oidc, &obj_context))
 		die(_("Not a valid object name %s"), obj_name);
 	if (!obj_context.path ||
diff --git a/builtin/ls-files.c b/builtin/ls-files.c
index cde87cb..29a8762 100644
--- a/builtin/ls-files.c
+++ b/builtin/ls-files.c
@@ -5,7 +5,6 @@
  *
  * Copyright (C) Linus Torvalds, 2005
  */
-#define NO_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "repository.h"
 #include "config.h"
diff --git a/builtin/merge-index.c b/builtin/merge-index.c
index c99443b..38ea6ad 100644
--- a/builtin/merge-index.c
+++ b/builtin/merge-index.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "run-command.h"
 
diff --git a/builtin/merge-ours.c b/builtin/merge-ours.c
index 0b07263..4594507 100644
--- a/builtin/merge-ours.c
+++ b/builtin/merge-ours.c
@@ -7,6 +7,7 @@
  *
  * Pretend we resolved the heads, but declare our tree trumps everybody else.
  */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "git-compat-util.h"
 #include "builtin.h"
 #include "diff.h"
diff --git a/builtin/merge-recursive.c b/builtin/merge-recursive.c
index 7545136..5b910e3 100644
--- a/builtin/merge-recursive.c
+++ b/builtin/merge-recursive.c
@@ -29,7 +29,7 @@
 	char *better1, *better2;
 	struct commit *result;
 
-	init_merge_options(&o);
+	init_merge_options(&o, the_repository);
 	if (argv[0] && ends_with(argv[0], "-subtree"))
 		o.subtree_shift = "";
 
diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index 5541ad0..34ca025 100644
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "tree-walk.h"
 #include "xdiff-interface.h"
@@ -76,7 +77,8 @@
 	their = NULL;
 	if (entry)
 		their = entry->blob;
-	return merge_blobs(&the_index, path, base, our, their, size);
+	return merge_blobs(the_repository->index, path,
+			   base, our, their, size);
 }
 
 static void *origin(struct merge_list *entry, unsigned long *size)
diff --git a/builtin/merge.c b/builtin/merge.c
index dc0b7cc..e47d77b 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -6,6 +6,7 @@
  * Based on git-merge.sh by Junio C Hamano.
  */
 
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "parse-options.h"
@@ -702,7 +703,7 @@
 			return 2;
 		}
 
-		init_merge_options(&o);
+		init_merge_options(&o, the_repository);
 		if (!strcmp(strategy, "subtree"))
 			o.subtree_shift = "";
 
diff --git a/builtin/mv.c b/builtin/mv.c
index 80bb967..be15ba7 100644
--- a/builtin/mv.c
+++ b/builtin/mv.c
@@ -3,6 +3,7 @@
  *
  * Copyright (C) 2006 Johannes Schindelin
  */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "config.h"
 #include "pathspec.h"
diff --git a/builtin/notes.c b/builtin/notes.c
index 4996a67..02e97f5 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -330,10 +330,10 @@
 	}
 
 	if (!rewrite_cmd) {
-		commit_notes(t, msg);
+		commit_notes(the_repository, t, msg);
 		free_notes(t);
 	} else {
-		finish_copy_notes_for_rewrite(c, msg);
+		finish_copy_notes_for_rewrite(the_repository, c, msg);
 	}
 	strbuf_release(&buf);
 	return ret;
@@ -469,12 +469,14 @@
 		write_note_data(&d, &new_note);
 		if (add_note(t, &object, &new_note, combine_notes_overwrite))
 			BUG("combine_notes_overwrite failed");
-		commit_notes(t, "Notes added by 'git notes add'");
+		commit_notes(the_repository, t,
+			     "Notes added by 'git notes add'");
 	} else {
 		fprintf(stderr, _("Removing note for object %s\n"),
 			oid_to_hex(&object));
 		remove_note(t, object.hash);
-		commit_notes(t, "Notes removed by 'git notes add'");
+		commit_notes(the_repository, t,
+			     "Notes removed by 'git notes add'");
 	}
 
 	free_note_data(&d);
@@ -552,7 +554,8 @@
 
 	if (add_note(t, &object, from_note, combine_notes_overwrite))
 		BUG("combine_notes_overwrite failed");
-	commit_notes(t, "Notes added by 'git notes copy'");
+	commit_notes(the_repository, t,
+		     "Notes added by 'git notes copy'");
 out:
 	free_notes(t);
 	return retval;
@@ -636,7 +639,7 @@
 		remove_note(t, object.hash);
 		logmsg = xstrfmt("Notes removed by 'git notes %s'", argv[0]);
 	}
-	commit_notes(t, logmsg);
+	commit_notes(the_repository, t, logmsg);
 
 	free(logmsg);
 	free_note_data(&d);
@@ -937,7 +940,8 @@
 		strbuf_release(&sb);
 	}
 	if (!retval)
-		commit_notes(t, "Notes removed by 'git notes remove'");
+		commit_notes(the_repository, t,
+			     "Notes removed by 'git notes remove'");
 	free_notes(t);
 	return retval;
 }
@@ -965,7 +969,8 @@
 	prune_notes(t, (verbose ? NOTES_PRUNE_VERBOSE : 0) |
 		(show_only ? NOTES_PRUNE_VERBOSE|NOTES_PRUNE_DRYRUN : 0) );
 	if (!show_only)
-		commit_notes(t, "Notes removed by 'git notes prune'");
+		commit_notes(the_repository, t,
+			     "Notes removed by 'git notes prune'");
 	free_notes(t);
 	return 0;
 }
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 0a70d04..a9fac7c 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -84,6 +84,7 @@
 static int depth = 50;
 static int delta_search_threads;
 static int pack_to_stdout;
+static int sparse;
 static int thin;
 static int num_preferred_base;
 static struct progress *progress_state;
@@ -970,7 +971,7 @@
 
 	if (!check)
 		check = attr_check_initl("delta", NULL);
-	git_check_attr(&the_index, path, check);
+	git_check_attr(the_repository->index, path, check);
 	if (ATTR_FALSE(check->items[0].value))
 		return 1;
 	return 0;
@@ -1642,7 +1643,7 @@
 
 		/*
 		 * No choice but to fall back to the recursive delta walk
-		 * with sha1_object_info() to find about the object type
+		 * with oid_object_info() to find about the object type
 		 * at this point...
 		 */
 		give_up:
@@ -1718,7 +1719,7 @@
 	if (packed_object_info(the_repository, IN_PACK(entry), entry->in_pack_offset, &oi) < 0) {
 		/*
 		 * We failed to get the info from this pack for some reason;
-		 * fall back to sha1_object_info, which may find another copy.
+		 * fall back to oid_object_info, which may find another copy.
 		 * And if that fails, the error will be recorded in oe_type(entry)
 		 * and dealt with in prepare_pack().
 		 */
@@ -1901,10 +1902,10 @@
 {
 	const struct object_entry *a = *(struct object_entry **)_a;
 	const struct object_entry *b = *(struct object_entry **)_b;
-	enum object_type a_type = oe_type(a);
-	enum object_type b_type = oe_type(b);
-	unsigned long a_size = SIZE(a);
-	unsigned long b_size = SIZE(b);
+	const enum object_type a_type = oe_type(a);
+	const enum object_type b_type = oe_type(b);
+	const unsigned long a_size = SIZE(a);
+	const unsigned long b_size = SIZE(b);
 
 	if (a_type > b_type)
 		return -1;
@@ -1919,7 +1920,7 @@
 	if (a->preferred_base < b->preferred_base)
 		return 1;
 	if (use_delta_islands) {
-		int island_cmp = island_delta_cmp(&a->idx.oid, &b->idx.oid);
+		const int island_cmp = island_delta_cmp(&a->idx.oid, &b->idx.oid);
 		if (island_cmp)
 			return island_cmp;
 	}
@@ -1953,11 +1954,6 @@
 	return 0;
 }
 
-/* Protect access to object database */
-static pthread_mutex_t read_mutex;
-#define read_lock()		pthread_mutex_lock(&read_mutex)
-#define read_unlock()		pthread_mutex_unlock(&read_mutex)
-
 /* Protect delta_cache_size */
 static pthread_mutex_t cache_mutex;
 #define cache_lock()		pthread_mutex_lock(&cache_mutex)
@@ -1993,11 +1989,11 @@
 	unsigned long used, avail, size;
 
 	if (e->type_ != OBJ_OFS_DELTA && e->type_ != OBJ_REF_DELTA) {
-		read_lock();
+		packing_data_lock(&to_pack);
 		if (oid_object_info(the_repository, &e->idx.oid, &size) < 0)
 			die(_("unable to get size of %s"),
 			    oid_to_hex(&e->idx.oid));
-		read_unlock();
+		packing_data_unlock(&to_pack);
 		return size;
 	}
 
@@ -2005,7 +2001,7 @@
 	if (!p)
 		BUG("when e->type is a delta, it must belong to a pack");
 
-	read_lock();
+	packing_data_lock(&to_pack);
 	w_curs = NULL;
 	buf = use_pack(p, &w_curs, e->in_pack_offset, &avail);
 	used = unpack_object_header_buffer(buf, avail, &type, &size);
@@ -2014,7 +2010,7 @@
 		    oid_to_hex(&e->idx.oid));
 
 	unuse_pack(&w_curs);
-	read_unlock();
+	packing_data_unlock(&to_pack);
 	return size;
 }
 
@@ -2076,9 +2072,9 @@
 
 	/* Load data if not already done */
 	if (!trg->data) {
-		read_lock();
+		packing_data_lock(&to_pack);
 		trg->data = read_object_file(&trg_entry->idx.oid, &type, &sz);
-		read_unlock();
+		packing_data_unlock(&to_pack);
 		if (!trg->data)
 			die(_("object %s cannot be read"),
 			    oid_to_hex(&trg_entry->idx.oid));
@@ -2089,9 +2085,9 @@
 		*mem_usage += sz;
 	}
 	if (!src->data) {
-		read_lock();
+		packing_data_lock(&to_pack);
 		src->data = read_object_file(&src_entry->idx.oid, &type, &sz);
-		read_unlock();
+		packing_data_unlock(&to_pack);
 		if (!src->data) {
 			if (src_entry->preferred_base) {
 				static int warned = 0;
@@ -2171,7 +2167,7 @@
 	struct object_entry *child = DELTA_CHILD(me);
 	unsigned int m = n;
 	while (child) {
-		unsigned int c = check_delta_limit(child, n + 1);
+		const unsigned int c = check_delta_limit(child, n + 1);
 		if (m < c)
 			m = c;
 		child = DELTA_SIBLING(child);
@@ -2226,7 +2222,7 @@
 		while (window_memory_limit &&
 		       mem_usage > window_memory_limit &&
 		       count > 1) {
-			uint32_t tail = (idx + window - count) % window;
+			const uint32_t tail = (idx + window - count) % window;
 			mem_usage -= free_unpacked(array + tail);
 			count--;
 		}
@@ -2337,9 +2333,9 @@
 
 static void try_to_free_from_threads(size_t size)
 {
-	read_lock();
+	packing_data_lock(&to_pack);
 	release_pack_memory(size);
-	read_unlock();
+	packing_data_unlock(&to_pack);
 }
 
 static try_to_free_t old_try_to_free_routine;
@@ -2381,7 +2377,6 @@
  */
 static void init_threaded_search(void)
 {
-	init_recursive_mutex(&read_mutex);
 	pthread_mutex_init(&cache_mutex, NULL);
 	pthread_mutex_init(&progress_mutex, NULL);
 	pthread_cond_init(&progress_cond, NULL);
@@ -2392,7 +2387,6 @@
 {
 	set_try_to_free_routine(old_try_to_free_routine);
 	pthread_cond_destroy(&progress_cond);
-	pthread_mutex_destroy(&read_mutex);
 	pthread_mutex_destroy(&cache_mutex);
 	pthread_mutex_destroy(&progress_mutex);
 }
@@ -2710,6 +2704,10 @@
 		use_bitmap_index_default = git_config_bool(k, v);
 		return 0;
 	}
+	if (!strcmp(k, "pack.usesparse")) {
+		sparse = git_config_bool(k, v);
+		return 0;
+	}
 	if (!strcmp(k, "pack.threads")) {
 		delta_search_threads = git_config_int(k, v);
 		if (delta_search_threads < 0)
@@ -3137,7 +3135,7 @@
 
 	if (prepare_revision_walk(&revs))
 		die(_("revision walk setup failed"));
-	mark_edges_uninteresting(&revs, show_edge);
+	mark_edges_uninteresting(&revs, show_edge, sparse);
 
 	if (!fn_show_object)
 		fn_show_object = show_object;
@@ -3294,6 +3292,8 @@
 		{ OPTION_CALLBACK, 0, "unpack-unreachable", NULL, N_("time"),
 		  N_("unpack unreachable objects newer than <time>"),
 		  PARSE_OPT_OPTARG, option_parse_unpack_unreachable },
+		OPT_BOOL(0, "sparse", &sparse,
+			 N_("use the sparse reachability algorithm")),
 		OPT_BOOL(0, "thin", &thin,
 			 N_("create thin packs")),
 		OPT_BOOL(0, "shallow", &shallow,
@@ -3326,6 +3326,7 @@
 
 	read_replace_refs = 0;
 
+	sparse = git_env_bool("GIT_TEST_PACK_SPARSE", 0);
 	reset_pack_idx_option(&pack_idx_opts);
 	git_config(git_pack_config, NULL);
 
diff --git a/builtin/pack-redundant.c b/builtin/pack-redundant.c
index cf9a9aa..11bc514 100644
--- a/builtin/pack-redundant.c
+++ b/builtin/pack-redundant.c
@@ -166,7 +166,7 @@
 	l = (hint == NULL) ? list->front : hint;
 	prev = NULL;
 	while (l) {
-		int cmp = oidcmp(l->oid, oid);
+		const int cmp = oidcmp(l->oid, oid);
 		if (cmp > 0) /* not in list, since sorted */
 			return prev;
 		if (!cmp) { /* found */
@@ -264,7 +264,7 @@
 	while (p1_off < p1->pack->num_objects * p1_step &&
 	       p2_off < p2->pack->num_objects * p2_step)
 	{
-		int cmp = hashcmp(p1_base + p1_off, p2_base + p2_off);
+		const int cmp = hashcmp(p1_base + p1_off, p2_base + p2_off);
 		/* cmp ~ p1 - p2 */
 		if (cmp == 0) {
 			p1_hint = llist_sorted_remove(p1->unique_objects,
diff --git a/builtin/pull.c b/builtin/pull.c
index 74808b9..701d147 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -5,6 +5,7 @@
  *
  * Fetch one or more remote refs and merge it/them into the current HEAD.
  */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "builtin.h"
diff --git a/builtin/read-tree.c b/builtin/read-tree.c
index ac255ad..9083dcf 100644
--- a/builtin/read-tree.c
+++ b/builtin/read-tree.c
@@ -4,6 +4,7 @@
  * Copyright (C) Linus Torvalds, 2005
  */
 
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "lockfile.h"
diff --git a/builtin/rebase--interactive.c b/builtin/rebase--interactive.c
index c2c2d51..888390f 100644
--- a/builtin/rebase--interactive.c
+++ b/builtin/rebase--interactive.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "cache.h"
 #include "config.h"
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 774264b..b9d6177 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -4,6 +4,7 @@
  * Copyright (c) 2018 Pratik Karki
  */
 
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "run-command.h"
 #include "exec-cmd.h"
@@ -123,7 +124,7 @@
 	case REBASE_PRESERVE_MERGES:
 		break;
 	case REBASE_MERGE:
-		/* we silently *upgrade* --merge to --interactive if needed */
+		/* we now implement --merge via --interactive */
 	default:
 		opts->type = REBASE_INTERACTIVE; /* implied */
 		break;
@@ -186,10 +187,7 @@
 	if (get_oid(buf.buf, &opts->orig_head))
 		return error(_("invalid orig-head: '%s'"), buf.buf);
 
-	strbuf_reset(&buf);
-	if (read_one(state_dir_path("quiet", opts), &buf))
-		return -1;
-	if (buf.len)
+	if (file_exists(state_dir_path("quiet", opts)))
 		opts->flags &= ~REBASE_NO_QUIET;
 	else
 		opts->flags |= REBASE_NO_QUIET;
@@ -247,6 +245,37 @@
 	return 0;
 }
 
+static int write_basic_state(struct rebase_options *opts)
+{
+	write_file(state_dir_path("head-name", opts), "%s",
+		   opts->head_name ? opts->head_name : "detached HEAD");
+	write_file(state_dir_path("onto", opts), "%s",
+		   opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
+	write_file(state_dir_path("orig-head", opts), "%s",
+		   oid_to_hex(&opts->orig_head));
+	write_file(state_dir_path("quiet", opts), "%s",
+		   opts->flags & REBASE_NO_QUIET ? "" : "t");
+	if (opts->flags & REBASE_VERBOSE)
+		write_file(state_dir_path("verbose", opts), "%s", "");
+	if (opts->strategy)
+		write_file(state_dir_path("strategy", opts), "%s",
+			   opts->strategy);
+	if (opts->strategy_opts)
+		write_file(state_dir_path("strategy_opts", opts), "%s",
+			   opts->strategy_opts);
+	if (opts->allow_rerere_autoupdate >= 0)
+		write_file(state_dir_path("allow_rerere_autoupdate", opts),
+			   "-%s-rerere-autoupdate",
+			   opts->allow_rerere_autoupdate ? "" : "-no");
+	if (opts->gpg_sign_opt)
+		write_file(state_dir_path("gpg_sign_opt", opts), "%s",
+			   opts->gpg_sign_opt);
+	if (opts->signoff)
+		write_file(state_dir_path("strategy", opts), "--signoff");
+
+	return 0;
+}
+
 static int apply_autostash(struct rebase_options *opts)
 {
 	const char *path = state_dir_path("autostash", opts);
@@ -334,6 +363,161 @@
 	}
 }
 
+#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
+
+#define RESET_HEAD_DETACH (1<<0)
+#define RESET_HEAD_HARD (1<<1)
+#define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
+#define RESET_HEAD_REFS_ONLY (1<<3)
+
+static int reset_head(struct object_id *oid, const char *action,
+		      const char *switch_to_branch, unsigned flags,
+		      const char *reflog_orig_head, const char *reflog_head)
+{
+	unsigned detach_head = flags & RESET_HEAD_DETACH;
+	unsigned reset_hard = flags & RESET_HEAD_HARD;
+	unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
+	unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
+	struct object_id head_oid;
+	struct tree_desc desc[2] = { { NULL }, { NULL } };
+	struct lock_file lock = LOCK_INIT;
+	struct unpack_trees_options unpack_tree_opts;
+	struct tree *tree;
+	const char *reflog_action;
+	struct strbuf msg = STRBUF_INIT;
+	size_t prefix_len;
+	struct object_id *orig = NULL, oid_orig,
+		*old_orig = NULL, oid_old_orig;
+	int ret = 0, nr = 0;
+
+	if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
+		BUG("Not a fully qualified branch: '%s'", switch_to_branch);
+
+	if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
+		ret = -1;
+		goto leave_reset_head;
+	}
+
+	if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
+		ret = error(_("could not determine HEAD revision"));
+		goto leave_reset_head;
+	}
+
+	if (!oid)
+		oid = &head_oid;
+
+	if (refs_only)
+		goto reset_head_refs;
+
+	memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
+	setup_unpack_trees_porcelain(&unpack_tree_opts, action);
+	unpack_tree_opts.head_idx = 1;
+	unpack_tree_opts.src_index = the_repository->index;
+	unpack_tree_opts.dst_index = the_repository->index;
+	unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
+	unpack_tree_opts.update = 1;
+	unpack_tree_opts.merge = 1;
+	if (!detach_head)
+		unpack_tree_opts.reset = 1;
+
+	if (repo_read_index_unmerged(the_repository) < 0) {
+		ret = error(_("could not read index"));
+		goto leave_reset_head;
+	}
+
+	if (!reset_hard && !fill_tree_descriptor(&desc[nr++], &head_oid)) {
+		ret = error(_("failed to find tree of %s"),
+			    oid_to_hex(&head_oid));
+		goto leave_reset_head;
+	}
+
+	if (!fill_tree_descriptor(&desc[nr++], oid)) {
+		ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
+		goto leave_reset_head;
+	}
+
+	if (unpack_trees(nr, desc, &unpack_tree_opts)) {
+		ret = -1;
+		goto leave_reset_head;
+	}
+
+	tree = parse_tree_indirect(oid);
+	prime_cache_tree(the_repository, the_repository->index, tree);
+
+	if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
+		ret = error(_("could not write index"));
+		goto leave_reset_head;
+	}
+
+reset_head_refs:
+	reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
+	strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
+	prefix_len = msg.len;
+
+	if (!get_oid("ORIG_HEAD", &oid_old_orig))
+		old_orig = &oid_old_orig;
+	if (!get_oid("HEAD", &oid_orig)) {
+		orig = &oid_orig;
+		if (!reflog_orig_head) {
+			strbuf_addstr(&msg, "updating ORIG_HEAD");
+			reflog_orig_head = msg.buf;
+		}
+		update_ref(reflog_orig_head, "ORIG_HEAD", orig, old_orig, 0,
+			   UPDATE_REFS_MSG_ON_ERR);
+	} else if (old_orig)
+		delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
+	if (!reflog_head) {
+		strbuf_setlen(&msg, prefix_len);
+		strbuf_addstr(&msg, "updating HEAD");
+		reflog_head = msg.buf;
+	}
+	if (!switch_to_branch)
+		ret = update_ref(reflog_head, "HEAD", oid, orig,
+				 detach_head ? REF_NO_DEREF : 0,
+				 UPDATE_REFS_MSG_ON_ERR);
+	else {
+		ret = update_ref(reflog_orig_head, switch_to_branch, oid,
+				 NULL, 0, UPDATE_REFS_MSG_ON_ERR);
+		if (!ret)
+			ret = create_symref("HEAD", switch_to_branch,
+					    reflog_head);
+	}
+	if (run_hook)
+		run_hook_le(NULL, "post-checkout",
+			    oid_to_hex(orig ? orig : &null_oid),
+			    oid_to_hex(oid), "1", NULL);
+
+leave_reset_head:
+	strbuf_release(&msg);
+	rollback_lock_file(&lock);
+	while (nr)
+		free((void *)desc[--nr].buffer);
+	return ret;
+}
+
+static int move_to_original_branch(struct rebase_options *opts)
+{
+	struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
+	int ret;
+
+	if (!opts->head_name)
+		return 0; /* nothing to move back to */
+
+	if (!opts->onto)
+		BUG("move_to_original_branch without onto");
+
+	strbuf_addf(&orig_head_reflog, "rebase finished: %s onto %s",
+		    opts->head_name, oid_to_hex(&opts->onto->object.oid));
+	strbuf_addf(&head_reflog, "rebase finished: returning to %s",
+		    opts->head_name);
+	ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
+			 orig_head_reflog.buf, head_reflog.buf);
+
+	strbuf_release(&orig_head_reflog);
+	strbuf_release(&head_reflog);
+	return ret;
+}
+
 static const char *resolvemsg =
 N_("Resolve all conflicts manually, mark them as resolved with\n"
 "\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
@@ -341,6 +525,126 @@
 "To abort and get back to the state before \"git rebase\", run "
 "\"git rebase --abort\".");
 
+static int run_am(struct rebase_options *opts)
+{
+	struct child_process am = CHILD_PROCESS_INIT;
+	struct child_process format_patch = CHILD_PROCESS_INIT;
+	struct strbuf revisions = STRBUF_INIT;
+	int status;
+	char *rebased_patches;
+
+	am.git_cmd = 1;
+	argv_array_push(&am.args, "am");
+
+	if (opts->action && !strcmp("continue", opts->action)) {
+		argv_array_push(&am.args, "--resolved");
+		argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
+		if (opts->gpg_sign_opt)
+			argv_array_push(&am.args, opts->gpg_sign_opt);
+		status = run_command(&am);
+		if (status)
+			return status;
+
+		return move_to_original_branch(opts);
+	}
+	if (opts->action && !strcmp("skip", opts->action)) {
+		argv_array_push(&am.args, "--skip");
+		argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
+		status = run_command(&am);
+		if (status)
+			return status;
+
+		return move_to_original_branch(opts);
+	}
+	if (opts->action && !strcmp("show-current-patch", opts->action)) {
+		argv_array_push(&am.args, "--show-current-patch");
+		return run_command(&am);
+	}
+
+	strbuf_addf(&revisions, "%s...%s",
+		    oid_to_hex(opts->root ?
+			       /* this is now equivalent to !opts->upstream */
+			       &opts->onto->object.oid :
+			       &opts->upstream->object.oid),
+		    oid_to_hex(&opts->orig_head));
+
+	rebased_patches = xstrdup(git_path("rebased-patches"));
+	format_patch.out = open(rebased_patches,
+				O_WRONLY | O_CREAT | O_TRUNC, 0666);
+	if (format_patch.out < 0) {
+		status = error_errno(_("could not open '%s' for writing"),
+				     rebased_patches);
+		free(rebased_patches);
+		argv_array_clear(&am.args);
+		return status;
+	}
+
+	format_patch.git_cmd = 1;
+	argv_array_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
+			 "--full-index", "--cherry-pick", "--right-only",
+			 "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
+			 "--no-cover-letter", "--pretty=mboxrd", "--topo-order", NULL);
+	if (opts->git_format_patch_opt.len)
+		argv_array_split(&format_patch.args,
+				 opts->git_format_patch_opt.buf);
+	argv_array_push(&format_patch.args, revisions.buf);
+	if (opts->restrict_revision)
+		argv_array_pushf(&format_patch.args, "^%s",
+				 oid_to_hex(&opts->restrict_revision->object.oid));
+
+	status = run_command(&format_patch);
+	if (status) {
+		unlink(rebased_patches);
+		free(rebased_patches);
+		argv_array_clear(&am.args);
+
+		reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
+			   "HEAD", NULL);
+		error(_("\ngit encountered an error while preparing the "
+			"patches to replay\n"
+			"these revisions:\n"
+			"\n    %s\n\n"
+			"As a result, git cannot rebase them."),
+		      opts->revisions);
+
+		strbuf_release(&revisions);
+		return status;
+	}
+	strbuf_release(&revisions);
+
+	am.in = open(rebased_patches, O_RDONLY);
+	if (am.in < 0) {
+		status = error_errno(_("could not open '%s' for reading"),
+				     rebased_patches);
+		free(rebased_patches);
+		argv_array_clear(&am.args);
+		return status;
+	}
+
+	argv_array_pushv(&am.args, opts->git_am_opts.argv);
+	argv_array_push(&am.args, "--rebasing");
+	argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
+	argv_array_push(&am.args, "--patch-format=mboxrd");
+	if (opts->allow_rerere_autoupdate > 0)
+		argv_array_push(&am.args, "--rerere-autoupdate");
+	else if (opts->allow_rerere_autoupdate == 0)
+		argv_array_push(&am.args, "--no-rerere-autoupdate");
+	if (opts->gpg_sign_opt)
+		argv_array_push(&am.args, opts->gpg_sign_opt);
+	status = run_command(&am);
+	unlink(rebased_patches);
+	free(rebased_patches);
+
+	if (!status) {
+		return move_to_original_branch(opts);
+	}
+
+	if (is_directory(opts->state_dir))
+		write_basic_state(opts);
+
+	return status;
+}
+
 static int run_specific_rebase(struct rebase_options *opts)
 {
 	const char *argv[] = { NULL, NULL };
@@ -355,7 +659,8 @@
 		argv_array_pushf(&child.env_array, "GIT_CHERRY_PICK_HELP=%s",
 				 resolvemsg);
 		if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
-			argv_array_push(&child.env_array, "GIT_EDITOR=:");
+			argv_array_push(&child.env_array,
+					"GIT_SEQUENCE_EDITOR=:");
 			opts->autosquash = 0;
 		}
 
@@ -423,6 +728,11 @@
 		goto finished_rebase;
 	}
 
+	if (opts->type == REBASE_AM) {
+		status = run_am(opts);
+		goto finished_rebase;
+	}
+
 	add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 	add_var(&script_snippet, "state_dir", opts->state_dir);
 
@@ -478,7 +788,7 @@
 	if (is_interactive(opts) &&
 	    !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 		strbuf_addstr(&script_snippet,
-			      "GIT_EDITOR=:; export GIT_EDITOR; ");
+			      "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
 		opts->autosquash = 0;
 	}
 
@@ -487,10 +797,6 @@
 		backend = "git-rebase--am";
 		backend_func = "git_rebase__am";
 		break;
-	case REBASE_MERGE:
-		backend = "git-rebase--merge";
-		backend_func = "git_rebase__merge";
-		break;
 	case REBASE_PRESERVE_MERGES:
 		backend = "git-rebase--preserve-merges";
 		backend_func = "git_rebase__preserve_merges";
@@ -529,131 +835,6 @@
 	return status ? -1 : 0;
 }
 
-#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
-
-#define RESET_HEAD_DETACH (1<<0)
-#define RESET_HEAD_HARD (1<<1)
-#define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
-
-static int reset_head(struct object_id *oid, const char *action,
-		      const char *switch_to_branch, unsigned flags,
-		      const char *reflog_orig_head, const char *reflog_head)
-{
-	unsigned detach_head = flags & RESET_HEAD_DETACH;
-	unsigned reset_hard = flags & RESET_HEAD_HARD;
-	unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
-	struct object_id head_oid;
-	struct tree_desc desc[2] = { { NULL }, { NULL } };
-	struct lock_file lock = LOCK_INIT;
-	struct unpack_trees_options unpack_tree_opts;
-	struct tree *tree;
-	const char *reflog_action;
-	struct strbuf msg = STRBUF_INIT;
-	size_t prefix_len;
-	struct object_id *orig = NULL, oid_orig,
-		*old_orig = NULL, oid_old_orig;
-	int ret = 0, nr = 0;
-
-	if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
-		BUG("Not a fully qualified branch: '%s'", switch_to_branch);
-
-	if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
-		ret = -1;
-		goto leave_reset_head;
-	}
-
-	if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
-		ret = error(_("could not determine HEAD revision"));
-		goto leave_reset_head;
-	}
-
-	if (!oid)
-		oid = &head_oid;
-
-	memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
-	setup_unpack_trees_porcelain(&unpack_tree_opts, action);
-	unpack_tree_opts.head_idx = 1;
-	unpack_tree_opts.src_index = the_repository->index;
-	unpack_tree_opts.dst_index = the_repository->index;
-	unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
-	unpack_tree_opts.update = 1;
-	unpack_tree_opts.merge = 1;
-	if (!detach_head)
-		unpack_tree_opts.reset = 1;
-
-	if (read_index_unmerged(the_repository->index) < 0) {
-		ret = error(_("could not read index"));
-		goto leave_reset_head;
-	}
-
-	if (!reset_hard && !fill_tree_descriptor(&desc[nr++], &head_oid)) {
-		ret = error(_("failed to find tree of %s"),
-			    oid_to_hex(&head_oid));
-		goto leave_reset_head;
-	}
-
-	if (!fill_tree_descriptor(&desc[nr++], oid)) {
-		ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
-		goto leave_reset_head;
-	}
-
-	if (unpack_trees(nr, desc, &unpack_tree_opts)) {
-		ret = -1;
-		goto leave_reset_head;
-	}
-
-	tree = parse_tree_indirect(oid);
-	prime_cache_tree(the_repository, the_repository->index, tree);
-
-	if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
-		ret = error(_("could not write index"));
-		goto leave_reset_head;
-	}
-
-	reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
-	strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
-	prefix_len = msg.len;
-
-	if (!get_oid("ORIG_HEAD", &oid_old_orig))
-		old_orig = &oid_old_orig;
-	if (!get_oid("HEAD", &oid_orig)) {
-		orig = &oid_orig;
-		if (!reflog_orig_head) {
-			strbuf_addstr(&msg, "updating ORIG_HEAD");
-			reflog_orig_head = msg.buf;
-		}
-		update_ref(reflog_orig_head, "ORIG_HEAD", orig, old_orig, 0,
-			   UPDATE_REFS_MSG_ON_ERR);
-	} else if (old_orig)
-		delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
-	if (!reflog_head) {
-		strbuf_setlen(&msg, prefix_len);
-		strbuf_addstr(&msg, "updating HEAD");
-		reflog_head = msg.buf;
-	}
-	if (!switch_to_branch)
-		ret = update_ref(reflog_head, "HEAD", oid, orig,
-				 detach_head ? REF_NO_DEREF : 0,
-				 UPDATE_REFS_MSG_ON_ERR);
-	else {
-		ret = create_symref("HEAD", switch_to_branch, msg.buf);
-		if (!ret)
-			ret = update_ref(reflog_head, "HEAD", oid, NULL, 0,
-					 UPDATE_REFS_MSG_ON_ERR);
-	}
-	if (run_hook)
-		run_hook_le(NULL, "post-checkout",
-			    oid_to_hex(orig ? orig : &null_oid),
-			    oid_to_hex(oid), "1", NULL);
-
-leave_reset_head:
-	strbuf_release(&msg);
-	rollback_lock_file(&lock);
-	while (nr)
-		free((void *)desc[--nr].buffer);
-	return ret;
-}
-
 static int rebase_config(const char *var, const char *value, void *data)
 {
 	struct rebase_options *opts = data;
@@ -824,6 +1005,19 @@
 	strbuf_release(&buf);
 }
 
+static int check_exec_cmd(const char *cmd)
+{
+	if (strchr(cmd, '\n'))
+		return error(_("exec commands cannot contain newlines"));
+
+	/* Does the command consist purely of whitespace? */
+	if (!cmd[strspn(cmd, " \t\r\f\v")])
+		return error(_("empty exec command"));
+
+	return 0;
+}
+
+
 int cmd_rebase(int argc, const char **argv, const char *prefix)
 {
 	struct rebase_options options = {
@@ -1053,13 +1247,12 @@
 			die(_("Cannot read HEAD"));
 
 		fd = hold_locked_index(&lock_file, 0);
-		if (read_index(the_repository->index) < 0)
+		if (repo_read_index(the_repository) < 0)
 			die(_("could not read index"));
 		refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
 			      NULL);
 		if (0 <= fd)
-			update_index_if_able(the_repository->index,
-					     &lock_file);
+			repo_update_index_if_able(the_repository, &lock_file);
 		rollback_lock_file(&lock_file);
 
 		if (has_unstaged_changes(the_repository, 1)) {
@@ -1168,6 +1361,10 @@
 		}
 	}
 
+	for (i = 0; i < exec.nr; i++)
+		if (check_exec_cmd(exec.items[i].string))
+			exit(1);
+
 	if (!(options.flags & REBASE_NO_QUIET))
 		argv_array_push(&options.git_am_opts, "-q");
 
@@ -1232,6 +1429,9 @@
 		}
 	}
 
+	if (options.type == REBASE_MERGE)
+		imply_interactive(&options, "--merge");
+
 	if (options.root && !options.onto_name)
 		imply_interactive(&options, "--root without --onto");
 
@@ -1264,14 +1464,8 @@
 				break;
 
 		if (is_interactive(&options) && i >= 0)
-			die(_("error: cannot combine interactive options "
-			      "(--interactive, --exec, --rebase-merges, "
-			      "--preserve-merges, --keep-empty, --root + "
-			      "--onto) with am options (%s)"), buf.buf);
-		if (options.type == REBASE_MERGE && i >= 0)
-			die(_("error: cannot combine merge options (--merge, "
-			      "--strategy, --strategy-option) with am options "
-			      "(%s)"), buf.buf);
+			die(_("cannot combine am options with either "
+			      "interactive or merge options"));
 	}
 
 	if (options.signoff) {
@@ -1289,7 +1483,7 @@
 		 *       git-rebase.txt caveats with "unless you know what you are doing"
 		 */
 		if (options.rebase_merges)
-			die(_("error: cannot combine '--preserve-merges' with "
+			die(_("cannot combine '--preserve-merges' with "
 			      "'--rebase-merges'"));
 
 		if (options.reschedule_failed_exec)
@@ -1299,10 +1493,10 @@
 
 	if (options.rebase_merges) {
 		if (strategy_options.nr)
-			die(_("error: cannot combine '--rebase-merges' with "
+			die(_("cannot combine '--rebase-merges' with "
 			      "'--strategy-option'"));
 		if (options.strategy)
-			die(_("error: cannot combine '--rebase-merges' with "
+			die(_("cannot combine '--rebase-merges' with "
 			      "'--strategy'"));
 	}
 
@@ -1414,7 +1608,7 @@
 			get_fork_point(options.upstream_name, head);
 	}
 
-	if (read_index(the_repository->index) < 0)
+	if (repo_read_index(the_repository) < 0)
 		die(_("could not read index"));
 
 	if (options.autostash) {
@@ -1424,7 +1618,7 @@
 		fd = hold_locked_index(&lock_file, 0);
 		refresh_cache(REFRESH_QUIET);
 		if (0 <= fd)
-			update_index_if_able(&the_index, &lock_file);
+			repo_update_index_if_able(the_repository, &lock_file);
 		rollback_lock_file(&lock_file);
 
 		if (has_unstaged_changes(the_repository, 1) ||
@@ -1469,7 +1663,7 @@
 			putchar('\n');
 
 			if (discard_index(the_repository->index) < 0 ||
-				read_index(the_repository->index) < 0)
+				repo_read_index(the_repository) < 0)
 				die(_("could not read index"));
 		}
 	}
diff --git a/builtin/reflog.c b/builtin/reflog.c
index 1f1010e..4d34309 100644
--- a/builtin/reflog.c
+++ b/builtin/reflog.c
@@ -94,7 +94,7 @@
 	init_tree_desc(&desc, tree->buffer, tree->size);
 	complete = 1;
 	while (tree_entry(&desc, &entry)) {
-		if (!has_sha1_file(entry.oid.hash) ||
+		if (!has_object_file(&entry.oid) ||
 		    (S_ISDIR(entry.mode) && !tree_is_complete(&entry.oid))) {
 			tree->object.flags |= INCOMPLETE;
 			complete = 0;
diff --git a/builtin/replace.c b/builtin/replace.c
index affcdfb..5b80b7f 100644
--- a/builtin/replace.c
+++ b/builtin/replace.c
@@ -295,7 +295,7 @@
 			close(fd);
 			return -1;
 		}
-		if (index_fd(&the_index, oid, fd, &st, type, NULL, flags) < 0)
+		if (index_fd(the_repository->index, oid, fd, &st, type, NULL, flags) < 0)
 			return error(_("unable to write object to database"));
 		/* index_fd close()s fd for us */
 	}
diff --git a/builtin/reset.c b/builtin/reset.c
index 59898c9..4d18a46 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -7,6 +7,7 @@
  *
  * Copyright (c) 2005, 2006 Linus Torvalds and Junio C Hamano
  */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "config.h"
 #include "lockfile.h"
diff --git a/builtin/rev-list.c b/builtin/rev-list.c
index 14ef659..5b5b6db 100644
--- a/builtin/rev-list.c
+++ b/builtin/rev-list.c
@@ -546,7 +546,7 @@
 	if (prepare_revision_walk(&revs))
 		die("revision walk setup failed");
 	if (revs.tree_objects)
-		mark_edges_uninteresting(&revs, show_edge);
+		mark_edges_uninteresting(&revs, show_edge, 0);
 
 	if (bisect_list) {
 		int reaches, all;
diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index 10d4dab..f8bbe6d 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c
@@ -3,6 +3,7 @@
  *
  * Copyright (C) Linus Torvalds, 2005
  */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "commit.h"
@@ -933,7 +934,8 @@
 			name++;
 			type = REVERSED;
 		}
-		if (!get_oid_with_context(name, flags, &oid, &unused)) {
+		if (!get_oid_with_context(the_repository, name,
+					  flags, &oid, &unused)) {
 			if (verify)
 				revs_count++;
 			else
diff --git a/builtin/rm.c b/builtin/rm.c
index 17086d3..db85b33 100644
--- a/builtin/rm.c
+++ b/builtin/rm.c
@@ -3,6 +3,7 @@
  *
  * Copyright (C) Linus Torvalds 2006
  */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "config.h"
 #include "lockfile.h"
diff --git a/builtin/show-ref.c b/builtin/show-ref.c
index ed888ff..6a706c0 100644
--- a/builtin/show-ref.c
+++ b/builtin/show-ref.c
@@ -23,7 +23,7 @@
 	const char *hex;
 	struct object_id peeled;
 
-	if (!has_sha1_file(oid->hash))
+	if (!has_object_file(oid))
 		die("git show-ref: bad ref %s (%s)", refname,
 		    oid_to_hex(oid));
 
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 0e140f1..b80fc4b 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "repository.h"
 #include "cache.h"
diff --git a/builtin/update-index.c b/builtin/update-index.c
index e19da77..02ace60 100644
--- a/builtin/update-index.c
+++ b/builtin/update-index.c
@@ -3,6 +3,7 @@
  *
  * Copyright (C) Linus Torvalds, 2005
  */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "lockfile.h"
diff --git a/builtin/write-tree.c b/builtin/write-tree.c
index cdcbf82..3d46d22 100644
--- a/builtin/write-tree.c
+++ b/builtin/write-tree.c
@@ -3,6 +3,7 @@
  *
  * Copyright (C) Linus Torvalds, 2005
  */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "cache.h"
 #include "config.h"
diff --git a/bulk-checkin.c b/bulk-checkin.c
index 409ecb5..39ee7d6 100644
--- a/bulk-checkin.c
+++ b/bulk-checkin.c
@@ -67,7 +67,7 @@
 	int i;
 
 	/* The object may already exist in the repository */
-	if (has_sha1_file(oid->hash))
+	if (has_object_file(oid))
 		return 1;
 
 	/* Might want to keep the list sorted */
diff --git a/bundle.c b/bundle.c
index 37b1daa6..b45666c 100644
--- a/bundle.c
+++ b/bundle.c
@@ -424,8 +424,8 @@
 	return ref_count;
 }
 
