diff --git a/.gitattributes b/.gitattributes
index 49b3051..acf853e 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -5,7 +5,7 @@
 *.pl eof=lf diff=perl
 *.pm eol=lf diff=perl
 *.py eol=lf diff=python
-/Documentation/git-*.txt eol=lf
+/Documentation/**/*.txt eol=lf
 /command-list.txt eol=lf
 /GIT-VERSION-GEN eol=lf
 /mergetools/* eol=lf
diff --git a/.mailmap b/.mailmap
index bef3352..eb7b5fc 100644
--- a/.mailmap
+++ b/.mailmap
@@ -21,6 +21,8 @@
 Aneesh Kumar K.V <aneesh.kumar@gmail.com>
 Amos Waterland <apw@debian.org> <apw@rossby.metr.ou.edu>
 Amos Waterland <apw@debian.org> <apw@us.ibm.com>
+Ben Peart <benpeart@microsoft.com> <Ben.Peart@microsoft.com>
+Ben Peart <benpeart@microsoft.com> <peartben@gmail.com>
 Ben Walton <bdwalton@gmail.com> <bwalton@artsci.utoronto.ca>
 Benoit Sigoure <tsunanet@gmail.com> <tsuna@lrde.epita.fr>
 Bernt Hansen <bernt@norang.ca> <bernt@alumni.uwaterloo.ca>
@@ -32,6 +34,7 @@
 Cheng Renquan <crquan@gmail.com>
 Chris Shoemaker <c.shoemaker@cox.net>
 Chris Wright <chrisw@sous-sol.org> <chrisw@osdl.org>
+Christian Ludwig <chrissicool@gmail.com> <chrissicool@googlemail.com>
 Cord Seele <cowose@gmail.com> <cowose@googlemail.com>
 Christian Couder <chriscool@tuxfamily.org> <christian.couder@gmail.com>
 Christian Stimming <stimming@tuhh.de> <chs@ckiste.goetheallee>
@@ -51,6 +54,7 @@
 David S. Miller <davem@davemloft.net>
 David Turner <novalis@novalis.org> <dturner@twopensource.com>
 David Turner <novalis@novalis.org> <dturner@twosigma.com>
+Derrick Stolee <dstolee@microsoft.com> <stolee@gmail.com>
 Deskin Miller <deskinm@umich.edu>
 Dirk Süsserott <newsletter@dirk.my1.cc>
 Eric Blake <eblake@redhat.com> <ebb9@byu.net>
@@ -98,6 +102,7 @@
 Jens Lindström <jl@opera.com> Jens Lindstrom <jl@opera.com>
 Jim Meyering <jim@meyering.net> <meyering@redhat.com>
 Joachim Berdal Haga <cjhaga@fys.uio.no>
+Joachim Jablon <joachim.jablon@people-doc.com> <ewjoachim@gmail.com>
 Johannes Schindelin <Johannes.Schindelin@gmx.de> <johannes.schindelin@gmx.de>
 Johannes Sixt <j6t@kdbg.org> <J.Sixt@eudaptics.com>
 Johannes Sixt <j6t@kdbg.org> <j.sixt@viscovery.net>
@@ -150,6 +155,7 @@
 Mark Rada <marada@uwaterloo.ca>
 Martin Langhoff <martin@laptop.org> <martin@catalyst.net.nz>
 Martin von Zweigbergk <martinvonz@gmail.com> <martin.von.zweigbergk@gmail.com>
+Masaya Suzuki <masayasuzuki@google.com> <draftcode@gmail.com>
 Matt Draisey <matt@draisey.ca> <mattdraisey@sympatico.ca>
 Matt Kraai <kraai@ftbfs.org> <matt.kraai@amo.abbott.com>
 Matt McCutchen <matt@mattmccutchen.net> <hashproduct@gmail.com>
@@ -157,6 +163,7 @@
 Matthias Rüster <matthias.ruester@gmail.com> Matthias Ruester
 Matthias Urlichs <matthias@urlichs.de> <smurf@kiste.(none)>
 Matthias Urlichs <matthias@urlichs.de> <smurf@smurf.noris.de>
+Matthieu Moy <git@matthieu-moy.fr> <Matthieu.Moy@imag.fr>
 Michael Coleman <tutufan@gmail.com>
 Michael J Gruber <git@grubix.eu> <michaeljgruber+gmane@fastmail.fm>
 Michael J Gruber <git@grubix.eu> <git@drmicha.warpmail.net>
@@ -180,7 +187,11 @@
 Nick Stokoe <nick@noodlefactory.co.uk> Nick Woolley <nickwoolley@yahoo.co.uk>
 Nicolas Morey-Chaisemartin <devel-git@morey-chaisemartin.com> <nicolas.morey@free.fr>
 Nicolas Morey-Chaisemartin <devel-git@morey-chaisemartin.com> <nmorey@kalray.eu>
+Nicolas Morey-Chaisemartin <devel-git@morey-chaisemartin.com> <nicolas@morey-chaisemartin.com>
+Nicolas Morey-Chaisemartin <devel-git@morey-chaisemartin.com> <NMoreyChaisemartin@suse.com>
+Nicolas Morey-Chaisemartin <devel-git@morey-chaisemartin.com> <nmoreychaisemartin@suse.com>
 Nicolas Sebrecht <nicolas.s.dev@gmx.fr> <ni.s@laposte.net>
+Orgad Shaneh <orgads@gmail.com> <orgad.shaneh@audiocodes.com>
 Paolo Bonzini <bonzini@gnu.org> <paolo.bonzini@lu.unisi.ch>
 Pascal Obry <pascal@obry.net> <pascal.obry@gmail.com>
 Pascal Obry <pascal@obry.net> <pascal.obry@wanadoo.fr>
@@ -200,6 +211,7 @@
 Philippe Bruhat <book@cpan.org>
 Ralf Thielow <ralf.thielow@gmail.com> <ralf.thielow@googlemail.com>
 Ramsay Jones <ramsay@ramsayjones.plus.com> <ramsay@ramsay1.demon.co.uk>
+Randall S. Becker <randall.becker@nexbridge.ca> <rsbecker@nexbridge.com>
 René Scharfe <l.s.r@web.de> <rene.scharfe@lsrfire.ath.cx>
 René Scharfe <l.s.r@web.de> Rene Scharfe
 Richard Hansen <rhansen@rhansen.org> <hansenr@google.com>
@@ -238,6 +250,7 @@
 Sven Verdoolaege <skimo@kotnet.org> <Sven.Verdoolaege@cs.kuleuven.ac.be>
 Sven Verdoolaege <skimo@kotnet.org> <skimo@liacs.nl>
 SZEDER Gábor <szeder.dev@gmail.com> <szeder@ira.uka.de>
+Tao Qingyun <taoqy@ls-a.me> <845767657@qq.com>
 Tay Ray Chuan <rctay89@gmail.com>
 Ted Percival <ted@midg3t.net> <ted.percival@quest.com>
 Theodore Ts'o <tytso@mit.edu>
diff --git a/.travis.yml b/.travis.yml
index a5a82d6..03c8e4c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,7 +14,7 @@
 