-int create_bundle(struct repository *r, struct bundle_header *header,
-		  const char *path, int argc, const char **argv)
+int create_bundle(struct repository *r, const char *path,
+		  int argc, const char **argv)
 {
 	struct lock_file lock = LOCK_INIT;
 	int bundle_fd = -1;
diff --git a/bundle.h b/bundle.h
index 781e6f5..37c37d7 100644
--- a/bundle.h
+++ b/bundle.h
@@ -18,8 +18,8 @@
 
 int is_bundle(const char *path, int quiet);
 int read_bundle_header(const char *path, struct bundle_header *header);
-int create_bundle(struct repository *r, struct bundle_header *header,
-		  const char *path, int argc, const char **argv);
+int create_bundle(struct repository *r, const char *path,
+		  int argc, const char **argv);
 int verify_bundle(struct repository *r, struct bundle_header *header, int verbose);
 #define BUNDLE_VERBOSE 1
 int unbundle(struct repository *r, struct bundle_header *header,
diff --git a/cache-tree.c b/cache-tree.c
index c4b8a1f..b13bfaf 100644
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -225,7 +225,7 @@
 	int i;
 	if (!it)
 		return 0;
-	if (it->entry_count < 0 || !has_sha1_file(it->oid.hash))
+	if (it->entry_count < 0 || !has_object_file(&it->oid))
 		return 0;
 	for (i = 0; i < it->subtree_nr; i++) {
 		if (!cache_tree_fully_valid(it->down[i]->cache_tree))
@@ -253,7 +253,7 @@
 
 	*skip_count = 0;
 
-	if (0 <= it->entry_count && has_sha1_file(it->oid.hash))
+	if (0 <= it->entry_count && has_object_file(&it->oid))
 		return it->entry_count;
 
 	/*
diff --git a/cache-tree.h b/cache-tree.h
index 3262091..757bbc4 100644
--- a/cache-tree.h
+++ b/cache-tree.h
@@ -51,7 +51,7 @@
 
 int cache_tree_matches_traversal(struct cache_tree *, struct name_entry *ent, struct traverse_info *info);
 
-#ifndef NO_THE_INDEX_COMPATIBILITY_MACROS
+#ifdef USE_THE_INDEX_COMPATIBILITY_MACROS
 static inline int write_cache_as_tree(struct object_id *oid, int flags, const char *prefix)
 {
 	return write_index_as_tree(oid, &the_index, get_index_file(), flags, prefix);
diff --git a/cache.h b/cache.h
index 009e8b3..27fe635 100644
--- a/cache.h
+++ b/cache.h
@@ -348,8 +348,6 @@
 	struct mem_pool *ce_mem_pool;
 };
 
-extern struct index_state the_index;
-
 /* Name hashing */
 extern int test_lazy_init_name_hash(struct index_state *istate, int try_threaded);
 extern void add_name_hash(struct index_state *istate, struct cache_entry *ce);
@@ -411,18 +409,20 @@
  */
 void validate_cache_entries(const struct index_state *istate);
 
-#ifndef NO_THE_INDEX_COMPATIBILITY_MACROS
+#ifdef USE_THE_INDEX_COMPATIBILITY_MACROS
+extern struct index_state the_index;
+
 #define active_cache (the_index.cache)
 #define active_nr (the_index.cache_nr)
 #define active_alloc (the_index.cache_alloc)
 #define active_cache_changed (the_index.cache_changed)
 #define active_cache_tree (the_index.cache_tree)
 
-#define read_cache() read_index(&the_index)
+#define read_cache() repo_read_index(the_repository)
 #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), 0)
+#define read_cache_preload(pathspec) repo_read_index_preload(the_repository, (pathspec), 0)
 #define is_cache_unborn() is_index_unborn(&the_index)
-#define read_cache_unmerged() read_index_unmerged(&the_index)
+#define read_cache_unmerged() repo_read_index_unmerged(the_repository)
 #define discard_cache() discard_index(&the_index)
 #define unmerged_cache() unmerged_index(&the_index)
 #define cache_name_pos(name, namelen) index_name_pos(&the_index,(name),(namelen))
@@ -443,6 +443,7 @@
 #define unmerge_cache_entry_at(at) unmerge_index_entry_at(&the_index, at)
 #define unmerge_cache(pathspec) unmerge_index(&the_index, pathspec)
 #define read_blob_data_from_cache(path, sz) read_blob_data_from_index(&the_index, (path), (sz))
+#define hold_locked_index(lock_file, flags) repo_hold_locked_index(the_repository, (lock_file), (flags))
 #endif
 
 #define TYPE_BITS 3
@@ -670,19 +671,14 @@
 
 /* Initialize and use the cache information */
 struct lock_file;
-extern int read_index(struct index_state *);
 extern void preload_index(struct index_state *index,
 			  const struct pathspec *pathspec,
 			  unsigned int refresh_flags);
-extern int read_index_preload(struct index_state *,
-			      const struct pathspec *pathspec,
-			      unsigned int refresh_flags);
 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,
 			   const char *gitdir);
 extern int is_index_unborn(struct index_state *);
-extern int read_index_unmerged(struct index_state *);
 
 /* For use with `write_locked_index()`. */
 #define COMMIT_LOCK		(1 << 0)
@@ -720,9 +716,9 @@
  * provided, the space-separated list of files that differ will be appended
  * to it.
  */
-extern int index_has_changes(struct index_state *istate,
-			     struct tree *tree,
-			     struct strbuf *sb);
+extern int repo_index_has_changes(struct repository *repo,
+				  struct tree *tree,
+				  struct strbuf *sb);
 
 extern int verify_path(const char *path, unsigned mode);
 extern int strcmp_offset(const char *s1, const char *s2, size_t *first_change);
@@ -755,6 +751,7 @@
 #define ADD_CACHE_JUST_APPEND 8		/* Append only; tree.c::read_tree() */
 #define ADD_CACHE_NEW_ONLY 16		/* Do not replace existing ones */
 #define ADD_CACHE_KEEP_CACHE_TREE 32	/* Do not invalidate cache-tree */
+#define ADD_CACHE_RENORMALIZE 64        /* Pass along HASH_RENORMALIZE */
 extern int add_index_entry(struct index_state *, struct cache_entry *ce, int option);
 extern void rename_index_entry_at(struct index_state *, int pos, const char *new_name);
 
@@ -837,13 +834,6 @@
 extern int refresh_index(struct index_state *, unsigned int flags, const struct pathspec *pathspec, char *seen, const char *header_msg);
 extern struct cache_entry *refresh_cache_entry(struct index_state *, struct cache_entry *, unsigned int);
 
-/*
- * Opportunistically update the index but do not complain if we can't.
- * The lockfile is always committed or rolled back.
- */
-extern void update_index_if_able(struct index_state *, struct lock_file *);
-
-extern int hold_locked_index(struct lock_file *, int);
 extern void set_alternate_index_output(const char *);
 
 extern int verify_index_checksum;
@@ -1281,8 +1271,8 @@
 
 extern int git_open_cloexec(const char *name, int flags);
 #define git_open(name) git_open_cloexec(name, O_RDONLY)
-extern int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz);
-extern int parse_sha1_header(const char *hdr, unsigned long *sizep);
+extern int unpack_loose_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz);
+extern int parse_loose_header(const char *hdr, unsigned long *sizep);
 
 extern int check_object_signature(const struct object_id *oid, void *buf, unsigned long size, const char *type);
 
@@ -1344,6 +1334,24 @@
 	GET_OID_TREE | GET_OID_TREEISH | \
 	GET_OID_BLOB)
 
+enum get_oid_result {
+	FOUND = 0,
+	MISSING_OBJECT = -1, /* The requested object is missing */
+	SHORT_NAME_AMBIGUOUS = -2,
+	/* The following only apply when symlinks are followed */
+	DANGLING_SYMLINK = -4, /*
+				* The initial symlink is there, but
+				* (transitively) points to a missing
+				* in-tree file
+				*/
+	SYMLINK_LOOP = -5,
+	NOT_DIR = -6, /*
+		       * Somewhere along the symlink chain, a path is
+		       * requested which contains a file as a
+		       * non-final element.
+		       */
+};
+
 extern int get_oid(const char *str, struct object_id *oid);
 extern int get_oid_commit(const char *str, struct object_id *oid);
 extern int get_oid_committish(const char *str, struct object_id *oid);
@@ -1351,8 +1359,9 @@
 extern int get_oid_treeish(const char *str, struct object_id *oid);
 extern int get_oid_blob(const char *str, struct object_id *oid);
 extern void maybe_die_on_misspelt_object_name(const char *name, const char *prefix);
-extern int get_oid_with_context(const char *str, unsigned flags, struct object_id *oid, struct object_context *oc);
-
+extern enum get_oid_result get_oid_with_context(struct repository *repo, const char *str,
+				unsigned flags, struct object_id *oid,
+				struct object_context *oc);
 
 typedef int each_abbrev_fn(const struct object_id *oid, void *);
 extern int for_each_abbrev(const char *prefix, each_abbrev_fn, void *);
@@ -1454,6 +1463,7 @@
 
 enum date_mode_type {
 	DATE_NORMAL = 0,
+	DATE_HUMAN,
 	DATE_RELATIVE,
 	DATE_SHORT,
 	DATE_ISO8601,
@@ -1479,7 +1489,9 @@
 struct date_mode *date_mode_from_type(enum date_mode_type type);
 
 const char *show_date(timestamp_t time, int timezone, const struct date_mode *mode);
-void show_date_relative(timestamp_t time, int tz, const struct timeval *now,
+void show_date_relative(timestamp_t time, const struct timeval *now,
+			struct strbuf *timebuf);
+void show_date_human(timestamp_t time, int tz, const struct timeval *now,
 			struct strbuf *timebuf);
 int parse_date(const char *date, struct strbuf *out);
 int parse_date_basic(const char *date, timestamp_t *timestamp, int *offset);
@@ -1607,7 +1619,7 @@
 extern int odb_pack_keep(const char *name);
 
 /*
- * Set this to 0 to prevent sha1_object_info_extended() from fetching missing
+ * Set this to 0 to prevent oid_object_info_extended() from fetching missing
  * blobs. This has a difference only if extensions.partialClone is set.
  *
  * Its default value is 1.
@@ -1803,4 +1815,7 @@
  */
 extern int print_sha1_ellipsis(void);
 
+/* Return 1 if the file is empty or does not exists, 0 otherwise. */
+extern int is_empty_or_missing_file(const char *filename);
+
 #endif /* CACHE_H */
diff --git a/ci/install-dependencies.sh b/ci/install-dependencies.sh
index 06c3546..d64667f 100755
--- a/ci/install-dependencies.sh
+++ b/ci/install-dependencies.sh
@@ -3,7 +3,7 @@
 # Install dependencies required to build and test Git on Linux and macOS
 #
 
-. ${0%/*}/lib-travisci.sh
+. ${0%/*}/lib.sh
 
 P4WHENCE=http://filehost.perforce.com/perforce/r$LINUX_P4_VERSION
 LFSWHENCE=https://github.com/github/git-lfs/releases/download/v$LINUX_GIT_LFS_VERSION
@@ -34,12 +34,18 @@
 	popd
 	;;
 osx-clang|osx-gcc)
-	brew update --quiet
+	brew update >/dev/null
 	# Uncomment this if you want to run perf tests:
 	# brew install gnu-time
-	brew install git-lfs gettext
+	test -z "$BREW_INSTALL_PACKAGES" ||
+	brew install $BREW_INSTALL_PACKAGES
 	brew link --force gettext
 	brew install caskroom/cask/perforce
+	case "$jobname" in
+	osx-gcc)
+		brew link gcc@8
+		;;
+	esac
 	;;
 StaticAnalysis)
 	sudo apt-get -q update
diff --git a/ci/lib-travisci.sh b/ci/lib-travisci.sh
deleted file mode 100755
index 69dff4d..0000000
--- a/ci/lib-travisci.sh
+++ /dev/null
@@ -1,129 +0,0 @@
-# Library of functions shared by all CI scripts
-
-skip_branch_tip_with_tag () {
-	# Sometimes, a branch is pushed at the same time the tag that points
-	# at the same commit as the tip of the branch is pushed, and building
-	# both at the same time is a waste.
-	#
-	# Travis gives a tagname e.g. v2.14.0 in $TRAVIS_BRANCH when
-	# the build is triggered by a push to a tag.  Let's see if
-	# $TRAVIS_BRANCH is exactly at a tag, and if so, if it is
-	# different from $TRAVIS_BRANCH.  That way, we can tell if
-	# we are building the tip of a branch that is tagged and
-	# we can skip the build because we won't be skipping a build
-	# of a tag.
-
-	if TAG=$(git describe --exact-match "$TRAVIS_BRANCH" 2>/dev/null) &&
-		test "$TAG" != "$TRAVIS_BRANCH"
-	then
-		echo "$(tput setaf 2)Tip of $TRAVIS_BRANCH is exactly at $TAG$(tput sgr0)"
-		exit 0
-	fi
-}
-
-# 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.
-save_good_tree () {
-	echo "$(git rev-parse $TRAVIS_COMMIT^{tree}) $TRAVIS_COMMIT $TRAVIS_JOB_NUMBER $TRAVIS_JOB_ID" >>"$good_trees_file"
-	# limit the file size
-	tail -1000 "$good_trees_file" >"$good_trees_file".tmp
-	mv "$good_trees_file".tmp "$good_trees_file"
-}
-
-# Skip the build job if the same tree has already been built and tested
-# successfully before (e.g. because the branch got rebased, changing only
-# the commit messages).
-skip_good_tree () {
-	if ! good_tree_info="$(grep "^$(git rev-parse $TRAVIS_COMMIT^{tree}) " "$good_trees_file")"
-	then
-		# Haven't seen this tree yet, or no cached good trees file yet.
-		# Continue the build job.
-		return
-	fi
-
-	echo "$good_tree_info" | {
-		read tree prev_good_commit prev_good_job_number prev_good_job_id
-
-		if test "$TRAVIS_JOB_ID" = "$prev_good_job_id"
-		then
-			cat <<-EOF
-			$(tput setaf 2)Skipping build job for commit $TRAVIS_COMMIT.$(tput sgr0)
-			This commit has already been built and tested successfully by this build job.
-			To force a re-build delete the branch's cache and then hit 'Restart job'.
-			EOF
-		else
-			cat <<-EOF
-			$(tput setaf 2)Skipping build job for commit $TRAVIS_COMMIT.$(tput sgr0)
-			This commit's tree has already been built and tested successfully in build job $prev_good_job_number for commit $prev_good_commit.
-			The log of that build job is available at https://travis-ci.org/$TRAVIS_REPO_SLUG/jobs/$prev_good_job_id
-			To force a re-build delete the branch's cache and then hit 'Restart job'.
-			EOF
-		fi
-	}
-
-	exit 0
-}
-
-check_unignored_build_artifacts ()
-{
-	! git ls-files --other --exclude-standard --error-unmatch \
-		-- ':/*' 2>/dev/null ||
-	{
-		echo "$(tput setaf 1)error: found unignored build artifacts$(tput sgr0)"
-		false
-	}
-}
-
-# Set 'exit on error' for all CI scripts to let the caller know that
-# something went wrong.
-# Set tracing executed commands, primarily setting environment variables
-# and installing dependencies.
-set -ex
-
-cache_dir="$HOME/travis-cache"
-good_trees_file="$cache_dir/good-trees"
-
-mkdir -p "$cache_dir"
-
-skip_branch_tip_with_tag
-skip_good_tree
-
-if test -z "$jobname"
-then
-	jobname="$TRAVIS_OS_NAME-$CC"
-fi
-
-export DEVELOPER=1
-export DEFAULT_TEST_TARGET=prove
-export GIT_PROVE_OPTS="--timer --jobs 3 --state=failed,slow,save"
-export GIT_TEST_OPTS="--verbose-log -x --immediate"
-export GIT_TEST_CLONE_2GB=YesPlease
-if [ "$jobname" = linux-gcc ]; then
-	export CC=gcc-8
-fi
-
-case "$jobname" in
-linux-clang|linux-gcc)
-	export GIT_TEST_HTTPD=YesPlease
-
-	# The Linux build installs the defined dependency versions below.
-	# The OS X build installs the latest available versions. Keep that
-	# in mind when you encounter a broken OS X build!
-	export LINUX_P4_VERSION="16.2"
-	export LINUX_GIT_LFS_VERSION="1.5.2"
-
-	P4_PATH="$HOME/custom/p4"
-	GIT_LFS_PATH="$HOME/custom/git-lfs"
-	export PATH="$GIT_LFS_PATH:$P4_PATH:$PATH"
-	;;
-osx-clang|osx-gcc)
-	# t9810 occasionally fails on Travis CI OS X
-	# t9816 occasionally fails with "TAP out of sequence errors" on
-	# Travis CI OS X
-	export GIT_SKIP_TESTS="t9810 t9816"
-	;;
-GIT_TEST_GETTEXT_POISON)
-	export GIT_TEST_GETTEXT_POISON=YesPlease
-	;;
-esac
diff --git a/ci/lib.sh b/ci/lib.sh
new file mode 100755
index 0000000..16f4ecb
--- /dev/null
+++ b/ci/lib.sh
@@ -0,0 +1,188 @@
+# Library of functions shared by all CI scripts
+
+skip_branch_tip_with_tag () {
+	# Sometimes, a branch is pushed at the same time the tag that points
+	# at the same commit as the tip of the branch is pushed, and building
+	# both at the same time is a waste.
+	#
+	# When the build is triggered by a push to a tag, $CI_BRANCH will
+	# have that tagname, e.g. v2.14.0.  Let's see if $CI_BRANCH is
+	# exactly at a tag, and if so, if it is different from $CI_BRANCH.
+	# That way, we can tell if we are building the tip of a branch that
+	# is tagged and we can skip the build because we won't be skipping a
+	# build of a tag.
+
+	if TAG=$(git describe --exact-match "$CI_BRANCH" 2>/dev/null) &&
+		test "$TAG" != "$CI_BRANCH"
+	then
+		echo "$(tput setaf 2)Tip of $CI_BRANCH is exactly at $TAG$(tput sgr0)"
+		exit 0
+	fi
+}
+
+# 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.
+save_good_tree () {
+	echo "$(git rev-parse $CI_COMMIT^{tree}) $CI_COMMIT $CI_JOB_NUMBER $CI_JOB_ID" >>"$good_trees_file"
+	# limit the file size
+	tail -1000 "$good_trees_file" >"$good_trees_file".tmp
+	mv "$good_trees_file".tmp "$good_trees_file"
+}
+
+# Skip the build job if the same tree has already been built and tested
+# successfully before (e.g. because the branch got rebased, changing only
+# the commit messages).
+skip_good_tree () {
+	if ! good_tree_info="$(grep "^$(git rev-parse $CI_COMMIT^{tree}) " "$good_trees_file")"
+	then
+		# Haven't seen this tree yet, or no cached good trees file yet.
+		# Continue the build job.
+		return
+	fi
+
+	echo "$good_tree_info" | {
+		read tree prev_good_commit prev_good_job_number prev_good_job_id
+
+		if test "$CI_JOB_ID" = "$prev_good_job_id"
+		then
+			cat <<-EOF
+			$(tput setaf 2)Skipping build job for commit $CI_COMMIT.$(tput sgr0)
+			This commit has already been built and tested successfully by this build job.
+			To force a re-build delete the branch's cache and then hit 'Restart job'.
+			EOF
+		else
+			cat <<-EOF
+			$(tput setaf 2)Skipping build job for commit $CI_COMMIT.$(tput sgr0)
+			This commit's tree has already been built and tested successfully in build job $prev_good_job_number for commit $prev_good_commit.
+			The log of that build job is available at $(url_for_job_id $prev_good_job_id)
+			To force a re-build delete the branch's cache and then hit 'Restart job'.
+			EOF
+		fi
+	}
+
+	exit 0
+}
+
+check_unignored_build_artifacts ()
+{
+	! git ls-files --other --exclude-standard --error-unmatch \
+		-- ':/*' 2>/dev/null ||
+	{
+		echo "$(tput setaf 1)error: found unignored build artifacts$(tput sgr0)"
+		false
+	}
+}
+
+# Set 'exit on error' for all CI scripts to let the caller know that
+# something went wrong.
+# Set tracing executed commands, primarily setting environment variables
+# and installing dependencies.
+set -ex
+
+if test true = "$TRAVIS"
+then
+	CI_TYPE=travis
+	# When building a PR, TRAVIS_BRANCH refers to the *target* branch. Not
+	# what we want here. We want the source branch instead.
+	CI_BRANCH="${TRAVIS_PULL_REQUEST_BRANCH:-$TRAVIS_BRANCH}"
+	CI_COMMIT="$TRAVIS_COMMIT"
+	CI_JOB_ID="$TRAVIS_JOB_ID"
+	CI_JOB_NUMBER="$TRAVIS_JOB_NUMBER"
+	CI_OS_NAME="$TRAVIS_OS_NAME"
+	CI_REPO_SLUG="$TRAVIS_REPO_SLUG"
+
+	cache_dir="$HOME/travis-cache"
+
+	url_for_job_id () {
+		echo "https://travis-ci.org/$CI_REPO_SLUG/jobs/$1"
+	}
+
+	BREW_INSTALL_PACKAGES="git-lfs gettext"
+	export GIT_PROVE_OPTS="--timer --jobs 3 --state=failed,slow,save"
+	export GIT_TEST_OPTS="--verbose-log -x --immediate"
+	export MAKEFLAGS="--jobs=2"
+elif test -n "$SYSTEM_COLLECTIONURI" || test -n "$SYSTEM_TASKDEFINITIONSURI"
+then
+	CI_TYPE=azure-pipelines
+	# We are running in Azure Pipelines
+	CI_BRANCH="$BUILD_SOURCEBRANCH"
+	CI_COMMIT="$BUILD_SOURCEVERSION"
+	CI_JOB_ID="$BUILD_BUILDID"
+	CI_JOB_NUMBER="$BUILD_BUILDNUMBER"
+	CI_OS_NAME="$(echo "$AGENT_OS" | tr A-Z a-z)"
+	test darwin != "$CI_OS_NAME" || CI_OS_NAME=osx
+	CI_REPO_SLUG="$(expr "$BUILD_REPOSITORY_URI" : '.*/\([^/]*/[^/]*\)$')"
+	CC="${CC:-gcc}"
+
+	# use a subdirectory of the cache dir (because the file share is shared
+	# among *all* phases)
+	cache_dir="$HOME/test-cache/$SYSTEM_PHASENAME"
+
+	url_for_job_id () {
+		echo "$SYSTEM_TASKDEFINITIONSURI$SYSTEM_TEAMPROJECT/_build/results?buildId=$1"
+	}
+
+	BREW_INSTALL_PACKAGES=gcc@8
+	export GIT_PROVE_OPTS="--timer --jobs 10 --state=failed,slow,save"
+	export GIT_TEST_OPTS="--verbose-log -x --write-junit-xml"
+	export MAKEFLAGS="--jobs=10"
+	test windows_nt != "$CI_OS_NAME" ||
+	GIT_TEST_OPTS="--no-chain-lint --no-bin-wrappers $GIT_TEST_OPTS"
+else
+	echo "Could not identify CI type" >&2
+	exit 1
+fi
+
+good_trees_file="$cache_dir/good-trees"
+
+mkdir -p "$cache_dir"
+
+skip_branch_tip_with_tag
+skip_good_tree
+
+if test -z "$jobname"
+then
+	jobname="$CI_OS_NAME-$CC"
+fi
+
+export DEVELOPER=1
+export DEFAULT_TEST_TARGET=prove
+export GIT_TEST_CLONE_2GB=YesPlease
+
+case "$jobname" in
+linux-clang|linux-gcc)
+	if [ "$jobname" = linux-gcc ]
+	then
+		export CC=gcc-8
+	fi
+
+	export GIT_TEST_HTTPD=YesPlease
+
+	# The Linux build installs the defined dependency versions below.
+	# The OS X build installs the latest available versions. Keep that
+	# in mind when you encounter a broken OS X build!
+	export LINUX_P4_VERSION="16.2"
+	export LINUX_GIT_LFS_VERSION="1.5.2"
+
+	P4_PATH="$HOME/custom/p4"
+	GIT_LFS_PATH="$HOME/custom/git-lfs"
+	export PATH="$GIT_LFS_PATH:$P4_PATH:$PATH"
+	;;
+osx-clang|osx-gcc)
+	if [ "$jobname" = osx-gcc ]
+	then
+		export CC=gcc-8
+	fi
+
+	# t9810 occasionally fails on Travis CI OS X
+	# t9816 occasionally fails with "TAP out of sequence errors" on
+	# Travis CI OS X
+	export GIT_SKIP_TESTS="t9810 t9816"
+	;;
+GIT_TEST_GETTEXT_POISON)
+	export GIT_TEST_GETTEXT_POISON=YesPlease
+	;;
+esac
+
+export MAKEFLAGS="CC=${CC:-cc}"
diff --git a/ci/make-test-artifacts.sh b/ci/make-test-artifacts.sh
new file mode 100755
index 0000000..6469674
--- /dev/null
+++ b/ci/make-test-artifacts.sh
@@ -0,0 +1,12 @@
+#!/bin/sh
+#
+# Build Git and store artifacts for testing
+#
+
+mkdir -p "$1" # in case ci/lib.sh decides to quit early
+
+. ${0%/*}/lib.sh
+
+make artifacts-tar ARTIFACTS_DIRECTORY="$1"
+
+check_unignored_build_artifacts
diff --git a/ci/mount-fileshare.sh b/ci/mount-fileshare.sh
new file mode 100755
index 0000000..26b58a8
--- /dev/null
+++ b/ci/mount-fileshare.sh
@@ -0,0 +1,25 @@
+#!/bin/sh
+
+die () {
+	echo "$*" >&2
+	exit 1
+}
+
+test $# = 4 ||
+die "Usage: $0 <share> <username> <password> <mountpoint>"
+
+mkdir -p "$4" || die "Could not create $4"
+
+case "$(uname -s)" in
+Linux)
+	sudo mount -t cifs -o vers=3.0,username="$2",password="$3",dir_mode=0777,file_mode=0777,serverino "$1" "$4"
+	;;
+Darwin)
+	pass="$(echo "$3" | sed -e 's/\//%2F/g' -e 's/+/%2B/g')" &&
+	mount -t smbfs,soft "smb://$2:$pass@${1#//}" "$4"
+	;;
+*)
+	die "No support for $(uname -s)"
+	;;
+esac ||
+die "Could not mount $4"
diff --git a/ci/print-test-failures.sh b/ci/print-test-failures.sh
index d55460a..e688a26 100755
--- a/ci/print-test-failures.sh
+++ b/ci/print-test-failures.sh
@@ -3,7 +3,7 @@
 # Print output of failing tests
 #
 
-. ${0%/*}/lib-travisci.sh
+. ${0%/*}/lib.sh
 
 # Tracing executed commands would produce too much noise in the loop below.
 set +x
@@ -38,6 +38,19 @@
 		test_name="${TEST_EXIT%.exit}"
 		test_name="${test_name##*/}"
 		trash_dir="trash directory.$test_name"
+		case "$CI_TYPE" in
+		travis)
+			;;
+		azure-pipelines)
+			mkdir -p failed-test-artifacts
+			mv "$trash_dir" failed-test-artifacts
+			continue
+			;;
+		*)
+			echo "Unhandled CI type: $CI_TYPE" >&2
+			exit 1
+			;;
+		esac
 		trash_tgz_b64="trash.$test_name.base64"
 		if [ -d "$trash_dir" ]
 		then
diff --git a/ci/run-build-and-tests.sh b/ci/run-build-and-tests.sh
index cda170d..cdd2913 100755
--- a/ci/run-build-and-tests.sh
+++ b/ci/run-build-and-tests.sh
@@ -3,12 +3,15 @@
 # Build and test Git
 #
 
-. ${0%/*}/lib-travisci.sh
+. ${0%/*}/lib.sh
 
-ln -s "$cache_dir/.prove" t/.prove
+case "$CI_OS_NAME" in
+windows*) cmd //c mklink //j t\\.prove "$(cygpath -aw "$cache_dir/.prove")";;
+*) ln -s "$cache_dir/.prove" t/.prove;;
+esac
 
-make --jobs=2
-make --quiet test
+make
+make test
 if test "$jobname" = "linux-gcc"
 then
 	export GIT_TEST_SPLIT_INDEX=yes
@@ -17,7 +20,7 @@
 	export GIT_TEST_OE_DELTA_SIZE=5
 	export GIT_TEST_COMMIT_GRAPH=1
 	export GIT_TEST_MULTI_PACK_INDEX=1
-	make --quiet test
+	make test
 fi
 
 check_unignored_build_artifacts
diff --git a/ci/run-linux32-build.sh b/ci/run-linux32-build.sh
index 2c60d2e..e3a193a 100755
--- a/ci/run-linux32-build.sh
+++ b/ci/run-linux32-build.sh
@@ -55,6 +55,6 @@
 	set -ex
 	cd /usr/src/git
 	test -n "$cache_dir" && ln -s "$cache_dir/.prove" t/.prove
-	make --jobs=2
-	make --quiet test
+	make
+	make test
 '
diff --git a/ci/run-linux32-docker.sh b/ci/run-linux32-docker.sh
index 2163790..751acfc 100755
--- a/ci/run-linux32-docker.sh
+++ b/ci/run-linux32-docker.sh
@@ -3,7 +3,7 @@
 # Download and run Docker image to build and test 32-bit Git
 #
 
-. ${0%/*}/lib-travisci.sh
+. ${0%/*}/lib.sh
 
 docker pull daald/ubuntu32:xenial
 
diff --git a/ci/run-static-analysis.sh b/ci/run-static-analysis.sh
index 5688f26..a19aa7e 100755
--- a/ci/run-static-analysis.sh
+++ b/ci/run-static-analysis.sh
@@ -3,9 +3,9 @@
 # Perform various static code analysis checks
 #
 
-. ${0%/*}/lib-travisci.sh
+. ${0%/*}/lib.sh
 
-make --jobs=2 coccicheck
+make coccicheck
 
 set +x
 
diff --git a/ci/run-test-slice.sh b/ci/run-test-slice.sh
new file mode 100755
index 0000000..f8c2c31
--- /dev/null
+++ b/ci/run-test-slice.sh
@@ -0,0 +1,17 @@
+#!/bin/sh
+#
+# Test Git in parallel
+#
+
+. ${0%/*}/lib.sh
+
+case "$CI_OS_NAME" in
+windows*) cmd //c mklink //j t\\.prove "$(cygpath -aw "$cache_dir/.prove")";;
+*) ln -s "$cache_dir/.prove" t/.prove;;
+esac
+
+make --quiet -C t T="$(cd t &&
+	./helper/test-tool path-utils slice-tests "$1" "$2" t[0-9]*.sh |
+	tr '\n' ' ')"
+
+check_unignored_build_artifacts
diff --git a/ci/run-windows-build.sh b/ci/run-windows-build.sh
index d99a180..a73a4ec 100755
--- a/ci/run-windows-build.sh
+++ b/ci/run-windows-build.sh
@@ -6,7 +6,7 @@
 # supported) and a commit hash.
 #
 
-. ${0%/*}/lib-travisci.sh
+. ${0%/*}/lib.sh
 
 test $# -ne 2 && echo "Unexpected number of parameters" && exit 1
 test -z "$GFW_CI_TOKEN" && echo "GFW_CI_TOKEN not defined" && exit
diff --git a/ci/test-documentation.sh b/ci/test-documentation.sh
index a20de9c..be3b7d3 100755
--- a/ci/test-documentation.sh
+++ b/ci/test-documentation.sh
@@ -3,15 +3,16 @@
 # Perform sanity checks on documentation and build it.
 #
 
-. ${0%/*}/lib-travisci.sh
+. ${0%/*}/lib.sh
 
+test -n "$ALREADY_HAVE_ASCIIDOCTOR" ||
 gem install asciidoctor
 
 make check-builtins
 make check-docs
 
 # Build docs with AsciiDoc
-make --jobs=2 doc > >(tee stdout.log) 2> >(tee stderr.log >&2)
+make doc > >(tee stdout.log) 2> >(tee stderr.log >&2)
 ! test -s stderr.log
 test -s Documentation/git.html
 test -s Documentation/git.xml
@@ -23,7 +24,7 @@
 
 # Build docs with AsciiDoctor
 make clean
-make --jobs=2 USE_ASCIIDOCTOR=1 doc > >(tee stdout.log) 2> >(tee stderr.log >&2)
+make USE_ASCIIDOCTOR=1 doc > >(tee stdout.log) 2> >(tee stderr.log >&2)
 sed '/^GIT_VERSION = / d' stderr.log
 ! test -s stderr.log
 test -s Documentation/git.html
diff --git a/column.c b/column.c
index 2165297..7a17c14 100644
--- a/column.c
+++ b/column.c
@@ -21,7 +21,7 @@
 };
 
 /* return length of 's' in letters, ANSI escapes stripped */
-static int item_length(unsigned int colopts, const char *s)
+static int item_length(const char *s)
 {
 	int len, i = 0;
 	struct strbuf str = STRBUF_INIT;
@@ -167,7 +167,7 @@
 
 	ALLOC_ARRAY(data.len, list->nr);
 	for (i = 0; i < list->nr; i++)
-		data.len[i] = item_length(colopts, list->items[i].string);
+		data.len[i] = item_length(list->items[i].string);
 
 	layout(&data, &initial_width);
 
diff --git a/combine-diff.c b/combine-diff.c
index a143c00..23d8fab 100644
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -1321,6 +1321,14 @@
 	return path->path;
 }
 
+/*
+ * Diff stat formats which we always compute solely against the first parent.
+ */
+#define STAT_FORMAT_MASK (DIFF_FORMAT_NUMSTAT \
+			  | DIFF_FORMAT_SHORTSTAT \
+			  | DIFF_FORMAT_SUMMARY \
+			  | DIFF_FORMAT_DIRSTAT \
+			  | DIFF_FORMAT_DIFFSTAT)
 
 /* find set of paths that every parent touches */
 static struct combine_diff_path *find_paths_generic(const struct object_id *oid,
@@ -1342,8 +1350,7 @@
 		 * show stat against the first parent even when doing
 		 * combined diff.
 		 */
-		int stat_opt = (output_format &
-				(DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
+		int stat_opt = output_format & STAT_FORMAT_MASK;
 		if (i == 0 && stat_opt)
 			opt->output_format = stat_opt;
 		else
@@ -1470,8 +1477,7 @@
 		 * show stat against the first parent even
 		 * when doing combined diff.
 		 */
-		stat_opt = (opt->output_format &
-				(DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
+		stat_opt = opt->output_format & STAT_FORMAT_MASK;
 		if (stat_opt) {
 			diffopts.output_format = stat_opt;
 
@@ -1515,8 +1521,7 @@
 				show_raw_diff(p, num_parent, rev);
 			needsep = 1;
 		}
-		else if (opt->output_format &
-			 (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT))
+		else if (opt->output_format & STAT_FORMAT_MASK)
 			needsep = 1;
 		else if (opt->output_format & DIFF_FORMAT_CALLBACK)
 			handle_combined_callback(opt, paths, num_parent, num_paths);
diff --git a/commit-graph.c b/commit-graph.c
index 18bd2b6..47e9be0 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -21,14 +21,14 @@
 #define GRAPH_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */
 #define GRAPH_CHUNKID_OIDLOOKUP 0x4f49444c /* "OIDL" */
 #define GRAPH_CHUNKID_DATA 0x43444154 /* "CDAT" */
-#define GRAPH_CHUNKID_LARGEEDGES 0x45444745 /* "EDGE" */
+#define GRAPH_CHUNKID_EXTRAEDGES 0x45444745 /* "EDGE" */
 
 #define GRAPH_DATA_WIDTH (the_hash_algo->rawsz + 16)
 
 #define GRAPH_VERSION_1 0x1
 #define GRAPH_VERSION GRAPH_VERSION_1
 
-#define GRAPH_OCTOPUS_EDGES_NEEDED 0x80000000
+#define GRAPH_EXTRA_EDGES_NEEDED 0x80000000
 #define GRAPH_EDGE_LAST_MASK 0x7fffffff
 #define GRAPH_PARENT_NONE 0x70000000
 
@@ -209,11 +209,11 @@
 				graph->chunk_commit_data = data + chunk_offset;
 			break;
 
-		case GRAPH_CHUNKID_LARGEEDGES:
-			if (graph->chunk_large_edges)
+		case GRAPH_CHUNKID_EXTRAEDGES:
+			if (graph->chunk_extra_edges)
 				chunk_repeated = 1;
 			else
-				graph->chunk_large_edges = data + chunk_offset;
+				graph->chunk_extra_edges = data + chunk_offset;
 			break;
 		}
 
@@ -374,12 +374,12 @@
 	edge_value = get_be32(commit_data + g->hash_len + 4);
 	if (edge_value == GRAPH_PARENT_NONE)
 		return 1;
-	if (!(edge_value & GRAPH_OCTOPUS_EDGES_NEEDED)) {
+	if (!(edge_value & GRAPH_EXTRA_EDGES_NEEDED)) {
 		pptr = insert_parent_or_die(r, g, edge_value, pptr);
 		return 1;
 	}
 
-	parent_data_ptr = (uint32_t*)(g->chunk_large_edges +
+	parent_data_ptr = (uint32_t*)(g->chunk_extra_edges +
 			  4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
 	do {
 		edge_value = get_be32(parent_data_ptr);
@@ -466,7 +466,9 @@
 
 static void write_graph_chunk_fanout(struct hashfile *f,
 				     struct commit **commits,
-				     int nr_commits)
+				     int nr_commits,
+				     struct progress *progress,
+				     uint64_t *progress_cnt)
 {
 	int i, count = 0;
 	struct commit **list = commits;
@@ -480,6 +482,7 @@
 		while (count < nr_commits) {
 			if ((*list)->object.oid.hash[0] != i)
 				break;
+			display_progress(progress, ++*progress_cnt);
 			count++;
 			list++;
 		}
@@ -489,12 +492,16 @@
 }
 
 static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
-				   struct commit **commits, int nr_commits)
+				   struct commit **commits, int nr_commits,
+				   struct progress *progress,
+				   uint64_t *progress_cnt)
 {
 	struct commit **list = commits;
 	int count;
-	for (count = 0; count < nr_commits; count++, list++)
+	for (count = 0; count < nr_commits; count++, list++) {
+		display_progress(progress, ++*progress_cnt);
 		hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
+	}
 }
 
 static const unsigned char *commit_to_sha1(size_t index, void *table)
@@ -504,7 +511,9 @@
 }
 
 static void write_graph_chunk_data(struct hashfile *f, int hash_len,
-				   struct commit **commits, int nr_commits)
+				   struct commit **commits, int nr_commits,
+				   struct progress *progress,
+				   uint64_t *progress_cnt)
 {
 	struct commit **list = commits;
 	struct commit **last = commits + nr_commits;
@@ -514,6 +523,7 @@
 		struct commit_list *parent;
 		int edge_value;
 		uint32_t packedDate[2];
+		display_progress(progress, ++*progress_cnt);
 
 		parse_commit(*list);
 		hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
@@ -542,7 +552,7 @@
 		if (!parent)
 			edge_value = GRAPH_PARENT_NONE;
 		else if (parent->next)
-			edge_value = GRAPH_OCTOPUS_EDGES_NEEDED | num_extra_edges;
+			edge_value = GRAPH_EXTRA_EDGES_NEEDED | num_extra_edges;
 		else {
 			edge_value = sha1_pos(parent->item->object.oid.hash,
 					      commits,
@@ -556,7 +566,7 @@
 
 		hashwrite_be32(f, edge_value);
 
-		if (edge_value & GRAPH_OCTOPUS_EDGES_NEEDED) {
+		if (edge_value & GRAPH_EXTRA_EDGES_NEEDED) {
 			do {
 				num_extra_edges++;
 				parent = parent->next;
@@ -577,9 +587,11 @@
 	}
 }
 
-static void write_graph_chunk_large_edges(struct hashfile *f,
+static void write_graph_chunk_extra_edges(struct hashfile *f,
 					  struct commit **commits,
-					  int nr_commits)
+					  int nr_commits,
+					  struct progress *progress,
+					  uint64_t *progress_cnt)
 {
 	struct commit **list = commits;
 	struct commit **last = commits + nr_commits;
@@ -587,6 +599,9 @@
 
 	while (list < last) {
 		int num_parents = 0;
+
+		display_progress(progress, ++*progress_cnt);
+
 		for (parent = (*list)->parents; num_parents < 3 && parent;
 		     parent = parent->next)
 			num_parents++;
@@ -680,15 +695,15 @@
 
 static void close_reachable(struct packed_oid_list *oids, int report_progress)
 {
-	int i, j;
+	int i;
 	struct commit *commit;
 	struct progress *progress = NULL;
 
 	if (report_progress)
 		progress = start_delayed_progress(
-			_("Loading known commits in commit graph"), j = 0);
+			_("Loading known commits in commit graph"), oids->nr);
 	for (i = 0; i < oids->nr; i++) {
-		display_progress(progress, ++j);
+		display_progress(progress, i + 1);
 		commit = lookup_commit(the_repository, &oids->list[i]);
 		if (commit)
 			commit->object.flags |= UNINTERESTING;
@@ -702,9 +717,9 @@
 	 */
 	if (report_progress)
 		progress = start_delayed_progress(
-			_("Expanding reachable commits in commit graph"), j = 0);
+			_("Expanding reachable commits in commit graph"), oids->nr);
 	for (i = 0; i < oids->nr; i++) {
-		display_progress(progress, ++j);
+		display_progress(progress, i + 1);
 		commit = lookup_commit(the_repository, &oids->list[i]);
 
 		if (commit && !parse_commit(commit))
@@ -714,9 +729,9 @@
 
 	if (report_progress)
 		progress = start_delayed_progress(
-			_("Clearing commit marks in commit graph"), j = 0);
+			_("Clearing commit marks in commit graph"), oids->nr);
 	for (i = 0; i < oids->nr; i++) {
-		display_progress(progress, ++j);
+		display_progress(progress, i + 1);
 		commit = lookup_commit(the_repository, &oids->list[i]);
 
 		if (commit)
@@ -811,12 +826,16 @@
 	struct commit_list *parent;
 	struct progress *progress = NULL;
 	const unsigned hashsz = the_hash_algo->rawsz;
+	uint64_t progress_cnt = 0;
+	struct strbuf progress_title = STRBUF_INIT;
+	unsigned long approx_nr_objects;
 
 	if (!commit_graph_compatible(the_repository))
 		return;
 
 	oids.nr = 0;
-	oids.alloc = approximate_object_count() / 32;
+	approx_nr_objects = approximate_object_count();
+	oids.alloc = approx_nr_objects / 32;
 	oids.progress = NULL;
 	oids.progress_done = 0;
 
@@ -846,8 +865,12 @@
 		strbuf_addf(&packname, "%s/pack/", obj_dir);
 		dirlen = packname.len;
 		if (report_progress) {
-			oids.progress = start_delayed_progress(
-				_("Finding commits for commit graph"), 0);
+			strbuf_addf(&progress_title,
+				    Q_("Finding commits for commit graph in %d pack",
+				       "Finding commits for commit graph in %d packs",
+				       pack_indexes->nr),
+				    pack_indexes->nr);
+			oids.progress = start_delayed_progress(progress_title.buf, 0);
 			oids.progress_done = 0;
 		}
 		for (i = 0; i < pack_indexes->nr; i++) {
@@ -859,19 +882,26 @@
 				die(_("error adding pack %s"), packname.buf);
 			if (open_pack_index(p))
 				die(_("error opening index for %s"), packname.buf);
-			for_each_object_in_pack(p, add_packed_commits, &oids, 0);
+			for_each_object_in_pack(p, add_packed_commits, &oids,
+						FOR_EACH_OBJECT_PACK_ORDER);
 			close_pack(p);
 			free(p);
 		}
 		stop_progress(&oids.progress);
+		strbuf_reset(&progress_title);
 		strbuf_release(&packname);
 	}
 
 	if (commit_hex) {
-		if (report_progress)
-			progress = start_delayed_progress(
-				_("Finding commits for commit graph"),
-				commit_hex->nr);
+		if (report_progress) {
+			strbuf_addf(&progress_title,
+				    Q_("Finding commits for commit graph from %d ref",
+				       "Finding commits for commit graph from %d refs",
+				       commit_hex->nr),
+				    commit_hex->nr);
+			progress = start_delayed_progress(progress_title.buf,
+							  commit_hex->nr);
+		}
 		for (i = 0; i < commit_hex->nr; i++) {
 			const char *end;
 			struct object_id oid;
@@ -891,25 +921,36 @@
 			}
 		}
 		stop_progress(&progress);
+		strbuf_reset(&progress_title);
 	}
 
 	if (!pack_indexes && !commit_hex) {
 		if (report_progress)
 			oids.progress = start_delayed_progress(
-				_("Finding commits for commit graph"), 0);
-		for_each_packed_object(add_packed_commits, &oids, 0);
+				_("Finding commits for commit graph among packed objects"),
+				approx_nr_objects);
+		for_each_packed_object(add_packed_commits, &oids,
+				       FOR_EACH_OBJECT_PACK_ORDER);
+		if (oids.progress_done < approx_nr_objects)
+			display_progress(oids.progress, approx_nr_objects);
 		stop_progress(&oids.progress);
 	}
 
 	close_reachable(&oids, report_progress);
 
+	if (report_progress)
+		progress = start_delayed_progress(
+			_("Counting distinct commits in commit graph"),
+			oids.nr);
+	display_progress(progress, 0); /* TODO: Measure QSORT() progress */
 	QSORT(oids.list, oids.nr, commit_compare);
-
 	count_distinct = 1;
 	for (i = 1; i < oids.nr; i++) {
+		display_progress(progress, i + 1);
 		if (!oideq(&oids.list[i - 1], &oids.list[i]))
 			count_distinct++;
 	}
+	stop_progress(&progress);
 
 	if (count_distinct >= GRAPH_EDGE_LAST_MASK)
 		die(_("the commit graph format cannot write %d commits"), count_distinct);
@@ -919,8 +960,13 @@
 	ALLOC_ARRAY(commits.list, commits.alloc);
 
 	num_extra_edges = 0;
+	if (report_progress)
+		progress = start_delayed_progress(
+			_("Finding extra edges in commit graph"),
+			oids.nr);
 	for (i = 0; i < oids.nr; i++) {
 		int num_parents = 0;
+		display_progress(progress, i + 1);
 		if (i > 0 && oideq(&oids.list[i - 1], &oids.list[i]))
 			continue;
 
@@ -937,6 +983,7 @@
 		commits.nr++;
 	}
 	num_chunks = num_extra_edges ? 4 : 3;
+	stop_progress(&progress);
 
 	if (commits.nr >= GRAPH_EDGE_LAST_MASK)
 		die(_("too many commits to write graph"));
@@ -964,7 +1011,7 @@
 	chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
 	chunk_ids[2] = GRAPH_CHUNKID_DATA;
 	if (num_extra_edges)
-		chunk_ids[3] = GRAPH_CHUNKID_LARGEEDGES;
+		chunk_ids[3] = GRAPH_CHUNKID_EXTRAEDGES;
 	else
 		chunk_ids[3] = 0;
 	chunk_ids[4] = 0;
@@ -984,10 +1031,23 @@
 		hashwrite(f, chunk_write, 12);
 	}
 
-	write_graph_chunk_fanout(f, commits.list, commits.nr);
-	write_graph_chunk_oids(f, hashsz, commits.list, commits.nr);
-	write_graph_chunk_data(f, hashsz, commits.list, commits.nr);
-	write_graph_chunk_large_edges(f, commits.list, commits.nr);
+	if (report_progress) {
+		strbuf_addf(&progress_title,
+			    Q_("Writing out commit graph in %d pass",
+			       "Writing out commit graph in %d passes",
+			       num_chunks),
+			    num_chunks);
+		progress = start_delayed_progress(
+			progress_title.buf,
+			num_chunks * commits.nr);
+	}
+	write_graph_chunk_fanout(f, commits.list, commits.nr, progress, &progress_cnt);
+	write_graph_chunk_oids(f, hashsz, commits.list, commits.nr, progress, &progress_cnt);
+	write_graph_chunk_data(f, hashsz, commits.list, commits.nr, progress, &progress_cnt);
+	if (num_extra_edges)
+		write_graph_chunk_extra_edges(f, commits.list, commits.nr, progress, &progress_cnt);
+	stop_progress(&progress);
+	strbuf_release(&progress_title);
 
 	close_commit_graph(the_repository);
 	finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
diff --git a/commit-graph.h b/commit-graph.h
index 813e7c1..096d8ba 100644
--- a/commit-graph.h
+++ b/commit-graph.h
@@ -49,7 +49,7 @@
 	const uint32_t *chunk_oid_fanout;
 	const unsigned char *chunk_oid_lookup;
 	const unsigned char *chunk_commit_data;
-	const unsigned char *chunk_large_edges;
+	const unsigned char *chunk_extra_edges;
 };
 
 struct commit_graph *load_commit_graph_one(const char *graph_file);
diff --git a/compat/mingw.c b/compat/mingw.c
index b459e1a..4276297 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -7,6 +7,7 @@
 #include "../cache.h"
 #include "win32/lazyload.h"
 #include "../config.h"
+#include "dir.h"
 
 #define HCAST(type, handle) ((type)(intptr_t)handle)
 
@@ -1031,7 +1032,7 @@
  * See "Parsing C++ Command-Line Arguments" at Microsoft's Docs:
  * https://docs.microsoft.com/en-us/cpp/cpp/parsing-cpp-command-line-arguments
  */
-static const char *quote_arg(const char *arg)
+static const char *quote_arg_msvc(const char *arg)
 {
 	/* count chars to quote */
 	int len = 0, n = 0;
@@ -1086,6 +1087,37 @@
 	return q;
 }
 
+#include "quote.h"
+
+static const char *quote_arg_msys2(const char *arg)
+{
+	struct strbuf buf = STRBUF_INIT;
+	const char *p2 = arg, *p;
+
+	for (p = arg; *p; p++) {
+		int ws = isspace(*p);
+		if (!ws && *p != '\\' && *p != '"' && *p != '{')
+			continue;
+		if (!buf.len)
+			strbuf_addch(&buf, '"');
+		if (p != p2)
+			strbuf_add(&buf, p2, p - p2);
+		if (!ws && *p != '{')
+			strbuf_addch(&buf, '\\');
+		p2 = p;
+	}
+
+	if (p == arg)
+		strbuf_addch(&buf, '"');
+	else if (!buf.len)
+		return arg;
+	else
+		strbuf_add(&buf, p2, p - p2),
+
+	strbuf_addch(&buf, '"');
+	return strbuf_detach(&buf, 0);
+}
+
 static const char *parse_interpreter(const char *cmd)
 {
 	static char buf[100];
@@ -1317,6 +1349,47 @@
 static struct pinfo_t *pinfo = NULL;
 CRITICAL_SECTION pinfo_cs;
 
+/* Used to match and chomp off path components */
+static inline int match_last_path_component(const char *path, size_t *len,
+					    const char *component)
+{
+	size_t component_len = strlen(component);
+	if (*len < component_len + 1 ||
+	    !is_dir_sep(path[*len - component_len - 1]) ||
+	    fspathncmp(path + *len - component_len, component, component_len))
+		return 0;
+	*len -= component_len + 1;
+	/* chomp off repeated dir separators */
+	while (*len > 0 && is_dir_sep(path[*len - 1]))
+		(*len)--;
+	return 1;
+}
+
+static int is_msys2_sh(const char *cmd)
+{
+	if (cmd && !strcmp(cmd, "sh")) {
+		static int ret = -1;
+		char *p;
+
+		if (ret >= 0)
+			return ret;
+
+		p = path_lookup(cmd, 0);
+		if (!p)
+			ret = 0;
+		else {
+			size_t len = strlen(p);
+
+			ret = match_last_path_component(p, &len, "sh.exe") &&
+				match_last_path_component(p, &len, "bin") &&
+				match_last_path_component(p, &len, "usr");
+			free(p);
+		}
+		return ret;
+	}
+	return 0;
+}
+
 static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaenv,
 			      const char *dir,
 			      int prepend_cmd, int fhin, int fhout, int fherr)
@@ -1328,6 +1401,8 @@
 	unsigned flags = CREATE_UNICODE_ENVIRONMENT;
 	BOOL ret;
 	HANDLE cons;
+	const char *(*quote_arg)(const char *arg) =
+		is_msys2_sh(*argv) ? quote_arg_msys2 : quote_arg_msvc;
 
 	do_unset_environment_variables();
 
@@ -2100,7 +2175,7 @@
 	if (timer_event)
 		SetEvent(timer_event);	/* tell thread to terminate */
 	if (timer_thread) {
-		int rc = WaitForSingleObject(timer_thread, 1000);
+		int rc = WaitForSingleObject(timer_thread, 10000);
 		if (rc == WAIT_TIMEOUT)
 			error("timer thread did not terminate timely");
 		else if (rc != WAIT_OBJECT_0)
diff --git a/compat/precompose_utf8.c b/compat/precompose_utf8.c
index de61c15..136250f 100644
--- a/compat/precompose_utf8.c
+++ b/compat/precompose_utf8.c
@@ -79,7 +79,7 @@
 		size_t namelen;
 		oldarg = argv[i];
 		if (has_non_ascii(oldarg, (size_t)-1, &namelen)) {
-			newarg = reencode_string_iconv(oldarg, namelen, ic_precompose, NULL);
+			newarg = reencode_string_iconv(oldarg, namelen, ic_precompose, 0, NULL);
 			if (newarg)
 				argv[i] = newarg;
 		}
diff --git a/config.c b/config.c
index ff521eb..24ad1a9 100644
--- a/config.c
+++ b/config.c
@@ -2565,7 +2565,6 @@
  * entry (which all are to be removed).
  */
 static void maybe_remove_section(struct config_store_data *store,
-				 const char *contents,
 				 size_t *begin_offset, size_t *end_offset,
 				 int *seen_ptr)
 {
@@ -2850,7 +2849,7 @@
 				replace_end = store.parsed[j].end;
 				copy_end = store.parsed[j].begin;
 				if (!value)
-					maybe_remove_section(&store, contents,
+					maybe_remove_section(&store,
 							     &copy_end,
 							     &replace_end, &i);
 				/*
diff --git a/config.mak.uname b/config.mak.uname
index 7b36a1d..786bb2f 100644
--- a/config.mak.uname
+++ b/config.mak.uname
@@ -555,7 +555,6 @@
 	RC = windres -O coff
 	NATIVE_CRLF = YesPlease
 	X = .exe
-	SPARSE_FLAGS = -Wno-one-bit-signed-bitfield
 ifneq (,$(wildcard ../THIS_IS_MSYSGIT))
 	htmldir = doc/git/html/
 	prefix =
diff --git a/contrib/coccinelle/strbuf.cocci b/contrib/coccinelle/strbuf.cocci
index e34eada..d9ada69 100644
--- a/contrib/coccinelle/strbuf.cocci
+++ b/contrib/coccinelle/strbuf.cocci
@@ -13,6 +13,36 @@
   );
 
 @@
+expression E;
+struct strbuf SB;
+format F =~ "s";
+@@
+- strbuf_addf(E, "%@F@", SB.buf);
++ strbuf_addbuf(E, &SB);
+
+@@
+expression E;
+struct strbuf *SBP;
+format F =~ "s";
+@@
+- strbuf_addf(E, "%@F@", SBP->buf);
++ strbuf_addbuf(E, SBP);
+
+@@
+expression E;
+struct strbuf SB;
+@@
+- strbuf_addstr(E, SB.buf);
++ strbuf_addbuf(E, &SB);
+
+@@
+expression E;
+struct strbuf *SBP;
+@@
+- strbuf_addstr(E, SBP->buf);
++ strbuf_addbuf(E, SBP);
+
+@@
 expression E1, E2;
 format F =~ "s";
 @@
diff --git a/convert.c b/convert.c
index 0d89ae7..5d0307f 100644
--- a/convert.c
+++ b/convert.c
@@ -1,4 +1,3 @@
-#define NO_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "object-store.h"
@@ -92,7 +91,7 @@
  * The same heuristics as diff.c::mmfile_is_binary()
  * We treat files with bare CR as binary
  */
-static int convert_is_binary(unsigned long size, const struct text_stat *stats)
+static int convert_is_binary(const struct text_stat *stats)
 {
 	if (stats->lonecr)
 		return 1;
@@ -110,7 +109,7 @@
 	if (!data || !size)
 		return 0;
 	gather_stats(data, size, &stats);
-	if (convert_is_binary(size, &stats))
+	if (convert_is_binary(&stats))
 		ret |= CONVERT_STAT_BITS_BIN;
 	if (stats.crlf)
 		ret |= CONVERT_STAT_BITS_TXT_CRLF;
@@ -245,7 +244,7 @@
 	return has_crlf;
 }
 
-static int will_convert_lf_to_crlf(size_t len, struct text_stat *stats,
+static int will_convert_lf_to_crlf(struct text_stat *stats,
 				   enum crlf_action crlf_action)
 {
 	if (output_eol(crlf_action) != EOL_CRLF)
@@ -260,7 +259,7 @@
 		if (stats->lonecr || stats->crlf)
 			return 0;
 
-		if (convert_is_binary(len, stats))
+		if (convert_is_binary(stats))
 			return 0;
 	}
 	return 1;
@@ -527,7 +526,7 @@
 	convert_crlf_into_lf = !!stats.crlf;
 
 	if (crlf_action == CRLF_AUTO || crlf_action == CRLF_AUTO_INPUT || crlf_action == CRLF_AUTO_CRLF) {
-		if (convert_is_binary(len, &stats))
+		if (convert_is_binary(&stats))
 			return 0;
 		/*
 		 * If the file in the index has any CR in it, do not
@@ -549,7 +548,7 @@
 			new_stats.crlf = 0;
 		}
 		/* simulate "git checkout" */
-		if (will_convert_lf_to_crlf(len, &new_stats, crlf_action)) {
+		if (will_convert_lf_to_crlf(&new_stats, crlf_action)) {
 			new_stats.crlf += new_stats.lonelf;
 			new_stats.lonelf = 0;
 		}
@@ -591,7 +590,7 @@
 	return 1;
 }
 
-static int crlf_to_worktree(const char *path, const char *src, size_t len,
+static int crlf_to_worktree(const char *src, size_t len,
 			    struct strbuf *buf, enum crlf_action crlf_action)
 {
 	char *to_free = NULL;
@@ -601,7 +600,7 @@
 		return 0;
 
 	gather_stats(src, len, &stats);
-	if (!will_convert_lf_to_crlf(len, &stats, crlf_action))
+	if (!will_convert_lf_to_crlf(&stats, crlf_action))
 		return 0;
 
 	/* are we "faking" in place editing ? */
@@ -1091,7 +1090,7 @@
 	return cnt;
 }
 
-static int ident_to_git(const char *path, const char *src, size_t len,
+static int ident_to_git(const char *src, size_t len,
 			struct strbuf *buf, int ident)
 {
 	char *dst, *dollar;
@@ -1135,7 +1134,7 @@
 	return 1;
 }
 
-static int ident_to_worktree(const char *path, const char *src, size_t len,
+static int ident_to_worktree(const char *src, size_t len,
 			     struct strbuf *buf, int ident)
 {
 	struct object_id oid;
@@ -1416,7 +1415,7 @@
 			len = dst->len;
 		}
 	}
-	return ret | ident_to_git(path, src, len, dst, ca.ident);
+	return ret | ident_to_git(src, len, dst, ca.ident);
 }
 
 void convert_to_git_filter_fd(const struct index_state *istate,
@@ -1434,7 +1433,7 @@
 
 	encode_to_git(path, dst->buf, dst->len, dst, ca.working_tree_encoding, conv_flags);
 	crlf_to_git(istate, path, dst->buf, dst->len, dst, ca.crlf_action, conv_flags);
-	ident_to_git(path, dst->buf, dst->len, dst, ca.ident);
+	ident_to_git(dst->buf, dst->len, dst, ca.ident);
 }
 
 static int convert_to_working_tree_internal(const struct index_state *istate,
@@ -1447,7 +1446,7 @@
 
 	convert_attrs(istate, &ca, path);
 
-	ret |= ident_to_worktree(path, src, len, dst, ca.ident);
+	ret |= ident_to_worktree(src, len, dst, ca.ident);
 	if (ret) {
 		src = dst->buf;
 		len = dst->len;
@@ -1458,7 +1457,7 @@
 	 * support smudge).  The filters might expect CRLFs.
 	 */
 	if ((ca.drv && (ca.drv->smudge || ca.drv->process)) || !normalizing) {
-		ret |= crlf_to_worktree(path, src, len, dst, ca.crlf_action);
+		ret |= crlf_to_worktree(src, len, dst, ca.crlf_action);
 		if (ret) {
 			src = dst->buf;
 			len = dst->len;
diff --git a/date.c b/date.c
index 9bc15df..9c5870e 100644
--- a/date.c
+++ b/date.c
@@ -77,22 +77,16 @@
 }
 
 /*
- * What value of "tz" was in effect back then at "time" in the
- * local timezone?
+ * Fill in the localtime 'struct tm' for the supplied time,
+ * and return the local tz.
  */
-static int local_tzoffset(timestamp_t time)
+static int local_time_tzoffset(time_t t, struct tm *tm)
 {
-	time_t t, t_local;
-	struct tm tm;
+	time_t t_local;
 	int offset, eastwest;
 
-	if (date_overflows(time))
-		die("Timestamp too large for this system: %"PRItime, time);
-
-	t = (time_t)time;
-	localtime_r(&t, &tm);
-	t_local = tm_to_time_t(&tm);
-
+	localtime_r(&t, tm);
+	t_local = tm_to_time_t(tm);
 	if (t_local == -1)
 		return 0; /* error; just use +0000 */
 	if (t_local < t) {
@@ -107,9 +101,36 @@
 	return offset * eastwest;
 }
 
-void show_date_relative(timestamp_t time, int tz,
-			       const struct timeval *now,
-			       struct strbuf *timebuf)
+/*
+ * What value of "tz" was in effect back then at "time" in the
+ * local timezone?
+ */
+static int local_tzoffset(timestamp_t time)
+{
+	struct tm tm;
+
+	if (date_overflows(time))
+		die("Timestamp too large for this system: %"PRItime, time);
+
+	return local_time_tzoffset((time_t)time, &tm);
+}
+
+static void get_time(struct timeval *now)
+{
+	const char *x;
+
+	x = getenv("GIT_TEST_DATE_NOW");
+	if (x) {
+		now->tv_sec = atoi(x);
+		now->tv_usec = 0;
+	}
+	else
+		gettimeofday(now, NULL);
+}
+
+void show_date_relative(timestamp_t time,
+			const struct timeval *now,
+			struct strbuf *timebuf)
 {
 	timestamp_t diff;
 	if (now->tv_sec < time) {
@@ -191,9 +212,80 @@
 	return &mode;
 }
 
+static void show_date_normal(struct strbuf *buf, timestamp_t time, struct tm *tm, int tz, struct tm *human_tm, int human_tz, int local)
+{
+	struct {
+		unsigned int	year:1,
+				date:1,
+				wday:1,
+				time:1,
+				seconds:1,
+				tz:1;
+	} hide = { 0 };
+
+	hide.tz = local || tz == human_tz;
+	hide.year = tm->tm_year == human_tm->tm_year;
+	if (hide.year) {
+		if (tm->tm_mon == human_tm->tm_mon) {
+			if (tm->tm_mday > human_tm->tm_mday) {
+				/* Future date: think timezones */
+			} else if (tm->tm_mday == human_tm->tm_mday) {
+				hide.date = hide.wday = 1;
+			} else if (tm->tm_mday + 5 > human_tm->tm_mday) {
+				/* Leave just weekday if it was a few days ago */
+				hide.date = 1;
+			}
+		}
+	}
+
+	/* Show "today" times as just relative times */
+	if (hide.wday) {
+		struct timeval now;
+		get_time(&now);
+		show_date_relative(time, &now, buf);
+		return;
+	}
+
+	/*
+	 * Always hide seconds for human-readable.
+	 * Hide timezone if showing date.
+	 * Hide weekday and time if showing year.
+	 *
+	 * The logic here is two-fold:
+	 *  (a) only show details when recent enough to matter
+	 *  (b) keep the maximum length "similar", and in check
+	 */
+	if (human_tm->tm_year) {
+		hide.seconds = 1;
+		hide.tz |= !hide.date;
+		hide.wday = hide.time = !hide.year;
+	}
+
+	if (!hide.wday)
+		strbuf_addf(buf, "%.3s ", weekday_names[tm->tm_wday]);
+	if (!hide.date)
+		strbuf_addf(buf, "%.3s %d ", month_names[tm->tm_mon], tm->tm_mday);
+
+	/* Do we want AM/PM depending on locale? */
+	if (!hide.time) {
+		strbuf_addf(buf, "%02d:%02d", tm->tm_hour, tm->tm_min);
+		if (!hide.seconds)
+			strbuf_addf(buf, ":%02d", tm->tm_sec);
+	} else
+		strbuf_rtrim(buf);
+
+	if (!hide.year)
+		strbuf_addf(buf, " %d", tm->tm_year + 1900);
+
+	if (!hide.tz)
+		strbuf_addf(buf, " %+05d", tz);
+}
+
 const char *show_date(timestamp_t time, int tz, const struct date_mode *mode)
 {
 	struct tm *tm;
+	struct tm human_tm = { 0 };
+	int human_tz = -1;
 	static struct strbuf timebuf = STRBUF_INIT;
 
 	if (mode->type == DATE_UNIX) {
@@ -202,6 +294,15 @@
 		return timebuf.buf;
 	}
 
+	if (mode->type == DATE_HUMAN) {
+		struct timeval now;
+
+		get_time(&now);
+
+		/* Fill in the data for "current time" in human_tz and human_tm */
+		human_tz = local_time_tzoffset(now.tv_sec, &human_tm);
+	}
+
 	if (mode->local)
 		tz = local_tzoffset(time);
 
@@ -215,8 +316,8 @@
 		struct timeval now;
 
 		strbuf_reset(&timebuf);
-		gettimeofday(&now, NULL);
-		show_date_relative(time, tz, &now, &timebuf);
+		get_time(&now);
+		show_date_relative(time, &now, &timebuf);
 		return timebuf.buf;
 	}
 
@@ -258,14 +359,7 @@
 		strbuf_addftime(&timebuf, mode->strftime_fmt, tm, tz,
 				!mode->local);
 	else
-		strbuf_addf(&timebuf, "%.3s %.3s %d %02d:%02d:%02d %d%c%+05d",
-				weekday_names[tm->tm_wday],
-				month_names[tm->tm_mon],
-				tm->tm_mday,
-				tm->tm_hour, tm->tm_min, tm->tm_sec,
-				tm->tm_year + 1900,
-				mode->local ? 0 : ' ',
-				tz);
+		show_date_normal(&timebuf, time, tm, tz, &human_tm, human_tz, mode->local);
 	return timebuf.buf;
 }
 
@@ -819,6 +913,8 @@
 		return DATE_SHORT;
 	if (skip_prefix(format, "default", end))
 		return DATE_NORMAL;
+	if (skip_prefix(format, "human", end))
+		return DATE_HUMAN;
 	if (skip_prefix(format, "raw", end))
 		return DATE_RAW;
 	if (skip_prefix(format, "unix", end))
@@ -833,6 +929,14 @@
 {
 	const char *p;
 
+	/* "auto:foo" is "if tty/pager, then foo, otherwise normal" */
+	if (skip_prefix(format, "auto:", &p)) {
+		if (isatty(1) || pager_in_use())
+			format = p;
+		else
+			format = "default";
+	}
+
 	/* historical alias */
 	if (!strcmp(format, "local"))
 		format = "default-local";
@@ -1205,7 +1309,7 @@
 		return timestamp;
 	}
 
-	gettimeofday(&tv, NULL);
+	get_time(&tv);
 	return approxidate_str(date, &tv, error_ret);
 }
 
diff --git a/diff.c b/diff.c
index e8c3e80..5306c48 100644
--- a/diff.c
+++ b/diff.c
@@ -5962,8 +5962,10 @@
 
 		for (i = 0; i < esm.nr; i++)
 			free((void *)esm.buf[i].line);
+		esm.nr = 0;
+
+		o->emitted_symbols = NULL;
 	}
-	esm.nr = 0;
 }
 
 void diff_flush(struct diff_options *options)
diff --git a/dir.c b/dir.c
index 2128448..b2cabad 100644
--- a/dir.c
+++ b/dir.c
@@ -7,7 +7,6 @@
  * Copyright (C) Linus Torvalds, 2005-2006
  *		 Junio Hamano, 2005-2006
  */
-#define NO_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "dir.h"
diff --git a/fetch-pack.c b/fetch-pack.c
index 08b3b35..812be15 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -1290,6 +1290,8 @@
 		setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
 					NULL);
 		args->deepen = 1;
+	} else {
+		alternate_shallow_file = NULL;
 	}
 }
 
@@ -1514,6 +1516,7 @@
 			rollback_lock_file(&shallow_lock);
 		} else
 			commit_lock_file(&shallow_lock);
+		alternate_shallow_file = NULL;
 		return;
 	}
 
@@ -1537,6 +1540,7 @@
 						&alternate_shallow_file,
 						&extra);
 			commit_lock_file(&shallow_lock);
+			alternate_shallow_file = NULL;
 		}
 		oid_array_clear(&extra);
 		return;
@@ -1576,6 +1580,7 @@
 		commit_lock_file(&shallow_lock);
 		oid_array_clear(&extra);
 		oid_array_clear(&ref);
+		alternate_shallow_file = NULL;
 		return;
 	}
 
diff --git a/git-bisect.sh b/git-bisect.sh
index 54cbfec..efee12b 100755
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -71,122 +71,7 @@
 }
 
 bisect_start() {
-	#
-	# Check for one bad and then some good revisions.
-	#
-	has_double_dash=0
-	for arg; do
-		case "$arg" in --) has_double_dash=1; break ;; esac
-	done
-	orig_args=$(git rev-parse --sq-quote "$@")
-	bad_seen=0
-	eval=''
-	must_write_terms=0
-	revs=''
-	if test "z$(git rev-parse --is-bare-repository)" != zfalse
-	then
-		mode=--no-checkout
-	else
-		mode=''
-	fi
-	while [ $# -gt 0 ]; do
-		arg="$1"
-		case "$arg" in
-		--)
-			shift
-			break
-		;;
-		--no-checkout)
-			mode=--no-checkout
-			shift ;;
-		--term-good|--term-old)
-			shift
-			must_write_terms=1
-			TERM_GOOD=$1
-			shift ;;
-		--term-good=*|--term-old=*)
-			must_write_terms=1
-			TERM_GOOD=${1#*=}
-			shift ;;
-		--term-bad|--term-new)
-			shift
-			must_write_terms=1
-			TERM_BAD=$1
-			shift ;;
-		--term-bad=*|--term-new=*)
-			must_write_terms=1
-			TERM_BAD=${1#*=}
-			shift ;;
-		--*)
-			die "$(eval_gettext "unrecognised option: '\$arg'")" ;;
-		*)
-			rev=$(git rev-parse -q --verify "$arg^{commit}") || {
-				test $has_double_dash -eq 1 &&
-				die "$(eval_gettext "'\$arg' does not appear to be a valid revision")"
-				break
-			}
-			revs="$revs $rev"
-			shift
-			;;
-		esac
-	done
-
-	for rev in $revs
-	do
-		# The user ran "git bisect start <sha1>
-		# <sha1>", hence did not explicitly specify
-		# the terms, but we are already starting to
-		# set references named with the default terms,
-		# and won't be able to change afterwards.
-		must_write_terms=1
-
-		case $bad_seen in
-		0) state=$TERM_BAD ; bad_seen=1 ;;
-		*) state=$TERM_GOOD ;;
-		esac
-		eval="$eval bisect_write '$state' '$rev' 'nolog' &&"
-	done
-	#
-	# Verify HEAD.
-	#
-	head=$(GIT_DIR="$GIT_DIR" git symbolic-ref -q HEAD) ||
-	head=$(GIT_DIR="$GIT_DIR" git rev-parse --verify HEAD) ||
-	die "$(gettext "Bad HEAD - I need a HEAD")"
-
-	#
-	# Check if we are bisecting.
-	#
-	start_head=''
-	if test -s "$GIT_DIR/BISECT_START"
-	then
-		# Reset to the rev from where we started.
-		start_head=$(cat "$GIT_DIR/BISECT_START")
-		if test "z$mode" != "z--no-checkout"
-		then
-			git checkout "$start_head" -- ||
-			die "$(eval_gettext "Checking out '\$start_head' failed. Try 'git bisect reset <valid-branch>'.")"
-		fi
-	else
-		# Get rev from where we start.
-		case "$head" in
-		refs/heads/*|$_x40)
-			# This error message should only be triggered by
-			# cogito usage, and cogito users should understand
-			# it relates to cg-seek.
-			[ -s "$GIT_DIR/head-name" ] &&
-				die "$(gettext "won't bisect on cg-seek'ed tree")"
-			start_head="${head#refs/heads/}"
-			;;
-		*)
-			die "$(gettext "Bad HEAD - strange symbolic ref")"
-			;;
-		esac
-	fi
-
-	#
-	# Get rid of any old bisect state.
-	#
-	git bisect--helper --bisect-clean-state || exit
+	git bisect--helper --bisect-start $@ || exit
 
 	#
 	# Change state.
@@ -199,44 +84,14 @@
 	trap 'exit 255' 1 2 3 15
 
 	#
-	# Write new start state.
-	#
-	echo "$start_head" >"$GIT_DIR/BISECT_START" && {
-		test "z$mode" != "z--no-checkout" ||
-		git update-ref --no-deref BISECT_HEAD "$start_head"
-	} &&
-	git rev-parse --sq-quote "$@" >"$GIT_DIR/BISECT_NAMES" &&
-	eval "$eval true" &&
-	if test $must_write_terms -eq 1
-	then
-		git bisect--helper --write-terms "$TERM_BAD" "$TERM_GOOD" || exit
-	fi &&
-	echo "git bisect start$orig_args" >>"$GIT_DIR/BISECT_LOG" || exit
-	#
 	# Check if we can proceed to the next bisect state.
 	#
+	get_terms
 	bisect_auto_next
 
 	trap '-' 0
 }
 
-bisect_write() {
-	state="$1"
-	rev="$2"
-	nolog="$3"
-	case "$state" in
-		"$TERM_BAD")
-			tag="$state" ;;
-		"$TERM_GOOD"|skip)
-			tag="$state"-"$rev" ;;
-		*)
-			die "$(eval_gettext "Bad bisect_write argument: \$state")" ;;
-	esac
-	git update-ref "refs/bisect/$tag" "$rev" || exit
-	echo "# $state: $(git show-branch $rev)" >>"$GIT_DIR/BISECT_LOG"
-	test -n "$nolog" || echo "git bisect $state $rev" >>"$GIT_DIR/BISECT_LOG"
-}
-
 bisect_skip() {
 	all=''
 	for arg in "$@"
@@ -255,7 +110,8 @@
 bisect_state() {
 	bisect_autostart
 	state=$1
-	check_and_set_terms $state
+	git bisect--helper --check-and-set-terms $state $TERM_GOOD $TERM_BAD || exit
+	get_terms
 	case "$#,$state" in
 	0,*)
 		die "Please call 'bisect_state' with at least one argument." ;;
@@ -263,7 +119,7 @@
 		bisected_head=$(bisect_head)
 		rev=$(git rev-parse --verify "$bisected_head") ||
 			die "$(eval_gettext "Bad rev input: \$bisected_head")"
-		bisect_write "$state" "$rev"
+		git bisect--helper --bisect-write "$state" "$rev" "$TERM_GOOD" "$TERM_BAD" || exit
 		git bisect--helper --check-expected-revs "$rev" ;;
 	2,"$TERM_BAD"|*,"$TERM_GOOD"|*,skip)
 		shift
@@ -276,7 +132,7 @@
 		done
 		for rev in $hash_list
 		do
-			bisect_write "$state" "$rev"
+			git bisect--helper --bisect-write "$state" "$rev" "$TERM_GOOD" "$TERM_BAD" || exit
 		done
 		git bisect--helper --check-expected-revs $hash_list ;;
 	*,"$TERM_BAD")
@@ -287,59 +143,14 @@
 	bisect_auto_next
 }
 
-bisect_next_check() {
-	missing_good= missing_bad=
-	git show-ref -q --verify refs/bisect/$TERM_BAD || missing_bad=t
-	test -n "$(git for-each-ref "refs/bisect/$TERM_GOOD-*")" || missing_good=t
-
-	case "$missing_good,$missing_bad,$1" in
-	,,*)
-		: have both $TERM_GOOD and $TERM_BAD - ok
-		;;
-	*,)
-		# do not have both but not asked to fail - just report.
-		false
-		;;
-	t,,"$TERM_GOOD")
-		# have bad (or new) but not good (or old).  we could bisect although
-		# this is less optimum.
-		eval_gettextln "Warning: bisecting only with a \$TERM_BAD commit." >&2
-		if test -t 0
-		then
-			# TRANSLATORS: Make sure to include [Y] and [n] in your
-			# translation. The program will only accept English input
-			# at this point.
-			gettext "Are you sure [Y/n]? " >&2
-			read yesno
-			case "$yesno" in [Nn]*) exit 1 ;; esac
-		fi
-		: bisect without $TERM_GOOD...
-		;;
-	*)
-		bad_syn=$(bisect_voc bad)
-		good_syn=$(bisect_voc good)
-		if test -s "$GIT_DIR/BISECT_START"
-		then
-
-			eval_gettextln "You need to give me at least one \$bad_syn and one \$good_syn revision.
-(You can use \"git bisect \$bad_syn\" and \"git bisect \$good_syn\" for that.)" >&2
-		else
-			eval_gettextln "You need to start by \"git bisect start\".
-You then need to give me at least one \$good_syn and one \$bad_syn revision.
-(You can use \"git bisect \$bad_syn\" and \"git bisect \$good_syn\" for that.)" >&2
-		fi
-		exit 1 ;;
-	esac
-}
-
 bisect_auto_next() {
-	bisect_next_check && bisect_next || :
+	git bisect--helper --bisect-next-check $TERM_GOOD $TERM_BAD && bisect_next || :
 }
 
 bisect_next() {
 	case "$#" in 0) ;; *) usage ;; esac
 	bisect_autostart
-	bisect_next_check $TERM_GOOD
+	git bisect--helper --bisect-next-check $TERM_GOOD $TERM_BAD $TERM_GOOD|| exit
 
 	# Perform all bisection computation, display and checkout
 	git bisect--helper --next-all $(test -f "$GIT_DIR/BISECT_HEAD" && echo --no-checkout)
@@ -371,7 +182,7 @@
 }
 
 bisect_visualize() {
-	bisect_next_check fail
+	git bisect--helper --bisect-next-check $TERM_GOOD $TERM_BAD fail || exit
 
 	if test $# = 0
 	then
@@ -393,35 +204,11 @@
 	eval '"$@"' --bisect -- $(cat "$GIT_DIR/BISECT_NAMES")
 }
 
-bisect_reset() {
-	test -s "$GIT_DIR/BISECT_START" || {
-		gettextln "We are not bisecting."
-		return
-	}
-	case "$#" in
-	0) branch=$(cat "$GIT_DIR/BISECT_START") ;;
-	1) git rev-parse --quiet --verify "$1^{commit}" >/dev/null || {
-			invalid="$1"
-			die "$(eval_gettext "'\$invalid' is not a valid commit")"
-		}
-		branch="$1" ;;
-	*)
-		usage ;;
-	esac
-
-	if ! test -f "$GIT_DIR/BISECT_HEAD" && ! git checkout "$branch" --
-	then
-		die "$(eval_gettext "Could not check out original HEAD '\$branch'.
-Try 'git bisect reset <commit>'.")"
-	fi
-	git bisect--helper --bisect-clean-state || exit
-}
-
 bisect_replay () {
 	file="$1"
 	test "$#" -eq 1 || die "$(gettext "No logfile given")"
 	test -r "$file" || die "$(eval_gettext "cannot read \$file for replaying")"
-	bisect_reset
+	git bisect--helper --bisect-reset || exit
 	while read git bisect command rev
 	do
 		test "$git $bisect" = "git bisect" || test "$git" = "git-bisect" || continue
@@ -431,15 +218,16 @@
 			command="$bisect"
 		fi
 		get_terms
-		check_and_set_terms "$command"
+		git bisect--helper --check-and-set-terms "$command" "$TERM_GOOD" "$TERM_BAD" || exit
+		get_terms
 		case "$command" in
 		start)
 			cmd="bisect_start $rev"
 			eval "$cmd" ;;
 		"$TERM_GOOD"|"$TERM_BAD"|skip)
-			bisect_write "$command" "$rev" ;;
+			git bisect--helper --bisect-write "$command" "$rev" "$TERM_GOOD" "$TERM_BAD" || exit;;
 		terms)
-			bisect_terms $rev ;;
+			git bisect--helper --bisect-terms $rev || exit;;
 		*)
 			die "$(gettext "?? what are you talking about?")" ;;
 		esac
@@ -448,7 +236,7 @@
 }
 
 bisect_run () {
-	bisect_next_check fail
+	git bisect--helper --bisect-next-check $TERM_GOOD $TERM_BAD fail || exit
 
 	test -n "$*" || die "$(gettext "bisect run failed: no command provided.")"
 