 matrix:
   include:
-    - env: jobname=GETTEXT_POISON
+    - env: jobname=GIT_TEST_GETTEXT_POISON
       os: linux
       compiler:
       addons:
diff --git a/Documentation/Makefile b/Documentation/Makefile
index 48d261d..d5d936e 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -73,6 +73,7 @@
 TECH_DOCS += technical/http-protocol
 TECH_DOCS += technical/index-format
 TECH_DOCS += technical/long-running-process-protocol
+TECH_DOCS += technical/multi-pack-index
 TECH_DOCS += technical/pack-format
 TECH_DOCS += technical/pack-heuristics
 TECH_DOCS += technical/pack-protocol
diff --git a/Documentation/RelNotes/2.19.2.txt b/Documentation/RelNotes/2.19.2.txt
new file mode 100644
index 0000000..759e6ca
--- /dev/null
+++ b/Documentation/RelNotes/2.19.2.txt
@@ -0,0 +1,108 @@
+Git v2.19.2 Release Notes
+=========================
+
+Fixes since v2.19.1
+-------------------
+
+ * "git interpret-trailers" and its underlying machinery had a buggy
+   code that attempted to ignore patch text after commit log message,
+   which triggered in various codepaths that will always get the log
+   message alone and never get such an input.
+
+ * "git rebase -i" did not clear the state files correctly when a run
+   of "squash/fixup" is aborted and then the user manually amended the
+   commit instead, which has been corrected.
+
+ * When fsmonitor is in use, after operation on submodules updates
+   .gitmodules, we lost track of the fact that we did so and relied on
+   stale fsmonitor data.
+
+ * Fix for a long-standing bug that leaves the index file corrupt when
+   it shrinks during a partial commit.
+
+ * Further fix for O_APPEND emulation on Windows
+
+ * A corner case bugfix in "git rerere" code.
+
+ * "git add ':(attr:foo)'" is not supported and is supposed to be
+   rejected while the command line arguments are parsed, but we fail
+   to reject such a command line upfront.
+
+ * "git rebase" etc. in Git 2.19 fails to abort when given an empty
+   commit log message as result of editing, which has been corrected.
+
+ * The code to backfill objects in lazily cloned repository did not
+   work correctly, which has been corrected.
+
+ * Update error messages given by "git remote" and make them consistent.
+
+ * "git update-ref" learned to make both "--no-deref" and "--stdin"
+   work at the same time.
+
+ * Recently added "range-diff" had a corner-case bug to cause it
+   segfault, which has been corrected.
+
+ * The recently introduced commit-graph auxiliary data is incompatible
+   with mechanisms such as replace & grafts that "breaks" immutable
+   nature of the object reference relationship.  Disable optimizations
+   based on its use (and updating existing commit-graph) when these
+   incompatible features are in use in the repository.
+
+ * The mailmap file update.
+
+ * The code in "git status" sometimes hit an assertion failure.  This
+   was caused by a structure that was reused without cleaning the data
+   used for the first run, which has been corrected.
+
+ * A corner-case bugfix.
+
+ * A partial clone that is configured to lazily fetch missing objects
+   will on-demand issue a "git fetch" request to the originating
+   repository to fill not-yet-obtained objects.  The request has been
+   optimized for requesting a tree object (and not the leaf blob
+   objects contained in it) by telling the originating repository that
+   no blobs are needed.
+
+ * The codepath to support the experimental split-index mode had
+   remaining "racily clean" issues fixed.
+
+ * "git log --graph" showing an octopus merge sometimes miscounted the
+   number of display columns it is consuming to show the merge and its
+   parent commits, which has been corrected.
+
+ * The implementation of run_command() API on the UNIX platforms had a
+   bug that caused a command not on $PATH to be found in the current
+   directory.
+
+ * A mutex used in "git pack-objects" were not correctly initialized
+   and this caused "git repack" to dump core on Windows.
+
+ * Under certain circumstances, "git diff D:/a/b/c D:/a/b/d" on
+   Windows would strip initial parts from the paths because they
+   were not recognized as absolute, which has been corrected.
+
+ * The receive.denyCurrentBranch=updateInstead codepath kicked in even
+   when the push should have been rejected due to other reasons, such
+   as it does not fast-forward or the update-hook rejects it, which
+   has been corrected.
+
+ * "git repack" in a shallow clone did not correctly update the
+   shallow points in the repository, leading to a repository that
+   does not pass fsck.
+
+ * Operations on promisor objects make sense in the context of only a
+   small subset of the commands that internally use the revisions
+   machinery, but the "--exclude-promisor-objects" option were taken
+   and led to nonsense results by commands like "log", to which it
+   didn't make much sense.  This has been corrected.
+
+ * The "container" mode of TravisCI is going away.  Our .travis.yml
+   file is getting prepared for the transition.
+
+ * Our test scripts can now take the '-V' option as a synonym for the
+   '--verbose-log' option.
+
+ * A regression in Git 2.12 era made "git fsck" fall into an infinite
+   loop while processing truncated loose objects.
+
+Also contains various documentation updates and code clean-ups.
diff --git a/Documentation/RelNotes/2.20.0.txt b/Documentation/RelNotes/2.20.0.txt
index 519c894..8e26664 100644
--- a/Documentation/RelNotes/2.20.0.txt
+++ b/Documentation/RelNotes/2.20.0.txt
@@ -1,5 +1,5 @@
-Git Release Notes
-=================
+Git 2.20 Release Notes
+======================
 
 Backward Compatibility Notes
 ----------------------------
@@ -173,6 +173,15 @@
    each other.
    (merge e5bbe09e88 nd/wildmatch-double-asterisk later to maint).
 
+ * The "--no-patch" option, which can be used to get a high-level
+   overview without the actual line-by-line patch difference shown, of
+   the "range-diff" command was earlier broken, which has been
+   corrected.
+
+ * The recently merged "rebase in C" has an escape hatch to use the
+   scripted version when necessary, but it hasn't been documented,
+   which has been corrected.
+
 
 Performance, Internal Implementation, Development Support etc.
 
@@ -249,8 +258,8 @@
    used during tests are getting renamed for consistency.
    (merge 4231d1ba99 bp/rename-test-env-var later to maint).
 