@@ -523,74 +311,6 @@
 	fi
 }
 
-check_and_set_terms () {
-	cmd="$1"
-	case "$cmd" in
-	skip|start|terms) ;;
-	*)
-		if test -s "$GIT_DIR/BISECT_TERMS" && test "$cmd" != "$TERM_BAD" && test "$cmd" != "$TERM_GOOD"
-		then
-			die "$(eval_gettext "Invalid command: you're currently in a \$TERM_BAD/\$TERM_GOOD bisect.")"
-		fi
-		case "$cmd" in
-		bad|good)
-			if ! test -s "$GIT_DIR/BISECT_TERMS"
-			then
-				TERM_BAD=bad
-				TERM_GOOD=good
-				git bisect--helper --write-terms "$TERM_BAD" "$TERM_GOOD" || exit
-			fi
-			;;
-		new|old)
-			if ! test -s "$GIT_DIR/BISECT_TERMS"
-			then
-				TERM_BAD=new
-				TERM_GOOD=old
-				git bisect--helper --write-terms "$TERM_BAD" "$TERM_GOOD" || exit
-			fi
-			;;
-		esac ;;
-	esac
-}
-
-bisect_voc () {
-	case "$1" in
-	bad) echo "bad|new" ;;
-	good) echo "good|old" ;;
-	esac
-}
-
-bisect_terms () {
-	get_terms
-	if ! test -s "$GIT_DIR/BISECT_TERMS"
-	then
-		die "$(gettext "no terms defined")"
-	fi
-	case "$#" in
-	0)
-		gettextln "Your current terms are $TERM_GOOD for the old state
-and $TERM_BAD for the new state."
-		;;
-	1)
-		arg=$1
-		case "$arg" in
-			--term-good|--term-old)
-				printf '%s\n' "$TERM_GOOD"
-				;;
-			--term-bad|--term-new)
-				printf '%s\n' "$TERM_BAD"
-				;;
-			*)
-				die "$(eval_gettext "invalid argument \$arg for 'git bisect terms'.
-Supported options are: --term-good|--term-old and --term-bad|--term-new.")"
-				;;
-		esac
-		;;
-	*)
-		usage ;;
-	esac
-}
-
 case "$#" in
 0)
 	usage ;;
@@ -613,7 +333,7 @@
 	visualize|view)
 		bisect_visualize "$@" ;;
 	reset)
-		bisect_reset "$@" ;;
+		git bisect--helper --bisect-reset "$@" ;;
 	replay)
 		bisect_replay "$@" ;;
 	log)
@@ -621,7 +341,7 @@
 	run)
 		bisect_run "$@" ;;
 	terms)
-		bisect_terms "$@" ;;
+		git bisect--helper --bisect-terms "$@" || exit;;
 	*)
 		usage ;;
 	esac
diff --git a/git-instaweb.sh b/git-instaweb.sh
index eec264e..7c55229 100755
--- a/git-instaweb.sh
+++ b/git-instaweb.sh
@@ -67,6 +67,13 @@
 		httpd_only="${httpd%% *}" # cut on first space
 		return
 		;;
+	*python*)
+		# server is started by running via generated gitweb.py in
+		# $fqgitdir/gitweb
+		full_httpd="$fqgitdir/gitweb/gitweb.py"
+		httpd_only="${httpd%% *}" # cut on first space
+		return
+		;;
 	esac
 
 	httpd_only="$(echo $httpd | cut -f1 -d' ')"
@@ -110,7 +117,7 @@
 
 	# don't quote $full_httpd, there can be arguments to it (-f)
 	case "$httpd" in
-	*mongoose*|*plackup*)
+	*mongoose*|*plackup*|*python*)
 		#These servers don't have a daemon mode so we'll have to fork it
 		$full_httpd "$conf" &
 		#Save the pid before doing anything else (we'll print it later)
@@ -595,6 +602,121 @@
 	rm -f "$conf"
 }
 
+python_conf() {
+	# Python's builtin http.server and its CGI support is very limited.
+	# CGI handler is capable of running CGI script only from inside a directory.
+	# Trying to set cgi_directories=["/"] will add double slash to SCRIPT_NAME
+	# and that in turn breaks gitweb's relative link generation.
+
+	# create a simple web root where $fqgitdir/gitweb/$httpd_only is our root
+	mkdir -p "$fqgitdir/gitweb/$httpd_only/cgi-bin"
+	# Python http.server follows the symlinks
+	ln -sf "$root/gitweb.cgi" "$fqgitdir/gitweb/$httpd_only/cgi-bin/gitweb.cgi"
+	ln -sf "$root/static" "$fqgitdir/gitweb/$httpd_only/"
+
+	# generate a standalone 'python http.server' script in $fqgitdir/gitweb
+	# This asumes that python is in user's $PATH
+	# This script is Python 2 and 3 compatible
+	cat > "$fqgitdir/gitweb/gitweb.py" <<EOF
+#!/usr/bin/env python
+import os
+import sys
+
+# Open log file in line buffering mode
+accesslogfile = open("$fqgitdir/gitweb/access.log", 'a', buffering=1)
+errorlogfile = open("$fqgitdir/gitweb/error.log", 'a', buffering=1)
+
+# and replace our stdout and stderr with log files
+# also do a lowlevel duplicate of the logfile file descriptors so that
+# our CGI child process writes any stderr warning also to the log file
+_orig_stdout_fd = sys.stdout.fileno()
+sys.stdout.close()
+os.dup2(accesslogfile.fileno(), _orig_stdout_fd)
+sys.stdout = accesslogfile
+
+_orig_stderr_fd = sys.stderr.fileno()
+sys.stderr.close()
+os.dup2(errorlogfile.fileno(), _orig_stderr_fd)
+sys.stderr = errorlogfile
+
+from functools import partial
+
+if sys.version_info < (3, 0):  # Python 2
+	from CGIHTTPServer import CGIHTTPRequestHandler
+	from BaseHTTPServer import HTTPServer as ServerClass
+else:  # Python 3
+	from http.server import CGIHTTPRequestHandler
+	from http.server import HTTPServer as ServerClass
+
+
+# Those environment variables will be passed to the cgi script
+os.environ.update({
+	"GIT_EXEC_PATH": "$GIT_EXEC_PATH",
+	"GIT_DIR": "$GIT_DIR",
+	"GITWEB_CONFIG": "$GITWEB_CONFIG"
+})
+
+
+class GitWebRequestHandler(CGIHTTPRequestHandler):
+
+	def log_message(self, format, *args):
+		# Write access logs to stdout
+		sys.stdout.write("%s - - [%s] %s\n" %
+				(self.address_string(),
+				self.log_date_time_string(),
+				format%args))
+
+	def do_HEAD(self):
+		self.redirect_path()
+		CGIHTTPRequestHandler.do_HEAD(self)
+
+	def do_GET(self):
+		if self.path == "/":
+			self.send_response(303, "See Other")
+			self.send_header("Location", "/cgi-bin/gitweb.cgi")
+			self.end_headers()
+			return
+		self.redirect_path()
+		CGIHTTPRequestHandler.do_GET(self)
+
+	def do_POST(self):
+		self.redirect_path()
+		CGIHTTPRequestHandler.do_POST(self)
+
+	# rewrite path of every request that is not gitweb.cgi to out of cgi-bin
+	def redirect_path(self):
+		if not self.path.startswith("/cgi-bin/gitweb.cgi"):
+			self.path = self.path.replace("/cgi-bin/", "/")
+
+	# gitweb.cgi is the only thing that is ever going to be run here.
+	# Ignore everything else
+	def is_cgi(self):
+		result = False
+		if self.path.startswith('/cgi-bin/gitweb.cgi'):
+			result = CGIHTTPRequestHandler.is_cgi(self)
+		return result
+
+
+bind = "127.0.0.1"
+if "$local" == "true":
+	bind = "0.0.0.0"
+
+# Set our http root directory
+# This is a work around for a missing directory argument in older Python versions
+# as this was added to SimpleHTTPRequestHandler in Python 3.7
+os.chdir("$fqgitdir/gitweb/$httpd_only/")
+
+GitWebRequestHandler.protocol_version = "HTTP/1.0"
+httpd = ServerClass((bind, $port), GitWebRequestHandler)
+
+sa = httpd.socket.getsockname()
+print("Serving HTTP on", sa[0], "port", sa[1], "...")
+httpd.serve_forever()
+EOF
+
+	chmod a+x "$fqgitdir/gitweb/gitweb.py"
+}
+
 gitweb_conf() {
 	cat > "$fqgitdir/gitweb/gitweb_config.perl" <<EOF
 #!@@PERL@@
@@ -623,6 +745,9 @@
 	*plackup*)
 		plackup_conf
 		;;
+	*python*)
+		python_conf
+		;;
 	*)
 		echo "Unknown httpd specified: $httpd"
 		exit 1
diff --git a/git-legacy-rebase.sh b/git-legacy-rebase.sh
index 3bb0682..8d6c9ac 100755
--- a/git-legacy-rebase.sh
+++ b/git-legacy-rebase.sh
@@ -118,7 +118,7 @@
 	else
 		orig_head=$(cat "$state_dir"/head)
 	fi &&
-	GIT_QUIET=$(cat "$state_dir"/quiet) &&
+	test -f "$state_dir"/quiet && GIT_QUIET=t
 	test -f "$state_dir"/verbose && verbose=t
 	test -f "$state_dir"/strategy && strategy="$(cat "$state_dir"/strategy)"
 	test -f "$state_dir"/strategy_opts &&
@@ -176,8 +176,8 @@
 
 run_specific_rebase () {
 	if [ "$interactive_rebase" = implied ]; then
-		GIT_EDITOR=:
-		export GIT_EDITOR
+		GIT_SEQUENCE_EDITOR=:
+		export GIT_SEQUENCE_EDITOR
 		autosquash=
 	fi
 
@@ -226,6 +226,7 @@
 	state_dir="$apply_dir"
 elif test -d "$merge_dir"
 then
+	type=interactive
 	if test -d "$merge_dir"/rewritten
 	then
 		type=preserve-merges
@@ -233,10 +234,7 @@
 		preserve_merges=t
 	elif test -f "$merge_dir"/interactive
 	then
-		type=interactive
 		interactive_rebase=explicit
-	else
-		type=merge
 	fi
 	state_dir="$merge_dir"
 fi
@@ -496,6 +494,7 @@
 	test -z "$interactive_rebase" && interactive_rebase=implied
 fi
 
+actually_interactive=
 if test -n "$interactive_rebase"
 then
 	if test -z "$preserve_merges"
@@ -504,11 +503,12 @@
 	else
 		type=preserve-merges
 	fi
-
+	actually_interactive=t
 	state_dir="$merge_dir"
 elif test -n "$do_merge"
 then
-	type=merge
+	interactive_rebase=implied
+	type=interactive
 	state_dir="$merge_dir"
 else
 	type=am
@@ -520,28 +520,20 @@
 	git_format_patch_opt="$git_format_patch_opt --progress"
 fi
 
-if test -n "$git_am_opt"; then
-	incompatible_opts=$(echo " $git_am_opt " | \
-			    sed -e 's/ -q / /g' -e 's/^ \(.*\) $/\1/')
-	if test -n "$interactive_rebase"
+incompatible_opts=$(echo " $git_am_opt " | \
+		    sed -e 's/ -q / /g' -e 's/^ \(.*\) $/\1/')
+if test -n "$incompatible_opts"
+then
+	if test -n "$actually_interactive" || test "$do_merge"
 	then
-		if test -n "$incompatible_opts"
-		then
-			die "$(gettext "error: cannot combine interactive options (--interactive, --exec, --rebase-merges, --preserve-merges, --keep-empty, --root + --onto) with am options ($incompatible_opts)")"
-		fi
-	fi
-	if test -n "$do_merge"; then
-		if test -n "$incompatible_opts"
-		then
-			die "$(gettext "error: cannot combine merge options (--merge, --strategy, --strategy-option) with am options ($incompatible_opts)")"
-		fi
+		die "$(gettext "fatal: cannot combine am options with either interactive or merge options")"
 	fi
 fi
 
 if test -n "$signoff"
 then
 	test -n "$preserve_merges" &&
-		die "$(gettext "error: cannot combine '--signoff' with '--preserve-merges'")"
+		die "$(gettext "fatal: cannot combine '--signoff' with '--preserve-merges'")"
 	git_am_opt="$git_am_opt $signoff"
 	force_rebase=t
 fi
@@ -552,7 +544,7 @@
 	# Note: incompatibility with --interactive is just a strong warning;
 	#       git-rebase.txt caveats with "unless you know what you are doing"
 	test -n "$rebase_merges" &&
-		die "$(gettext "error: cannot combine '--preserve-merges' with '--rebase-merges'")"
+		die "$(gettext "fatal: cannot combine '--preserve-merges' with '--rebase-merges'")"
 
 	test -n "$reschedule_failed_exec" &&
 		die "$(gettext "error: cannot combine '--preserve-merges' with '--reschedule-failed-exec'")"
@@ -561,9 +553,9 @@
 if test -n "$rebase_merges"
 then
 	test -n "$strategy_opts" &&
-		die "$(gettext "error: cannot combine '--rebase-merges' with '--strategy-option'")"
+		die "$(gettext "fatal: cannot combine '--rebase-merges' with '--strategy-option'")"
 	test -n "$strategy" &&
-		die "$(gettext "error: cannot combine '--rebase-merges' with '--strategy'")"
+		die "$(gettext "fatal: cannot combine '--rebase-merges' with '--strategy'")"
 fi
 
 if test -z "$rebase_root"
@@ -702,7 +694,7 @@
 # but this should be done only when upstream and onto are the same
 # and if this is not an interactive rebase.
 mb=$(git merge-base "$onto" "$orig_head")
-if test -z "$interactive_rebase" && test "$upstream" = "$onto" &&
+if test -z "$actually_interactive" && test "$upstream" = "$onto" &&
 	test "$mb" = "$onto" && test -z "$restrict_revision" &&
 	# linear history?
 	! (git rev-list --parents "$onto".."$orig_head" | sane_grep " .* ") > /dev/null
@@ -752,6 +744,19 @@
 	GIT_PAGER='' git diff --stat --summary "$mb_tree" "$onto"
 fi
 
+if test -z "$actually_interactive" && test "$mb" = "$orig_head"
+then
+	say "$(eval_gettext "Fast-forwarded \$branch_name to \$onto_name.")"
+	GIT_REFLOG_ACTION="$GIT_REFLOG_ACTION: checkout $onto_name" \
+		git checkout -q "$onto^0" || die "could not detach HEAD"
+	# If the $onto is a proper descendant of the tip of the branch, then
+	# we just fast-forwarded.
+	git update-ref ORIG_HEAD $orig_head
+	move_to_original_branch
+	finish_rebase
+	exit 0
+fi
+
 test -n "$interactive_rebase" && run_specific_rebase
 
 # Detach HEAD and reset the tree
@@ -761,16 +766,6 @@
 	git checkout -q "$onto^0" || die "could not detach HEAD"
 git update-ref ORIG_HEAD $orig_head
 
-# If the $onto is a proper descendant of the tip of the branch, then
-# we just fast-forwarded.
-if test "$mb" = "$orig_head"
-then
-	say "$(eval_gettext "Fast-forwarded \$branch_name to \$onto_name.")"
-	move_to_original_branch
-	finish_rebase
-	exit 0
-fi
-
 if test -n "$rebase_root"
 then
 	revisions="$onto..$orig_head"
diff --git a/git-rebase--am.sh b/git-rebase--am.sh
index 99b8c17..6416716 100644
--- a/git-rebase--am.sh
+++ b/git-rebase--am.sh
@@ -36,7 +36,7 @@
 
 git format-patch -k --stdout --full-index --cherry-pick --right-only \
 	--src-prefix=a/ --dst-prefix=b/ --no-renames --no-cover-letter \
-	--pretty=mboxrd \
+	--pretty=mboxrd --topo-order \
 	$git_format_patch_opt \
 	"$revisions" ${restrict_revision+^$restrict_revision} \
 	>"$GIT_DIR/rebased-patches"
diff --git a/git-rebase--common.sh b/git-rebase--common.sh
index a8a4460..f00e13e 100644
--- a/git-rebase--common.sh
+++ b/git-rebase--common.sh
@@ -10,7 +10,7 @@
 	echo "$head_name" > "$state_dir"/head-name &&
 	echo "$onto" > "$state_dir"/onto &&
 	echo "$orig_head" > "$state_dir"/orig-head &&
-	echo "$GIT_QUIET" > "$state_dir"/quiet &&
+	test t = "$GIT_QUIET" && : > "$state_dir"/quiet
 	test t = "$verbose" && : > "$state_dir"/verbose
 	test -n "$strategy" && echo "$strategy" > "$state_dir"/strategy
 	test -n "$strategy_opts" && echo "$strategy_opts" > \
diff --git a/git-rebase--merge.sh b/git-rebase--merge.sh
deleted file mode 100644
index aa2f2f0..0000000
--- a/git-rebase--merge.sh
+++ /dev/null
@@ -1,164 +0,0 @@
-# This shell script fragment is sourced by git-rebase to implement
-# its merge-based non-interactive mode that copes well with renamed
-# files.
-#
-# Copyright (c) 2010 Junio C Hamano.
-#
-
-prec=4
-
-read_state () {
-	onto_name=$(cat "$state_dir"/onto_name) &&
-	end=$(cat "$state_dir"/end) &&
-	msgnum=$(cat "$state_dir"/msgnum)
-}
-
-continue_merge () {
-	test -d "$state_dir" || die "$state_dir directory does not exist"
-
-	unmerged=$(git ls-files -u)
-	if test -n "$unmerged"
-	then
-		echo "You still have unmerged paths in your index"
-		echo "did you forget to use git add?"
-		die "$resolvemsg"
-	fi
-
-	cmt=$(cat "$state_dir/current")
-	if ! git diff-index --quiet --ignore-submodules HEAD --
-	then
-		if ! git commit ${gpg_sign_opt:+"$gpg_sign_opt"} $signoff $allow_empty_message \
-			--no-verify -C "$cmt"
-		then
-			echo "Commit failed, please do not call \"git commit\""
-			echo "directly, but instead do one of the following: "
-			die "$resolvemsg"
-		fi
-		if test -z "$GIT_QUIET"
-		then
-			printf "Committed: %0${prec}d " $msgnum
-		fi
-		echo "$cmt $(git rev-parse HEAD^0)" >> "$state_dir/rewritten"
-	else
-		if test -z "$GIT_QUIET"
-		then
-			printf "Already applied: %0${prec}d " $msgnum
-		fi
-	fi
-	test -z "$GIT_QUIET" &&
-	GIT_PAGER='' git log --format=%s -1 "$cmt"
-
-	# onto the next patch:
-	msgnum=$(($msgnum + 1))
-	echo "$msgnum" >"$state_dir/msgnum"
-}
-
-call_merge () {
-	msgnum="$1"
-	echo "$msgnum" >"$state_dir/msgnum"
-	cmt="$(cat "$state_dir/cmt.$msgnum")"
-	echo "$cmt" > "$state_dir/current"
-	git update-ref REBASE_HEAD "$cmt"
-	hd=$(git rev-parse --verify HEAD)
-	cmt_name=$(git symbolic-ref HEAD 2> /dev/null || echo HEAD)
-	eval GITHEAD_$cmt='"${cmt_name##refs/heads/}~$(($end - $msgnum))"'
-	eval GITHEAD_$hd='$onto_name'
-	export GITHEAD_$cmt GITHEAD_$hd
-	if test -n "$GIT_QUIET"
-	then
-		GIT_MERGE_VERBOSITY=1 && export GIT_MERGE_VERBOSITY
-	fi
-	test -z "$strategy" && strategy=recursive
-	# If cmt doesn't have a parent, don't include it as a base
-	base=$(git rev-parse --verify --quiet $cmt^)
-	eval 'git merge-$strategy' $strategy_opts $base ' -- "$hd" "$cmt"'
-	rv=$?
-	case "$rv" in
-	0)
-		unset GITHEAD_$cmt GITHEAD_$hd
-		return
-		;;
-	1)
-		git rerere $allow_rerere_autoupdate
-		die "$resolvemsg"
-		;;
-	2)
-		echo "Strategy: $strategy failed, try another" 1>&2
-		die "$resolvemsg"
-		;;
-	*)
-		die "Unknown exit code ($rv) from command:" \
-			"git merge-$strategy $cmt^ -- HEAD $cmt"
-		;;
-	esac
-}
-
-finish_rb_merge () {
-	move_to_original_branch
-	if test -s "$state_dir"/rewritten
-	then
-		git notes copy --for-rewrite=rebase <"$state_dir"/rewritten
-		hook="$(git rev-parse --git-path hooks/post-rewrite)"
-		test -x "$hook" && "$hook" rebase <"$state_dir"/rewritten
-	fi
-	say All done.
-}
-
-git_rebase__merge () {
-
-case "$action" in
-continue)
-	read_state
-	continue_merge
-	while test "$msgnum" -le "$end"
-	do
-		call_merge "$msgnum"
-		continue_merge
-	done
-	finish_rb_merge
-	return
-	;;
-skip)
-	read_state
-	git rerere clear
-	msgnum=$(($msgnum + 1))
-	while test "$msgnum" -le "$end"
-	do
-		call_merge "$msgnum"
-		continue_merge
-	done
-	finish_rb_merge
-	return
-	;;
-show-current-patch)
-	exec git show REBASE_HEAD --
-	;;
-esac
-
-mkdir -p "$state_dir"
-echo "$onto_name" > "$state_dir/onto_name"
-write_basic_state
-rm -f "$(git rev-parse --git-path REBASE_HEAD)"
-
-msgnum=0
-for cmt in $(git rev-list --reverse --no-merges "$revisions")
-do
-	msgnum=$(($msgnum + 1))
-	echo "$cmt" > "$state_dir/cmt.$msgnum"
-done
-
-echo 1 >"$state_dir/msgnum"
-echo $msgnum >"$state_dir/end"
-
-end=$msgnum
-msgnum=1
-
-while test "$msgnum" -le "$end"
-do
-	call_merge "$msgnum"
-	continue_merge
-done
-
-finish_rb_merge
-
-}
diff --git a/git-submodule.sh b/git-submodule.sh
index 5e608f8..b5f2bee 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -548,7 +548,7 @@
 	do
 		die_if_unmatched "$quickabort" "$sha1"
 
-		git submodule--helper ensure-core-worktree "$sm_path"
+		git submodule--helper ensure-core-worktree "$sm_path" || exit 1
 
 		update_module=$(git submodule--helper update-module-mode $just_cloned "$sm_path" $update)
 
@@ -850,8 +850,11 @@
 			;;
 		esac
 
-		sha1_abbr_src=$(echo $sha1_src | cut -c1-7)
-		sha1_abbr_dst=$(echo $sha1_dst | cut -c1-7)
+		sha1_abbr_src=$(GIT_DIR="$name/.git" git rev-parse --short $sha1_src 2>/dev/null ||
+			echo $sha1_src | cut -c1-7)
+		sha1_abbr_dst=$(GIT_DIR="$name/.git" git rev-parse --short $sha1_dst 2>/dev/null ||
+			echo $sha1_dst | cut -c1-7)
+
 		if test $status = T
 		then
 			blob="$(gettext "blob")"
diff --git a/git.c b/git.c
index 0ce0e13..2dd5886 100644
--- a/git.c
+++ b/git.c
@@ -418,9 +418,9 @@
 
 	trace_argv_printf(argv, "trace: built-in: git");
 
-	validate_cache_entries(&the_index);
+	validate_cache_entries(the_repository->index);
 	status = p->fn(argc, argv, prefix);
-	validate_cache_entries(&the_index);
+	validate_cache_entries(the_repository->index);
 
 	if (status)
 		return status;
diff --git a/help.c b/help.c
index ff05fd2..520c908 100644
--- a/help.c
+++ b/help.c
@@ -85,7 +85,8 @@
 		if (cmds[i].category & mask) {
 			size_t len = strlen(cmds[i].name);
 			printf("   %s   ", cmds[i].name);
-			mput_char(' ', longest > len ? longest - len : 1);
+			if (longest > len)
+				mput_char(' ', longest - len);
 			puts(_(cmds[i].help));
 		}
 	}
diff --git a/http-push.c b/http-push.c
index bb802d8..b22c7ca 100644
--- a/http-push.c
+++ b/http-push.c
@@ -255,7 +255,7 @@
 	struct active_request_slot *slot;
 	struct http_object_request *obj_req;
 
-	obj_req = new_http_object_request(repo->url, request->obj->oid.hash);
+	obj_req = new_http_object_request(repo->url, &request->obj->oid);
 	if (obj_req == NULL) {
 		request->state = ABORTED;
 		return;
@@ -1933,7 +1933,7 @@
 		pushing = 0;
 		if (prepare_revision_walk(&revs))
 			die("revision walk setup failed");
-		mark_edges_uninteresting(&revs, NULL);
+		mark_edges_uninteresting(&revs, NULL, 0);
 		objects_to_send = get_delta(&revs, ref_lock);
 		finish_all_active_slots();
 
diff --git a/http-walker.c b/http-walker.c
index 0a392c8..8ae5d76 100644
--- a/http-walker.c
+++ b/http-walker.c
@@ -58,7 +58,7 @@
 	struct active_request_slot *slot;
 	struct http_object_request *req;
 
-	req = new_http_object_request(obj_req->repo->base, obj_req->oid.hash);
+	req = new_http_object_request(obj_req->repo->base, &obj_req->oid);
 	if (req == NULL) {
 		obj_req->state = ABORTED;
 		return;
@@ -131,7 +131,7 @@
 	list_for_each_safe(pos, tmp, head) {
 		obj_req = list_entry(pos, struct object_request, node);
 		if (obj_req->state == WAITING) {
-			if (has_sha1_file(obj_req->oid.hash))
+			if (has_object_file(&obj_req->oid))
 				obj_req->state = COMPLETE;
 			else {
 				start_object_request(walker, obj_req);
@@ -489,7 +489,7 @@
 	if (obj_req == NULL)
 		return error("Couldn't find request for %s in the queue", hex);
 
-	if (has_sha1_file(obj_req->oid.hash)) {
+	if (has_object_file(&obj_req->oid)) {
 		if (obj_req->req != NULL)
 			abort_http_object_request(obj_req->req);
 		abort_object_request(obj_req);
@@ -543,11 +543,11 @@
 	} else if (req->zret != Z_STREAM_END) {
 		walker->corrupt_object_found++;
 		ret = error("File %s (%s) corrupt", hex, req->url);
-	} else if (!hasheq(obj_req->oid.hash, req->real_sha1)) {
+	} else if (!oideq(&obj_req->oid, &req->real_oid)) {
 		ret = error("File %s has bad hash", hex);
 	} else if (req->rename < 0) {
 		struct strbuf buf = STRBUF_INIT;
-		loose_object_path(the_repository, &buf, req->sha1);
+		loose_object_path(the_repository, &buf, &req->oid);
 		ret = error("unable to write sha1 filename %s", buf.buf);
 		strbuf_release(&buf);
 	}
diff --git a/http.c b/http.c
index 954bebf..a32ad36 100644
--- a/http.c
+++ b/http.c
@@ -2343,9 +2343,9 @@
 }
 
 struct http_object_request *new_http_object_request(const char *base_url,
-	unsigned char *sha1)
+						    const struct object_id *oid)
 {
-	char *hex = sha1_to_hex(sha1);
+	char *hex = oid_to_hex(oid);
 	struct strbuf filename = STRBUF_INIT;
 	struct strbuf prevfile = STRBUF_INIT;
 	int prevlocal;
@@ -2356,10 +2356,10 @@
 
 	freq = xcalloc(1, sizeof(*freq));
 	strbuf_init(&freq->tmpfile, 0);
-	hashcpy(freq->sha1, sha1);
+	oidcpy(&freq->oid, oid);
 	freq->localfile = -1;
 
-	loose_object_path(the_repository, &filename, sha1);
+	loose_object_path(the_repository, &filename, oid);
 	strbuf_addf(&freq->tmpfile, "%s.temp", filename.buf);
 
 	strbuf_addf(&prevfile, "%s.prev", filename.buf);
@@ -2501,16 +2501,16 @@
 	}
 
 	git_inflate_end(&freq->stream);
-	git_SHA1_Final(freq->real_sha1, &freq->c);
+	git_SHA1_Final(freq->real_oid.hash, &freq->c);
 	if (freq->zret != Z_STREAM_END) {
 		unlink_or_warn(freq->tmpfile.buf);
 		return -1;
 	}
-	if (!hasheq(freq->sha1, freq->real_sha1)) {
+	if (!oideq(&freq->oid, &freq->real_oid)) {
 		unlink_or_warn(freq->tmpfile.buf);
 		return -1;
 	}
-	loose_object_path(the_repository, &filename, freq->sha1);
+	loose_object_path(the_repository, &filename, &freq->oid);
 	freq->rename = finalize_object_file(freq->tmpfile.buf, filename.buf);
 	strbuf_release(&filename);
 
diff --git a/http.h b/http.h
index eebf406..4eb4e80 100644
--- a/http.h
+++ b/http.h
@@ -223,8 +223,8 @@
 	CURLcode curl_result;
 	char errorstr[CURL_ERROR_SIZE];
 	long http_code;
-	unsigned char sha1[20];
-	unsigned char real_sha1[20];
+	struct object_id oid;
+	struct object_id real_oid;
 	git_SHA_CTX c;
 	git_zstream stream;
 	int zret;
@@ -233,7 +233,7 @@
 };
 
 extern struct http_object_request *new_http_object_request(
-	const char *base_url, unsigned char *sha1);
+	const char *base_url, const struct object_id *oid);
 extern void process_http_object_request(struct http_object_request *freq);
 extern int finish_http_object_request(struct http_object_request *freq);
 extern void abort_http_object_request(struct http_object_request *freq);
diff --git a/list-objects-filter-options.c b/list-objects-filter-options.c
index 9efb3e9..b71bd1f 100644
--- a/list-objects-filter-options.c
+++ b/list-objects-filter-options.c
@@ -71,7 +71,7 @@
 		 * command, but DO NOT complain if we don't have the blob or
 		 * ref locally.
 		 */
-		if (!get_oid_with_context(v0, GET_OID_BLOB,
+		if (!get_oid_with_context(the_repository, v0, GET_OID_BLOB,
 					  &sparse_oid, &oc))
 			filter_options->sparse_oid_value = oiddup(&sparse_oid);
 		filter_options->choice = LOFC_SPARSE_OID;
diff --git a/list-objects.c b/list-objects.c
index a2296a8..dc77361 100644
--- a/list-objects.c
+++ b/list-objects.c
@@ -226,25 +226,73 @@
 	}
 }
 
-void mark_edges_uninteresting(struct rev_info *revs, show_edge_fn show_edge)
+static void add_edge_parents(struct commit *commit,
+			     struct rev_info *revs,
+			     show_edge_fn show_edge,
+			     struct oidset *set)
+{
+	struct commit_list *parents;
+
+	for (parents = commit->parents; parents; parents = parents->next) {
+		struct commit *parent = parents->item;
+		struct tree *tree = get_commit_tree(parent);
+
+		if (!tree)
+			continue;
+
+		oidset_insert(set, &tree->object.oid);
+
+		if (!(parent->object.flags & UNINTERESTING))
+			continue;
+		tree->object.flags |= UNINTERESTING;
+
+		if (revs->edge_hint && !(parent->object.flags & SHOWN)) {
+			parent->object.flags |= SHOWN;
+			show_edge(parent);
+		}
+	}
+}
+
+void mark_edges_uninteresting(struct rev_info *revs,
+			      show_edge_fn show_edge,
+			      int sparse)
 {
 	struct commit_list *list;
 	int i;
 
-	for (list = revs->commits; list; list = list->next) {
-		struct commit *commit = list->item;
+	if (sparse) {
+		struct oidset set;
+		oidset_init(&set, 16);
 
-		if (commit->object.flags & UNINTERESTING) {
-			mark_tree_uninteresting(revs->repo,
-						get_commit_tree(commit));
-			if (revs->edge_hint_aggressive && !(commit->object.flags & SHOWN)) {
-				commit->object.flags |= SHOWN;
-				show_edge(commit);
-			}
-			continue;
+		for (list = revs->commits; list; list = list->next) {
+			struct commit *commit = list->item;
+			struct tree *tree = get_commit_tree(commit);
+
+			if (commit->object.flags & UNINTERESTING)
+				tree->object.flags |= UNINTERESTING;
+
+			oidset_insert(&set, &tree->object.oid);
+			add_edge_parents(commit, revs, show_edge, &set);
 		}
-		mark_edge_parents_uninteresting(commit, revs, show_edge);
+
+		mark_trees_uninteresting_sparse(revs->repo, &set);
+		oidset_clear(&set);
+	} else {
+		for (list = revs->commits; list; list = list->next) {
+			struct commit *commit = list->item;
+			if (commit->object.flags & UNINTERESTING) {
+				mark_tree_uninteresting(revs->repo,
+							get_commit_tree(commit));
+				if (revs->edge_hint_aggressive && !(commit->object.flags & SHOWN)) {
+					commit->object.flags |= SHOWN;
+					show_edge(commit);
+				}
+				continue;
+			}
+			mark_edge_parents_uninteresting(commit, revs, show_edge);
+		}
 	}
+
 	if (revs->edge_hint_aggressive) {
 		for (i = 0; i < revs->cmdline.nr; i++) {
 			struct object *obj = revs->cmdline.rev[i].item;
diff --git a/list-objects.h b/list-objects.h
index ad40762..a952680 100644
--- a/list-objects.h
+++ b/list-objects.h
@@ -10,7 +10,9 @@
 void traverse_commit_list(struct rev_info *, show_commit_fn, show_object_fn, void *);
 
 typedef void (*show_edge_fn)(struct commit *);
-void mark_edges_uninteresting(struct rev_info *, show_edge_fn);
+void mark_edges_uninteresting(struct rev_info *revs,
+			      show_edge_fn show_edge,
+			      int sparse);
 
 struct oidset;
 struct list_objects_filter_options;
diff --git a/ls-refs.c b/ls-refs.c
index 9c9a7c6..0a7dbc6 100644
--- a/ls-refs.c
+++ b/ls-refs.c
@@ -44,7 +44,7 @@
 	if (ref_is_hidden(refname_nons, refname))
 		return 0;
 
-	if (!ref_match(&data->prefixes, refname))
+	if (!ref_match(&data->prefixes, refname_nons))
 		return 0;
 
 	strbuf_addf(&refline, "%s %s", oid_to_hex(oid), refname_nons);
diff --git a/match-trees.c b/match-trees.c
index 18ab825..ddc4d39 100644
--- a/match-trees.c
+++ b/match-trees.c
@@ -3,7 +3,7 @@
 #include "tree-walk.h"
 #include "object-store.h"
 
-static int score_missing(unsigned mode, const char *path)
+static int score_missing(unsigned mode)
 {
 	int score;
 
@@ -16,7 +16,7 @@
 	return score;
 }
 
-static int score_differs(unsigned mode1, unsigned mode2, const char *path)
+static int score_differs(unsigned mode1, unsigned mode2)
 {
 	int score;
 
@@ -29,7 +29,7 @@
 	return score;
 }
 
-static int score_matches(unsigned mode1, unsigned mode2, const char *path)
+static int score_matches(unsigned mode1, unsigned mode2)
 {
 	int score;
 
@@ -98,24 +98,22 @@
 
 		if (cmp < 0) {
 			/* path1 does not appear in two */
-			score += score_missing(one.entry.mode, one.entry.path);
+			score += score_missing(one.entry.mode);
 			update_tree_entry(&one);
 		} else if (cmp > 0) {
 			/* path2 does not appear in one */
-			score += score_missing(two.entry.mode, two.entry.path);
+			score += score_missing(two.entry.mode);
 			update_tree_entry(&two);
 		} else {
 			/* path appears in both */
 			if (!oideq(&one.entry.oid, &two.entry.oid)) {
 				/* they are different */
 				score += score_differs(one.entry.mode,
-						       two.entry.mode,
-						       one.entry.path);
+						       two.entry.mode);
 			} else {
 				/* same subtree or blob */
 				score += score_matches(one.entry.mode,
-						       two.entry.mode,
-						       one.entry.path);
+						       two.entry.mode);
 			}
 			update_tree_entry(&one);
 			update_tree_entry(&two);
diff --git a/merge-recursive.c b/merge-recursive.c
index 59ba4b4..4851825 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -146,7 +146,8 @@
 	return -1;
 }
 
-static struct tree *shift_tree_object(struct tree *one, struct tree *two,
+static struct tree *shift_tree_object(struct repository *repo,
+				      struct tree *one, struct tree *two,
 				      const char *subtree_shift)
 {
 	struct object_id shifted;
@@ -159,12 +160,14 @@
 	}
 	if (oideq(&two->object.oid, &shifted))
 		return two;
-	return lookup_tree(the_repository, &shifted);
+	return lookup_tree(repo, &shifted);
 }
 
-static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
+static struct commit *make_virtual_commit(struct repository *repo,
+					  struct tree *tree,
+					  const char *comment)
 {
-	struct commit *commit = alloc_commit_node(the_repository);
+	struct commit *commit = alloc_commit_node(repo);
 
 	set_merge_remote_desc(commit, comment, (struct object *)commit);
 	commit->maybe_tree = tree;
@@ -343,22 +346,24 @@
 			 unsigned int mode, const struct object_id *oid,
 			 const char *path, int stage, int refresh, int options)
 {
+	struct index_state *istate = o->repo->index;
 	struct cache_entry *ce;
 	int ret;
 
-	ce = make_cache_entry(&the_index, mode, oid ? oid : &null_oid, path, stage, 0);
+	ce = make_cache_entry(istate, mode, oid ? oid : &null_oid, path, stage, 0);
 	if (!ce)
 		return err(o, _("add_cacheinfo failed for path '%s'; merge aborting."), path);
 
-	ret = add_cache_entry(ce, options);
+	ret = add_index_entry(istate, ce, options);
 	if (refresh) {
 		struct cache_entry *nce;
 
-		nce = refresh_cache_entry(&the_index, ce, CE_MATCH_REFRESH | CE_MATCH_IGNORE_MISSING);
+		nce = refresh_cache_entry(istate, ce,
+					  CE_MATCH_REFRESH | CE_MATCH_IGNORE_MISSING);
 		if (!nce)
 			return err(o, _("add_cacheinfo failed to refresh for path '%s'; merge aborting."), path);
 		if (nce != ce)
-			ret = add_cache_entry(nce, options);
+			ret = add_index_entry(istate, nce, options);
 	}
 	return ret;
 }
@@ -386,7 +391,7 @@
 	o->unpack_opts.merge = 1;
 	o->unpack_opts.head_idx = 2;
 	o->unpack_opts.fn = threeway_merge;
-	o->unpack_opts.src_index = &the_index;
+	o->unpack_opts.src_index = o->repo->index;
 	o->unpack_opts.dst_index = &tmp_index;
 	o->unpack_opts.aggressive = !merge_detect_rename(o);
 	setup_unpack_trees_porcelain(&o->unpack_opts, "merge");
@@ -396,16 +401,16 @@
 	init_tree_desc_from_tree(t+2, merge);
 
 	rc = unpack_trees(3, t, &o->unpack_opts);
-	cache_tree_free(&active_cache_tree);
+	cache_tree_free(&o->repo->index->cache_tree);
 
 	/*
-	 * Update the_index to match the new results, AFTER saving a copy
+	 * Update o->repo->index to match the new results, AFTER saving a copy
 	 * in o->orig_index.  Update src_index to point to the saved copy.
 	 * (verify_uptodate() checks src_index, and the original index is
 	 * the one that had the necessary modification timestamps.)
 	 */
-	o->orig_index = the_index;
-	the_index = tmp_index;
+	o->orig_index = *o->repo->index;
+	*o->repo->index = tmp_index;
 	o->unpack_opts.src_index = &o->orig_index;
 
 	return rc;
@@ -420,12 +425,13 @@
 struct tree *write_tree_from_memory(struct merge_options *o)
 {
 	struct tree *result = NULL;
+	struct index_state *istate = o->repo->index;
 
-	if (unmerged_cache()) {
+	if (unmerged_index(istate)) {
 		int i;
 		fprintf(stderr, "BUG: There are unmerged index entries:\n");
-		for (i = 0; i < active_nr; i++) {
-			const struct cache_entry *ce = active_cache[i];
+		for (i = 0; i < istate->cache_nr; i++) {
+			const struct cache_entry *ce = istate->cache[i];
 			if (ce_stage(ce))
 				fprintf(stderr, "BUG: %d %.*s\n", ce_stage(ce),
 					(int)ce_namelen(ce), ce->name);
@@ -433,16 +439,16 @@
 		BUG("unmerged index entries in merge-recursive.c");
 	}
 
-	if (!active_cache_tree)
-		active_cache_tree = cache_tree();
+	if (!istate->cache_tree)
+		istate->cache_tree = cache_tree();
 
-	if (!cache_tree_fully_valid(active_cache_tree) &&
-	    cache_tree_update(&the_index, 0) < 0) {
+	if (!cache_tree_fully_valid(istate->cache_tree) &&
+	    cache_tree_update(istate, 0) < 0) {
 		err(o, _("error building trees"));
 		return NULL;
 	}
 
-	result = lookup_tree(the_repository, &active_cache_tree->oid);
+	result = lookup_tree(o->repo, &istate->cache_tree->oid);
 
 	return result;
 }
@@ -513,17 +519,17 @@
  * Create a dictionary mapping file names to stage_data objects. The
  * dictionary contains one entry for every path with a non-zero stage entry.
  */
-static struct string_list *get_unmerged(void)
+static struct string_list *get_unmerged(struct index_state *istate)
 {
 	struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
 	int i;
 
 	unmerged->strdup_strings = 1;
 
-	for (i = 0; i < active_nr; i++) {
+	for (i = 0; i < istate->cache_nr; i++) {
 		struct string_list_item *item;
 		struct stage_data *e;
-		const struct cache_entry *ce = active_cache[i];
+		const struct cache_entry *ce = istate->cache[i];
 		if (!ce_stage(ce))
 			continue;
 
@@ -683,7 +689,7 @@
 	int clear = 1;
 	int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
 	if (clear)
-		if (remove_file_from_cache(path))
+		if (remove_file_from_index(opt->repo->index, path))
 			return -1;
 	if (o)
 		if (add_cacheinfo(opt, o->mode, &o->oid, path, 1, 0, options))
@@ -718,13 +724,14 @@
 	int update_working_directory = !o->call_depth && !no_wd;
 
 	if (update_cache) {
-		if (remove_file_from_cache(path))
+		if (remove_file_from_index(o->repo->index, path))
 			return -1;
 	}
 	if (update_working_directory) {
 		if (ignore_case) {
 			struct cache_entry *ce;
-			ce = cache_file_exists(path, strlen(path), ignore_case);
+			ce = index_file_exists(o->repo->index, path, strlen(path),
+					       ignore_case);
 			if (ce && ce_stage(ce) == 0 && strcmp(path, ce->name))
 				return 0;
 		}
@@ -774,7 +781,8 @@
  * check the working directory.  If empty_ok is non-zero, also return
  * 0 in the case where the working-tree dir exists but is empty.
  */
-static int dir_in_way(const char *path, int check_working_copy, int empty_ok)
+static int dir_in_way(struct index_state *istate, const char *path,
+		      int check_working_copy, int empty_ok)
 {
 	int pos;
 	struct strbuf dirpath = STRBUF_INIT;
@@ -783,12 +791,12 @@
 	strbuf_addstr(&dirpath, path);
 	strbuf_addch(&dirpath, '/');
 
-	pos = cache_name_pos(dirpath.buf, dirpath.len);
+	pos = index_name_pos(istate, dirpath.buf, dirpath.len);
 
 	if (pos < 0)
 		pos = -1 - pos;
-	if (pos < active_nr &&
-	    !strncmp(dirpath.buf, active_cache[pos]->name, dirpath.len)) {
+	if (pos < istate->cache_nr &&
+	    !strncmp(dirpath.buf, istate->cache[pos]->name, dirpath.len)) {
 		strbuf_release(&dirpath);
 		return 1;
 	}
@@ -831,8 +839,10 @@
 	return 0;
 }
 
-static int would_lose_untracked(const char *path)
+static int would_lose_untracked(struct merge_options *o, const char *path)
 {
+	struct index_state *istate = o->repo->index;
+
 	/*
 	 * This may look like it can be simplified to:
 	 *   return !was_tracked(o, path) && file_exists(path)
@@ -850,19 +860,19 @@
 	 * update_file()/would_lose_untracked(); see every comment in this
 	 * file which mentions "update_stages".
 	 */
-	int pos = cache_name_pos(path, strlen(path));
+	int pos = index_name_pos(istate, path, strlen(path));
 
 	if (pos < 0)
 		pos = -1 - pos;
-	while (pos < active_nr &&
-	       !strcmp(path, active_cache[pos]->name)) {
+	while (pos < istate->cache_nr &&
+	       !strcmp(path, istate->cache[pos]->name)) {
 		/*
 		 * If stage #0, it is definitely tracked.
 		 * If it has stage #2 then it was tracked
 		 * before this merge started.  All other
 		 * cases the path was not tracked.
 		 */
-		switch (ce_stage(active_cache[pos])) {
+		switch (ce_stage(istate->cache[pos])) {
 		case 0:
 		case 2:
 			return 0;
@@ -922,7 +932,7 @@
 	 * Do not unlink a file in the work tree if we are not
 	 * tracking it.
 	 */
-	if (would_lose_untracked(path))
+	if (would_lose_untracked(o, path))
 		return err(o, _("refusing to lose untracked file at '%s'"),
 			   path);
 
@@ -972,7 +982,7 @@
 		}
 		if (S_ISREG(mode)) {
 			struct strbuf strbuf = STRBUF_INIT;
-			if (convert_to_working_tree(&the_index, path, buf, size, &strbuf)) {
+			if (convert_to_working_tree(o->repo->index, path, buf, size, &strbuf)) {
 				free(buf);
 				size = strbuf.len;
 				buf = strbuf_detach(&strbuf, NULL);
@@ -1092,7 +1102,7 @@
 
 	merge_status = ll_merge(result_buf, a->path, &orig, base_name,
 				&src1, name1, &src2, name2,
-				&the_index, &ll_opts);
+				o->repo->index, &ll_opts);
 
 	free(base_name);
 	free(name1);
@@ -1103,7 +1113,8 @@
 	return merge_status;
 }
 
-static int find_first_merges(struct object_array *result, const char *path,
+static int find_first_merges(struct repository *repo,
+			     struct object_array *result, const char *path,
 			     struct commit *a, struct commit *b)
 {
 	int i, j;
@@ -1123,7 +1134,7 @@
 	/* get all revisions that merge commit a */
 	xsnprintf(merged_revision, sizeof(merged_revision), "^%s",
 		  oid_to_hex(&a->object.oid));
-	repo_init_revisions(the_repository, &revs, NULL);
+	repo_init_revisions(repo, &revs, NULL);
 	rev_opts.submodule = path;
 	/* FIXME: can't handle linked worktrees in submodules yet */
 	revs.single_worktree = path != NULL;
@@ -1201,9 +1212,9 @@
 		return 0;
 	}
 