- * A new extension to the index file has been introduced, which allows
-   the index file to be read in parallel for performance.
+ * A pair of new extensions to the index file have been introduced.
+   They allow the index file to be read in parallel for performance.
 
  * The oidset API was built on top of the oidmap API which in turn is
    on the hashmap API.  Replace the implementation to build on top of
@@ -332,6 +341,52 @@
  * The support for format-patch (and send-email) by the command-line
    completion script (in contrib/) has been simplified a bit.
 
+ * The revision walker machinery learned to take advantage of the
+   commit generation numbers stored in the commit-graph file.
+
+ * The codebase has been cleaned up to reduce "#ifndef NO_PTHREADS".
+
+ * The way -lcurl library gets linked has been simplified by taking
+   advantage of the fact that we can just ask curl-config command how.
+
+ * Various functions have been audited for "-Wunused-parameter" warnings
+   and bugs in them got fixed.
+
+ * A sanity check for start-up sequence has been added in the config
+   API codepath.
+
+ * The build procedure to link for fuzzing test has been made
+   customizable with a new Makefile variable.
+
+ * The way "git rebase" parses and forwards the command line options
+   meant for underlying "git am" has been revamped, which fixed for
+   options with parameters that were not passed correctly.
+
+ * Our testing framework uses a special i18n "poisoned localization"
+   feature to find messages that ought to stay constant but are
+   incorrectly marked to be translated.  This feature has been made
+   into a runtime option (it used to be a compile-time option).
+
+ * "git push" used to check ambiguities between object-names and
+   refnames while processing the list of refs' old and new values,
+   which was unnecessary (as it knew that it is feeding raw object
+   names).  This has been optimized out.
+
+ * The xcurl_off_t() helper function is used to cast size_t to
+   curl_off_t, but some compilers gave warnings against the code to
+   ensure the casting is done without wraparound, when size_t is
+   narrower than curl_off_t.  This warning has been squelched.
+
+ * Code preparation to replace ulong vars with size_t vars where
+   appropriate continues.
+
+ * The "test installed Git" mode of our test suite has been updated to
+   work better.
+
+ * A coding convention around the Coccinelle semantic patches to have
+   two classes to ease code migration process has been proposed and
+   its support has been added to the Makefile.
+
 
 Fixes since v2.19
 -----------------
@@ -544,6 +599,46 @@
    pathspec elements were involved, which has been fixed.
    (merge b7845cebc0 nd/tree-walk-path-exclusion later to maint).
 
+ * "git merge" and "git pull" that merges into an unborn branch used
+   to completely ignore "--verify-signatures", which has been
+   corrected.
+   (merge 01a31f3bca jk/verify-sig-merge-into-void later to maint).
+
+ * "git rebase --autostash" did not correctly re-attach the HEAD at times.
+
+ * "rev-parse --exclude=<pattern> --branches=<pattern>" etc. did not
+   quite work, which has been corrected.
+   (merge 9ab9b5df0e ra/rev-parse-exclude-glob later to maint).
+
+ * When editing a patch in a "git add -i" session, a hunk could be
+   made to no-op.  The "git apply" program used to reject a patch with
+   such a no-op hunk to catch user mistakes, but it is now updated to
+   explicitly allow a no-op hunk in an edited patch.
+   (merge 22cb3835b9 js/apply-recount-allow-noop later to maint).
+
+ * The URL to an MSDN page in a comment has been updated.
+   (merge 2ef2ae2917 js/mingw-msdn-url later to maint).
+
+ * "git ls-remote --sort=<thing>" can feed an object that is not yet
+   available into the comparison machinery and segfault, which has
+   been corrected to check such a request upfront and reject it.
+
+ * When "git bundle" aborts due to an empty commit ranges
+   (i.e. resulting in an empty pack), it left a file descriptor to an
+   lockfile open, which resulted in leftover lockfile on Windows where
+   you cannot remove a file with an open file descriptor.  This has
+   been corrected.
+   (merge 2c8ee1f53c jk/close-duped-fd-before-unlock-for-bundle later to maint).
+
+ * "git format-patch --stat=<width>" can be used to specify the width
+   used by the diffstat (shown in the cover letter).
+   (merge 284aeb7e60 nd/format-patch-cover-letter-stat-width later to maint).
+
+ * The way .git/index and .git/sharedindex* files were initially
+   created gave these files different perm bits until they were
+   adjusted for shared repository settings.  This was made consistent.
+   (merge c9d6c78870 cc/shared-index-permbits later to maint).
+
  * Code cleanup, docfix, build fix, etc.
    (merge 96a7501aad ts/doc-build-manpage-xsl-quietly later to maint).
    (merge b9b07efdb2 tg/conflict-marker-size later to maint).
@@ -583,3 +678,4 @@
    (merge 3063477445 tb/char-may-be-unsigned later to maint).
    (merge 8c64bc9420 sg/test-rebase-editor-fix later to maint).
    (merge 71571cd7d6 ma/sequencer-do-reset-saner-loop-termination later to maint).
+   (merge 9a4cb8781e cb/notes-freeing-always-null-fix later to maint).
diff --git a/Documentation/config.txt b/Documentation/config.txt
index 3e735f1..d87846f 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -292,13 +292,6 @@
 
 include::config/core.txt[]
 
-extensions.worktreeConfig::
-	If set, by default "git config" reads from both "config" and
-	"config.worktree" file from GIT_DIR in that order. In
-	multiple working directory mode, "config" file is shared while
-	"config.worktree" is per-working directory (i.e., it's in
-	GIT_COMMON_DIR/worktrees/<id>/config.worktree)
-
 include::config/add.txt[]
 