-	if (!(commit_base = lookup_commit_reference(the_repository, base)) ||
-	    !(commit_a = lookup_commit_reference(the_repository, a)) ||
-	    !(commit_b = lookup_commit_reference(the_repository, b))) {
+	if (!(commit_base = lookup_commit_reference(o->repo, base)) ||
+	    !(commit_a = lookup_commit_reference(o->repo, a)) ||
+	    !(commit_b = lookup_commit_reference(o->repo, b))) {
 		output(o, 1, _("Failed to merge submodule %s (commits not present)"), path);
 		return 0;
 	}
@@ -1253,7 +1264,8 @@
 		return 0;
 
 	/* find commit which merges them */
-	parent_count = find_first_merges(&merges, path, commit_a, commit_b);
+	parent_count = find_first_merges(o->repo, &merges, path,
+					 commit_a, commit_b);
 	switch (parent_count) {
 	case 0:
 		output(o, 1, _("Failed to merge submodule %s (merge following commits not found)"), path);
@@ -1401,7 +1413,7 @@
 	 */
 	const struct diff_filespec *dest = pair->two;
 
-	if (!o->call_depth && would_lose_untracked(dest->path)) {
+	if (!o->call_depth && would_lose_untracked(o, dest->path)) {
 		char *alt_path = unique_path(o, dest->path, rename_branch);
 
 		output(o, 1, _("Error: Refusing to lose untracked file at %s; "
@@ -1439,8 +1451,8 @@
 	const char *update_path = path;
 	int ret = 0;
 
-	if (dir_in_way(path, !o->call_depth, 0) ||
-	    (!o->call_depth && would_lose_untracked(path))) {
+	if (dir_in_way(o->repo->index, path, !o->call_depth, 0) ||
+	    (!o->call_depth && would_lose_untracked(o, path))) {
 		update_path = alt_path = unique_path(o, path, change_branch);
 	}
 
@@ -1450,7 +1462,7 @@
 		 * correct; since there is no true "middle point" between
 		 * them, simply reuse the base version for virtual merge base.
 		 */
-		ret = remove_file_from_cache(path);
+		ret = remove_file_from_index(o->repo->index, path);
 		if (!ret)
 			ret = update_file(o, 0, o_oid, o_mode, update_path);
 	} else {
@@ -1526,7 +1538,7 @@
 		return -1;
 
 	if (o->call_depth)
-		return remove_file_from_cache(dest->path);
+		return remove_file_from_index(o->repo->index, dest->path);
 	else
 		return update_stages(o, dest->path, NULL,
 				     rename_branch == o->branch1 ? dest : NULL,
@@ -1607,10 +1619,10 @@
 	/* Remove rename sources if rename/add or rename/rename(2to1) */
 	if (prev_path1)
 		remove_file(o, 1, prev_path1,
-			    o->call_depth || would_lose_untracked(prev_path1));
+			    o->call_depth || would_lose_untracked(o, prev_path1));
 	if (prev_path2)
 		remove_file(o, 1, prev_path2,
-			    o->call_depth || would_lose_untracked(prev_path2));
+			    o->call_depth || would_lose_untracked(o, prev_path2));
 
 	/*
 	 * Remove the collision path, if it wouldn't cause dirty contents
@@ -1621,7 +1633,7 @@
 		output(o, 1, _("Refusing to lose dirty file at %s"),
 		       collide_path);
 		update_path = alt_path = unique_path(o, collide_path, "merged");
-	} else if (would_lose_untracked(collide_path)) {
+	} else if (would_lose_untracked(o, collide_path)) {
 		/*
 		 * Only way we get here is if both renames were from
 		 * a directory rename AND user had an untracked file
@@ -1717,12 +1729,12 @@
 				    const char *branch2)
 {
 	char *new_path = NULL;
-	if (dir_in_way(path, !o->call_depth, 0)) {
+	if (dir_in_way(o->repo->index, path, !o->call_depth, 0)) {
 		new_path = unique_path(o, path, branch1);
 		output(o, 1, _("%s is a directory in %s adding "
 			       "as %s instead"),
 		       path, branch2, new_path);
-	} else if (would_lose_untracked(path)) {
+	} else if (would_lose_untracked(o, path)) {
 		new_path = unique_path(o, path, branch1);
 		output(o, 1, _("Refusing to lose untracked file"
 			       " at %s; adding as %s instead"),
@@ -1783,14 +1795,14 @@
 				return -1;
 		}
 		else
-			remove_file_from_cache(a->path);
+			remove_file_from_index(o->repo->index, a->path);
 		add = filespec_from_entry(&other, ci->dst_entry2, 3 ^ 1);
 		if (add) {
 			if (update_file(o, 0, &add->oid, add->mode, b->path))
 				return -1;
 		}
 		else
-			remove_file_from_cache(b->path);
+			remove_file_from_index(o->repo->index, b->path);
 	} else {
 		/*
 		 * For each destination path, we need to see if there is a
@@ -1887,7 +1899,7 @@
 	struct diff_queue_struct *ret;
 	struct diff_options opts;
 
-	repo_diff_setup(the_repository, &opts);
+	repo_diff_setup(o->repo, &opts);
 	opts.flags.recursive = 1;
 	opts.flags.rename_empty = 0;
 	opts.detect_rename = merge_detect_rename(o);
@@ -3042,8 +3054,8 @@
 	 * performed.  Comparison can be skipped if both files are
 	 * unchanged since their sha1s have already been compared.
 	 */
-	if (renormalize_buffer(&the_index, path, o.buf, o.len, &o) |
-	    renormalize_buffer(&the_index, path, a.buf, a.len, &a))
+	if (renormalize_buffer(opt->repo->index, path, o.buf, o.len, &o) |
+	    renormalize_buffer(opt->repo->index, path, a.buf, a.len, &a))
 		ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
 
 error_return:
@@ -3124,7 +3136,7 @@
 		a.path = (char *)path1;
 		b.path = (char *)path2;
 
-		if (dir_in_way(path, !o->call_depth,
+		if (dir_in_way(o->repo->index, path, !o->call_depth,
 			       S_ISGITLINK(pair1->two->mode)))
 			df_conflict_remains = 1;
 	}
@@ -3158,8 +3170,8 @@
 		pos = index_name_pos(&o->orig_index, path, strlen(path));
 		ce = o->orig_index.cache[pos];
 		if (ce_skip_worktree(ce)) {
-			pos = index_name_pos(&the_index, path, strlen(path));
-			ce = the_index.cache[pos];
+			pos = index_name_pos(o->repo->index, path, strlen(path));
+			ce = o->repo->index->cache[pos];
 			ce->ce_flags |= CE_SKIP_WORKTREE;
 		}
 		return mfi.clean;
@@ -3178,7 +3190,7 @@
 	if (df_conflict_remains || is_dirty) {
 		char *new_path;
 		if (o->call_depth) {
-			remove_file_from_cache(path);
+			remove_file_from_index(o->repo->index, path);
 		} else {
 			if (!mfi.clean) {
 				if (update_stages(o, path, &one, &a, &b))
@@ -3338,7 +3350,7 @@
 			oid = b_oid;
 			conf = _("directory/file");
 		}
-		if (dir_in_way(path,
+		if (dir_in_way(o->repo->index, path,
 			       !o->call_depth && !S_ISGITLINK(a_mode),
 			       0)) {
 			char *new_path = unique_path(o, path, add_branch);
@@ -3349,7 +3361,7 @@
 			if (update_file(o, 0, oid, mode, new_path))
 				clean_merge = -1;
 			else if (o->call_depth)
-				remove_file_from_cache(path);
+				remove_file_from_index(o->repo->index, path);
 			free(new_path);
 		} else {
 			output(o, 2, _("Adding %s"), path);
@@ -3397,18 +3409,19 @@
 		struct tree *common,
 		struct tree **result)
 {
+	struct index_state *istate = o->repo->index;
 	int code, clean;
 	struct strbuf sb = STRBUF_INIT;
 
-	if (!o->call_depth && index_has_changes(&the_index, head, &sb)) {
+	if (!o->call_depth && repo_index_has_changes(o->repo, head, &sb)) {
 		err(o, _("Your local changes to the following files would be overwritten by merge:\n  %s"),
 		    sb.buf);
 		return -1;
 	}
 
 	if (o->subtree_shift) {
-		merge = shift_tree_object(head, merge, o->subtree_shift);
-		common = shift_tree_object(head, common, o->subtree_shift);
+		merge = shift_tree_object(o->repo, head, merge, o->subtree_shift);
+		common = shift_tree_object(o->repo, head, common, o->subtree_shift);
 	}
 
 	if (oid_eq(&common->object.oid, &merge->object.oid)) {
@@ -3428,7 +3441,7 @@
 		return -1;
 	}
 
-	if (unmerged_cache()) {
+	if (unmerged_index(istate)) {
 		struct string_list *entries;
 		struct rename_info re_info;
 		int i;
@@ -3443,7 +3456,7 @@
 		get_files_dirs(o, head);
 		get_files_dirs(o, merge);
 
-		entries = get_unmerged();
+		entries = get_unmerged(o->repo->index);
 		clean = detect_and_process_renames(o, common, head, merge,
 						   entries, &re_info);
 		record_df_conflict_files(o, entries);
@@ -3544,8 +3557,8 @@
 		/* if there is no common ancestor, use an empty tree */
 		struct tree *tree;
 
-		tree = lookup_tree(the_repository, the_repository->hash_algo->empty_tree);
-		merged_common_ancestors = make_virtual_commit(tree, "ancestor");
+		tree = lookup_tree(o->repo, o->repo->hash_algo->empty_tree);
+		merged_common_ancestors = make_virtual_commit(o->repo, tree, "ancestor");
 	}
 
 	for (iter = ca; iter; iter = iter->next) {
@@ -3559,7 +3572,7 @@
 		 * overwritten it: the committed "conflicts" were
 		 * already resolved.
 		 */
-		discard_cache();
+		discard_index(o->repo->index);
 		saved_b1 = o->branch1;
 		saved_b2 = o->branch2;
 		o->branch1 = "Temporary merge branch 1";
@@ -3575,9 +3588,9 @@
 			return err(o, _("merge returned no commit"));
 	}
 
-	discard_cache();
+	discard_index(o->repo->index);
 	if (!o->call_depth)
-		read_cache();
+		repo_read_index(o->repo);
 
 	o->ancestor = "merged common ancestors";
 	clean = merge_trees(o, get_commit_tree(h1), get_commit_tree(h2),
@@ -3589,7 +3602,7 @@
 	}
 
 	if (o->call_depth) {
-		*result = make_virtual_commit(mrtree, "merged tree");
+		*result = make_virtual_commit(o->repo, mrtree, "merged tree");
 		commit_list_insert(h1, &(*result)->parents);
 		commit_list_insert(h2, &(*result)->parents->next);
 	}
@@ -3602,17 +3615,17 @@
 	return clean;
 }
 
-static struct commit *get_ref(const struct object_id *oid, const char *name)
+static struct commit *get_ref(struct repository *repo, const struct object_id *oid,
+			      const char *name)
 {
 	struct object *object;
 
-	object = deref_tag(the_repository, parse_object(the_repository, oid),
-			   name,
-			   strlen(name));
+	object = deref_tag(repo, parse_object(repo, oid),
+			   name, strlen(name));
 	if (!object)
 		return NULL;
 	if (object->type == OBJ_TREE)
-		return make_virtual_commit((struct tree*)object, name);
+		return make_virtual_commit(repo, (struct tree*)object, name);
 	if (object->type != OBJ_COMMIT)
 		return NULL;
 	if (parse_commit((struct commit *)object))
@@ -3629,22 +3642,22 @@
 {
 	int clean;
 	struct lock_file lock = LOCK_INIT;
-	struct commit *head_commit = get_ref(head, o->branch1);
-	struct commit *next_commit = get_ref(merge, o->branch2);
+	struct commit *head_commit = get_ref(o->repo, head, o->branch1);
+	struct commit *next_commit = get_ref(o->repo, merge, o->branch2);
 	struct commit_list *ca = NULL;
 
 	if (base_list) {
 		int i;
 		for (i = 0; i < num_base_list; ++i) {
 			struct commit *base;
-			if (!(base = get_ref(base_list[i], oid_to_hex(base_list[i]))))
+			if (!(base = get_ref(o->repo, base_list[i], oid_to_hex(base_list[i]))))
 				return err(o, _("Could not parse object '%s'"),
 					   oid_to_hex(base_list[i]));
 			commit_list_insert(base, &ca);
 		}
 	}
 
-	hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
+	repo_hold_locked_index(o->repo, &lock, LOCK_DIE_ON_ERROR);
 	clean = merge_recursive(o, head_commit, next_commit, ca,
 				result);
 	if (clean < 0) {
@@ -3652,7 +3665,7 @@
 		return clean;
 	}
 
-	if (write_locked_index(&the_index, &lock,
+	if (write_locked_index(o->repo->index, &lock,
 			       COMMIT_LOCK | SKIP_IF_UNCHANGED))
 		return err(o, _("Unable to write index."));
 
@@ -3676,10 +3689,12 @@
 	git_config(git_xmerge_config, NULL);
 }
 
-void init_merge_options(struct merge_options *o)
+void init_merge_options(struct merge_options *o,
+			struct repository *repo)
 {
 	const char *merge_verbosity;
 	memset(o, 0, sizeof(struct merge_options));
+	o->repo = repo;
 	o->verbosity = 2;
 	o->buffer_output = 1;
 	o->diff_rename_limit = -1;
diff --git a/merge-recursive.h b/merge-recursive.h
index e6a0828..c2b7bb6 100644
--- a/merge-recursive.h
+++ b/merge-recursive.h
@@ -6,6 +6,8 @@
 
 struct commit;
 
+struct repository;
+
 struct merge_options {
 	const char *ancestor;
 	const char *branch1;
@@ -34,6 +36,7 @@
 	struct string_list df_conflict_file_set;
 	struct unpack_trees_options unpack_opts;
 	struct index_state orig_index;
+	struct repository *repo;
 };
 
 /*
@@ -92,7 +95,8 @@
 			    const struct object_id **ca,
 			    struct commit **result);
 
-void init_merge_options(struct merge_options *o);
+void init_merge_options(struct merge_options *o,
+			struct repository *repo);
 struct tree *write_tree_from_memory(struct merge_options *o);
 
 int parse_merge_opt(struct merge_options *out, const char *s);
diff --git a/merge.c b/merge.c
index 91008f7..7c1d756 100644
--- a/merge.c
+++ b/merge.c
@@ -37,7 +37,7 @@
 	argv_array_clear(&args);
 
 	discard_index(r->index);
-	if (read_index(r->index) < 0)
+	if (repo_read_index(r) < 0)
 		die(_("failed to read the cache"));
 	resolve_undo_clear_index(r->index);
 
@@ -58,7 +58,7 @@
 
 	refresh_index(r->index, REFRESH_QUIET, NULL, NULL, NULL);
 
-	if (hold_locked_index(&lock_file, LOCK_REPORT_ON_ERROR) < 0)
+	if (repo_hold_locked_index(r, &lock_file, LOCK_REPORT_ON_ERROR) < 0)
 		return -1;
 
 	memset(&trees, 0, sizeof(trees));
diff --git a/name-hash.c b/name-hash.c
index 623ca69..b4861bc 100644
--- a/name-hash.c
+++ b/name-hash.c
@@ -5,7 +5,6 @@
  *
  * Copyright (C) 2008 Linus Torvalds
  */
-#define NO_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "thread-utils.h"
 
diff --git a/notes-merge.c b/notes-merge.c
index 72688d3..280aa8e 100644
--- a/notes-merge.c
+++ b/notes-merge.c
@@ -649,7 +649,7 @@
 		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,
+		create_notes_commit(o->repo, local_tree, parents, o->commit_msg.buf,
 				    o->commit_msg.len, result_oid);
 	}
 
@@ -724,7 +724,7 @@
 		strbuf_setlen(&path, baselen);
 	}
 
-	create_notes_commit(partial_tree, partial_commit->parents, msg,
+	create_notes_commit(o->repo, partial_tree, partial_commit->parents, msg,
 			    strlen(msg), result_oid);
 	unuse_commit_buffer(partial_commit, buffer);
 	if (o->verbosity >= 4)
diff --git a/notes-utils.c b/notes-utils.c
index 14ea031..a819410 100644
--- a/notes-utils.c
+++ b/notes-utils.c
@@ -5,7 +5,9 @@
 #include "notes-utils.h"
 #include "repository.h"
 
-void create_notes_commit(struct notes_tree *t, struct commit_list *parents,
+void create_notes_commit(struct repository *r,
+			 struct notes_tree *t,
+			 struct commit_list *parents,
 			 const char *msg, size_t msg_len,
 			 struct object_id *result_oid)
 {
@@ -20,8 +22,7 @@
 		/* Deduce parent commit from t->ref */
 		struct object_id parent_oid;
 		if (!read_ref(t->ref, &parent_oid)) {
-			struct commit *parent = lookup_commit(the_repository,
-							      &parent_oid);
+			struct commit *parent = lookup_commit(r, &parent_oid);
 			if (parse_commit(parent))
 				die("Failed to find/parse commit %s", t->ref);
 			commit_list_insert(parent, &parents);
@@ -34,7 +35,7 @@
 		die("Failed to commit notes tree to database");
 }
 
-void commit_notes(struct notes_tree *t, const char *msg)
+void commit_notes(struct repository *r, struct notes_tree *t, const char *msg)
 {
 	struct strbuf buf = STRBUF_INIT;
 	struct object_id commit_oid;
@@ -50,7 +51,7 @@
 	strbuf_addstr(&buf, msg);
 	strbuf_complete_line(&buf);
 
-	create_notes_commit(t, NULL, buf.buf, buf.len, &commit_oid);
+	create_notes_commit(r, 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);
@@ -171,11 +172,13 @@
 	return ret;
 }
 
-void finish_copy_notes_for_rewrite(struct notes_rewrite_cfg *c, const char *msg)
+void finish_copy_notes_for_rewrite(struct repository *r,
+				   struct notes_rewrite_cfg *c,
+				   const char *msg)
 {
 	int i;
 	for (i = 0; c->trees[i]; i++) {
-		commit_notes(c->trees[i], msg);
+		commit_notes(r, c->trees[i], msg);
 		free_notes(c->trees[i]);
 	}
 	free(c->trees);
diff --git a/notes-utils.h b/notes-utils.h
index 5408306..d9b3c09 100644
--- a/notes-utils.h
+++ b/notes-utils.h
@@ -5,6 +5,7 @@
 
 struct commit_list;
 struct object_id;
+struct repository;
 
 /*
  * Create new notes commit from the given notes tree
@@ -17,11 +18,13 @@
  *
  * The resulting commit SHA1 is stored in result_sha1.
  */
-void create_notes_commit(struct notes_tree *t, struct commit_list *parents,
+void create_notes_commit(struct repository *r,
+			 struct notes_tree *t,
+			 struct commit_list *parents,
 			 const char *msg, size_t msg_len,
 			 struct object_id *result_oid);
 
-void commit_notes(struct notes_tree *t, const char *msg);
+void commit_notes(struct repository *r, struct notes_tree *t, const char *msg);
 
 enum notes_merge_strategy {
 		NOTES_MERGE_RESOLVE_MANUAL = 0,
@@ -45,6 +48,8 @@
 struct notes_rewrite_cfg *init_copy_notes_for_rewrite(const char *cmd);
 int copy_note_for_rewrite(struct notes_rewrite_cfg *c,
 			  const struct object_id *from_obj, const struct object_id *to_obj);
-void finish_copy_notes_for_rewrite(struct notes_rewrite_cfg *c, const char *msg);
+void finish_copy_notes_for_rewrite(struct repository *r,
+				   struct notes_rewrite_cfg *c,
+				   const char *msg);
 
 #endif
diff --git a/object-store.h b/object-store.h
index ba57630..14fc935 100644
--- a/object-store.h
+++ b/object-store.h
@@ -154,11 +154,13 @@
 
 /*
  * 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.
+ * would be used to store a loose object with the specified oid.
  */
-const char *loose_object_path(struct repository *r, struct strbuf *buf, const unsigned char *sha1);
+const char *loose_object_path(struct repository *r, struct strbuf *buf,
+			      const struct object_id *oid);
 
-void *map_sha1_file(struct repository *r, const unsigned char *sha1, unsigned long *size);
+void *map_loose_object(struct repository *r, const struct object_id *oid,
+		       unsigned long *size);
 
 extern void *read_object_file_extended(struct repository *r,
 				       const struct object_id *oid,
@@ -206,19 +208,6 @@
 		      unsigned long *size,
 		      void **contents);
 
-/*
- * Convenience for sha1_object_info_extended() with a NULL struct
- * object_info. OBJECT_INFO_SKIP_CACHED is automatically set; pass
- * nonzero flags to also set other flags.
- */
-int repo_has_sha1_file_with_flags(struct repository *r,
-				  const unsigned char *sha1, int flags);
-static inline int repo_has_sha1_file(struct repository *r,
-				     const unsigned char *sha1)
-{
-	return repo_has_sha1_file_with_flags(r, sha1, 0);
-}
-
 #ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
 #define has_sha1_file_with_flags(sha1, flags) repo_has_sha1_file_with_flags(the_repository, sha1, flags)
 #define has_sha1_file(sha1) repo_has_sha1_file(the_repository, sha1)
diff --git a/object.c b/object.c
index 541934e..59ea24c 100644
--- a/object.c
+++ b/object.c
@@ -164,8 +164,9 @@
 		return obj;
 	else if (obj->type == OBJ_NONE) {
 		if (type == OBJ_COMMIT)
-			((struct commit *)obj)->index = alloc_commit_index(r);
-		obj->type = type;
+			init_commit_node(r, (struct commit *) obj);
+		else
+			obj->type = type;
 		return obj;
 	}
 	else {
@@ -263,7 +264,7 @@
 	    (!obj && repo_has_object_file(r, oid) &&
 	     oid_object_info(r, oid, NULL) == OBJ_BLOB)) {
 		if (check_object_signature(repl, NULL, 0, NULL) < 0) {
-			error(_("sha1 mismatch %s"), oid_to_hex(oid));
+			error(_("hash mismatch %s"), oid_to_hex(oid));
 			return NULL;
 		}
 		parse_blob_buffer(lookup_blob(r, oid), NULL, 0);
@@ -274,7 +275,7 @@
 	if (buffer) {
 		if (check_object_signature(repl, buffer, size, type_name(type)) < 0) {
 			free(buffer);
-			error(_("sha1 mismatch %s"), oid_to_hex(repl));
+			error(_("hash mismatch %s"), oid_to_hex(repl));
 			return NULL;
 		}
 
diff --git a/pack-objects.c b/pack-objects.c
index 9c45842..e7cd337 100644
--- a/pack-objects.c
+++ b/pack-objects.c
@@ -150,9 +150,7 @@
 					     1U << OE_SIZE_BITS);
 	pdata->oe_delta_size_limit = git_env_ulong("GIT_TEST_OE_DELTA_SIZE",
 						   1UL << OE_DELTA_SIZE_BITS);
-#ifndef NO_PTHREADS
-	pthread_mutex_init(&pdata->lock, NULL);
-#endif
+	init_recursive_mutex(&pdata->odb_lock);
 }
 
 struct object_entry *packlist_alloc(struct packing_data *pdata,
diff --git a/pack-objects.h b/pack-objects.h
index 3cd8d1f..6bfacc7 100644
--- a/pack-objects.h
+++ b/pack-objects.h
@@ -148,7 +148,11 @@
 	struct packed_git **in_pack_by_idx;
 	struct packed_git **in_pack;
 
-	pthread_mutex_t lock;
+	/*
+	 * During packing with multiple threads, protect the in-core
+	 * object database from concurrent accesses.
+	 */
+	pthread_mutex_t odb_lock;
 
 	/*
 	 * This list contains entries for bases which we know the other side
@@ -168,13 +172,14 @@
 
 void prepare_packing_data(struct repository *r, struct packing_data *pdata);
 
+/* Protect access to object database */
 static inline void packing_data_lock(struct packing_data *pdata)
 {
-	pthread_mutex_lock(&pdata->lock);
+	pthread_mutex_lock(&pdata->odb_lock);
 }
 static inline void packing_data_unlock(struct packing_data *pdata)
 {
-	pthread_mutex_unlock(&pdata->lock);
+	pthread_mutex_unlock(&pdata->odb_lock);
 }
 
 struct object_entry *packlist_alloc(struct packing_data *pdata,
diff --git a/pack-revindex.c b/pack-revindex.c
index 3c58784..50891f7 100644
--- a/pack-revindex.c
+++ b/pack-revindex.c
@@ -119,7 +119,7 @@
  */
 static void create_pack_revindex(struct packed_git *p)
 {
-	unsigned num_ent = p->num_objects;
+	const unsigned num_ent = p->num_objects;
 	unsigned i;
 	const char *index = p->index_data;
 	const unsigned hashsz = the_hash_algo->rawsz;
@@ -132,7 +132,7 @@
 			(uint32_t *)(index + 8 + p->num_objects * (hashsz + 4));
 		const uint32_t *off_64 = off_32 + p->num_objects;
 		for (i = 0; i < num_ent; i++) {
-			uint32_t off = ntohl(*off_32++);
+			const uint32_t off = ntohl(*off_32++);
 			if (!(off & 0x80000000)) {
 				p->revindex[i].offset = off;
 			} else {
@@ -143,7 +143,7 @@
 		}
 	} else {
 		for (i = 0; i < num_ent; i++) {
-			uint32_t hl = *((uint32_t *)(index + (hashsz + 4) * i));
+			const uint32_t hl = *((uint32_t *)(index + (hashsz + 4) * i));
 			p->revindex[i].offset = ntohl(hl);
 			p->revindex[i].nr = i;
 		}
@@ -168,10 +168,10 @@
 {
 	int lo = 0;
 	int hi = p->num_objects + 1;
-	struct revindex_entry *revindex = p->revindex;
+	const struct revindex_entry *revindex = p->revindex;
 
 	do {
-		unsigned mi = lo + (hi - lo) / 2;
+		const unsigned mi = lo + (hi - lo) / 2;
 		if (revindex[mi].offset == ofs) {
 			return mi;
 		} else if (ofs < revindex[mi].offset)
diff --git a/pathspec.c b/pathspec.c
index e85298f..12c2b32 100644
--- a/pathspec.c
+++ b/pathspec.c
@@ -1,4 +1,3 @@
-#define NO_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "dir.h"
diff --git a/preload-index.c b/preload-index.c
index c7dc3f2..e73600e 100644
--- a/preload-index.c
+++ b/preload-index.c
@@ -8,6 +8,7 @@
 #include "config.h"
 #include "progress.h"
 #include "thread-utils.h"
+#include "repository.h"
 
 /*
  * Mostly randomly chosen maximum thread counts: we
@@ -146,12 +147,12 @@
 	trace_performance_leave("preload index");
 }
 
-int read_index_preload(struct index_state *index,
-		       const struct pathspec *pathspec,
-		       unsigned int refresh_flags)
+int repo_read_index_preload(struct repository *repo,
+			    const struct pathspec *pathspec,
+			    unsigned int refresh_flags)
 {
-	int retval = read_index(index);
+	int retval = repo_read_index(repo);
 
-	preload_index(index, pathspec, refresh_flags);
+	preload_index(repo->index, pathspec, refresh_flags);
 	return retval;
 }
diff --git a/read-cache.c b/read-cache.c
index bfff271..0e0c93e 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -3,7 +3,6 @@
  *
  * Copyright (C) Linus Torvalds, 2005
  */
-#define NO_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "diff.h"
@@ -95,7 +94,6 @@
 	return *pool_ptr;
 }
 
-struct index_state the_index;
 static const char *alternate_index_output;
 
 static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
@@ -703,10 +701,10 @@
 	int intent_only = flags & ADD_CACHE_INTENT;
 	int add_option = (ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE|
 			  (intent_only ? ADD_CACHE_NEW_ONLY : 0));
-	int newflags = HASH_WRITE_OBJECT;
+	int hash_flags = HASH_WRITE_OBJECT;
 
-	if (flags & HASH_RENORMALIZE)
-		newflags |= HASH_RENORMALIZE;
+	if (flags & ADD_CACHE_RENORMALIZE)
+		hash_flags |= HASH_RENORMALIZE;
 
 	if (!S_ISREG(st_mode) && !S_ISLNK(st_mode) && !S_ISDIR(st_mode))
 		return error(_("%s: can only add regular files, symbolic links or git-directories"), path);
@@ -746,7 +744,7 @@
 	if (ignore_case) {
 		adjust_dirname_case(istate, ce->name);
 	}
-	if (!(flags & HASH_RENORMALIZE)) {
+	if (!(flags & ADD_CACHE_RENORMALIZE)) {
 		alias = index_file_exists(istate, ce->name,
 					  ce_namelen(ce), ignore_case);
 		if (alias &&
@@ -762,7 +760,7 @@
 		}
 	}
 	if (!intent_only) {
-		if (index_path(istate, &ce->oid, path, st, newflags)) {
+		if (index_path(istate, &ce->oid, path, st, hash_flags)) {
 			discard_cache_entry(ce);
 			return error(_("unable to index file '%s'"), path);
 		}
@@ -1733,16 +1731,6 @@
 	return 0;
 }
 
-int hold_locked_index(struct lock_file *lk, int lock_flags)
-{
-	return hold_lock_file_for_update(lk, get_index_file(), lock_flags);
-}
-
-int read_index(struct index_state *istate)
-{
-	return read_index_from(istate, get_index_file(), get_git_dir());
-}
-
 static struct cache_entry *create_from_disk(struct mem_pool *ce_mem_pool,
 					    unsigned int version,
 					    struct ondisk_cache_entry *ondisk,
@@ -2375,22 +2363,20 @@
 	return 0;
 }
 
-int index_has_changes(struct index_state *istate,
-		      struct tree *tree,
-		      struct strbuf *sb)
+int repo_index_has_changes(struct repository *repo,
+			   struct tree *tree,
+			   struct strbuf *sb)
 {
+	struct index_state *istate = repo->index;
 	struct object_id cmp;
 	int i;
 
-	if (istate != &the_index) {
-		BUG("index_has_changes cannot yet accept istate != &the_index; do_diff_cache needs updating first.");
-	}
 	if (tree)
 		cmp = tree->object.oid;
 	if (tree || !get_oid_tree("HEAD", &cmp)) {
 		struct diff_options opt;
 
-		repo_diff_setup(the_repository, &opt);
+		repo_diff_setup(repo, &opt);
 		opt.flags.exit_with_status = 1;
 		if (!sb)
 			opt.flags.quick = 1;
@@ -2664,9 +2650,9 @@
 	return 0;
 }
 
-static int verify_index(const struct index_state *istate)
+static int repo_verify_index(struct repository *repo)
 {
-	return verify_index_from(istate, get_index_file());
+	return verify_index_from(repo->index, repo->index_file);
 }
 
 static int has_racy_timestamp(struct index_state *istate)
@@ -2682,11 +2668,13 @@
 	return 0;
 }
 
-void update_index_if_able(struct index_state *istate, struct lock_file *lockfile)
+void repo_update_index_if_able(struct repository *repo,
+			       struct lock_file *lockfile)
 {
-	if ((istate->cache_changed || has_racy_timestamp(istate)) &&
-	    verify_index(istate))
-		write_locked_index(istate, lockfile, COMMIT_LOCK);
+	if ((repo->index->cache_changed ||
+	     has_racy_timestamp(repo->index)) &&
+	    repo_verify_index(repo))
+		write_locked_index(repo->index, lockfile, COMMIT_LOCK);
 	else
 		rollback_lock_file(lockfile);
 }
@@ -3223,12 +3211,14 @@
  * state can call this and check its return value, instead of calling
  * read_cache().
  */
-int read_index_unmerged(struct index_state *istate)
+int repo_read_index_unmerged(struct repository *repo)
 {
+	struct index_state *istate;
 	int i;
 	int unmerged = 0;
 
-	read_index(istate);
+	repo_read_index(repo);
+	istate = repo->index;
 	for (i = 0; i < istate->cache_nr; i++) {
 		struct cache_entry *ce = istate->cache[i];
 		struct cache_entry *new_ce;
diff --git a/refs.c b/refs.c
index f993635..142888a 100644
--- a/refs.c
+++ b/refs.c
@@ -188,7 +188,7 @@
 {
 	if (flags & REF_ISBROKEN)
 		return 0;
-	if (!has_sha1_file(oid->hash)) {
+	if (!has_object_file(oid)) {
 		error(_("%s does not point to a valid object!"), refname);
 		return 0;
 	}
diff --git a/repository.c b/repository.c
index 20c509a..65e6f8b 100644
--- a/repository.c
+++ b/repository.c
@@ -1,13 +1,20 @@
+/*
+ * not really _using_ the compat macros, just make sure the_index
+ * declaration matches the definition in this file.
+ */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "repository.h"
 #include "object-store.h"
 #include "config.h"
 #include "object.h"
+#include "lockfile.h"
 #include "submodule-config.h"
 
 /* The main repository */
 static struct repository the_repo;
 struct repository *the_repository;
+struct index_state the_index;
 
 void initialize_the_repository(void)
 {
@@ -256,3 +263,12 @@
 
 	return read_index_from(repo->index, repo->index_file, repo->gitdir);
 }
+
+int repo_hold_locked_index(struct repository *repo,
+			   struct lock_file *lf,
+			   int flags)
+{
+	if (!repo->index_file)
+		BUG("the repo hasn't been setup");
+	return hold_lock_file_for_update(lf, repo->index_file, flags);
+}
diff --git a/repository.h b/repository.h
index 0e482b7..8981649 100644
--- a/repository.h
+++ b/repository.h
@@ -6,6 +6,8 @@
 struct config_set;
 struct git_hash_algo;
 struct index_state;
+struct lock_file;
+struct pathspec;
 struct raw_object_store;
 struct submodule_cache;
 
@@ -138,5 +140,19 @@
  * populated then the number of entries will simply be returned.
  */
 int repo_read_index(struct repository *repo);
+int repo_hold_locked_index(struct repository *repo,
+			   struct lock_file *lf,
+			   int flags);
+
+int repo_read_index_preload(struct repository *,
+			    const struct pathspec *pathspec,
+			    unsigned refresh_flags);
+int repo_read_index_unmerged(struct repository *);
+/*
+ * Opportunistically update the index but do not complain if we can't.
+ * The lockfile is always committed or rolled back.
+ */
+void repo_update_index_if_able(struct repository *, struct lock_file *);
+
 
 #endif /* REPOSITORY_H */
diff --git a/rerere.c b/rerere.c
index 1362403..17abb47 100644
--- a/rerere.c
+++ b/rerere.c
@@ -561,7 +561,7 @@
 {
 	int i;
 
-	if (read_index(r->index) < 0)
+	if (repo_read_index(r) < 0)
 		return error(_("index file corrupt"));
 
 	for (i = 0; i < r->index->cache_nr;) {
@@ -595,7 +595,7 @@
 
 	if (setup_rerere(r, merge_rr, RERERE_READONLY))
 		return 0;
-	if (read_index(r->index) < 0)
+	if (repo_read_index(r) < 0)
 		return error(_("index file corrupt"));
 
 	for (i = 0; i < r->index->cache_nr;) {
@@ -705,7 +705,7 @@
 	struct lock_file index_lock = LOCK_INIT;
 	int i;
 
-	hold_locked_index(&index_lock, LOCK_DIE_ON_ERROR);
+	repo_hold_locked_index(r, &index_lock, LOCK_DIE_ON_ERROR);
 
 	for (i = 0; i < update->nr; i++) {
 		struct string_list_item *item = &update->items[i];
@@ -1107,7 +1107,7 @@
 	struct string_list conflict = STRING_LIST_INIT_DUP;
 	struct string_list merge_rr = STRING_LIST_INIT_DUP;
 
-	if (read_index(r->index) < 0)
+	if (repo_read_index(r) < 0)
 		return error(_("index file corrupt"));
 
 	fd = setup_rerere(r, &merge_rr, RERERE_NOAUTOUPDATE);
diff --git a/revision.c b/revision.c
index 8f886fe..162d511 100644
--- a/revision.c
+++ b/revision.c
@@ -27,6 +27,7 @@
 #include "commit-reach.h"
 #include "commit-graph.h"
 #include "prio-queue.h"
+#include "hashmap.h"
 
 volatile show_early_output_fn_t show_early_output;
 
@@ -99,6 +100,148 @@
 	mark_tree_contents_uninteresting(r, tree);
 }
 
+struct path_and_oids_entry {
+	struct hashmap_entry ent;
+	char *path;
+	struct oidset trees;
+};
+
+static int path_and_oids_cmp(const void *hashmap_cmp_fn_data,
+			     const struct path_and_oids_entry *e1,
+			     const struct path_and_oids_entry *e2,
+			     const void *keydata)
+{
+	return strcmp(e1->path, e2->path);
+}
+
+static void paths_and_oids_init(struct hashmap *map)
+{
+	hashmap_init(map, (hashmap_cmp_fn) path_and_oids_cmp, NULL, 0);
+}
+
+static void paths_and_oids_clear(struct hashmap *map)
+{
+	struct hashmap_iter iter;
+	struct path_and_oids_entry *entry;
+	hashmap_iter_init(map, &iter);
+
+	while ((entry = (struct path_and_oids_entry *)hashmap_iter_next(&iter))) {
+		oidset_clear(&entry->trees);
+		free(entry->path);
+	}
+
+	hashmap_free(map, 1);
+}
+
+static void paths_and_oids_insert(struct hashmap *map,
+				  const char *path,
+				  const struct object_id *oid)
+{
+	int hash = strhash(path);
+	struct path_and_oids_entry key;
+	struct path_and_oids_entry *entry;
+
+	hashmap_entry_init(&key, hash);
+
+	/* use a shallow copy for the lookup */
+	key.path = (char *)path;
+	oidset_init(&key.trees, 0);
+
+	if (!(entry = (struct path_and_oids_entry *)hashmap_get(map, &key, NULL))) {
+		entry = xcalloc(1, sizeof(struct path_and_oids_entry));
+		hashmap_entry_init(entry, hash);
+		entry->path = xstrdup(key.path);
+		oidset_init(&entry->trees, 16);
+		hashmap_put(map, entry);
+	}
+
+	oidset_insert(&entry->trees, oid);
+}
+
+static void add_children_by_path(struct repository *r,
+				 struct tree *tree,
+				 struct hashmap *map)
+{
+	struct tree_desc desc;
+	struct name_entry entry;
+
+	if (!tree)
+		return;
+
+	if (parse_tree_gently(tree, 1) < 0)
+		return;
+
+	init_tree_desc(&desc, tree->buffer, tree->size);
+	while (tree_entry(&desc, &entry)) {
+		switch (object_type(entry.mode)) {
+		case OBJ_TREE:
+			paths_and_oids_insert(map, entry.path, &entry.oid);
+
+			if (tree->object.flags & UNINTERESTING) {
+				struct tree *child = lookup_tree(r, &entry.oid);
+				if (child)
+					child->object.flags |= UNINTERESTING;
+			}
+			break;
+		case OBJ_BLOB:
+			if (tree->object.flags & UNINTERESTING) {
+				struct blob *child = lookup_blob(r, &entry.oid);
+				if (child)
+					child->object.flags |= UNINTERESTING;
+			}
+			break;
+		default:
+			/* Subproject commit - not in this repository */
+			break;
+		}
+	}
+
+	free_tree_buffer(tree);
+}
+
+void mark_trees_uninteresting_sparse(struct repository *r,
+				     struct oidset *trees)
+{
+	unsigned has_interesting = 0, has_uninteresting = 0;
+	struct hashmap map;
+	struct hashmap_iter map_iter;
+	struct path_and_oids_entry *entry;
+	struct object_id *oid;
+	struct oidset_iter iter;
+
+	oidset_iter_init(trees, &iter);
+	while ((!has_interesting || !has_uninteresting) &&
+	       (oid = oidset_iter_next(&iter))) {
+		struct tree *tree = lookup_tree(r, oid);
+
+		if (!tree)
+			continue;
+
+		if (tree->object.flags & UNINTERESTING)
+			has_uninteresting = 1;
+		else
+			has_interesting = 1;
+	}
+
+	/* Do not walk unless we have both types of trees. */
+	if (!has_uninteresting || !has_interesting)
+		return;
+
+	paths_and_oids_init(&map);
+
+	oidset_iter_init(trees, &iter);
+	while ((oid = oidset_iter_next(&iter))) {
+		struct tree *tree = lookup_tree(r, oid);
+		add_children_by_path(r, tree, &map);
+	}
+
+	hashmap_iter_init(&map, &map_iter);
+	while ((entry = hashmap_iter_next(&map_iter)))
+		mark_trees_uninteresting_sparse(r, &entry->trees);
+
+	paths_and_oids_clear(&map);
+}
+
 struct commit_stack {
 	struct commit **items;
 	size_t nr, alloc;
@@ -1397,7 +1540,7 @@
 {
 	struct worktree **worktrees, **p;
 
-	read_index(revs->repo->index);
+	repo_read_index(revs->repo);
 	do_add_index_objects_to_pending(revs, revs->repo->index, flags);
 
 	if (revs->single_worktree)
@@ -1544,7 +1687,7 @@
 	head->object.flags |= SYMMETRIC_LEFT;
 
 	if (!istate->cache_nr)
-		read_index(istate);
+		repo_read_index(revs->repo);
 	for (i = 0; i < istate->cache_nr; i++) {
 		const struct cache_entry *ce = istate->cache[i];
 		if (!ce_stage(ce))
@@ -1603,8 +1746,8 @@
 	if (!*b_name)
 		b_name = "HEAD";
 
-	if (get_oid_with_context(a_name, oc_flags, &a_oid, a_oc) ||
-	    get_oid_with_context(b_name, oc_flags, &b_oid, b_oc))
+	if (get_oid_with_context(revs->repo, a_name, oc_flags, &a_oid, a_oc) ||
+	    get_oid_with_context(revs->repo, b_name, oc_flags, &b_oid, b_oc))
 		return -1;
 
 	if (!cant_be_filename) {
@@ -1738,7 +1881,7 @@
 	if (revarg_opt & REVARG_COMMITTISH)
 		get_sha1_flags |= GET_OID_COMMITTISH;
 
-	if (get_oid_with_context(arg, get_sha1_flags, &oid, &oc))
+	if (get_oid_with_context(revs->repo, arg, get_sha1_flags, &oid, &oc))
 		return revs->ignore_missing ? 0 : -1;
 	if (!cant_be_filename)
 		verify_non_filename(revs->prefix, arg);
@@ -2471,7 +2614,7 @@
 		struct object_id oid;
 		struct object *object;
 		struct object_context oc;
-		if (get_oid_with_context(revs->def, 0, &oid, &oc))
+		if (get_oid_with_context(revs->repo, revs->def, 0, &oid, &oc))
 			diagnose_missing_default(revs->def);
 		object = get_reference(revs, revs->def, &oid, 0);
 		add_pending_object_with_mode(revs, object, revs->def, oc.mode);
diff --git a/revision.h b/revision.h
index 52e5a88..d32d62a 100644
--- a/revision.h
+++ b/revision.h
@@ -67,6 +67,7 @@
 #define REVISION_WALK_NO_WALK_SORTED 1
 #define REVISION_WALK_NO_WALK_UNSORTED 2
 
+struct oidset;
 struct topo_walk_info;
 
 struct rev_info {
@@ -327,6 +328,7 @@
 
 void mark_parents_uninteresting(struct commit *commit);
 void mark_tree_uninteresting(struct repository *r, struct tree *tree);
+void mark_trees_uninteresting_sparse(struct repository *r, struct oidset *trees);
 
 void show_object_with_name(FILE *, struct object *, const char *);
 
diff --git a/send-pack.c b/send-pack.c
index 7b9829f..6dc16c3 100644
--- a/send-pack.c
+++ b/send-pack.c
@@ -40,7 +40,7 @@
 
 static void feed_object(const struct object_id *oid, FILE *fh, int negative)
 {
-	if (negative && !has_sha1_file(oid->hash))
+	if (negative && !has_object_file(oid))
 		return;
 
 	if (negative)
diff --git a/sequencer.c b/sequencer.c
index 213815d..972402e 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -150,6 +150,7 @@
 static GIT_PATH_FUNC(rebase_path_gpg_sign_opt, "rebase-merge/gpg_sign_opt")
 static GIT_PATH_FUNC(rebase_path_orig_head, "rebase-merge/orig-head")
 static GIT_PATH_FUNC(rebase_path_verbose, "rebase-merge/verbose")
+static GIT_PATH_FUNC(rebase_path_quiet, "rebase-merge/quiet")
 static GIT_PATH_FUNC(rebase_path_signoff, "rebase-merge/signoff")
 static GIT_PATH_FUNC(rebase_path_head_name, "rebase-merge/head-name")
 static GIT_PATH_FUNC(rebase_path_onto, "rebase-merge/onto")
@@ -157,7 +158,6 @@
 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 GIT_PATH_FUNC(rebase_path_quiet, "rebase-merge/quiet")
 static GIT_PATH_FUNC(rebase_path_reschedule_failed_exec, "rebase-merge/reschedule-failed-exec")
 
 static int git_sequencer_config(const char *k, const char *v, void *cb)
@@ -447,9 +447,9 @@
 	return lookup_tree(r, the_hash_algo->empty_tree);
 }
 
-static int error_dirty_index(struct index_state *istate, struct replay_opts *opts)
+static int error_dirty_index(struct repository *repo, struct replay_opts *opts)
 {
-	if (read_index_unmerged(istate))
+	if (repo_read_index_unmerged(repo))
 		return error_resolve_conflict(_(action_name(opts)));
 
 	error(_("your local changes would be overwritten by %s."),
@@ -484,7 +484,7 @@
 	struct strbuf sb = STRBUF_INIT;
 	struct strbuf err = STRBUF_INIT;
 
-	read_index(r->index);
+	repo_read_index(r);
 	if (checkout_fast_forward(r, from, to, 1))
 		return -1; /* the callee should have complained already */
 
@@ -541,12 +541,12 @@
 	char **xopt;
 	struct lock_file index_lock = LOCK_INIT;
 
-	if (hold_locked_index(&index_lock, LOCK_REPORT_ON_ERROR) < 0)
+	if (repo_hold_locked_index(r, &index_lock, LOCK_REPORT_ON_ERROR) < 0)
 		return -1;
 
-	read_index(r->index);
+	repo_read_index(r);
 
-	init_merge_options(&o);
+	init_merge_options(&o, r);
 	o.ancestor = base ? base_label : "(empty tree)";
 	o.branch1 = "HEAD";
 	o.branch2 = next ? next_label : "(empty tree)";
@@ -1116,7 +1116,8 @@
 	return finish_command(&proc);
 }
 
-void commit_post_rewrite(const struct commit *old_head,
+void commit_post_rewrite(struct repository *r,
+			 const struct commit *old_head,
 			 const struct object_id *new_head)
 {
 	struct notes_rewrite_cfg *cfg;
@@ -1125,7 +1126,7 @@
 	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'");
+		finish_copy_notes_for_rewrite(r, cfg, "Notes added by 'git commit --amend'");
 	}
 	run_rewrite_hook(&old_head->object.oid, new_head);
 }
@@ -1406,7 +1407,7 @@
 	}
 
 	if (flags & AMEND_MSG)
-		commit_post_rewrite(current_head, oid);
+		commit_post_rewrite(r, current_head, oid);
 
 out:
 	free_commit_extra_headers(extra);
@@ -1768,7 +1769,7 @@
 			oidcpy(&head, the_hash_algo->empty_tree);
 		if (index_differs_from(r, unborn ? empty_tree_oid_hex() : "HEAD",
 				       NULL, 0))
-			return error_dirty_index(r->index, opts);
+			return error_dirty_index(r, opts);
 	}
 	discard_index(r->index);
 
@@ -1998,8 +1999,8 @@
 				  struct replay_opts *opts)
 {
 	struct lock_file index_lock = LOCK_INIT;
-	int index_fd = hold_locked_index(&index_lock, 0);
-	if (read_index(r->index) < 0) {
+	int index_fd = repo_hold_locked_index(r, &index_lock, 0);
+	if (repo_read_index(r) < 0) {
 		rollback_lock_file(&index_lock);
 		return error(_("git %s: failed to read the index"),
 			_(action_name(opts)));
@@ -2390,6 +2391,9 @@
 		if (file_exists(rebase_path_verbose()))
 			opts->verbose = 1;
 
+		if (file_exists(rebase_path_quiet()))
+			opts->quiet = 1;
+
 		if (file_exists(rebase_path_signoff())) {
 			opts->allow_ff = 0;
 			opts->signoff = 1;
@@ -2460,9 +2464,6 @@
 
 	if (quiet)
 		write_file(rebase_path_quiet(), "%s\n", quiet);
-	else
-		write_file(rebase_path_quiet(), "\n");
-
 	if (opts->verbose)
 		write_file(rebase_path_verbose(), "%s", "");
 	if (opts->strategy)
@@ -2865,7 +2866,7 @@
 					  child_env.argv);
 
 	/* force re-reading of the cache */
-	if (discard_index(r->index) < 0 || read_index(r->index) < 0)
+	if (discard_index(r->index) < 0 || repo_read_index(r) < 0)
 		return error(_("could not read index"));
 
 	dirty = require_clean_work_tree(r, "rebase", NULL, 1, 1);
@@ -2989,7 +2990,7 @@
 	struct unpack_trees_options unpack_tree_opts;
 	int ret = 0;
 
-	if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
+	if (repo_hold_locked_index(r, &lock, LOCK_REPORT_ON_ERROR) < 0)
 		return -1;
 
 	if (len == 10 && !strncmp("[new root]", name, len)) {
@@ -3034,7 +3035,7 @@
 	unpack_tree_opts.merge = 1;
 	unpack_tree_opts.update = 1;
 
-	if (read_index_unmerged(r->index)) {
+	if (repo_read_index_unmerged(r)) {
 		rollback_lock_file(&lock);
 		strbuf_release(&ref_name);
 		return error_resolve_conflict(_(action_name(opts)));
@@ -3107,7 +3108,7 @@
 	static struct lock_file lock;
 	const char *p;
 
-	if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
+	if (repo_hold_locked_index(r, &lock, LOCK_REPORT_ON_ERROR) < 0) {
 		ret = -1;
 		goto leave_merge;
 	}
@@ -3288,7 +3289,7 @@
 
 		/* force re-reading of the cache */
 		if (!ret && (discard_index(r->index) < 0 ||
-			     read_index(r->index) < 0))
+			     repo_read_index(r) < 0))
 			ret = error(_("could not read index"));
 		goto leave_merge;
 	}
@@ -3310,8 +3311,8 @@
 		commit_list_insert(j->item, &reversed);
 	free_commit_list(bases);
 
-	read_index(r->index);
-	init_merge_options(&o);
+	repo_read_index(r);
+	init_merge_options(&o, r);
 	o.branch1 = "HEAD";
 	o.branch2 = ref_name.buf;
 	o.buffer_output = 2;
@@ -3555,10 +3556,11 @@
 					fprintf(f, "%d\n", todo_list->done_nr);
 					fclose(f);
 				}
-				fprintf(stderr, "Rebasing (%d/%d)%s",
-					todo_list->done_nr,
-					todo_list->total_nr,
-					opts->verbose ? "\n" : "\r");
+				if (!opts->quiet)
+					fprintf(stderr, "Rebasing (%d/%d)%s",
+						todo_list->done_nr,
+						todo_list->total_nr,
+						opts->verbose ? "\n" : "\r");
 			}
 			unlink(rebase_path_message());
 			unlink(rebase_path_author_script());
@@ -3792,8 +3794,10 @@
 		}
 		apply_autostash(opts);
 
-		fprintf(stderr, "Successfully rebased and updated %s.\n",
-			head_ref.buf);
+		if (!opts->quiet)
+			fprintf(stderr,
+				"Successfully rebased and updated %s.\n",
+				head_ref.buf);
 
 		strbuf_release(&buf);
 		strbuf_release(&head_ref);
@@ -3984,7 +3988,7 @@
 				goto release_todo_list;
 		}
 		if (index_differs_from(r, "HEAD", NULL, 0)) {
-			res = error_dirty_index(r->index, opts);
+			res = error_dirty_index(r, opts);
 			goto release_todo_list;
 		}
 		todo_list.current++;
diff --git a/sequencer.h b/sequencer.h
index 5d7bc04..93e8913 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -40,6 +40,7 @@
 	int allow_empty_message;
 	int keep_redundant_commits;
 	int verbose;
+	int quiet;
 	int reschedule_failed_exec;
 
 	int mainline;
@@ -125,7 +126,8 @@
 			    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,
+void commit_post_rewrite(struct repository *r,
+			 const struct commit *current_head,
 			 const struct object_id *new_head);
 
 int prepare_branch_to_be_rebased(struct replay_opts *opts, const char *commit);
diff --git a/setup.c b/setup.c
index 12bf25a..ca9e8a9 100644
--- a/setup.c
+++ b/setup.c
@@ -39,7 +39,7 @@
 	off = offset_1st_component(path);
 
 	/* check if work tree is already the prefix */
-	if (wtlen <= len && !strncmp(path, work_tree, wtlen)) {
+	if (wtlen <= len && !fspathncmp(path, work_tree, wtlen)) {
 		if (path[wtlen] == '/') {
 			memmove(path, path + wtlen + 1, len - wtlen);
 			return 0;
@@ -59,7 +59,7 @@
 		path++;
 		if (*path == '/') {
 			*path = '\0';
-			if (strcmp(real_path(path0), work_tree) == 0) {
+			if (fspathcmp(real_path(path0), work_tree) == 0) {
 				memmove(path0, path + 1, len - (path - path0));
 				return 0;
 			}
@@ -68,7 +68,7 @@
 	}
 
 	/* check whole path */
-	if (strcmp(real_path(path0), work_tree) == 0) {
+	if (fspathcmp(real_path(path0), work_tree) == 0) {
 		*path0 = '\0';
 		return 0;
 	}
diff --git a/sha1-file.c b/sha1-file.c
index c8da9f3..494606f 100644
--- a/sha1-file.c
+++ b/sha1-file.c
@@ -192,7 +192,7 @@
 
 /*
  * This is meant to hold a *small* number of objects that you would
- * want read_sha1_file() to be able to return, but yet you do not want
+ * want read_object_file() to be able to return, but yet you do not want
  * to write them into the object store (e.g. a browse-only
  * application).
  */
@@ -401,12 +401,12 @@
 	return ret;
 }
 
-static void fill_sha1_path(struct strbuf *buf, const unsigned char *sha1)
+static void fill_loose_path(struct strbuf *buf, const struct object_id *oid)
 {
 	int i;
 	for (i = 0; i < the_hash_algo->rawsz; i++) {
 		static char hex[] = "0123456789abcdef";
-		unsigned int val = sha1[i];
+		unsigned int val = oid->hash[i];
 		strbuf_addch(buf, hex[val >> 4]);
 		strbuf_addch(buf, hex[val & 0xf]);
 		if (!i)
@@ -416,19 +416,19 @@
 
 static const char *odb_loose_path(struct object_directory *odb,
 				  struct strbuf *buf,
-				  const unsigned char *sha1)
+				  const struct object_id *oid)
 {
 	strbuf_reset(buf);
 	strbuf_addstr(buf, odb->path);
 	strbuf_addch(buf, '/');
-	fill_sha1_path(buf, sha1);
+	fill_loose_path(buf, oid);
 	return buf->buf;
 }
 
 const char *loose_object_path(struct repository *r, struct strbuf *buf,
-			      const unsigned char *sha1)
+			      const struct object_id *oid)
 {
-	return odb_loose_path(r->objects->odb, buf, sha1);
+	return odb_loose_path(r->objects->odb, buf, oid);
 }
 
 /*
@@ -789,7 +789,7 @@
 				 int freshen)
 {
 	static struct strbuf path = STRBUF_INIT;
-	odb_loose_path(odb, &path, oid->hash);
+	odb_loose_path(odb, &path, oid);
 	return check_and_freshen_file(path.buf, freshen);
 }
 
@@ -866,8 +866,8 @@
 
 /*
  * With an in-core object data in "map", rehash it to make sure the
- * object name actually matches "sha1" to detect object corruption.
- * With "map" == NULL, try reading the object named with "sha1" using
+ * object name actually matches "oid" to detect object corruption.
+ * With "map" == NULL, try reading the object named with "oid" using
  * the streaming interface and rehash it to do the same.
  */
 int check_object_signature(const struct object_id *oid, void *map,
@@ -940,22 +940,22 @@
 }
 
 /*
- * Find "sha1" as a loose object in the local repository or in an alternate.
+ * Find "oid" as a loose object in the local repository or in an alternate.
  * Returns 0 on success, negative on failure.
  *
  * The "path" out-parameter will give the path of the object we found (if any).
  * Note that it may point to static storage and is only valid until another
- * call to stat_sha1_file().
+ * call to stat_loose_object().
  */
-static int stat_sha1_file(struct repository *r, const unsigned char *sha1,
-			  struct stat *st, const char **path)
+static int stat_loose_object(struct repository *r, const struct object_id *oid,
+			     struct stat *st, const char **path)
 {
 	struct object_directory *odb;
 	static struct strbuf buf = STRBUF_INIT;
 
 	prepare_alt_odb(r);
 	for (odb = r->objects->odb; odb; odb = odb->next) {
-		*path = odb_loose_path(odb, &buf, sha1);
+		*path = odb_loose_path(odb, &buf, oid);
 		if (!lstat(*path, st))
 			return 0;
 	}
@@ -964,11 +964,11 @@
 }
 
 /*
- * Like stat_sha1_file(), but actually open the object and return the
+ * Like stat_loose_object(), but actually open the object and return the
  * descriptor. See the caveats on the "path" parameter above.
  */
-static int open_sha1_file(struct repository *r,
-			  const unsigned char *sha1, const char **path)
+static int open_loose_object(struct repository *r,
+			     const struct object_id *oid, const char **path)
 {
 	int fd;
 	struct object_directory *odb;
@@ -977,7 +977,7 @@
 
 	prepare_alt_odb(r);
 	for (odb = r->objects->odb; odb; odb = odb->next) {
-		*path = odb_loose_path(odb, &buf, sha1);
+		*path = odb_loose_path(odb, &buf, oid);
 		fd = git_open(*path);
 		if (fd >= 0)
 			return fd;
@@ -990,16 +990,13 @@
 }
 
 static int quick_has_loose(struct repository *r,
-			   const unsigned char *sha1)
+			   const struct object_id *oid)
 {
-	struct object_id oid;
 	struct object_directory *odb;
 
-	hashcpy(oid.hash, sha1);
-
 	prepare_alt_odb(r);
 	for (odb = r->objects->odb; odb; odb = odb->next) {
-		if (oid_array_lookup(odb_loose_cache(odb, &oid), &oid) >= 0)
+		if (oid_array_lookup(odb_loose_cache(odb, oid), oid) >= 0)
 			return 1;
 	}
 	return 0;
@@ -1007,10 +1004,10 @@
 
 /*
  * Map the loose object at "path" if it is not NULL, or the path found by
- * searching for a loose object named "sha1".
+ * searching for a loose object named "oid".
  */
-static void *map_sha1_file_1(struct repository *r, const char *path,
-			     const unsigned char *sha1, unsigned long *size)
+static void *map_loose_object_1(struct repository *r, const char *path,
+			     const struct object_id *oid, unsigned long *size)
 {
 	void *map;
 	int fd;
@@ -1018,7 +1015,7 @@
 	if (path)
 		fd = git_open(path);
 	else
-		fd = open_sha1_file(r, sha1, &path);
+		fd = open_loose_object(r, oid, &path);
 	map = NULL;
 	if (fd >= 0) {
 		struct stat st;
@@ -1038,15 +1035,16 @@
 	return map;
 }
 
-void *map_sha1_file(struct repository *r,
-		    const unsigned char *sha1, unsigned long *size)
+void *map_loose_object(struct repository *r,
+		       const struct object_id *oid,
+		       unsigned long *size)
 {
-	return map_sha1_file_1(r, NULL, sha1, size);
+	return map_loose_object_1(r, NULL, oid, size);
 }
 
-static int unpack_sha1_short_header(git_zstream *stream,
-				    unsigned char *map, unsigned long mapsize,
-				    void *buffer, unsigned long bufsiz)
+static int unpack_loose_short_header(git_zstream *stream,
+				     unsigned char *map, unsigned long mapsize,
+				     void *buffer, unsigned long bufsiz)
 {
 	/* Get the data stream */
 	memset(stream, 0, sizeof(*stream));
@@ -1059,12 +1057,12 @@
 	return git_inflate(stream, 0);
 }
 
-int unpack_sha1_header(git_zstream *stream,
-		       unsigned char *map, unsigned long mapsize,
-		       void *buffer, unsigned long bufsiz)
+int unpack_loose_header(git_zstream *stream,
+			unsigned char *map, unsigned long mapsize,
+			void *buffer, unsigned long bufsiz)
 {
-	int status = unpack_sha1_short_header(stream, map, mapsize,
-					      buffer, bufsiz);
+	int status = unpack_loose_short_header(stream, map, mapsize,
+					       buffer, bufsiz);
 
 	if (status < Z_OK)
 		return status;
@@ -1075,13 +1073,13 @@
 	return 0;
 }
 
-static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
-					unsigned long mapsize, void *buffer,
-					unsigned long bufsiz, struct strbuf *header)
+static int unpack_loose_header_to_strbuf(git_zstream *stream, unsigned char *map,
+					 unsigned long mapsize, void *buffer,
+					 unsigned long bufsiz, struct strbuf *header)
 {
 	int status;
 
-	status = unpack_sha1_short_header(stream, map, mapsize, buffer, bufsiz);
+	status = unpack_loose_short_header(stream, map, mapsize, buffer, bufsiz);
 	if (status < Z_OK)
 		return -1;
 
@@ -1111,7 +1109,9 @@
 	return -1;
 }
 
-static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
+static void *unpack_loose_rest(git_zstream *stream,
+			       void *buffer, unsigned long size,
+			       const struct object_id *oid)
 {
 	int bytes = strlen(buffer) + 1;
 	unsigned char *buf = xmallocz(size);
@@ -1148,10 +1148,10 @@
 	}
 
 	if (status < 0)
-		error(_("corrupt loose object '%s'"), sha1_to_hex(sha1));
+		error(_("corrupt loose object '%s'"), oid_to_hex(oid));
 	else if (stream->avail_in)
 		error(_("garbage at end of loose object '%s'"),
-		      sha1_to_hex(sha1));
+		      oid_to_hex(oid));
 	free(buf);
 	return NULL;
 }
@@ -1161,8 +1161,8 @@
  * too permissive for what we want to check. So do an anal
  * object header parse by hand.
  */
-static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
-			       unsigned int flags)
+static int parse_loose_header_extended(const char *hdr, struct object_info *oi,
+				       unsigned int flags)
 {
 	const char *type_buf = hdr;
 	unsigned long size;
@@ -1222,17 +1222,17 @@
 	return *hdr ? -1 : type;
 }
 
-int parse_sha1_header(const char *hdr, unsigned long *sizep)
+int parse_loose_header(const char *hdr, unsigned long *sizep)
 {
 	struct object_info oi = OBJECT_INFO_INIT;
 
 	oi.sizep = sizep;
-	return parse_sha1_header_extended(hdr, &oi, 0);
+	return parse_loose_header_extended(hdr, &oi, 0);
 }
 
-static int sha1_loose_object_info(struct repository *r,
-				  const unsigned char *sha1,
-				  struct object_info *oi, int flags)
+static int loose_object_info(struct repository *r,
+			     const struct object_id *oid,
+			     struct object_info *oi, int flags)
 {
 	int status = 0;
 	unsigned long mapsize;
@@ -1257,15 +1257,15 @@
 		const char *path;
 		struct stat st;
 		if (!oi->disk_sizep && (flags & OBJECT_INFO_QUICK))
-			return quick_has_loose(r, sha1) ? 0 : -1;
-		if (stat_sha1_file(r, sha1, &st, &path) < 0)
+			return quick_has_loose(r, oid) ? 0 : -1;
+		if (stat_loose_object(r, oid, &st, &path) < 0)
 			return -1;
 		if (oi->disk_sizep)
 			*oi->disk_sizep = st.st_size;
 		return 0;
 	}
 
-	map = map_sha1_file(r, sha1, &mapsize);
+	map = map_loose_object(r, oid, &mapsize);
 	if (!map)
 		return -1;
 
@@ -1275,24 +1275,24 @@
 	if (oi->disk_sizep)
 		*oi->disk_sizep = mapsize;
 	if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE)) {
-		if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
+		if (unpack_loose_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
 			status = error(_("unable to unpack %s header with --allow-unknown-type"),
-				       sha1_to_hex(sha1));
-	} else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
+				       oid_to_hex(oid));
+	} else if (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
 		status = error(_("unable to unpack %s header"),
-			       sha1_to_hex(sha1));
+			       oid_to_hex(oid));
 	if (status < 0)
 		; /* Do nothing */
 	else if (hdrbuf.len) {
-		if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
+		if ((status = parse_loose_header_extended(hdrbuf.buf, oi, flags)) < 0)
 			status = error(_("unable to parse %s header with --allow-unknown-type"),
-				       sha1_to_hex(sha1));
-	} else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
-		status = error(_("unable to parse %s header"), sha1_to_hex(sha1));
+				       oid_to_hex(oid));
+	} else if ((status = parse_loose_header_extended(hdr, oi, flags)) < 0)
+		status = error(_("unable to parse %s header"), oid_to_hex(oid));
 
 	if (status >= 0 && oi->contentp) {
-		*oi->contentp = unpack_sha1_rest(&stream, hdr,
-						 *oi->sizep, sha1);
+		*oi->contentp = unpack_loose_rest(&stream, hdr,
+						  *oi->sizep, oid);
 		if (!*oi->contentp) {
 			git_inflate_end(&stream);
 			status = -1;
@@ -1358,7 +1358,7 @@
 			return -1;
 
 		/* Most likely it's a loose object. */
-		if (!sha1_loose_object_info(r, real->hash, oi, flags))
+		if (!loose_object_info(r, real, oi, flags))
 			return 0;
 
 		/* Not a loose object; someone else may have just packed it. */
@@ -1422,20 +1422,16 @@
 }
 
 static void *read_object(struct repository *r,
-			 const unsigned char *sha1,
-			 enum object_type *type,
+			 const struct object_id *oid, enum object_type *type,
 			 unsigned long *size)
 {
-	struct object_id oid;
 	struct object_info oi = OBJECT_INFO_INIT;
 	void *content;
 	oi.typep = type;
 	oi.sizep = size;
 	oi.contentp = &content;
 
-	hashcpy(oid.hash, sha1);
-
-	if (oid_object_info_extended(r, &oid, &oi, 0) < 0)
+	if (oid_object_info_extended(r, oid, &oi, 0) < 0)
 		return NULL;
 	return content;
 }
@@ -1446,7 +1442,7 @@
 	struct cached_object *co;
 
 	hash_object_file(buf, len, type_name(type), oid);
-	if (has_sha1_file(oid->hash) || find_cached_object(oid))
+	if (has_object_file(oid) || find_cached_object(oid))
 		return 0;
 	ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
 	co = &cached_objects[cached_object_nr++];
@@ -1477,7 +1473,7 @@
 		lookup_replace_object(r, oid) : oid;
 
 	errno = 0;
-	data = read_object(r, repl->hash, type, size);
+	data = read_object(r, repl, type, size);
 	if (data)
 		return data;
 
@@ -1489,7 +1485,7 @@
 		die(_("replacement %s not found for %s"),
 		    oid_to_hex(repl), oid_to_hex(oid));
 
-	if (!stat_sha1_file(r, repl->hash, &st, &path))
+	if (!stat_loose_object(r, repl, &st, &path))
 		die(_("loose object %s (stored in %s) is corrupt"),
 		    oid_to_hex(repl), path);
 
@@ -1596,7 +1592,7 @@
 	unlink_or_warn(tmpfile);
 	if (ret) {
 		if (ret != EEXIST) {
-			return error_errno(_("unable to write sha1 filename %s"), filename);
+			return error_errno(_("unable to write file %s"), filename);
 		}
 		/* FIXME!!! Collision check here ? */
 	}
@@ -1624,12 +1620,12 @@
 }
 
 /* Finalize a file on disk, and close it. */
-static void close_sha1_file(int fd)
+static void close_loose_object(int fd)
 {
 	if (fsync_object_files)
-		fsync_or_die(fd, "sha1 file");
+		fsync_or_die(fd, "loose object file");
 	if (close(fd) != 0)
-		die_errno(_("error when closing sha1 file"));
+		die_errno(_("error when closing loose object file"));
 }
 
 /* Size of directory component, including the ending '/' */
@@ -1689,7 +1685,7 @@
 	static struct strbuf tmp_file = STRBUF_INIT;
 	static struct strbuf filename = STRBUF_INIT;
 
-	loose_object_path(the_repository, &filename, oid->hash);
+	loose_object_path(the_repository, &filename, oid);
 
 	fd = create_tmpfile(&tmp_file, filename.buf);
 	if (fd < 0) {
@@ -1720,7 +1716,7 @@
 		ret = git_deflate(&stream, Z_FINISH);
 		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"));
+			die(_("unable to write loose object file"));
 		stream.next_out = compressed;
 		stream.avail_out = sizeof(compressed);
 	} while (ret == Z_OK);
@@ -1737,7 +1733,7 @@
 		die(_("confused by unstable object source data for %s"),
 		    oid_to_hex(oid));
 
-	close_sha1_file(fd);
+	close_loose_object(fd);
 
 	if (mtime) {
 		struct utimbuf utb;
@@ -1817,9 +1813,9 @@
 
 	if (has_loose_object(oid))
 		return 0;
-	buf = read_object(the_repository, oid->hash, &type, &len);
+	buf = read_object(the_repository, oid, &type, &len);
 	if (!buf)
-		return error(_("cannot read sha1_file for %s"), oid_to_hex(oid));
+		return error(_("cannot read object for %s"), oid_to_hex(oid));
 	hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX , type_name(type), (uintmax_t)len) + 1;
 	ret = write_loose_object(oid, hdr, hdrlen, buf, len, mtime);
 	free(buf);
@@ -1827,27 +1823,19 @@
 	return ret;
 }
 
-int repo_has_sha1_file_with_flags(struct repository *r,
-				  const unsigned char *sha1, int flags)
+int repo_has_object_file_with_flags(struct repository *r,
+				    const struct object_id *oid, int flags)
 {
-	struct object_id oid;
 	if (!startup_info->have_repository)
 		return 0;
-	hashcpy(oid.hash, sha1);
-	return oid_object_info_extended(r, &oid, NULL,
+	return oid_object_info_extended(r, oid, NULL,
 					flags | OBJECT_INFO_SKIP_CACHED) >= 0;
 }
 
 int repo_has_object_file(struct repository *r,
 			 const struct object_id *oid)
 {
-	return repo_has_sha1_file(r, oid->hash);
-}
-
-int repo_has_object_file_with_flags(struct repository *r,
-				    const struct object_id *oid, int flags)
-{
-	return repo_has_sha1_file_with_flags(r, oid->hash, flags);
+	return repo_has_object_file_with_flags(r, oid, 0);
 }
 
 static void check_tree(const void *buf, size_t size)
@@ -2258,14 +2246,14 @@
 	       sizeof(odb->loose_objects_subdir_seen));
 }
 
-static int check_stream_sha1(git_zstream *stream,
-			     const char *hdr,
-			     unsigned long size,
-			     const char *path,
-			     const unsigned char *expected_sha1)
+static int check_stream_oid(git_zstream *stream,
+			    const char *hdr,
+			    unsigned long size,
+			    const char *path,
+			    const struct object_id *expected_oid)
 {
 	git_hash_ctx c;
-	unsigned char real_sha1[GIT_MAX_RAWSZ];
+	struct object_id real_oid;
 	unsigned char buf[4096];
 	unsigned long total_read;
 	int status = Z_OK;
@@ -2281,7 +2269,7 @@
 
 	/*
 	 * This size comparison must be "<=" to read the final zlib packets;
-	 * see the comment in unpack_sha1_rest for details.
+	 * see the comment in unpack_loose_rest for details.
 	 */
 	while (total_read <= size &&
 	       (status == Z_OK ||
@@ -2297,19 +2285,19 @@
 	git_inflate_end(stream);
 
 	if (status != Z_STREAM_END) {
-		error(_("corrupt loose object '%s'"), sha1_to_hex(expected_sha1));
+		error(_("corrupt loose object '%s'"), oid_to_hex(expected_oid));
 		return -1;
 	}
 	if (stream->avail_in) {
 		error(_("garbage at end of loose object '%s'"),
-		      sha1_to_hex(expected_sha1));
+		      oid_to_hex(expected_oid));
 		return -1;
 	}
 
-	the_hash_algo->final_fn(real_sha1, &c);
-	if (!hasheq(expected_sha1, real_sha1)) {
-		error(_("sha1 mismatch for %s (expected %s)"), path,
-		      sha1_to_hex(expected_sha1));
+	the_hash_algo->final_fn(real_oid.hash, &c);
+	if (!oideq(expected_oid, &real_oid)) {
+		error(_("hash mismatch for %s (expected %s)"), path,
+		      oid_to_hex(expected_oid));
 		return -1;
 	}
 
@@ -2330,18 +2318,18 @@
 
 	*contents = NULL;
 
-	map = map_sha1_file_1(the_repository, path, NULL, &mapsize);
+	map = map_loose_object_1(the_repository, path, NULL, &mapsize);
 	if (!map) {
 		error_errno(_("unable to mmap %s"), path);
 		goto out;
 	}
 
-	if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) {
+	if (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) {
 		error(_("unable to unpack header of %s"), path);
 		goto out;
 	}
 
-	*type = parse_sha1_header(hdr, size);
+	*type = parse_loose_header(hdr, size);
 	if (*type < 0) {
 		error(_("unable to parse header of %s"), path);
 		git_inflate_end(&stream);
@@ -2349,10 +2337,10 @@
 	}
 
 	if (*type == OBJ_BLOB && *size > big_file_threshold) {
-		if (check_stream_sha1(&stream, hdr, *size, path, expected_oid->hash) < 0)
+		if (check_stream_oid(&stream, hdr, *size, path, expected_oid) < 0)
 			goto out;
 	} else {
-		*contents = unpack_sha1_rest(&stream, hdr, *size, expected_oid->hash);
+		*contents = unpack_loose_rest(&stream, hdr, *size, expected_oid);
 		if (!*contents) {
 			error(_("unable to unpack contents of %s"), path);
 			git_inflate_end(&stream);
@@ -2360,7 +2348,7 @@
 		}
 		if (check_object_signature(expected_oid, *contents,
 					 *size, type_name(*type))) {
-			error(_("sha1 mismatch for %s (expected %s)"), path,
+			error(_("hash mismatch for %s (expected %s)"), path,
 			      oid_to_hex(expected_oid));
 			free(*contents);
 			goto out;
diff --git a/sha1-name.c b/sha1-name.c
index a656481..d1cc77c 100644
--- a/sha1-name.c
+++ b/sha1-name.c
@@ -190,9 +190,6 @@
 		unique_in_pack(p, ds);
 }
 
-#define SHORT_NAME_NOT_FOUND (-1)
-#define SHORT_NAME_AMBIGUOUS (-2)
-
 static int finish_object_disambiguation(struct disambiguate_state *ds,
 					struct object_id *oid)
 {
@@ -200,7 +197,7 @@
 		return SHORT_NAME_AMBIGUOUS;
 
 	if (!ds->candidate_exists)
-		return SHORT_NAME_NOT_FOUND;
+		return MISSING_OBJECT;
 
 	if (!ds->candidate_checked)
 		/*
@@ -414,8 +411,9 @@
 	return a_type_sort > b_type_sort ? 1 : -1;
 }
 
-static int get_short_oid(const char *name, int len, struct object_id *oid,
-			  unsigned flags)
+static enum get_oid_result get_short_oid(const char *name, int len,
+					 struct object_id *oid,
+					 unsigned flags)
 {
 	int status;
 	struct disambiguate_state ds;
@@ -733,7 +731,7 @@
 	return at_mark(string, len, suffix, ARRAY_SIZE(suffix));
 }
 
-static int get_oid_1(const char *name, int len, struct object_id *oid, unsigned lookup_flags);
+static enum get_oid_result get_oid_1(const char *name, int len, struct object_id *oid, unsigned lookup_flags);
 static int interpret_nth_prior_checkout(const char *name, int namelen, struct strbuf *buf);
 
 static int get_oid_basic(const char *str, int len, struct object_id *oid,
@@ -883,11 +881,12 @@
 	return 0;
 }
 
-static int get_parent(const char *name, int len,
-		      struct object_id *result, int idx)
+static enum get_oid_result get_parent(const char *name, int len,
+				      struct object_id *result, int idx)
 {
 	struct object_id oid;
-	int ret = get_oid_1(name, len, &oid, GET_OID_COMMITTISH);
+	enum get_oid_result ret = get_oid_1(name, len, &oid,
+					    GET_OID_COMMITTISH);
 	struct commit *commit;
 	struct commit_list *p;
 
@@ -895,24 +894,25 @@
 		return ret;
 	commit = lookup_commit_reference(the_repository, &oid);
 	if (parse_commit(commit))
-		return -1;
+		return MISSING_OBJECT;
 	if (!idx) {
 		oidcpy(result, &commit->object.oid);
-		return 0;
+		return FOUND;
 	}
 	p = commit->parents;
 	while (p) {
 		if (!--idx) {
 			oidcpy(result, &p->item->object.oid);
-			return 0;
+			return FOUND;
 		}
 		p = p->next;
 	}
-	return -1;
+	return MISSING_OBJECT;
 }
 
-static int get_nth_ancestor(const char *name, int len,
-			    struct object_id *result, int generation)
+static enum get_oid_result get_nth_ancestor(const char *name, int len,
+					    struct object_id *result,
+					    int generation)
 {
 	struct object_id oid;
 	struct commit *commit;
@@ -923,15 +923,15 @@
 		return ret;
 	commit = lookup_commit_reference(the_repository, &oid);
 	if (!commit)
-		return -1;
+		return MISSING_OBJECT;
 
 	while (generation--) {
 		if (parse_commit(commit) || !commit->parents)
-			return -1;
+			return MISSING_OBJECT;
 		commit = commit->parents->item;
 	}
 	oidcpy(result, &commit->object.oid);
-	return 0;
+	return FOUND;
 }
 
 struct object *peel_to_type(const char *name, int namelen,
@@ -1077,7 +1077,9 @@
 	return -1;
 }
 
-static int get_oid_1(const char *name, int len, struct object_id *oid, unsigned lookup_flags)
+static enum get_oid_result get_oid_1(const char *name, int len,
+				     struct object_id *oid,
+				     unsigned lookup_flags)
 {
 	int ret, has_suffix;
 	const char *cp;
@@ -1111,16 +1113,16 @@
 
 	ret = peel_onion(name, len, oid, lookup_flags);
 	if (!ret)
-		return 0;
+		return FOUND;
 
 	ret = get_oid_basic(name, len, oid, lookup_flags);
 	if (!ret)
-		return 0;
+		return FOUND;
 
 	/* It could be describe output that is "SOMETHING-gXXXX" */
 	ret = get_describe_name(name, len, oid);
 	if (!ret)
-		return 0;
+		return FOUND;
 
 	return get_short_oid(name, len, oid, lookup_flags);
 }
@@ -1513,7 +1515,7 @@
 int get_oid(const char *name, struct object_id *oid)
 {
 	struct object_context unused;
-	return get_oid_with_context(name, 0, oid, &unused);
+	return get_oid_with_context(the_repository, name, 0, oid, &unused);
 }
 
 
@@ -1530,35 +1532,40 @@
 int get_oid_committish(const char *name, struct object_id *oid)
 {
 	struct object_context unused;
-	return get_oid_with_context(name, GET_OID_COMMITTISH,
+	return get_oid_with_context(the_repository,
+				    name, GET_OID_COMMITTISH,
 				    oid, &unused);
 }
 
 int get_oid_treeish(const char *name, struct object_id *oid)
 {
 	struct object_context unused;
-	return get_oid_with_context(name, GET_OID_TREEISH,
+	return get_oid_with_context(the_repository,
+				    name, GET_OID_TREEISH,
 				    oid, &unused);
 }
 
 int get_oid_commit(const char *name, struct object_id *oid)
 {
 	struct object_context unused;
-	return get_oid_with_context(name, GET_OID_COMMIT,
+	return get_oid_with_context(the_repository,
+				    name, GET_OID_COMMIT,
 				    oid, &unused);
 }
 
 int get_oid_tree(const char *name, struct object_id *oid)
 {
 	struct object_context unused;
-	return get_oid_with_context(name, GET_OID_TREE,
+	return get_oid_with_context(the_repository,
+				    name, GET_OID_TREE,
 				    oid, &unused);
 }
 
 int get_oid_blob(const char *name, struct object_id *oid)
 {
 	struct object_context unused;
-	return get_oid_with_context(name, GET_OID_BLOB,
+	return get_oid_with_context(the_repository,
+				    name, GET_OID_BLOB,
 				    oid, &unused);
 }
 
@@ -1597,7 +1604,8 @@
 }
 
 /* Must be called only when :stage:filename doesn't exist. */
-static void diagnose_invalid_index_path(int stage,
+static void diagnose_invalid_index_path(struct index_state *istate,
+					int stage,
 					const char *prefix,
 					const char *filename)
 {
@@ -1610,11 +1618,11 @@
 		prefix = "";
 
 	/* Wrong stage number? */
-	pos = cache_name_pos(filename, namelen);
+	pos = index_name_pos(istate, filename, namelen);
 	if (pos < 0)
 		pos = -pos - 1;
-	if (pos < active_nr) {
-		ce = active_cache[pos];
+	if (pos < istate->cache_nr) {
+		ce = istate->cache[pos];
 		if (ce_namelen(ce) == namelen &&
 		    !memcmp(ce->name, filename, namelen))
 			die("Path '%s' is in the index, but not at stage %d.\n"
@@ -1626,11 +1634,11 @@
 	/* Confusion between relative and absolute filenames? */
 	strbuf_addstr(&fullname, prefix);
 	strbuf_addstr(&fullname, filename);
-	pos = cache_name_pos(fullname.buf, fullname.len);
+	pos = index_name_pos(istate, fullname.buf, fullname.len);
 	if (pos < 0)
 		pos = -pos - 1;
-	if (pos < active_nr) {
-		ce = active_cache[pos];
+	if (pos < istate->cache_nr) {
+		ce = istate->cache[pos];
 		if (ce_namelen(ce) == fullname.len &&
 		    !memcmp(ce->name, fullname.buf, fullname.len))
 			die("Path '%s' is in the index, but not '%s'.\n"
@@ -1664,7 +1672,8 @@
 			   rel);
 }
 
-static int get_oid_with_context_1(const char *name,
+static enum get_oid_result get_oid_with_context_1(struct repository *repo,
+				  const char *name,
 				  unsigned flags,
 				  const char *prefix,
 				  struct object_id *oid,
@@ -1723,13 +1732,13 @@
 		if (flags & GET_OID_RECORD_PATH)
 			oc->path = xstrdup(cp);
 
-		if (!active_cache)
-			read_cache();
-		pos = cache_name_pos(cp, namelen);
+		if (!repo->index->cache)
+			repo_read_index(the_repository);
+		pos = index_name_pos(repo->index, cp, namelen);
 		if (pos < 0)
 			pos = -pos - 1;
-		while (pos < active_nr) {
-			ce = active_cache[pos];
+		while (pos < repo->index->cache_nr) {
+			ce = repo->index->cache[pos];
 			if (ce_namelen(ce) != namelen ||
 			    memcmp(ce->name, cp, namelen))
 				break;
@@ -1742,7 +1751,7 @@
 			pos++;
 		}
 		if (only_to_die && name[1] && name[1] != '/')
-			diagnose_invalid_index_path(stage, prefix, cp);
+			diagnose_invalid_index_path(repo->index, stage, prefix, cp);
 		free(new_path);
 		return -1;
 	}
@@ -1807,12 +1816,15 @@
 {
 	struct object_context oc;
 	struct object_id oid;
-	get_oid_with_context_1(name, GET_OID_ONLY_TO_DIE, prefix, &oid, &oc);
+	get_oid_with_context_1(the_repository, name, GET_OID_ONLY_TO_DIE,
+			       prefix, &oid, &oc);
 }
 
-int get_oid_with_context(const char *str, unsigned flags, struct object_id *oid, struct object_context *oc)
+int get_oid_with_context(struct repository *repo, const char *str,
+			 unsigned flags, struct object_id *oid,
+			 struct object_context *oc)
 {
 	if (flags & GET_OID_FOLLOW_SYMLINKS && flags & GET_OID_ONLY_TO_DIE)
 		BUG("incompatible flags for get_sha1_with_context");
-	return get_oid_with_context_1(str, flags, NULL, oid, oc);
+	return get_oid_with_context_1(repo, str, flags, NULL, oid, oc);
 }
diff --git a/streaming.c b/streaming.c
index 891f82f..fcd6303 100644
--- a/streaming.c
+++ b/streaming.c
@@ -338,16 +338,16 @@
 
 static open_method_decl(loose)
 {
-	st->u.loose.mapped = map_sha1_file(the_repository,
-					   oid->hash, &st->u.loose.mapsize);
+	st->u.loose.mapped = map_loose_object(the_repository,
+					      oid, &st->u.loose.mapsize);
 	if (!st->u.loose.mapped)
 		return -1;
-	if ((unpack_sha1_header(&st->z,
-				st->u.loose.mapped,
-				st->u.loose.mapsize,
-				st->u.loose.hdr,
-				sizeof(st->u.loose.hdr)) < 0) ||
-	    (parse_sha1_header(st->u.loose.hdr, &st->size) < 0)) {
+	if ((unpack_loose_header(&st->z,
+				 st->u.loose.mapped,
+				 st->u.loose.mapsize,
+				 st->u.loose.hdr,
+				 sizeof(st->u.loose.hdr)) < 0) ||
+	    (parse_loose_header(st->u.loose.hdr, &st->size) < 0)) {
 		git_inflate_end(&st->z);
 		munmap(st->u.loose.mapped, st->u.loose.mapsize);
 		return -1;
diff --git a/submodule.c b/submodule.c
index a5f2694..934ecfa 100644
--- a/submodule.c
+++ b/submodule.c
@@ -1,4 +1,3 @@
-#define NO_THE_INDEX_COMPATIBILITY_MACROS
 
 #include "cache.h"
 #include "repository.h"
diff --git a/t/.gitignore b/t/.gitignore
index 348715f..91cf577 100644
--- a/t/.gitignore
+++ b/t/.gitignore
@@ -2,3 +2,4 @@
 /test-results
 /.prove
 /chainlinttmp
+/out/
diff --git a/t/README b/t/README
index 25864ec..1326fd7 100644
--- a/t/README
+++ b/t/README
@@ -170,6 +170,15 @@
 	implied by other options like --valgrind and
 	GIT_TEST_INSTALLED.
 