 include::config/alias.txt[]
diff --git a/Documentation/config/index.txt b/Documentation/config/index.txt
index 4b94b6b..f181503 100644
--- a/Documentation/config/index.txt
+++ b/Documentation/config/index.txt
@@ -1,3 +1,19 @@
+index.recordEndOfIndexEntries::
+	Specifies whether the index file should include an "End Of Index
+	Entry" section. This reduces index load time on multiprocessor
+	machines but produces a message "ignoring EOIE extension" when
+	reading the index using Git versions before 2.20. Defaults to
+	'true' if index.threads has been explicitly enabled, 'false'
+	otherwise.
+
+index.recordOffsetTable::
+	Specifies whether the index file should include an "Index Entry
+	Offset Table" section. This reduces index load time on
+	multiprocessor machines but produces a message "ignoring IEOT
+	extension" when reading the index using Git versions before 2.20.
+	Defaults to 'true' if index.threads has been explicitly enabled,
+	'false' otherwise.
+
 index.threads::
 	Specifies the number of threads to spawn when loading the index.
 	This is meant to reduce index load time on multiprocessor machines.
diff --git a/Documentation/config/rebase.txt b/Documentation/config/rebase.txt
index 42e1ba7..f079bf6 100644
--- a/Documentation/config/rebase.txt
+++ b/Documentation/config/rebase.txt
@@ -1,3 +1,17 @@
+rebase.useBuiltin::
+	Set to `false` to use the legacy shellscript implementation of
+	linkgit:git-rebase[1]. Is `true` by default, which means use
+	the built-in rewrite of it in C.
++
+The C rewrite is first included with Git version 2.20. This option
+serves an an escape hatch to re-enable the legacy version in case any
+bugs are found in the rewrite. This option and the shellscript version
+of linkgit:git-rebase[1] will be removed in some future release.
++
+If you find some reason to set this option to `false` other than
+one-off testing you should report the behavior difference as a bug in
+git.
+
 rebase.stat::
 	Whether to show a diffstat of what changed upstream since the last
 	rebase. False by default.
diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
index aba4c5f..2730442 100644
--- a/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@ -250,6 +250,11 @@
 	feature/v2`), or a revision range if the two versions of the series are
 	disjoint (for example `git format-patch --cover-letter
 	--range-diff=feature/v1~3..feature/v1 -3 feature/v2`).
++
+Note that diff options passed to the command affect how the primary
+product of `format-patch` is generated, and they are not passed to
+the underlying `range-diff` machinery used to generate the cover-letter
+material (this may change in the future).
 
 --creation-factor=<percent>::
 	Used with `--range-diff`, tweak the heuristic which matches up commits
diff --git a/Documentation/git-range-diff.txt b/Documentation/git-range-diff.txt
index f693930..8a6ea2c 100644
--- a/Documentation/git-range-diff.txt
+++ b/Documentation/git-range-diff.txt
@@ -78,6 +78,23 @@
 corresponding old/new commits. There is currently no means to tweak the
 diff options passed to `git log` when generating those patches.
 
+OUTPUT STABILITY
+----------------
+
+The output of the `range-diff` command is subject to change. It is
+intended to be human-readable porcelain output, not something that can
+be used across versions of Git to get a textually stable `range-diff`
+(as opposed to something like the `--stable` option to
+linkgit:git-patch-id[1]). There's also no equivalent of
+linkgit:git-apply[1] for `range-diff`, the output is not intended to
+be machine-readable.
+
+This is particularly true when passing in diff options. Currently some
+options like `--stat` can, as an emergent effect, produce output
+that's quite useless in the context of `range-diff`. Future versions
+of `range-diff` may learn to interpret such options in a manner
+specific to `range-diff` (e.g. for `--stat` producing human-readable
+output which summarizes how the diffstat changed).
 
 CONFIGURATION
 -------------
diff --git a/Documentation/git-reset.txt b/Documentation/git-reset.txt
index 2dac95c..9f69ae8 100644
--- a/Documentation/git-reset.txt
+++ b/Documentation/git-reset.txt
@@ -14,14 +14,14 @@
 
 DESCRIPTION
 -----------
-In the first and second form, copy entries from <tree-ish> to the index.
-In the third form, set the current branch head (HEAD) to <commit>, optionally
-modifying index and working tree to match.  The <tree-ish>/<commit> defaults
-to HEAD in all forms.
+In the first and second form, copy entries from `<tree-ish>` to the index.
+In the third form, set the current branch head (`HEAD`) to `<commit>`,
+optionally modifying index and working tree to match.
+The `<tree-ish>`/`<commit>` defaults to `HEAD` in all forms.
 
 'git reset' [-q] [<tree-ish>] [--] <paths>...::
-	This form resets the index entries for all <paths> to their
-	state at <tree-ish>.  (It does not affect the working tree or
+	This form resets the index entries for all `<paths>` to their
+	state at `<tree-ish>`.  (It does not affect the working tree or
 	the current branch.)
 +
 This means that `git reset <paths>` is the opposite of `git add
@@ -36,7 +36,7 @@
 
 'git reset' (--patch | -p) [<tree-ish>] [--] [<paths>...]::
 	Interactively select hunks in the difference between the index
-	and <tree-ish> (defaults to HEAD).  The chosen hunks are applied
+	and `<tree-ish>` (defaults to `HEAD`).  The chosen hunks are applied
 	in reverse to the index.
 +
 This means that `git reset -p` is the opposite of `git add -p`, i.e.
@@ -44,16 +44,16 @@
 section of linkgit:git-add[1] to learn how to operate the `--patch` mode.
 
 'git reset' [<mode>] [<commit>]::
-	This form resets the current branch head to <commit> and
-	possibly updates the index (resetting it to the tree of <commit>) and
-	the working tree depending on <mode>. If <mode> is omitted,
-	defaults to "--mixed". The <mode> must be one of the following:
+	This form resets the current branch head to `<commit>` and
+	possibly updates the index (resetting it to the tree of `<commit>`) and
+	the working tree depending on `<mode>`. If `<mode>` is omitted,
+	defaults to `--mixed`. The `<mode>` must be one of the following:
 +
 --
 --soft::
 	Does not touch the index file or the working tree at all (but
-	resets the head to <commit>, just like all modes do). This leaves
-	all your changed files "Changes to be committed", as 'git status'
+	resets the head to `<commit>`, just like all modes do). This leaves
+	all your changed files "Changes to be committed", as `git status`
 	would put it.
 
 --mixed::
@@ -66,24 +66,24 @@
 
 --hard::
 	Resets the index and working tree. Any changes to tracked files in the
-	working tree since <commit> are discarded.
+	working tree since `<commit>` are discarded.
 
 --merge::
 	Resets the index and updates the files in the working tree that are
-	different between <commit> and HEAD, but keeps those which are
+	different between `<commit>` and `HEAD`, but keeps those which are
 	different between the index and working tree (i.e. which have changes
 	which have not been added).
-	If a file that is different between <commit> and the index has unstaged
-	changes, reset is aborted.
+	If a file that is different between `<commit>` and the index has
+	unstaged changes, reset is aborted.
 +
-In other words, --merge does something like a 'git read-tree -u -m <commit>',
+In other words, `--merge` does something like a `git read-tree -u -m <commit>`,
 but carries forward unmerged index entries.
 
 --keep::
 	Resets index entries and updates files in the working tree that are
-	different between <commit> and HEAD.
-	If a file that is different between <commit> and HEAD has local changes,
-	reset is aborted.
+	different between `<commit>` and `HEAD`.
+	If a file that is different between `<commit>` and `HEAD` has local
+	changes, reset is aborted.
 --
 
 If you want to undo a commit other than the latest on a branch,
@@ -116,15 +116,15 @@
 +
 <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
+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
+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
+<4> Then you can pull and merge, leaving `frotz.c` and `filfre.c`
 changes still in the working tree.
 
 Undo a commit and redo::
@@ -140,11 +140,11 @@
 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
+<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.
+edit the message further, you can give `-C` option instead.
 +
-See also the --amend option to linkgit:git-commit[1].
+See also the `--amend` option to linkgit:git-commit[1].
 
 Undo a commit, making it a topic branch::
 +
@@ -155,11 +155,11 @@
 ------------
 +
 <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.
+<3> Switch to `topic/wip` branch and keep working.
 
 Undo commits permanently::
 +
@@ -168,7 +168,7 @@
 $ git reset --hard HEAD~3   <1>
 ------------
 +
-<1> The last three commits (HEAD, HEAD^, and HEAD~2) were bad
+<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
@@ -191,14 +191,14 @@
 <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.
-<2> "pull" has not made merge commit, so "git reset --hard"
-which is a synonym for "git reset --hard HEAD" clears the mess
+<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.
 <3> Merge a topic branch into the current branch, which resulted
 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
+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.
 
@@ -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
+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
+`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.
+want.  `git reset --merge` keeps your local changes.
 
 
 Interrupted workflow::
@@ -287,13 +287,13 @@
 $ git reset --keep start                    <3>
 ------------
 +
-<1> This commits your first edits in branch1.
+<1> This commits your first edits in `branch1`.
 <2> In the ideal world, you could have realized that the earlier
     commit did not belong to the new topic when you created and switched
-    to branch2 (i.e. "git checkout -b branch2 start"), but nobody is
+    to `branch2` (i.e. `git checkout -b branch2 start`), but nobody is
     perfect.
-<3> But you can use "reset --keep" to remove the unwanted commit after
-    you switched to "branch2".
+<3> But you can use `reset --keep` to remove the unwanted commit after
+    you switched to `branch2`.
 
 Split a commit apart into a sequence of commits::
 +
@@ -317,26 +317,27 @@
 +
 <1> First, reset the history back one commit so that we remove the original
     commit, but leave the working tree with all the changes. The -N ensures
-    that any new files added with HEAD are still marked so that git add -p
+    that any new files added with `HEAD` are still marked so that `git add -p`
     will find them.
-<2> Next, we interactively select diff hunks to add using the git add -p
+<2> Next, we interactively select diff hunks to add using the `git add -p`
     facility. This will ask you about each diff hunk in sequence and you can
     use simple commands such as "yes, include this", "No don't include this"
     or even the very powerful "edit" facility.
 <3> Once satisfied with the hunks you want to include, you should verify what
-    has been prepared for the first commit by using git diff --cached. This
+    has been prepared for the first commit by using `git diff --cached`. This
     shows all the changes that have been moved into the index and are about
     to be committed.
-<4> Next, commit the changes stored in the index. The -c option specifies to
+<4> Next, commit the changes stored in the index. The `-c` option specifies to
     pre-populate the commit message from the original message that you started
-    with in the first commit. This is helpful to avoid retyping it. The HEAD@{1}
-    is a special notation for the commit that HEAD used to be at prior to the
-    original reset commit (1 change ago). See linkgit:git-reflog[1] for more
-    details. You may also use any other valid commit reference.
+    with in the first commit. This is helpful to avoid retyping it. The
+    `HEAD@{1}` is a special notation for the commit that `HEAD` used to be at
+    prior to the original reset commit (1 change ago).
+    See linkgit:git-reflog[1] for more details. You may also use any other
+    valid commit reference.
 <5> You can repeat steps 2-4 multiple times to break the original code into
     any number of commits.
 <6> Now you've split out many of the changes into their own commits, and might
-    no longer use the patch mode of git add, in order to select all remaining
+    no longer use the patch mode of `git add`, in order to select all remaining
     uncommitted changes.
 <7> Once again, check to verify that you've included what you want to. You may
     also wish to verify that git diff doesn't show any remaining changes to be
@@ -353,104 +354,120 @@
 git reset --option target
 ----------
 
-to reset the HEAD to another commit (`target`) with the different
+to reset the `HEAD` to another commit (`target`) with the different
 reset options depending on the state of the files.
 
-In these tables, A, B, C and D are some different states of a
+In these tables, `A`, `B`, `C` and `D` are some different states of a
 file. For example, the first line of the first table means that if a
-file is in state A in the working tree, in state B in the index, in
-state C in HEAD and in state D in the target, then "git reset --soft
-target" will leave the file in the working tree in state A and in the
-index in state B.  It resets (i.e. moves) the HEAD (i.e. the tip of
-the current branch, if you are on one) to "target" (which has the file
-in state D).
+file is in state `A` in the working tree, in state `B` in the index, in
+state `C` in `HEAD` and in state `D` in the target, then `git reset --soft
+target` will leave the file in the working tree in state `A` and in the
+index in state `B`.  It resets (i.e. moves) the `HEAD` (i.e. the tip of
+the current branch, if you are on one) to `target` (which has the file
+in state `D`).
 
-      working index HEAD target         working index HEAD
-      ----------------------------------------------------
-       A       B     C    D     --soft   A       B     D
-				--mixed  A       D     D
-				--hard   D       D     D
-				--merge (disallowed)
-				--keep  (disallowed)
+....
+working index HEAD target         working index HEAD
+----------------------------------------------------
+ A       B     C    D     --soft   A       B     D
+			  --mixed  A       D     D
+			  --hard   D       D     D
+			  --merge (disallowed)
+			  --keep  (disallowed)
+....
 
-      working index HEAD target         working index HEAD
-      ----------------------------------------------------
-       A       B     C    C     --soft   A       B     C
-				--mixed  A       C     C
-				--hard   C       C     C
-				--merge (disallowed)
-				--keep   A       C     C
+....
+working index HEAD target         working index HEAD
+----------------------------------------------------
+ A       B     C    C     --soft   A       B     C
+			  --mixed  A       C     C
+			  --hard   C       C     C
+			  --merge (disallowed)
+			  --keep   A       C     C
+....
 
-      working index HEAD target         working index HEAD
-      ----------------------------------------------------
-       B       B     C    D     --soft   B       B     D
-				--mixed  B       D     D
-				--hard   D       D     D
-				--merge  D       D     D
-				--keep  (disallowed)
+....
+working index HEAD target         working index HEAD
+----------------------------------------------------
+ B       B     C    D     --soft   B       B     D
+			  --mixed  B       D     D
+			  --hard   D       D     D
+			  --merge  D       D     D
+			  --keep  (disallowed)
+....
 