+--no-bin-wrappers::
+	By default, the test suite uses the wrappers in
+	`../bin-wrappers/` to execute `git` and friends. With this option,
+	`../git` and friends are run directly. This is not recommended
+	in general, as the wrappers contain safeguards to ensure that no
+	files from an installed Git are used, but can speed up test runs
+	especially on platforms where running shell scripts is expensive
+	(most notably, Windows).
+
 --root=<directory>::
 	Create "trash" directories used to store all temporary data during
 	testing under <directory>, instead of the t/ directory.
@@ -358,6 +367,10 @@
 for the index version specified.  Can be set to any valid version
 (currently 2, 3, or 4).
 
+GIT_TEST_PACK_SPARSE=<boolean> if enabled will default the pack-objects
+builtin to use the sparse object walk. This can still be overridden by
+the --no-sparse command-line argument.
+
 GIT_TEST_PRELOAD_INDEX=<boolean> exercises the preload-index code path
 by overriding the minimum number of cache entries required per thread.
 
diff --git a/t/check-non-portable-shell.pl b/t/check-non-portable-shell.pl
index 8037eef..166d64d 100755
--- a/t/check-non-portable-shell.pl
+++ b/t/check-non-portable-shell.pl
@@ -36,7 +36,7 @@
 	}
 
 	/\bcp\s+-a/ and err 'cp -a is not portable';
-	/\bsed\s+-i/ and err 'sed -i is not portable';
+	/\bsed\s+-[^efn]\s+/ and err 'sed option not portable (use only -n, -e, -f)';
 	/\becho\s+-[neE]/ and err 'echo with option is not portable (use printf)';
 	/^\s*declare\s+/ and err 'arrays/declare not portable';
 	/^\s*[^#]\s*which\s/ and err 'which is not portable (use type)';
diff --git a/t/helper/test-date.c b/t/helper/test-date.c
index a083737..b325380 100644
--- a/t/helper/test-date.c
+++ b/t/helper/test-date.c
@@ -3,10 +3,12 @@
 
 static const char *usage_msg = "\n"
 "  test-tool date relative [time_t]...\n"
+"  test-tool date human [time_t]...\n"
 "  test-tool date show:<format> [time_t]...\n"
 "  test-tool date parse [date]...\n"
 "  test-tool date approxidate [date]...\n"
 "  test-tool date timestamp [date]...\n"
+"  test-tool date getnanos [start-nanos]\n"
 "  test-tool date is64bit\n"
 "  test-tool date time_t-is64bit\n";
 
@@ -16,12 +18,20 @@
 
 	for (; *argv; argv++) {
 		time_t t = atoi(*argv);
-		show_date_relative(t, 0, now, &buf);
+		show_date_relative(t, now, &buf);
 		printf("%s -> %s\n", *argv, buf.buf);
 	}
 	strbuf_release(&buf);
 }
 
+static void show_human_dates(const char **argv)
+{
+	for (; *argv; argv++) {
+		time_t t = atoi(*argv);
+		printf("%s -> %s\n", *argv, show_date(t, 0, DATE_MODE(HUMAN)));
+	}
+}
+
 static void show_dates(const char **argv, const char *format)
 {
 	struct date_mode mode;
@@ -82,12 +92,21 @@
 	}
 }
 
+static void getnanos(const char **argv)
+{
+	double seconds = getnanotime() / 1.0e9;
+
+	if (*argv)
+		seconds -= strtod(*argv, NULL);
+	printf("%lf\n", seconds);
+}
+
 int cmd__date(int argc, const char **argv)
 {
 	struct timeval now;
 	const char *x;
 
-	x = getenv("TEST_DATE_NOW");
+	x = getenv("GIT_TEST_DATE_NOW");
 	if (x) {
 		now.tv_sec = atoi(x);
 		now.tv_usec = 0;
@@ -100,6 +119,8 @@
 		usage(usage_msg);
 	if (!strcmp(*argv, "relative"))
 		show_relative_dates(argv+1, &now);
+	else if (!strcmp(*argv, "human"))
+		show_human_dates(argv+1);
 	else if (skip_prefix(*argv, "show:", &x))
 		show_dates(argv+1, x);
 	else if (!strcmp(*argv, "parse"))
@@ -108,6 +129,8 @@
 		parse_approxidate(argv+1, &now);
 	else if (!strcmp(*argv, "timestamp"))
 		parse_approx_timestamp(argv+1, &now);
+	else if (!strcmp(*argv, "getnanos"))
+		getnanos(argv+1);
 	else if (!strcmp(*argv, "is64bit"))
 		return sizeof(timestamp_t) == 8 ? 0 : 1;
 	else if (!strcmp(*argv, "time_t-is64bit"))
diff --git a/t/helper/test-dump-fsmonitor.c b/t/helper/test-dump-fsmonitor.c
index 08e3684..2786f47 100644
--- a/t/helper/test-dump-fsmonitor.c
+++ b/t/helper/test-dump-fsmonitor.c
@@ -3,11 +3,11 @@
 
 int cmd__dump_fsmonitor(int ac, const char **av)
 {
-	struct index_state *istate = &the_index;
+	struct index_state *istate = the_repository->index;
 	int i;
 
 	setup_git_directory();
-	if (do_read_index(istate, get_index_file(), 0) < 0)
+	if (do_read_index(istate, the_repository->index_file, 0) < 0)
 		die("unable to read index file");
 	if (!istate->fsmonitor_last_update) {
 		printf("no fsmonitor\n");
diff --git a/t/helper/test-dump-untracked-cache.c b/t/helper/test-dump-untracked-cache.c
index 52870eb..cf0f2c7 100644
--- a/t/helper/test-dump-untracked-cache.c
+++ b/t/helper/test-dump-untracked-cache.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "test-tool.h"
 #include "cache.h"
 #include "dir.h"
diff --git a/t/helper/test-path-utils.c b/t/helper/test-path-utils.c
index ae091d9..5d543ad 100644
--- a/t/helper/test-path-utils.c
+++ b/t/helper/test-path-utils.c
@@ -177,6 +177,14 @@
 	return is_hfs_dotgitmodules(path) || is_ntfs_dotgitmodules(path);
 }
 
+static int cmp_by_st_size(const void *a, const void *b)
+{
+	intptr_t x = (intptr_t)((struct string_list_item *)a)->util;
+	intptr_t y = (intptr_t)((struct string_list_item *)b)->util;
+
+	return x > y ? -1 : (x < y ? +1 : 0);
+}
+
 int cmd__path_utils(int argc, const char **argv)
 {
 	if (argc == 3 && !strcmp(argv[1], "normalize_path_copy")) {
@@ -291,6 +299,62 @@
 		return !!res;
 	}
 
+	if (argc > 2 && !strcmp(argv[1], "file-size")) {
+		int res = 0, i;
+		struct stat st;
+
+		for (i = 2; i < argc; i++)
+			if (stat(argv[i], &st))
+				res = error_errno("Cannot stat '%s'", argv[i]);
+			else
+				printf("%"PRIuMAX"\n", (uintmax_t)st.st_size);
+		return !!res;
+	}
+
+	if (argc == 4 && !strcmp(argv[1], "skip-n-bytes")) {
+		int fd = open(argv[2], O_RDONLY), offset = atoi(argv[3]);
+		char buffer[65536];
+
+		if (fd < 0)
+			die_errno("could not open '%s'", argv[2]);
+		if (lseek(fd, offset, SEEK_SET) < 0)
+			die_errno("could not skip %d bytes", offset);
+		for (;;) {
+			ssize_t count = read(fd, buffer, sizeof(buffer));
+			if (count < 0)
+				die_errno("could not read '%s'", argv[2]);
+			if (!count)
+				break;
+			if (write(1, buffer, count) < 0)
+				die_errno("could not write to stdout");
+		}
+		close(fd);
+		return 0;
+	}
+
+	if (argc > 5 && !strcmp(argv[1], "slice-tests")) {
+		int res = 0;
+		long offset, stride, i;
+		struct string_list list = STRING_LIST_INIT_NODUP;
+		struct stat st;
+
+		offset = strtol(argv[2], NULL, 10);
+		stride = strtol(argv[3], NULL, 10);
+		if (stride < 1)
+			stride = 1;
+		for (i = 4; i < argc; i++)
+			if (stat(argv[i], &st))
+				res = error_errno("Cannot stat '%s'", argv[i]);
+			else
+				string_list_append(&list, argv[i])->util =
+					(void *)(intptr_t)st.st_size;
+		QSORT(list.items, list.nr, cmp_by_st_size);
+		for (i = offset; i < list.nr; i+= stride)
+			printf("%s\n", list.items[i].string);
+
+		return !!res;
+	}
+
 	fprintf(stderr, "%s: unknown function name: %s\n", argv[0],
 		argv[1] ? argv[1] : "(there was none)");
 	return 1;
diff --git a/t/helper/test-ref-store.c b/t/helper/test-ref-store.c
index e9e0541..799fc00 100644
--- a/t/helper/test-ref-store.c
+++ b/t/helper/test-ref-store.c
@@ -233,7 +233,7 @@
 {
 	const char *msg = notnull(*argv++, "msg");
 	const char *refname = notnull(*argv++, "refname");
-	const char *new_sha1_buf = notnull(*argv++, "old-sha1");
+	const char *new_sha1_buf = notnull(*argv++, "new-sha1");
 	const char *old_sha1_buf = notnull(*argv++, "old-sha1");
 	unsigned int flags = arg_flags(*argv++, "flags");
 	struct object_id old_oid;
diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
index 5b13787..50c55f8 100644
--- a/t/helper/test-tool.c
+++ b/t/helper/test-tool.c
@@ -51,6 +51,7 @@
 	{ "submodule-nested-repo-config", cmd__submodule_nested_repo_config },
 	{ "subprocess", cmd__subprocess },
 	{ "urlmatch-normalization", cmd__urlmatch_normalization },
+	{ "xml-encode", cmd__xml_encode },
 	{ "wildmatch", cmd__wildmatch },
 #ifdef GIT_WINDOWS_NATIVE
 	{ "windows-named-pipe", cmd__windows_named_pipe },
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
index ca5c88e..a563df4 100644
--- a/t/helper/test-tool.h
+++ b/t/helper/test-tool.h
@@ -1,6 +1,7 @@
 #ifndef TEST_TOOL_H
 #define TEST_TOOL_H
 
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "git-compat-util.h"
 
 int cmd__chmtime(int argc, const char **argv);
@@ -47,6 +48,7 @@
 int cmd__submodule_nested_repo_config(int argc, const char **argv);
 int cmd__subprocess(int argc, const char **argv);
 int cmd__urlmatch_normalization(int argc, const char **argv);
+int cmd__xml_encode(int argc, const char **argv);
 int cmd__wildmatch(int argc, const char **argv);
 #ifdef GIT_WINDOWS_NATIVE
 int cmd__windows_named_pipe(int argc, const char **argv);
diff --git a/t/helper/test-xml-encode.c b/t/helper/test-xml-encode.c
new file mode 100644
index 0000000..a648bbd
--- /dev/null
+++ b/t/helper/test-xml-encode.c
@@ -0,0 +1,80 @@
+#include "test-tool.h"
+
+static const char *utf8_replace_character = "&#xfffd;";
+
+/*
+ * Encodes (possibly incorrect) UTF-8 on <stdin> to <stdout>, to be embedded
+ * in an XML file.
+ */
+int cmd__xml_encode(int argc, const char **argv)
+{
+	unsigned char buf[1024], tmp[4], *tmp2 = NULL;
+	ssize_t cur = 0, len = 1, remaining = 0;
+	unsigned char ch;
+
+	for (;;) {
+		if (++cur == len) {
+			len = xread(0, buf, sizeof(buf));
+			if (!len)
+				return 0;
+			if (len < 0)
+				die_errno("Could not read <stdin>");
+			cur = 0;
+		}
+		ch = buf[cur];
+
+		if (tmp2) {
+			if ((ch & 0xc0) != 0x80) {
+				fputs(utf8_replace_character, stdout);
+				tmp2 = NULL;
+				cur--;
+				continue;
+			}
+			*tmp2 = ch;
+			tmp2++;
+			if (--remaining == 0) {
+				fwrite(tmp, tmp2 - tmp, 1, stdout);
+				tmp2 = NULL;
+			}
+			continue;
+		}
+
+		if (!(ch & 0x80)) {
+			/* 0xxxxxxx */
+			if (ch == '&')
+				fputs("&amp;", stdout);
+			else if (ch == '\'')
+				fputs("&apos;", stdout);
+			else if (ch == '"')
+				fputs("&quot;", stdout);
+			else if (ch == '<')
+				fputs("&lt;", stdout);
+			else if (ch == '>')
+				fputs("&gt;", stdout);
+			else if (ch >= 0x20)
+				fputc(ch, stdout);
+			else if (ch == 0x09 || ch == 0x0a || ch == 0x0d)
+				fprintf(stdout, "&#x%02x;", ch);
+			else
+				fputs(utf8_replace_character, stdout);
+		} else if ((ch & 0xe0) == 0xc0) {
+			/* 110XXXXx 10xxxxxx */
+			tmp[0] = ch;
+			remaining = 1;
+			tmp2 = tmp + 1;
+		} else if ((ch & 0xf0) == 0xe0) {
+			/* 1110XXXX 10Xxxxxx 10xxxxxx */
+			tmp[0] = ch;
+			remaining = 2;
+			tmp2 = tmp + 1;
+		} else if ((ch & 0xf8) == 0xf0) {
+			/* 11110XXX 10XXxxxx 10xxxxxx 10xxxxxx */
+			tmp[0] = ch;
+			remaining = 3;
+			tmp2 = tmp + 1;
+		} else
+			fputs(utf8_replace_character, stdout);
+	}
+
+	return 0;
+}
diff --git a/t/lib-gpg.sh b/t/lib-gpg.sh
index f1277be..8d28652 100755
--- a/t/lib-gpg.sh
+++ b/t/lib-gpg.sh
@@ -63,8 +63,7 @@
 		cut -d" " -f4 |
 		tr -d '\n' >"${GNUPGHOME}/trustlist.txt" &&
 
-		echo " S relax" >> ${GNUPGHOME}/trustlist.txt &&
-		(gpgconf --kill gpg-agent >/dev/null 2>&1 || : ) &&
+		echo " S relax" >>"${GNUPGHOME}/trustlist.txt" &&
 		echo hello | gpgsm --homedir "${GNUPGHOME}" >/dev/null \
 			-u committer@example.com -o /dev/null --sign - 2>&1 &&
 		test_set_prereq GPGSM
diff --git a/t/t0003-attributes.sh b/t/t0003-attributes.sh
index 22499bc..71e63d8 100755
--- a/t/t0003-attributes.sh
+++ b/t/t0003-attributes.sh
@@ -322,4 +322,24 @@
 	)
 '
 
+test_expect_success 'binary macro expanded by -a' '
+	echo "file binary" >.gitattributes &&
+	cat >expect <<-\EOF &&
+	file: binary: set
+	file: diff: unset
+	file: merge: unset
+	file: text: unset
+	EOF
+	git check-attr -a file >actual &&
+	test_cmp expect actual
+'
+
+
+test_expect_success 'query binary macro directly' '
+	echo "file binary" >.gitattributes &&
+	echo file: binary: set >expect &&
+	git check-attr binary file >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t0006-date.sh b/t/t0006-date.sh
index ffb2975..d9fcc82 100755
--- a/t/t0006-date.sh
+++ b/t/t0006-date.sh
@@ -4,10 +4,10 @@
 . ./test-lib.sh
 
 # arbitrary reference time: 2009-08-30 19:20:00
-TEST_DATE_NOW=1251660000; export TEST_DATE_NOW
+GIT_TEST_DATE_NOW=1251660000; export GIT_TEST_DATE_NOW
 
 check_relative() {
-	t=$(($TEST_DATE_NOW - $1))
+	t=$(($GIT_TEST_DATE_NOW - $1))
 	echo "$t -> $2" >expect
 	test_expect_${3:-success} "relative date ($2)" "
 	test-tool date relative $t >actual &&
@@ -128,4 +128,22 @@
 check_approxidate '2008-12-01' '2008-12-01 19:20:00'
 check_approxidate '2009-12-01' '2009-12-01 19:20:00'
 
+check_date_format_human() {
+	t=$(($GIT_TEST_DATE_NOW - $1))
+	echo "$t -> $2" >expect
+	test_expect_success "human date $t" '
+		test-tool date human $t >actual &&
+		test_i18ncmp expect actual
+'
+}
+
+check_date_format_human 18000 "5 hours ago" # 5 hours ago
+check_date_format_human 432000 "Tue Aug 25 19:20" # 5 days ago
+check_date_format_human 1728000 "Mon Aug 10 19:20" # 3 weeks ago
+check_date_format_human 13000000 "Thu Apr 2 08:13" # 5 months ago
+check_date_format_human 31449600 "Aug 31 2008" # 12 months ago
+check_date_format_human 37500000 "Jun 22 2008" # 1 year, 2 months ago
+check_date_format_human 55188000 "Dec 1 2007" # 1 year, 9 months ago
+check_date_format_human 630000000 "Sep 13 1989" # 20 years ago
+
 test_done
diff --git a/t/t0021-conversion.sh b/t/t0021-conversion.sh
index fd5f1ac..e10f5f7 100755
--- a/t/t0021-conversion.sh
+++ b/t/t0021-conversion.sh
@@ -24,7 +24,7 @@
 }
 
 file_size () {
-	perl -e 'print -s $ARGV[0]' "$1"
+	test-tool path-utils file-size "$1"
 }
 
 filter_git () {
diff --git a/t/t0025-crlf-renormalize.sh b/t/t0025-crlf-renormalize.sh
index 9d9e02a..e13363a 100755
--- a/t/t0025-crlf-renormalize.sh
+++ b/t/t0025-crlf-renormalize.sh
@@ -27,4 +27,13 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'ignore-errors not mistaken for renormalize' '
+	git reset --hard &&
+	echo "*.txt text=auto" >.gitattributes &&
+	git ls-files --eol >expect &&
+	git add --ignore-errors "*.txt" &&
+	git ls-files --eol >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t0028-working-tree-encoding.sh b/t/t0028-working-tree-encoding.sh
index 7e87b5a..e58ecbf 100755
--- a/t/t0028-working-tree-encoding.sh
+++ b/t/t0028-working-tree-encoding.sh
@@ -11,9 +11,12 @@
 
 	text="hallo there!\ncan you read me?" &&
 	echo "*.utf16 text working-tree-encoding=utf-16" >.gitattributes &&
+	echo "*.utf16lebom text working-tree-encoding=UTF-16LE-BOM" >>.gitattributes &&
 	printf "$text" >test.utf8.raw &&
 	printf "$text" | iconv -f UTF-8 -t UTF-16 >test.utf16.raw &&
 	printf "$text" | iconv -f UTF-8 -t UTF-32 >test.utf32.raw &&
+	printf "\377\376"                         >test.utf16lebom.raw &&
+	printf "$text" | iconv -f UTF-8 -t UTF-32LE >>test.utf16lebom.raw &&
 
 	# Line ending tests
 	printf "one\ntwo\nthree\n" >lf.utf8.raw &&
@@ -32,7 +35,8 @@
 	# Add only UTF-16 file, we will add the UTF-32 file later
 	cp test.utf16.raw test.utf16 &&
 	cp test.utf32.raw test.utf32 &&
-	git add .gitattributes test.utf16 &&
+	cp test.utf16lebom.raw test.utf16lebom &&
+	git add .gitattributes test.utf16 test.utf16lebom &&
 	git commit -m initial
 '
 
@@ -51,6 +55,12 @@
 	test_cmp_bin test.utf16.raw test.utf16
 '
 
+test_expect_success 're-encode to UTF-16-LE-BOM on checkout' '
+	rm test.utf16lebom &&
+	git checkout test.utf16lebom &&
+	test_cmp_bin test.utf16lebom.raw test.utf16lebom
+'
+
 test_expect_success 'check $GIT_DIR/info/attributes support' '
 	test_when_finished "rm -f test.utf32.git" &&
 	test_when_finished "git reset --hard HEAD" &&
diff --git a/t/t0061-run-command.sh b/t/t0061-run-command.sh
index 99a614b..ebc4956 100755
--- a/t/t0061-run-command.sh
+++ b/t/t0061-run-command.sh
@@ -166,7 +166,8 @@
 	expect="$1"
 	shift
 	GIT_TRACE=1 test-tool run-command "$@" run-command true 2>&1 >/dev/null | \
-		sed -e 's/.* run_command: //' -e '/trace: .*/d' >actual &&
+		sed -e 's/.* run_command: //' -e '/trace: .*/d' \
+			-e '/RUNTIME_PREFIX requested/d' >actual &&
 	echo "$expect true" >expect &&
 	test_cmp expect actual
 }
@@ -199,4 +200,14 @@
 	)
 '
 
+test_expect_success MINGW 'verify curlies are quoted properly' '
+	: force the rev-parse through the MSYS2 Bash &&
+	git -c alias.r="!git rev-parse" r -- a{b}c >actual &&
+	cat >expect <<-\EOF &&
+	--
+	a{b}c
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t1050-large.sh b/t/t1050-large.sh
index 1a9b21b..dcb4dbb 100755
--- a/t/t1050-large.sh
+++ b/t/t1050-large.sh
@@ -8,7 +8,7 @@
 # This should be moved to test-lib.sh together with the
 # copy in t0021 after both topics have graduated to 'master'.
 file_size () {
-	perl -e 'print -s $ARGV[0]' "$1"
+	test-tool path-utils file-size "$1"
 }
 
 test_expect_success setup '
diff --git a/t/t1450-fsck.sh b/t/t1450-fsck.sh
index 2e5e979..c61f972 100755
--- a/t/t1450-fsck.sh
+++ b/t/t1450-fsck.sh
@@ -406,7 +406,7 @@
 
 	test_might_fail git rev-list --verify-objects refs/heads/bogus >/dev/null 2>out &&
 	cat out &&
-	test_i18ngrep -q "error: sha1 mismatch 63ffffffffffffffffffffffffffffffffffffff" out
+	test_i18ngrep -q "error: hash mismatch 63ffffffffffffffffffffffffffffffffffffff" out
 '
 
 test_expect_success 'force fsck to ignore double author' '
diff --git a/t/t1512-rev-parse-disambiguation.sh b/t/t1512-rev-parse-disambiguation.sh
index e4d5b56..c19fb50 100755
--- a/t/t1512-rev-parse-disambiguation.sh
+++ b/t/t1512-rev-parse-disambiguation.sh
@@ -388,4 +388,14 @@
 	done
 '
 
+test_expect_success 'cat-file --batch and --batch-check show ambiguous' '
+	echo "0000 ambiguous" >expect &&
+	echo 0000 | git cat-file --batch-check >actual 2>err &&
+	test_cmp expect actual &&
+	test_i18ngrep hint: err &&
+	echo 0000 | git cat-file --batch >actual 2>err &&
+	test_cmp expect actual &&
+	test_i18ngrep hint: err
+'
+
 test_done
diff --git a/t/t2018-checkout-branch.sh b/t/t2018-checkout-branch.sh
index 2131fb2..c5014ad 100755
--- a/t/t2018-checkout-branch.sh
+++ b/t/t2018-checkout-branch.sh
@@ -198,4 +198,13 @@
 	test_dirty_mergeable
 '
 
+test_expect_success 'checkout -b after clone --no-checkout does a checkout of HEAD' '
+	git init src &&
+	test_commit -C src a &&
+	rev="$(git -C src rev-parse HEAD)" &&
+	git clone --no-checkout src dest &&
+	git -C dest checkout "$rev" -b branch &&
+	test_path_is_file dest/a.t
+'
+
 test_done
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 7a440e0..52fa41c 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -147,6 +147,25 @@
 	git rebase --continue
 '
 
+test_expect_success 'rebase -x with empty command fails' '
+	test_when_finished "git rebase --abort ||:" &&
+	test_must_fail git rebase -x "" @ 2>actual &&
+	test_write_lines "error: empty exec command" >expected &&
+	test_i18ncmp expected actual &&
+	test_must_fail git rebase -x " " @ 2>actual &&
+	test_i18ncmp expected actual
+'
+
+LF='
+'
+test_expect_success 'rebase -x with newline in command fails' '
+	test_when_finished "git rebase --abort ||:" &&
+	test_must_fail git rebase -x "a${LF}b" @ 2>actual &&
+	test_write_lines "error: exec commands cannot contain newlines" \
+			 >expected &&
+	test_i18ncmp expected actual
+'
+
 test_expect_success 'rebase -i with exec of inexistent command' '
 	git checkout master &&
 	test_when_finished "git rebase --abort" &&
@@ -156,6 +175,11 @@
 	! grep "Maybe git-rebase is broken" actual
 '
 
+test_expect_success 'implicit interactive rebase does not invoke sequence editor' '
+	test_when_finished "git rebase --abort ||:" &&
+	GIT_SEQUENCE_EDITOR="echo bad >" git rebase -x"echo one" @^
+'
+
 test_expect_success 'no changes are a nop' '
 	git checkout branch2 &&
 	set_fake_editor &&
diff --git a/t/t3406-rebase-message.sh b/t/t3406-rebase-message.sh
index f64b130..b393e1e 100755
--- a/t/t3406-rebase-message.sh
+++ b/t/t3406-rebase-message.sh
@@ -17,14 +17,9 @@
 	git tag start
 '
 
-cat >expect <<\EOF
-Already applied: 0001 A
-Already applied: 0002 B
-Committed: 0003 Z
-EOF
-
 test_expect_success 'rebase -m' '
 	git rebase -m master >report &&
+	>expect &&
 	sed -n -e "/^Already applied: /p" \
 		-e "/^Committed: /p" report >actual &&
 	test_cmp expect actual
diff --git a/t/t3420-rebase-autostash.sh b/t/t3420-rebase-autostash.sh
index 4c7494c..2d1094e 100755
--- a/t/t3420-rebase-autostash.sh
+++ b/t/t3420-rebase-autostash.sh
@@ -53,41 +53,6 @@
 	EOF
 }
 
-create_expected_success_merge () {
-	cat >expected <<-EOF
-	$(grep "^Created autostash: [0-9a-f][0-9a-f]*\$" actual)
-	HEAD is now at $(git rev-parse --short feature-branch) third commit
-	First, rewinding head to replay your work on top of it...
-	Merging unrelated-onto-branch with HEAD~1
-	Merging:
-	$(git rev-parse --short unrelated-onto-branch) unrelated commit
-	$(git rev-parse --short feature-branch^) second commit
-	found 1 common ancestor:
-	$(git rev-parse --short feature-branch~2) initial commit
-	[detached HEAD $(git rev-parse --short rebased-feature-branch~1)] second commit
-	 Author: A U Thor <author@example.com>
-	 Date: Thu Apr 7 15:14:13 2005 -0700
-	 2 files changed, 2 insertions(+)
-	 create mode 100644 file1
-	 create mode 100644 file2
-	Committed: 0001 second commit
-	Merging unrelated-onto-branch with HEAD~0
-	Merging:
-	$(git rev-parse --short rebased-feature-branch~1) second commit
-	$(git rev-parse --short feature-branch) third commit
-	found 1 common ancestor:
-	$(git rev-parse --short feature-branch~1) second commit
-	[detached HEAD $(git rev-parse --short rebased-feature-branch)] third commit
-	 Author: A U Thor <author@example.com>
-	 Date: Thu Apr 7 15:15:13 2005 -0700
-	 1 file changed, 1 insertion(+)
-	 create mode 100644 file3
-	Committed: 0002 third commit
-	All done.
-	Applied autostash.
-	EOF
-}
-
 create_expected_failure_am () {
 	cat >expected <<-EOF
 	$(grep "^Created autostash: [0-9a-f][0-9a-f]*\$" actual)
@@ -112,43 +77,6 @@
 	EOF
 }
 
-create_expected_failure_merge () {
-	cat >expected <<-EOF
-	$(grep "^Created autostash: [0-9a-f][0-9a-f]*\$" actual)
-	HEAD is now at $(git rev-parse --short feature-branch) third commit
-	First, rewinding head to replay your work on top of it...
-	Merging unrelated-onto-branch with HEAD~1
-	Merging:
-	$(git rev-parse --short unrelated-onto-branch) unrelated commit
-	$(git rev-parse --short feature-branch^) second commit
-	found 1 common ancestor:
-	$(git rev-parse --short feature-branch~2) initial commit
-	[detached HEAD $(git rev-parse --short rebased-feature-branch~1)] second commit
-	 Author: A U Thor <author@example.com>
-	 Date: Thu Apr 7 15:14:13 2005 -0700
-	 2 files changed, 2 insertions(+)
-	 create mode 100644 file1
-	 create mode 100644 file2
-	Committed: 0001 second commit
-	Merging unrelated-onto-branch with HEAD~0
-	Merging:
-	$(git rev-parse --short rebased-feature-branch~1) second commit
-	$(git rev-parse --short feature-branch) third commit
-	found 1 common ancestor:
-	$(git rev-parse --short feature-branch~1) second commit
-	[detached HEAD $(git rev-parse --short rebased-feature-branch)] third commit
-	 Author: A U Thor <author@example.com>
-	 Date: Thu Apr 7 15:15:13 2005 -0700
-	 1 file changed, 1 insertion(+)
-	 create mode 100644 file3
-	Committed: 0002 third commit
-	All done.
-	Applying autostash resulted in conflicts.
-	Your changes are safe in the stash.
-	You can run "git stash pop" or "git stash drop" at any time.
-	EOF
-}
-
 testrebase () {
 	type=$1
 	dotest=$2
@@ -177,6 +105,9 @@
 	test_expect_success "rebase$type --autostash: check output" '
 		test_when_finished git branch -D rebased-feature-branch &&
 		suffix=${type#\ --} && suffix=${suffix:-am} &&
+		if test ${suffix} = "merge"; then
+			suffix=interactive
+		fi &&
 		create_expected_success_$suffix &&
 		test_i18ncmp expected actual
 	'
@@ -274,6 +205,9 @@
 	test_expect_success "rebase$type: check output with conflicting stash" '
 		test_when_finished git branch -D rebased-feature-branch &&
 		suffix=${type#\ --} && suffix=${suffix:-am} &&
+		if test ${suffix} = "merge"; then
+			suffix=interactive
+		fi &&
 		create_expected_failure_$suffix &&
 		test_i18ncmp expected actual
 	'
diff --git a/t/t3421-rebase-topology-linear.sh b/t/t3421-rebase-topology-linear.sh
index 23ad4cf..7274dca 100755
--- a/t/t3421-rebase-topology-linear.sh
+++ b/t/t3421-rebase-topology-linear.sh
@@ -111,7 +111,7 @@
 	"
 }
 test_run_rebase success ''
-test_run_rebase failure -m
+test_run_rebase success -m
 test_run_rebase success -i
 test_have_prereq !REBASE_P || test_run_rebase success -p
 
@@ -126,7 +126,7 @@
 	"
 }
 test_run_rebase success ''
-test_run_rebase failure -m
+test_run_rebase success -m
 test_run_rebase success -i
 test_have_prereq !REBASE_P || test_run_rebase success -p
 
@@ -141,7 +141,7 @@
 	"
 }
 test_run_rebase success ''
-test_run_rebase failure -m
+test_run_rebase success -m
 test_run_rebase success -i
 test_have_prereq !REBASE_P || test_run_rebase success -p
 
@@ -284,7 +284,7 @@
 	"
 }
 test_run_rebase success ''
-test_run_rebase failure -m
+test_run_rebase success -m
 test_run_rebase success -i
 test_have_prereq !REBASE_P || test_run_rebase success -p
 
@@ -315,7 +315,7 @@
 	"
 }
 test_run_rebase success ''
-test_run_rebase failure -m
+test_run_rebase success -m
 test_run_rebase success -i
 test_have_prereq !REBASE_P || test_run_rebase failure -p
 
diff --git a/t/t3425-rebase-topology-merges.sh b/t/t3425-rebase-topology-merges.sh
index 5f892e3..fd8efe8 100755
--- a/t/t3425-rebase-topology-merges.sh
+++ b/t/t3425-rebase-topology-merges.sh
@@ -70,9 +70,8 @@
 		test_linear_range "\'"$expected"\'" d..
 	"
 }
-#TODO: make order consistent across all flavors of rebase
-test_run_rebase success 'e n o' ''
-test_run_rebase success 'e n o' -m
+test_run_rebase success 'n o e' ''
+test_run_rebase success 'n o e' -m
 test_run_rebase success 'n o e' -i
 
 test_run_rebase () {
@@ -87,9 +86,8 @@
 		test_linear_range "\'"$expected"\'" c..
 	"
 }
-#TODO: make order consistent across all flavors of rebase
-test_run_rebase success 'd e n o' ''
-test_run_rebase success 'd e n o' -m
+test_run_rebase success 'd n o e' ''
+test_run_rebase success 'd n o e' -m
 test_run_rebase success 'd n o e' -i
 
 test_run_rebase () {
@@ -104,9 +102,8 @@
 		test_linear_range "\'"$expected"\'" c..
 	"
 }
-#TODO: make order consistent across all flavors of rebase
-test_run_rebase success 'd e n o' ''
-test_run_rebase success 'd e n o' -m
+test_run_rebase success 'd n o e' ''
+test_run_rebase success 'd n o e' -m
 test_run_rebase success 'd n o e' -i
 
 if ! test_have_prereq REBASE_P; then
diff --git a/t/t3430-rebase-merges.sh b/t/t3430-rebase-merges.sh
index cc56468..4c69255 100755
--- a/t/t3430-rebase-merges.sh
+++ b/t/t3430-rebase-merges.sh
@@ -125,7 +125,7 @@
 	: >dont-overwrite-untracked.t &&
 	echo "reset refs/tags/dont-overwrite-untracked" >script-from-scratch &&
 	test_config sequence.editor \""$PWD"/replace-editor.sh\" &&
-	test_must_fail git rebase -r HEAD &&
+	test_must_fail git rebase -ir HEAD &&
 	git rebase --abort
 '
 
diff --git a/t/t3700-add.sh b/t/t3700-add.sh
index 37729ba..be582a5 100755
--- a/t/t3700-add.sh
+++ b/t/t3700-add.sh
@@ -402,4 +402,11 @@
 	test $(git ls-files --stage | grep ^100755 | wc -l) -eq 0
 '
 
+test_expect_success CASE_INSENSITIVE_FS 'path is case-insensitive' '
+	path="$(pwd)/BLUB" &&
+	touch "$path" &&
+	downcased="$(echo "$path" | tr A-Z a-z)" &&
+	git add "$downcased"
+'
+
 test_done
diff --git a/t/t4006-diff-mode.sh b/t/t4006-diff-mode.sh
index a8e01ec..03489af 100755
--- a/t/t4006-diff-mode.sh
+++ b/t/t4006-diff-mode.sh
@@ -32,28 +32,37 @@
 	git commit -m binbin
 '
 
-# test_expect_success '--stat output after text chmod' '
-# 	test_chmod -x rezrov &&
-# 	echo " 0 files changed" >expect &&
-# 	git diff HEAD --stat >actual &&
-#	test_i18ncmp expect actual
-# '
-#
-# test_expect_success '--shortstat output after text chmod' '
-# 	git diff HEAD --shortstat >actual &&
-# 	test_i18ncmp expect actual
-# '
-#
-# test_expect_success '--stat output after binary chmod' '
-# 	test_chmod +x binbin &&
-# 	echo " 0 files changed" >expect &&
-# 	git diff HEAD --stat >actual &&
-# 	test_i18ncmp expect actual
-# '
-#
-# test_expect_success '--shortstat output after binary chmod' '
-# 	git diff HEAD --shortstat >actual &&
-# 	test_i18ncmp expect actual
-# '
+test_expect_success '--stat output after text chmod' '
+	test_chmod -x rezrov &&
+	cat >expect <<-\EOF &&
+	 rezrov | 0
+	 1 file changed, 0 insertions(+), 0 deletions(-)
+	EOF
+	git diff HEAD --stat >actual &&
+	test_i18ncmp expect actual
+'
+
+test_expect_success '--shortstat output after text chmod' '
+	tail -n 1 <expect >expect.short &&
+	git diff HEAD --shortstat >actual &&
+	test_i18ncmp expect.short actual
+'
+
+test_expect_success '--stat output after binary chmod' '
+	test_chmod +x binbin &&
+	cat >expect <<-EOF &&
+	 binbin | Bin
+	 rezrov |   0
+	 2 files changed, 0 insertions(+), 0 deletions(-)
+	EOF
+	git diff HEAD --stat >actual &&
+	test_i18ncmp expect actual
+'
+
+test_expect_success '--shortstat output after binary chmod' '
+	tail -n 1 <expect >expect.short &&
+	git diff HEAD --shortstat >actual &&
+	test_i18ncmp expect.short actual
+'
 
 test_done
diff --git a/t/t4013-diff-various.sh b/t/t4013-diff-various.sh
index 7d985ff..9f8f0e8 100755
--- a/t/t4013-diff-various.sh
+++ b/t/t4013-diff-various.sh
@@ -98,6 +98,12 @@
 	git commit -m "update mode" &&
 	git checkout -f master &&
 