-      working index HEAD target         working index HEAD
-      ----------------------------------------------------
-       B       B     C    C     --soft   B       B     C
-				--mixed  B       C     C
-				--hard   C       C     C
-				--merge  C       C     C
-				--keep   B       C     C
+....
+working index HEAD target         working index HEAD
+----------------------------------------------------
+ B       B     C    C     --soft   B       B     C
+			  --mixed  B       C     C
+			  --hard   C       C     C
+			  --merge  C       C     C
+			  --keep   B       C     C
+....
 
-      working index HEAD target         working index HEAD
-      ----------------------------------------------------
-       B       C     C    D     --soft   B       C     D
-				--mixed  B       D     D
-				--hard   D       D     D
-				--merge (disallowed)
-				--keep  (disallowed)
+....
+working index HEAD target         working index HEAD
+----------------------------------------------------
+ B       C     C    D     --soft   B       C     D
+			  --mixed  B       D     D
+			  --hard   D       D     D
+			  --merge (disallowed)
+			  --keep  (disallowed)
+....
 
-      working index HEAD target         working index HEAD
-      ----------------------------------------------------
-       B       C     C    C     --soft   B       C     C
-				--mixed  B       C     C
-				--hard   C       C     C
-				--merge  B       C     C
-				--keep   B       C     C
+....
+working index HEAD target         working index HEAD
+----------------------------------------------------
+ B       C     C    C     --soft   B       C     C
+			  --mixed  B       C     C
+			  --hard   C       C     C
+			  --merge  B       C     C
+			  --keep   B       C     C
+....
 
-"reset --merge" is meant to be used when resetting out of a conflicted
+`reset --merge` is meant to be used when resetting out of a conflicted
 merge. Any mergy operation guarantees that the working tree file that is
 involved in the merge does not have local change wrt the index before
 it starts, and that it writes the result out to the working tree. So if
 we see some difference between the index and the target and also
 between the index and the working tree, then it means that we are not
 resetting out from a state that a mergy operation left after failing
-with a conflict. That is why we disallow --merge option in this case.
+with a conflict. That is why we disallow `--merge` option in this case.
 
-"reset --keep" is meant to be used when removing some of the last
+`reset --keep` is meant to be used when removing some of the last
 commits in the current branch while keeping changes in the working
 tree. If there could be conflicts between the changes in the commit we
 want to remove and the changes in the working tree we want to keep,
 the reset is disallowed. That's why it is disallowed if there are both
-changes between the working tree and HEAD, and between HEAD and the
+changes between the working tree and `HEAD`, and between `HEAD` and the
 target. To be safe, it is also disallowed when there are unmerged
 entries.
 
 The following tables show what happens when there are unmerged
 entries:
 
-      working index HEAD target         working index HEAD
-      ----------------------------------------------------
-       X       U     A    B     --soft  (disallowed)
-				--mixed  X       B     B
-				--hard   B       B     B
-				--merge  B       B     B
-				--keep  (disallowed)
+....
+working index HEAD target         working index HEAD
+----------------------------------------------------
+ X       U     A    B     --soft  (disallowed)
+			  --mixed  X       B     B
+			  --hard   B       B     B
+			  --merge  B       B     B
+			  --keep  (disallowed)
+....
 
-      working index HEAD target         working index HEAD
-      ----------------------------------------------------
-       X       U     A    A     --soft  (disallowed)
-				--mixed  X       A     A
-				--hard   A       A     A
-				--merge  A       A     A
-				--keep  (disallowed)
+....
+working index HEAD target         working index HEAD
+----------------------------------------------------
+ X       U     A    A     --soft  (disallowed)
+			  --mixed  X       A     A
+			  --hard   A       A     A
+			  --merge  A       A     A
+			  --keep  (disallowed)
+....
 
-X means any state and U means an unmerged index.
+`X` means any state and `U` means an unmerged index.
 
 GIT
 ---
diff --git a/Documentation/gitrepository-layout.txt b/Documentation/gitrepository-layout.txt
index d501af9..366dee2 100644
--- a/Documentation/gitrepository-layout.txt
+++ b/Documentation/gitrepository-layout.txt
@@ -290,6 +290,8 @@
 worktrees/<id>/config.worktree::
 	Working directory specific configuration file.
 
+include::technical/repository-version.txt[]
+
 SEE ALSO
 --------
 linkgit:git-init[1],
diff --git a/Documentation/technical/api-parse-options.txt b/Documentation/technical/api-parse-options.txt
index 829b558..2b036d7 100644
--- a/Documentation/technical/api-parse-options.txt
+++ b/Documentation/technical/api-parse-options.txt
@@ -183,10 +183,6 @@
 	scale the provided value by 1024, 1024^2 or 1024^3 respectively.
 	The scaled value is put into `unsigned_long_var`.
 
-`OPT_DATE(short, long, &timestamp_t_var, description)`::
-	Introduce an option with date argument, see `approxidate()`.
-	The timestamp is put into `timestamp_t_var`.
-
 `OPT_EXPIRY_DATE(short, long, &timestamp_t_var, description)`::
 	Introduce an option with expiry date argument, see `parse_expiry_date()`.
 	The timestamp is put into `timestamp_t_var`.
diff --git a/Documentation/technical/repository-version.txt b/Documentation/technical/repository-version.txt
index e03eacc..7844ef3 100644
--- a/Documentation/technical/repository-version.txt
+++ b/Documentation/technical/repository-version.txt
@@ -1,5 +1,4 @@
-Git Repository Format Versions
-==============================
+== Git Repository Format Versions
 
 Every git repository is marked with a numeric version in the
 `core.repositoryformatversion` key of its `config` file. This version
@@ -40,16 +39,14 @@
 
 The currently defined format versions are:
 
-Version `0`
------------
+=== Version `0`
 
 This is the format defined by the initial version of git, including but
 not limited to the format of the repository directory, the repository
 configuration file, and the object and ref storage. Specifying the
 complete behavior of git is beyond the scope of this document.
 
-Version `1`
------------
+=== Version `1`
 
 This format is identical to version `0`, with the following exceptions:
 
@@ -74,21 +71,18 @@
 
 The defined extensions are:
 
-`noop`
-~~~~~~
+==== `noop`
 
 This extension does not change git's behavior at all. It is useful only
 for testing format-1 compatibility.
 
-`preciousObjects`
-~~~~~~~~~~~~~~~~~
+==== `preciousObjects`
 
 When the config key `extensions.preciousObjects` is set to `true`,
 objects in the repository MUST NOT be deleted (e.g., by `git-prune` or
 `git repack -d`).
 
-`partialclone`
-~~~~~~~~~~~~~~
+==== `partialclone`
 
 When the config key `extensions.partialclone` is set, it indicates
 that the repo was created with a partial clone (or later performed
@@ -98,3 +92,11 @@
 in the future.
 
 The value of this key is the name of the promisor remote.
+
+==== `worktreeConfig`
+
+If set, by default "git config" reads from both "config" and
+"config.worktree" file from GIT_DIR in that order. In
+multiple working directory mode, "config" file is shared while
+"config.worktree" is per-working directory (i.e., it's in
+GIT_COMMON_DIR/worktrees/<id>/config.worktree)
diff --git a/GIT-VERSION-GEN b/GIT-VERSION-GEN
index 498fce8..bc15874 100755
--- a/GIT-VERSION-GEN
+++ b/GIT-VERSION-GEN
@@ -1,7 +1,7 @@
 #!/bin/sh
 
 GVF=GIT-VERSION-FILE
-DEF_VER=v2.19.GIT
+DEF_VER=v2.20.0-rc1
 
 LF='
 '
diff --git a/Makefile b/Makefile
index 016fdcd..1a44c81 100644
--- a/Makefile
+++ b/Makefile
@@ -59,6 +59,13 @@
 # Define CURL_CONFIG to curl's configuration program that prints information
 # about the library (e.g., its version number).  The default is 'curl-config'.
 #
+# Define CURL_LDFLAGS to specify flags that you need to link when using libcurl,
+# if you do not want to rely on the libraries provided by CURL_CONFIG.  The
+# default value is a result of `curl-config --libs`.  An example value for
+# CURL_LDFLAGS is as follows:
+#
+#     CURL_LDFLAGS=-lcurl
+#
 # Define NO_EXPAT if you do not have expat installed.  git-http-push is
 # not built, and you cannot push using http:// and https:// transports (dumb).
 #
@@ -183,10 +190,6 @@
 #
 # Define NEEDS_SSL_WITH_CRYPTO if you need -lssl when using -lcrypto (Darwin).
 #
-# Define NEEDS_SSL_WITH_CURL if you need -lssl with -lcurl (Minix).
-#
-# Define NEEDS_IDN_WITH_CURL if you need -lidn when using -lcurl (Minix).
-#
 # Define NEEDS_LIBICONV if linking with libc is not enough (Darwin).
 #
 # Define NEEDS_LIBINTL_BEFORE_LIBICONV if you need libintl before libiconv.
@@ -207,10 +210,12 @@
 # Define MMAP_PREVENTS_DELETE if a file that is currently mmapped cannot be
 # deleted or cannot be replaced using rename().
 #
+# Define NO_POLL_H if you don't have poll.h.
+#
 # Define NO_SYS_POLL_H if you don't have sys/poll.h.
 #
 # Define NO_POLL if you do not have or don't want to use poll().
-# This also implies NO_SYS_POLL_H.
+# This also implies NO_POLL_H and NO_SYS_POLL_H.
 #
 # Define NEEDS_SYS_PARAM_H if you need to include sys/param.h to compile,
 # *PLEASE* REPORT to git@vger.kernel.org if your platform needs this;
@@ -362,11 +367,6 @@
 # Define HAVE_DEV_TTY if your system can open /dev/tty to interact with the
 # user.
 #
-# Define GETTEXT_POISON if you are debugging the choice of strings marked
-# for translation.  In a GETTEXT_POISON build, you can turn all strings marked
-# for translation into gibberish by setting the GIT_GETTEXT_POISON variable
-# (to any value) in your environment.
-#
 # Define JSMIN to point to JavaScript minifier that functions as
 # a filter to have gitweb.js minified.
 #
@@ -993,6 +993,7 @@
 LIB_OBJS += symlinks.o
 LIB_OBJS += tag.o
 LIB_OBJS += tempfile.o
+LIB_OBJS += thread-utils.o
 LIB_OBJS += tmp-objdir.o
 LIB_OBJS += trace.o
 LIB_OBJS += trailer.o
@@ -1308,19 +1309,16 @@
 	ifdef CURLDIR
 		# Try "-Wl,-rpath=$(CURLDIR)/$(lib)" in such a case.
 		BASIC_CFLAGS += -I$(CURLDIR)/include
-		CURL_LIBCURL = -L$(CURLDIR)/$(lib) $(CC_LD_DYNPATH)$(CURLDIR)/$(lib) -lcurl
+		CURL_LIBCURL = -L$(CURLDIR)/$(lib) $(CC_LD_DYNPATH)$(CURLDIR)/$(lib)
 	else
-		CURL_LIBCURL = -lcurl
+		CURL_LIBCURL =
 	endif
-	ifdef NEEDS_SSL_WITH_CURL
-		CURL_LIBCURL += -lssl
-		ifdef NEEDS_CRYPTO_WITH_SSL
-			CURL_LIBCURL += -lcrypto
-		endif
-	endif
-	ifdef NEEDS_IDN_WITH_CURL
-		CURL_LIBCURL += -lidn
-	endif
+
+ifdef CURL_LDFLAGS
+	CURL_LIBCURL += $(CURL_LDFLAGS)
+else
+	CURL_LIBCURL += $(shell $(CURL_CONFIG) --libs)
+endif
 
 	REMOTE_CURL_PRIMARY = git-remote-http$X
 	REMOTE_CURL_ALIASES = git-remote-https$X git-remote-ftp$X git-remote-ftps$X
@@ -1453,13 +1451,14 @@
 	BASIC_CFLAGS += -DNO_SYMLINK_HEAD
 endif
 ifdef GETTEXT_POISON
-	BASIC_CFLAGS += -DGETTEXT_POISON
+$(warning The GETTEXT_POISON option has been removed in favor of runtime GIT_TEST_GETTEXT_POISON. See t/README!)
 endif
 ifdef NO_GETTEXT
 	BASIC_CFLAGS += -DNO_GETTEXT
 	USE_GETTEXT_SCHEME ?= fallthrough
 endif
 ifdef NO_POLL
+	NO_POLL_H = YesPlease
 	NO_SYS_POLL_H = YesPlease
 	COMPAT_CFLAGS += -DNO_POLL -Icompat/poll
 	COMPAT_OBJS += compat/poll/poll.o
@@ -1498,6 +1497,9 @@
 ifdef NO_SYS_SELECT_H
 	BASIC_CFLAGS += -DNO_SYS_SELECT_H
 endif
+ifdef NO_POLL_H
+	BASIC_CFLAGS += -DNO_POLL_H
+endif
 ifdef NO_SYS_POLL_H
 	BASIC_CFLAGS += -DNO_SYS_POLL_H
 endif
@@ -1677,7 +1679,6 @@
 else
 	BASIC_CFLAGS += $(PTHREAD_CFLAGS)
 	EXTLIBS += $(PTHREAD_LIBS)
-	LIB_OBJS += thread-utils.o
 endif
 
 ifdef HAVE_PATHS_H
@@ -2111,7 +2112,7 @@
 	$(QUIET_GEN)$(cmd_munge_script) && \
 	mv $@+ $@
 