+	# Same merge as master, but with parents reversed. Hide it in a
+	# pseudo-ref to avoid impacting tests with --all.
+	commit=$(echo reverse |
+		 git commit-tree -p master^2 -p master^1 master^{tree}) &&
+	git update-ref REVERSE $commit &&
+
 	git config diff.renames false &&
 
 	git show-branch
@@ -239,6 +245,8 @@
 # stat summary should show the diffstat and summary with the first parent
 diff-tree -c --stat --summary side
 diff-tree --cc --stat --summary side
+diff-tree --cc --shortstat master
+diff-tree --cc --summary REVERSE
 # improved by Timo's patch
 diff-tree --cc --patch-with-stat master
 # improved by Timo's patch
@@ -350,6 +358,7 @@
 diff --dirstat master~1 master~2
 diff --dirstat initial rearrange
 diff --dirstat-by-file initial rearrange
+diff --dirstat --cc master~1 master
 # No-index --abbrev and --no-abbrev
 diff --raw initial
 :noellipses diff --raw initial
diff --git a/t/t4013/diff.diff-tree_--cc_--shortstat_master b/t/t4013/diff.diff-tree_--cc_--shortstat_master
new file mode 100644
index 0000000..a4ca42d
--- /dev/null
+++ b/t/t4013/diff.diff-tree_--cc_--shortstat_master
@@ -0,0 +1,4 @@
+$ git diff-tree --cc --shortstat master
+59d314ad6f356dd08601a4cd5e530381da3e3c64
+ 2 files changed, 5 insertions(+)
+$
diff --git a/t/t4013/diff.diff-tree_--cc_--summary_REVERSE b/t/t4013/diff.diff-tree_--cc_--summary_REVERSE
new file mode 100644
index 0000000..e208dd5
--- /dev/null
+++ b/t/t4013/diff.diff-tree_--cc_--summary_REVERSE
@@ -0,0 +1,6 @@
+$ git diff-tree --cc --summary REVERSE
+2562325a7ee916efb2481da93073b82cec801cbc
+ create mode 100644 file1
+ delete mode 100644 file2
+ delete mode 100644 file3
+$
diff --git a/t/t4013/diff.diff_--dirstat_--cc_master~1_master b/t/t4013/diff.diff_--dirstat_--cc_master~1_master
new file mode 100644
index 0000000..fba4e34
--- /dev/null
+++ b/t/t4013/diff.diff_--dirstat_--cc_master~1_master
@@ -0,0 +1,3 @@
+$ git diff --dirstat --cc master~1 master
+  40.0% dir/
+$
diff --git a/t/t4066-diff-emit-delay.sh b/t/t4066-diff-emit-delay.sh
new file mode 100755
index 0000000..5df6b5e
--- /dev/null
+++ b/t/t4066-diff-emit-delay.sh
@@ -0,0 +1,79 @@
+#!/bin/sh
+
+test_description='test combined/stat/moved interaction'
+. ./test-lib.sh
+
+# This test covers a weird 3-way interaction between "--cc -p", which will run
+# the combined diff code, along with "--stat", which will be computed as a
+# first-parent stat during the combined diff, and "--color-moved", which
+# enables the emitted_symbols list to store the diff in memory.
+
+test_expect_success 'set up history with a merge' '
+	test_commit A &&
+	test_commit B &&
+	git checkout -b side HEAD^ &&
+	test_commit C &&
+	git merge -m M master &&
+	test_commit D
+'
+
+test_expect_success 'log --cc -p --stat --color-moved' '
+	cat >expect <<-\EOF &&
+	commit D
+	---
+	 D.t | 1 +
+	 1 file changed, 1 insertion(+)
+
+	diff --git a/D.t b/D.t
+	new file mode 100644
+	index 0000000..1784810
+	--- /dev/null
+	+++ b/D.t
+	@@ -0,0 +1 @@
+	+D
+	commit M
+
+	 B.t | 1 +
+	 1 file changed, 1 insertion(+)
+	commit C
+	---
+	 C.t | 1 +
+	 1 file changed, 1 insertion(+)
+
+	diff --git a/C.t b/C.t
+	new file mode 100644
+	index 0000000..3cc58df
+	--- /dev/null
+	+++ b/C.t
+	@@ -0,0 +1 @@
+	+C
+	commit B
+	---
+	 B.t | 1 +
+	 1 file changed, 1 insertion(+)
+
+	diff --git a/B.t b/B.t
+	new file mode 100644
+	index 0000000..223b783
+	--- /dev/null
+	+++ b/B.t
+	@@ -0,0 +1 @@
+	+B
+	commit A
+	---
+	 A.t | 1 +
+	 1 file changed, 1 insertion(+)
+
+	diff --git a/A.t b/A.t
+	new file mode 100644
+	index 0000000..f70f10e
+	--- /dev/null
+	+++ b/A.t
+	@@ -0,0 +1 @@
+	+A
+	EOF
+	git log --format="commit %s" --cc -p --stat --color-moved >actual &&
+	test_cmp expect actual
+'
+
+test_done
diff --git a/t/t5315-pack-objects-compression.sh b/t/t5315-pack-objects-compression.sh
index 34c47da..df970d7 100755
--- a/t/t5315-pack-objects-compression.sh
+++ b/t/t5315-pack-objects-compression.sh
@@ -7,7 +7,7 @@
 # This should be moved to test-lib.sh together with the
 # copy in t0021 after both topics have graduated to 'master'.
 file_size () {
-	perl -e 'print -s $ARGV[0]' "$1"
+	test-tool path-utils file-size "$1"
 }
 
 test_expect_success setup '
diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
index 694f260..16d10eb 100755
--- a/t/t5318-commit-graph.sh
+++ b/t/t5318-commit-graph.sh
@@ -122,7 +122,7 @@
 	cd "$TRASH_DIRECTORY/full" &&
 	git commit-graph write &&
 	test_path_is_file $objdir/info/commit-graph &&
-	graph_read_expect "10" "large_edges"
+	graph_read_expect "10" "extra_edges"
 '
 
 graph_git_behavior 'merge 1 vs 2' full merge/1 merge/2
@@ -157,7 +157,7 @@
 	cd "$TRASH_DIRECTORY/full" &&
 	git commit-graph write &&
 	test_path_is_file $objdir/info/commit-graph &&
-	graph_read_expect "11" "large_edges"
+	graph_read_expect "11" "extra_edges"
 '
 
 graph_git_behavior 'full graph, commit 8 vs merge 1' full commits/8 merge/1
@@ -167,7 +167,7 @@
 	cd "$TRASH_DIRECTORY/full" &&
 	git commit-graph write &&
 	test_path_is_file $objdir/info/commit-graph &&
-	graph_read_expect "11" "large_edges"
+	graph_read_expect "11" "extra_edges"
 '
 
 graph_git_behavior 'cleared graph, commit 8 vs merge 1' full commits/8 merge/1
@@ -177,7 +177,7 @@
 	cd "$TRASH_DIRECTORY/full" &&
 	cat new-idx | git commit-graph write --stdin-packs &&
 	test_path_is_file $objdir/info/commit-graph &&
-	graph_read_expect "9" "large_edges"
+	graph_read_expect "9" "extra_edges"
 '
 
 graph_git_behavior 'graph from pack, commit 8 vs merge 1' full commits/8 merge/1
@@ -200,7 +200,7 @@
 	cd "$TRASH_DIRECTORY/full" &&
 	git rev-parse merge/3 | git commit-graph write --stdin-commits --append &&
 	test_path_is_file $objdir/info/commit-graph &&
-	graph_read_expect "10" "large_edges"
+	graph_read_expect "10" "extra_edges"
 '
 
 graph_git_behavior 'append graph, commit 8 vs merge 1' full commits/8 merge/1
@@ -210,7 +210,7 @@
 	cd "$TRASH_DIRECTORY/full" &&
 	git commit-graph write --reachable &&
 	test_path_is_file $objdir/info/commit-graph &&
-	graph_read_expect "11" "large_edges"
+	graph_read_expect "11" "extra_edges"
 '
 
 graph_git_behavior 'append graph, commit 8 vs merge 1' full commits/8 merge/1
@@ -231,7 +231,7 @@
 	cd "$TRASH_DIRECTORY/bare" &&
 	git commit-graph write &&
 	test_path_is_file $baredir/info/commit-graph &&
-	graph_read_expect "11" "large_edges"
+	graph_read_expect "11" "extra_edges"
 '
 
 graph_git_behavior 'bare repo with graph, commit 8 vs merge 1' bare commits/8 merge/1
diff --git a/t/t5322-pack-objects-sparse.sh b/t/t5322-pack-objects-sparse.sh
new file mode 100755
index 0000000..7124b55
--- /dev/null
+++ b/t/t5322-pack-objects-sparse.sh
@@ -0,0 +1,136 @@
+#!/bin/sh
+
+test_description='pack-objects object selection using sparse algorithm'
+. ./test-lib.sh
+
+test_expect_success 'setup repo' '
+	test_commit initial &&
+	for i in $(test_seq 1 3)
+	do
+		mkdir f$i &&
+		for j in $(test_seq 1 3)
+		do
+			mkdir f$i/f$j &&
+			echo $j >f$i/f$j/data.txt
+		done
+	done &&
+	git add . &&
+	git commit -m "Initialized trees" &&
+	for i in $(test_seq 1 3)
+	do
+		git checkout -b topic$i master &&
+		echo change-$i >f$i/f$i/data.txt &&
+		git commit -a -m "Changed f$i/f$i/data.txt"
+	done &&
+	cat >packinput.txt <<-EOF &&
+	topic1
+	^topic2
+	^topic3
+	EOF
+	git rev-parse			\
+		topic1			\
+		topic1^{tree}		\
+		topic1:f1		\
+		topic1:f1/f1		\
+		topic1:f1/f1/data.txt | sort >expect_objects.txt
+'
+
+test_expect_success 'non-sparse pack-objects' '
+	git pack-objects --stdout --revs --no-sparse <packinput.txt >nonsparse.pack &&
+	git index-pack -o nonsparse.idx nonsparse.pack &&
+	git show-index <nonsparse.idx | awk "{print \$2}" >nonsparse_objects.txt &&
+	test_cmp expect_objects.txt nonsparse_objects.txt
+'
+
+test_expect_success 'sparse pack-objects' '
+	git pack-objects --stdout --revs --sparse <packinput.txt >sparse.pack &&
+	git index-pack -o sparse.idx sparse.pack &&
+	git show-index <sparse.idx | awk "{print \$2}" >sparse_objects.txt &&
+	test_cmp expect_objects.txt sparse_objects.txt
+'
+
+test_expect_success 'duplicate a folder from f3 and commit to topic1' '
+	git checkout topic1 &&
+	echo change-3 >f3/f3/data.txt &&
+	git commit -a -m "Changed f3/f3/data.txt" &&
+	git rev-parse			\
+		topic1~1		\
+		topic1~1^{tree}		\
+		topic1^{tree}		\
+		topic1			\
+		topic1:f1		\
+		topic1:f1/f1		\
+		topic1:f1/f1/data.txt | sort >required_objects.txt
+'
+
+test_expect_success 'non-sparse pack-objects' '
+	git pack-objects --stdout --revs --no-sparse <packinput.txt >nonsparse.pack &&
+	git index-pack -o nonsparse.idx nonsparse.pack &&
+	git show-index <nonsparse.idx | awk "{print \$2}" >nonsparse_objects.txt &&
+	comm -1 -2 required_objects.txt nonsparse_objects.txt >nonsparse_required_objects.txt &&
+	test_cmp required_objects.txt nonsparse_required_objects.txt
+'
+
+test_expect_success 'sparse pack-objects' '
+	git pack-objects --stdout --revs --sparse <packinput.txt >sparse.pack &&
+	git index-pack -o sparse.idx sparse.pack &&
+	git show-index <sparse.idx | awk "{print \$2}" >sparse_objects.txt &&
+	comm -1 -2 required_objects.txt sparse_objects.txt >sparse_required_objects.txt &&
+	test_cmp required_objects.txt sparse_required_objects.txt
+'
+
+# Demonstrate that the algorithms differ when we copy a tree wholesale
+# from one folder to another.
+
+test_expect_success 'duplicate a folder from f1 into f3' '
+	mkdir f3/f4 &&
+	cp -r f1/f1/* f3/f4 &&
+	git add f3/f4 &&
+	git commit -m "Copied f1/f1 to f3/f4" &&
+	cat >packinput.txt <<-EOF &&
+	topic1
+	^topic1~1
+	EOF
+	git rev-parse		\
+		topic1		\
+		topic1^{tree}   \
+		topic1:f3 | sort >required_objects.txt
+'
+
+test_expect_success 'non-sparse pack-objects' '
+	git pack-objects --stdout --revs --no-sparse <packinput.txt >nonsparse.pack &&
+	git index-pack -o nonsparse.idx nonsparse.pack &&
+	git show-index <nonsparse.idx | awk "{print \$2}" >nonsparse_objects.txt &&
+	comm -1 -2 required_objects.txt nonsparse_objects.txt >nonsparse_required_objects.txt &&
+	test_cmp required_objects.txt nonsparse_required_objects.txt
+'
+
+test_expect_success 'sparse pack-objects' '
+	git rev-parse			\
+		topic1			\
+		topic1^{tree}		\
+		topic1:f3		\
+		topic1:f3/f4		\
+		topic1:f3/f4/data.txt | sort >expect_sparse_objects.txt &&
+	git pack-objects --stdout --revs --sparse <packinput.txt >sparse.pack &&
+	git index-pack -o sparse.idx sparse.pack &&
+	git show-index <sparse.idx | awk "{print \$2}" >sparse_objects.txt &&
+	test_cmp expect_sparse_objects.txt sparse_objects.txt
+'
+
+test_expect_success 'pack.useSparse enables algorithm' '
+	git config pack.useSparse true &&
+	git pack-objects --stdout --revs <packinput.txt >sparse.pack &&
+	git index-pack -o sparse.idx sparse.pack &&
+	git show-index <sparse.idx | awk "{print \$2}" >sparse_objects.txt &&
+	test_cmp expect_sparse_objects.txt sparse_objects.txt
+'
+
+test_expect_success 'pack.useSparse overridden' '
+	git pack-objects --stdout --revs --no-sparse <packinput.txt >sparse.pack &&
+	git index-pack -o sparse.idx sparse.pack &&
+	git show-index <sparse.idx | awk "{print \$2}" >sparse_objects.txt &&
+	test_cmp required_objects.txt sparse_objects.txt
+'
+
+test_done
diff --git a/t/t5403-post-checkout-hook.sh b/t/t5403-post-checkout-hook.sh
index a539ffc..a39b3b5 100755
--- a/t/t5403-post-checkout-hook.sh
+++ b/t/t5403-post-checkout-hook.sh
@@ -67,7 +67,7 @@
 test_expect_success 'post-checkout hook is triggered by clone' '
 	mkdir -p templates/hooks &&
 	write_script templates/hooks/post-checkout <<-\EOF &&
-	echo "$@" >$GIT_DIR/post-checkout.args
+	echo "$@" >"$GIT_DIR/post-checkout.args"
 	EOF
 	git clone --template=templates . clone3 &&
 	test -f clone3/.git/post-checkout.args
diff --git a/t/t5407-post-rewrite-hook.sh b/t/t5407-post-rewrite-hook.sh
index 9b2a274..a4a5903 100755
--- a/t/t5407-post-rewrite-hook.sh
+++ b/t/t5407-post-rewrite-hook.sh
@@ -78,6 +78,7 @@
 	git rebase --continue &&
 	echo rebase >expected.args &&
 	cat >expected.data <<-EOF &&
+	$(git rev-parse C) $(git rev-parse HEAD^)
 	$(git rev-parse D) $(git rev-parse HEAD)
 	EOF
 	verify_hook_input
@@ -91,6 +92,7 @@
 	echo rebase >expected.args &&
 	cat >expected.data <<-EOF &&
 	$(git rev-parse E) $(git rev-parse HEAD)
+	$(git rev-parse F) $(git rev-parse HEAD)
 	EOF
 	verify_hook_input
 '
@@ -120,6 +122,38 @@
 	git rebase --continue &&
 	echo rebase >expected.args &&
 	cat >expected.data <<-EOF &&
+	$(git rev-parse C) $(git rev-parse HEAD^)
+	$(git rev-parse D) $(git rev-parse HEAD)
+	EOF
+	verify_hook_input
+'
+
+test_expect_success 'git rebase with implicit use of interactive backend' '
+	git reset --hard D &&
+	clear_hook_input &&
+	test_must_fail git rebase --keep --onto A B &&
+	echo C > foo &&
+	git add foo &&
+	git rebase --continue &&
+	echo rebase >expected.args &&
+	cat >expected.data <<-EOF &&
+	$(git rev-parse C) $(git rev-parse HEAD^)
+	$(git rev-parse D) $(git rev-parse HEAD)
+	EOF
+	verify_hook_input
+'
+
+test_expect_success 'git rebase --skip with implicit use of interactive backend' '
+	git reset --hard D &&
+	clear_hook_input &&
+	test_must_fail git rebase --keep --onto A B &&
+	test_must_fail git rebase --skip &&
+	echo D > foo &&
+	git add foo &&
+	git rebase --continue &&
+	echo rebase >expected.args &&
+	cat >expected.data <<-EOF &&
+	$(git rev-parse C) $(git rev-parse HEAD^)
 	$(git rev-parse D) $(git rev-parse HEAD)
 	EOF
 	verify_hook_input
diff --git a/t/t5580-clone-push-unc.sh b/t/t5580-clone-push-unc.sh
index ba548df..217adf3 100755
--- a/t/t5580-clone-push-unc.sh
+++ b/t/t5580-clone-push-unc.sh
@@ -40,6 +40,11 @@
 	git clone "file://$UNCPATH" clone
 '
 
+test_expect_success 'clone with backslashed path' '
+	BACKSLASHED="$(echo "$UNCPATH" | tr / \\\\)" &&
+	git clone "$BACKSLASHED" backslashed
+'
+
 test_expect_success push '
 	(
 		cd clone &&
diff --git a/t/t5702-protocol-v2.sh b/t/t5702-protocol-v2.sh
index 7ca1aab..db4ae09 100755
--- a/t/t5702-protocol-v2.sh
+++ b/t/t5702-protocol-v2.sh
@@ -561,6 +561,27 @@
 	grep "git< version 2" log
 '
 
+test_expect_success 'fetch from namespaced repo respects namespaces' '
+	test_when_finished "rm -f log" &&
+
+	git init "$HTTPD_DOCUMENT_ROOT_PATH/nsrepo" &&
+	test_commit -C "$HTTPD_DOCUMENT_ROOT_PATH/nsrepo" one &&
+	test_commit -C "$HTTPD_DOCUMENT_ROOT_PATH/nsrepo" two &&
+	git -C "$HTTPD_DOCUMENT_ROOT_PATH/nsrepo" \
+		update-ref refs/namespaces/ns/refs/heads/master one &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -C http_child -c protocol.version=2 \
+		fetch "$HTTPD_URL/smart_namespace/nsrepo" \
+		refs/heads/master:refs/heads/theirs &&
+
+	# Server responded using protocol v2
+	grep "fetch< version 2" log &&
+
+	git -C "$HTTPD_DOCUMENT_ROOT_PATH/nsrepo" rev-parse one >expect &&
+	git -C http_child rev-parse theirs >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'push with http:// and a config of v2 does not request v2' '
 	test_when_finished "rm -f log" &&
 	# Till v2 for push is designed, make sure that if a client has
diff --git a/t/t6030-bisect-porcelain.sh b/t/t6030-bisect-porcelain.sh
index f84ff94..55835ee 100755
--- a/t/t6030-bisect-porcelain.sh
+++ b/t/t6030-bisect-porcelain.sh
@@ -802,7 +802,7 @@
 	test_must_fail git bisect terms only-one &&
 	test_must_fail git bisect terms 1 2 &&
 	test_must_fail git bisect terms 2>actual &&
-	echo "no terms defined" >expected &&
+	echo "error: no terms defined" >expected &&
 	test_i18ncmp expected actual
 '
 
diff --git a/t/t6042-merge-rename-corner-cases.sh b/t/t6042-merge-rename-corner-cases.sh
index 7cc34e7..09dfa8b 100755
--- a/t/t6042-merge-rename-corner-cases.sh
+++ b/t/t6042-merge-rename-corner-cases.sh
@@ -1175,7 +1175,7 @@
 
 		# Handle the left side
 		git checkout L &&
-		git mv one three &&
+		git rm one two &&
 		mv -f file_v2 three &&
 		mv -f file_v5 two &&
 		git add two three &&
@@ -1183,7 +1183,7 @@
 
 		# Handle the right side
 		git checkout R &&
-		git mv two three &&
+		git rm one two &&
 		mv -f file_v3 one &&
 		mv -f file_v6 three &&
 		git add one three &&
diff --git a/t/t6120-describe.sh b/t/t6120-describe.sh
index d639d94..ee5b03e 100755
--- a/t/t6120-describe.sh
+++ b/t/t6120-describe.sh
@@ -143,16 +143,46 @@
 test_expect_success 'pack tag refs' 'git pack-refs'
 check_describe A-* HEAD
 
+test_expect_success 'describe works from outside repo using --git-dir' '
+	git clone --bare "$TRASH_DIRECTORY" "$TRASH_DIRECTORY/bare" &&
+	git --git-dir "$TRASH_DIRECTORY/bare" describe >out &&
+	grep "^A-[1-9][0-9]\?-g[0-9a-f]\+$" out
+'
+
 check_describe "A-*[0-9a-f]" --dirty
 
+test_expect_success 'describe --dirty with --work-tree' '
+	(
+		cd "$TEST_DIRECTORY" &&
+		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --dirty >"$TRASH_DIRECTORY/out"
+	) &&
+	grep "^A-[1-9][0-9]\?-g[0-9a-f]\+$" out
+'
+
 test_expect_success 'set-up dirty work tree' '
 	echo >>file
 '
 
 check_describe "A-*[0-9a-f]-dirty" --dirty
 
+test_expect_success 'describe --dirty with --work-tree (dirty)' '
+	(
+		cd "$TEST_DIRECTORY" &&
+		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --dirty >"$TRASH_DIRECTORY/out"
+	) &&
+	grep "^A-[1-9][0-9]\?-g[0-9a-f]\+-dirty$" out
+'
+
 check_describe "A-*[0-9a-f].mod" --dirty=.mod
 
+test_expect_success 'describe --dirty=.mod with --work-tree (dirty)' '
+	(
+		cd "$TEST_DIRECTORY" &&
+		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --dirty=.mod >"$TRASH_DIRECTORY/out"
+	) &&
+	grep "^A-[1-9][0-9]\?-g[0-9a-f]\+.mod$" out
+'
+
 test_expect_success 'describe --dirty HEAD' '
 	test_must_fail git describe --dirty HEAD
 '
@@ -303,8 +333,17 @@
 	mv .git/modules/sub1/ .git/modules/sub_moved &&
 	test_must_fail git describe --dirty
 '
+
 test_expect_success 'describe ignoring a broken submodule' '
 	git describe --broken >out &&
+	grep broken out
+'
+
+test_expect_success 'describe with --work-tree ignoring a broken submodule' '
+	(
+		cd "$TEST_DIRECTORY" &&
+		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --broken >"$TRASH_DIRECTORY/out"
+	) &&
 	test_when_finished "mv .git/modules/sub_moved .git/modules/sub1" &&
 	grep broken out
 '
diff --git a/t/t7505-prepare-commit-msg-hook.sh b/t/t7505-prepare-commit-msg-hook.sh
index ebfcad9..ba8bd1b 100755
--- a/t/t7505-prepare-commit-msg-hook.sh
+++ b/t/t7505-prepare-commit-msg-hook.sh
@@ -215,7 +215,7 @@
 test_rebase () {
 	expect=$1 &&
 	mode=$2 &&
-	test_expect_$expect C_LOCALE_OUTPUT "with hook (rebase $mode)" '
+	test_expect_$expect C_LOCALE_OUTPUT "with hook (rebase ${mode:--i})" '
 		test_when_finished "\
 			git rebase --abort
 			git checkout -f master
@@ -225,7 +225,7 @@
 		GIT_EDITOR="\"$FAKE_EDITOR\"" &&
 		(
 			export GIT_SEQUENCE_EDITOR GIT_EDITOR &&
-			test_must_fail git rebase $mode b &&
+			test_must_fail git rebase -i $mode b &&
 			echo x >a &&
 			git add a &&
 			test_must_fail git rebase --continue &&
@@ -241,18 +241,18 @@
 			git add b &&
 			git rebase --continue
 		) &&
-		if test $mode = -p # reword amended after pick
+		if test "$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$mode" actual
+		test_cmp "$TEST_DIRECTORY/t7505/expected-rebase${mode:--i}" actual
 	'
 }
 
-test_rebase success -i
+test_rebase success
 test_have_prereq !REBASE_P || test_rebase success -p
 
 test_expect_success 'with hook (cherry-pick)' '
diff --git a/t/t7510-signed-commit.sh b/t/t7510-signed-commit.sh
index 86d3f93..682b23a 100755
--- a/t/t7510-signed-commit.sh
+++ b/t/t7510-signed-commit.sh
@@ -49,15 +49,28 @@
 	git tag eighth-signed-alt &&
 
 	# commit.gpgsign is still on but this must not be signed
-	git tag ninth-unsigned $(echo 9 | git commit-tree HEAD^{tree}) &&
+	echo 9 | git commit-tree HEAD^{tree} >oid &&
+	test_line_count = 1 oid &&
+	git tag ninth-unsigned $(cat oid) &&
 	# explicit -S of course must sign.
-	git tag tenth-signed $(echo 9 | git commit-tree -S HEAD^{tree})
+	echo 10 | git commit-tree -S HEAD^{tree} >oid &&
+	test_line_count = 1 oid &&
+	git tag tenth-signed $(cat oid) &&
+
+	# --gpg-sign[=<key-id>] must sign.
+	echo 11 | git commit-tree --gpg-sign HEAD^{tree} >oid &&
+	test_line_count = 1 oid &&
+	git tag eleventh-signed $(cat oid) &&
+	echo 12 | git commit-tree --gpg-sign=B7227189 HEAD^{tree} >oid &&
+	test_line_count = 1 oid &&
+	git tag twelfth-signed-alt $(cat oid)
 '
 
 test_expect_success GPG 'verify and show signatures' '
 	(
 		for commit in initial second merge fourth-signed \
-			fifth-signed sixth-signed seventh-signed tenth-signed
+			fifth-signed sixth-signed seventh-signed tenth-signed \
+			eleventh-signed
 		do
 			git verify-commit $commit &&
 			git show --pretty=short --show-signature $commit >actual &&
@@ -78,7 +91,7 @@
 		done
 	) &&
 	(
-		for commit in eighth-signed-alt
+		for commit in eighth-signed-alt twelfth-signed-alt
 		do
 			git show --pretty=short --show-signature $commit >actual &&
 			grep "Good signature from" actual &&
diff --git a/t/t9303-fast-import-compression.sh b/t/t9303-fast-import-compression.sh
index 856219f..5045f02 100755
--- a/t/t9303-fast-import-compression.sh
+++ b/t/t9303-fast-import-compression.sh
@@ -6,7 +6,7 @@
 # This should be moved to test-lib.sh together with the
 # copy in t0021 after both topics have graduated to 'master'.
 file_size () {
-	perl -e 'print -s $ARGV[0]' "$1"
+	test-tool path-utils file-size "$1"
 }
 
 import_large () {
diff --git a/t/t9903-bash-prompt.sh b/t/t9903-bash-prompt.sh
index 81a5179..5cadedb 100755
--- a/t/t9903-bash-prompt.sh
+++ b/t/t9903-bash-prompt.sh
@@ -180,7 +180,7 @@
 '
 
 test_expect_success 'prompt - rebase merge' '
-	printf " (b2|REBASE-m 1/3)" >expected &&
+	printf " (b2|REBASE-i 1/3)" >expected &&
 	git checkout b2 &&
 	test_when_finished "git checkout master" &&
 	test_must_fail git rebase --merge b1 b2 &&
diff --git a/t/test-lib.sh b/t/test-lib.sh
index a1abb11..42b1a0a 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -111,6 +111,8 @@
 		test -z "$HARNESS_ACTIVE" && quiet=t ;;
 	--with-dashes)
 		with_dashes=t ;;
+	--no-bin-wrappers)
+		no_bin_wrappers=t ;;
 	--no-color)
 		color= ;;
 	--va|--val|--valg|--valgr|--valgri|--valgrin|--valgrind)
@@ -139,6 +141,9 @@
 		verbose_log=t
 		tee=t
 		;;
+	--write-junit-xml)
+		write_junit_xml=t
+		;;
 	--stress)
 		stress=t ;;
 	--stress=*)
@@ -622,11 +627,35 @@
 # the test_expect_* functions instead.
 
 test_ok_ () {
+	if test -n "$write_junit_xml"
+	then
+		write_junit_xml_testcase "$*"
+	fi
 	test_success=$(($test_success + 1))
 	say_color "" "ok $test_count - $@"
 }
 
 test_failure_ () {
+	if test -n "$write_junit_xml"
+	then
+		junit_insert="<failure message=\"not ok $test_count -"
+		junit_insert="$junit_insert $(xml_attr_encode "$1")\">"
+		junit_insert="$junit_insert $(xml_attr_encode \
+			"$(if test -n "$GIT_TEST_TEE_OUTPUT_FILE"
+			   then
+				test-tool path-utils skip-n-bytes \
+					"$GIT_TEST_TEE_OUTPUT_FILE" $GIT_TEST_TEE_OFFSET
+			   else
+				printf '%s\n' "$@" | sed 1d
+			   fi)")"
+		junit_insert="$junit_insert</failure>"
+		if test -n "$GIT_TEST_TEE_OUTPUT_FILE"
+		then
+			junit_insert="$junit_insert<system-err>$(xml_attr_encode \
+				"$(cat "$GIT_TEST_TEE_OUTPUT_FILE")")</system-err>"
+		fi
+		write_junit_xml_testcase "$1" "      $junit_insert"
+	fi
 	test_failure=$(($test_failure + 1))
 	say_color error "not ok $test_count - $1"
 	shift
@@ -635,11 +664,19 @@
 }
 
 test_known_broken_ok_ () {
+	if test -n "$write_junit_xml"
+	then
+		write_junit_xml_testcase "$* (breakage fixed)"
+	fi
 	test_fixed=$(($test_fixed+1))
 	say_color error "ok $test_count - $@ # TODO known breakage vanished"
 }
 
 test_known_broken_failure_ () {
+	if test -n "$write_junit_xml"
+	then
+		write_junit_xml_testcase "$* (known breakage)"
+	fi
 	test_broken=$(($test_broken+1))
 	say_color warn "not ok $test_count - $@ # TODO known breakage"
 }
@@ -897,12 +934,21 @@
 	test_count=$(($test_count+1))
 	maybe_setup_verbose
 	maybe_setup_valgrind
+	if test -n "$write_junit_xml"
+	then
+		junit_start=$(test-tool date getnanos)
+	fi
 }
 
 test_finish_ () {
 	echo >&3 ""
 	maybe_teardown_valgrind
 	maybe_teardown_verbose
+	if test -n "$GIT_TEST_TEE_OFFSET"
+	then
+		GIT_TEST_TEE_OFFSET=$(test-tool path-utils file-size \
+			"$GIT_TEST_TEE_OUTPUT_FILE")
+	fi
 }
 
 test_skip () {
@@ -934,6 +980,13 @@
 
 	case "$to_skip" in
 	t)
+		if test -n "$write_junit_xml"
+		then
+			message="$(xml_attr_encode "$skipped_reason")"
+			write_junit_xml_testcase "$1" \
+				"      <skipped message=\"$message\" />"
+		fi
+
 		say_color skip >&3 "skipping test: $@"
 		say_color skip "ok $test_count # skip $1 ($skipped_reason)"
 		: true
@@ -949,9 +1002,51 @@
 	:
 }
 
+write_junit_xml () {
+	case "$1" in
+	--truncate)
+		>"$junit_xml_path"
+		junit_have_testcase=
+		shift
+		;;
+	esac
+	printf '%s\n' "$@" >>"$junit_xml_path"
+}
+
+xml_attr_encode () {
+	printf '%s\n' "$@" | test-tool xml-encode
+}
+
+write_junit_xml_testcase () {
+	junit_attrs="name=\"$(xml_attr_encode "$this_test.$test_count $1")\""
+	shift
+	junit_attrs="$junit_attrs classname=\"$this_test\""
+	junit_attrs="$junit_attrs time=\"$(test-tool \
+		date getnanos $junit_start)\""
+	write_junit_xml "$(printf '%s\n' \
+		"    <testcase $junit_attrs>" "$@" "    </testcase>")"
+	junit_have_testcase=t
+}
+
 test_done () {
 	GIT_EXIT_OK=t
 
+	if test -n "$write_junit_xml" && test -n "$junit_xml_path"
+	then
+		test -n "$junit_have_testcase" || {
+			junit_start=$(test-tool date getnanos)
+			write_junit_xml_testcase "all tests skipped"
+		}
+
+		# adjust the overall time
+		junit_time=$(test-tool date getnanos $junit_suite_start)
+		sed "s/<testsuite [^>]*/& time=\"$junit_time\"/" \
+			<"$junit_xml_path" >"$junit_xml_path.new"
+		mv "$junit_xml_path.new" "$junit_xml_path"
+
+		write_junit_xml "  </testsuite>" "</testsuites>"
+	fi
+
 	if test -z "$HARNESS_ACTIVE"
 	then
 		mkdir -p "$TEST_RESULTS_DIR"
@@ -1011,7 +1106,11 @@
 			error "Tests passed but trash directory already removed before test cleanup; aborting"
 
 			cd "$TRASH_DIRECTORY/.." &&
-			rm -fr "$TRASH_DIRECTORY" ||
+			rm -fr "$TRASH_DIRECTORY" || {
+				# try again in a bit
+				sleep 5;
+				rm -fr "$TRASH_DIRECTORY"
+			} ||
 			error "Tests passed but test cleanup failed; aborting"
 		fi
 		test_at_end_hook_
@@ -1117,20 +1216,25 @@
 	PATH=$GIT_TEST_INSTALLED:$GIT_BUILD_DIR/t/helper:$PATH
 	GIT_EXEC_PATH=${GIT_TEST_EXEC_PATH:-$GIT_EXEC_PATH}
 else # normal case, use ../bin-wrappers only unless $with_dashes:
-	git_bin_dir="$GIT_BUILD_DIR/bin-wrappers"
-	if ! test -x "$git_bin_dir/git"
+	if test -n "$no_bin_wrappers"
 	then
-		if test -z "$with_dashes"
-		then
-			say "$git_bin_dir/git is not executable; using GIT_EXEC_PATH"
-		fi
 		with_dashes=t
+	else
+		git_bin_dir="$GIT_BUILD_DIR/bin-wrappers"
+		if ! test -x "$git_bin_dir/git"
+		then
+			if test -z "$with_dashes"
+			then
+				say "$git_bin_dir/git is not executable; using GIT_EXEC_PATH"
+			fi
+			with_dashes=t
+		fi
+		PATH="$git_bin_dir:$PATH"
 	fi
-	PATH="$git_bin_dir:$PATH"
 	GIT_EXEC_PATH=$GIT_BUILD_DIR
 	if test -n "$with_dashes"
 	then
-		PATH="$GIT_BUILD_DIR:$PATH"
+		PATH="$GIT_BUILD_DIR:$GIT_BUILD_DIR/t/helper:$PATH"
 	fi
 fi
 GIT_TEMPLATE_DIR="$GIT_BUILD_DIR"/templates/blt
@@ -1154,7 +1258,7 @@
 	error "You haven't built things yet, have you?"
 }
 
-if ! test -x "$GIT_BUILD_DIR"/t/helper/test-tool
+if ! test -x "$GIT_BUILD_DIR"/t/helper/test-tool$X
 then
 	echo >&2 'You need to build test-tool:'
 	echo >&2 'Run "make t/helper/test-tool" in the source (toplevel) directory'
@@ -1178,6 +1282,7 @@
 else
 	mkdir -p "$TRASH_DIRECTORY"
 fi
+
 # Use -P to resolve symlinks in our working directory so that the cwd
 # in subprocesses like git equals our $PWD (for pathname comparisons).
 cd -P "$TRASH_DIRECTORY" || exit 1
@@ -1191,6 +1296,23 @@
 	test_done
 fi
 
+if test -n "$write_junit_xml"
+then
+	junit_xml_dir="$TEST_OUTPUT_DIRECTORY/out"
+	mkdir -p "$junit_xml_dir"
+	junit_xml_base=${0##*/}
+	junit_xml_path="$junit_xml_dir/TEST-${junit_xml_base%.sh}.xml"
+	junit_attrs="name=\"${junit_xml_base%.sh}\""
+	junit_attrs="$junit_attrs timestamp=\"$(TZ=UTC \
+		date +%Y-%m-%dT%H:%M:%S)\""
+	write_junit_xml --truncate "<testsuites>" "  <testsuite $junit_attrs>"
+	junit_suite_start=$(test-tool date getnanos)
+	if test -n "$GIT_TEST_TEE_OUTPUT_FILE"
+	then
+		GIT_TEST_TEE_OFFSET=0
+	fi
+fi
+
 # Provide an implementation of the 'yes' utility
 yes () {
 	if test $# = 0
diff --git a/tree-walk.c b/tree-walk.c
index 277e3b3..1e4bbc8 100644
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -582,10 +582,10 @@
  * with the sha1 of the found object, and *mode will hold the mode of
  * the object.
  *
- * See the code for enum follow_symlink_result for a description of
+ * See the code for enum get_oid_result for a description of
  * the return values.
  */
-enum follow_symlinks_result get_tree_entry_follow_symlinks(struct object_id *tree_oid, const char *name, struct object_id *result, struct strbuf *result_path, unsigned *mode)
+enum get_oid_result get_tree_entry_follow_symlinks(struct object_id *tree_oid, const char *name, struct object_id *result, struct strbuf *result_path, unsigned *mode)
 {
 	int retval = MISSING_OBJECT;
 	struct dir_state *parents = NULL;
diff --git a/tree-walk.h b/tree-walk.h
index a4ad28e..8225171 100644
--- a/tree-walk.h
+++ b/tree-walk.h
@@ -51,23 +51,7 @@
 typedef int (*traverse_callback_t)(int n, unsigned long mask, unsigned long dirmask, struct name_entry *entry, struct traverse_info *);
 int traverse_trees(struct index_state *istate, int n, struct tree_desc *t, struct traverse_info *info);
 
-enum follow_symlinks_result {
-	FOUND = 0, /* This includes out-of-tree links */
-	MISSING_OBJECT = -1, /* The initial symlink is missing */
-	DANGLING_SYMLINK = -2, /*
-				* The initial symlink is there, but
-				* (transitively) points to a missing
-				* in-tree file
-				*/
-	SYMLINK_LOOP = -3,
-	NOT_DIR = -4, /*
-		       * Somewhere along the symlink chain, a path is
-		       * requested which contains a file as a
-		       * non-final element.
-		       */
-};
-
-enum follow_symlinks_result get_tree_entry_follow_symlinks(struct object_id *tree_oid, const char *name, struct object_id *result, struct strbuf *result_path, unsigned *mode);
+enum get_oid_result get_tree_entry_follow_symlinks(struct object_id *tree_oid, const char *name, struct object_id *result, struct strbuf *result_path, unsigned *mode);
 
 struct traverse_info {
 	const char *traverse_path;
diff --git a/tree.c b/tree.c
index 9f0457c..f416afc 100644
--- a/tree.c
+++ b/tree.c
@@ -1,4 +1,3 @@
-#define NO_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "cache-tree.h"
 #include "tree.h"
diff --git a/unpack-trees.c b/unpack-trees.c
index 01c2175..3563daa 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -1,4 +1,3 @@
-#define NO_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "argv-array.h"
 #include "repository.h"
diff --git a/utf8.c b/utf8.c
index eb78587..83824dc 100644
--- a/utf8.c
+++ b/utf8.c
@@ -4,6 +4,11 @@
 
 /* This code is originally from http://www.cl.cam.ac.uk/~mgk25/ucs/ */
 
+static const char utf16_be_bom[] = {'\xFE', '\xFF'};
+static const char utf16_le_bom[] = {'\xFF', '\xFE'};
+static const char utf32_be_bom[] = {'\0', '\0', '\xFE', '\xFF'};
+static const char utf32_le_bom[] = {'\xFF', '\xFE', '\0', '\0'};
+
 struct interval {
 	ucs_char_t first;
 	ucs_char_t last;
@@ -470,16 +475,17 @@
 #else
 	typedef char * iconv_ibp;
 #endif
-char *reencode_string_iconv(const char *in, size_t insz, iconv_t conv, size_t *outsz_p)
+char *reencode_string_iconv(const char *in, size_t insz, iconv_t conv,
+			    size_t bom_len, size_t *outsz_p)
 {
 	size_t outsz, outalloc;
 	char *out, *outpos;
 	iconv_ibp cp;
 
 	outsz = insz;
-	outalloc = st_add(outsz, 1); /* for terminating NUL */
+	outalloc = st_add(outsz, 1 + bom_len); /* for terminating NUL */
 	out = xmalloc(outalloc);
-	outpos = out;
+	outpos = out + bom_len;
 	cp = (iconv_ibp)in;
 
 	while (1) {
@@ -540,10 +546,30 @@
 {
 	iconv_t conv;
 	char *out;
+	const char *bom_str = NULL;
+	size_t bom_len = 0;
 
 	if (!in_encoding)
 		return NULL;
 
+	/* UTF-16LE-BOM is the same as UTF-16 for reading */
+	if (same_utf_encoding("UTF-16LE-BOM", in_encoding))
+		in_encoding = "UTF-16";
+
+	/*
+	 * For writing, UTF-16 iconv typically creates "UTF-16BE-BOM"
+	 * Some users under Windows want the little endian version
+	 */
+	if (same_utf_encoding("UTF-16LE-BOM", out_encoding)) {
+		bom_str = utf16_le_bom;
+		bom_len = sizeof(utf16_le_bom);
+		out_encoding = "UTF-16LE";
+	} else if (same_utf_encoding("UTF-16BE-BOM", out_encoding)) {
+		bom_str = utf16_be_bom;
+		bom_len = sizeof(utf16_be_bom);
+		out_encoding = "UTF-16BE";
+	}
+
 	conv = iconv_open(out_encoding, in_encoding);
 	if (conv == (iconv_t) -1) {
 		in_encoding = fallback_encoding(in_encoding);
@@ -553,9 +579,10 @@
 		if (conv == (iconv_t) -1)
 			return NULL;
 	}
-
-	out = reencode_string_iconv(in, insz, conv, outsz);
+	out = reencode_string_iconv(in, insz, conv, bom_len, outsz);
 	iconv_close(conv);
+	if (out && bom_str && bom_len)
+		memcpy(out, bom_str, bom_len);
 	return out;
 }
 #endif
@@ -566,11 +593,6 @@
 	return data && bom && (len >= bom_len) && !memcmp(data, bom, bom_len);
 }
 
-static const char utf16_be_bom[] = {'\xFE', '\xFF'};
-static const char utf16_le_bom[] = {'\xFF', '\xFE'};
-static const char utf32_be_bom[] = {'\0', '\0', '\xFE', '\xFF'};
-static const char utf32_le_bom[] = {'\xFF', '\xFE', '\0', '\0'};
-
 int has_prohibited_utf_bom(const char *enc, const char *data, size_t len)
 {
 	return (
diff --git a/utf8.h b/utf8.h
index edea55e..84efbfc 100644
--- a/utf8.h
+++ b/utf8.h
@@ -27,7 +27,7 @@
 
 #ifndef NO_ICONV
 char *reencode_string_iconv(const char *in, size_t insz,
-			    iconv_t conv, size_t *outsz);
+			    iconv_t conv, size_t bom_len, size_t *outsz);
 char *reencode_string_len(const char *in, size_t insz,
 			  const char *out_encoding,
 			  const char *in_encoding,
diff --git a/wrapper.c b/wrapper.c
index e4fa9d8..ea3cf64 100644
--- a/wrapper.c
+++ b/wrapper.c
@@ -690,3 +690,16 @@
 		buf[len - 1] = 0;
 	return ret;
 }
+
+int is_empty_or_missing_file(const char *filename)
+{
+	struct stat st;
+
+	if (stat(filename, &st) < 0) {
+		if (errno == ENOENT)
+			return 1;
+		die_errno(_("could not stat %s"), filename);
+	}
+
+	return !st.st_size;
+}
diff --git a/wt-status.c b/wt-status.c
index 0fe3bcd..1f564b1 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -2375,10 +2375,10 @@
 	struct lock_file lock_file = LOCK_INIT;
 	int err = 0, fd;
 
-	fd = hold_locked_index(&lock_file, 0);
+	fd = repo_hold_locked_index(r, &lock_file, 0);
 	refresh_index(r->index, REFRESH_QUIET, NULL, NULL, NULL);
 	if (0 <= fd)
-		update_index_if_able(r->index, &lock_file);
+		repo_update_index_if_able(r, &lock_file);
 	rollback_lock_file(&lock_file);
 
 	if (has_unstaged_changes(r, ignore_submodules)) {