-git.res: git.rc GIT-VERSION-FILE
+git.res: git.rc GIT-VERSION-FILE GIT-PREFIX
 	$(QUIET_RC)$(RC) \
 	  $(join -DMAJOR= -DMINOR= -DMICRO= -DPATCHLEVEL=, $(wordlist 1, 4, \
 	    $(shell echo $(GIT_VERSION) 0 0 0 0 | tr '.a-zA-Z-' ' '))) \
@@ -2591,6 +2592,7 @@
 	@echo NO_UNIX_SOCKETS=\''$(subst ','\'',$(subst ','\'',$(NO_UNIX_SOCKETS)))'\' >>$@+
 	@echo PAGER_ENV=\''$(subst ','\'',$(subst ','\'',$(PAGER_ENV)))'\' >>$@+
 	@echo DC_SHA1=\''$(subst ','\'',$(subst ','\'',$(DC_SHA1)))'\' >>$@+
+	@echo X=\'$(X)\' >>$@+
 ifdef TEST_OUTPUT_DIRECTORY
 	@echo TEST_OUTPUT_DIRECTORY=\''$(subst ','\'',$(subst ','\'',$(TEST_OUTPUT_DIRECTORY)))'\' >>$@+
 endif
@@ -2604,7 +2606,6 @@
 	@echo GIT_TEST_CMP_USE_COPIED_CONTEXT=YesPlease >>$@+
 endif
 	@echo NO_GETTEXT=\''$(subst ','\'',$(subst ','\'',$(NO_GETTEXT)))'\' >>$@+
-	@echo GETTEXT_POISON=\''$(subst ','\'',$(subst ','\'',$(GETTEXT_POISON)))'\' >>$@+
 ifdef GIT_PERF_REPEAT_COUNT
 	@echo GIT_PERF_REPEAT_COUNT=\''$(subst ','\'',$(subst ','\'',$(GIT_PERF_REPEAT_COUNT)))'\' >>$@+
 endif
@@ -2741,9 +2742,12 @@
 	then \
 		echo '    ' SPATCH result: $@; \
 	fi
-coccicheck: $(addsuffix .patch,$(wildcard contrib/coccinelle/*.cocci))
+coccicheck: $(addsuffix .patch,$(filter-out %.pending.cocci,$(wildcard contrib/coccinelle/*.cocci)))
 
-.PHONY: coccicheck
+# See contrib/coccinelle/README
+coccicheck-pending: $(addsuffix .patch,$(wildcard contrib/coccinelle/*.pending.cocci))
+
+.PHONY: coccicheck coccicheck-pending
 
 ### Installation rules
 
@@ -3099,14 +3103,16 @@
 # An example command to build against libFuzzer from LLVM 4.0.0:
 #
 # make CC=clang CXX=clang++ \
-#      CFLAGS="-fsanitize-coverage=trace-pc-guard -fsanitize=address" \
+#      FUZZ_CXXFLAGS="-fsanitize-coverage=trace-pc-guard -fsanitize=address" \
 #      LIB_FUZZING_ENGINE=/usr/lib/llvm-4.0/lib/libFuzzer.a \
 #      fuzz-all
 #
+FUZZ_CXXFLAGS ?= $(CFLAGS)
+
 .PHONY: fuzz-all
 
 $(FUZZ_PROGRAMS): all
-	$(QUIET_LINK)$(CXX) $(CFLAGS) $(LIB_OBJS) $(BUILTIN_OBJS) \
+	$(QUIET_LINK)$(CXX) $(FUZZ_CXXFLAGS) $(LIB_OBJS) $(BUILTIN_OBJS) \
 		$(XDIFF_OBJS) $(EXTLIBS) git.o $@.o $(LIB_FUZZING_ENGINE) -o $@
 
 fuzz-all: $(FUZZ_PROGRAMS)
diff --git a/apply.c b/apply.c
index 073d5f0..01793d6 100644
--- a/apply.c
+++ b/apply.c
@@ -1748,7 +1748,7 @@
 	}
 	if (oldlines || newlines)
 		return -1;
-	if (!deleted && !added)
+	if (!patch->recount && !deleted && !added)
 		return -1;
 
 	fragment->leading = leading;
@@ -4772,6 +4772,9 @@
 				      const char *arg, int unset)
 {
 	struct apply_state *state = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+
 	add_name_limit(state, arg, 1);
 	return 0;
 }
@@ -4780,6 +4783,9 @@
 				      const char *arg, int unset)
 {
 	struct apply_state *state = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+
 	add_name_limit(state, arg, 0);
 	state->has_include = 1;
 	return 0;
@@ -4790,6 +4796,9 @@
 				int unset)
 {
 	struct apply_state *state = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+
 	state->p_value = atoi(arg);
 	state->p_value_known = 1;
 	return 0;
@@ -4799,6 +4808,9 @@
 					   const char *arg, int unset)
 {
 	struct apply_state *state = opt->value;
+
+	BUG_ON_OPT_ARG(arg);
+
 	if (unset)
 		state->ws_ignore_action = ignore_ws_none;
 	else
@@ -4810,9 +4822,12 @@
 					 const char *arg, int unset)
 {
 	struct apply_state *state = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+
 	state->whitespace_option = arg;
 	if (parse_whitespace_option(state, arg))
-		exit(1);
+		return -1;
 	return 0;
 }
 
@@ -4820,6 +4835,9 @@
 					const char *arg, int unset)
 {
 	struct apply_state *state = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+
 	strbuf_reset(&state->root);
 	strbuf_addstr(&state->root, arg);
 	strbuf_complete(&state->root, '/');
@@ -4939,10 +4957,10 @@
 	struct option builtin_apply_options[] = {
 		{ OPTION_CALLBACK, 0, "exclude", state, N_("path"),
 			N_("don't apply changes matching the given path"),
-			0, apply_option_parse_exclude },
+			PARSE_OPT_NONEG, apply_option_parse_exclude },
 		{ OPTION_CALLBACK, 0, "include", state, N_("path"),
 			N_("apply changes matching the given path"),
-			0, apply_option_parse_include },
+			PARSE_OPT_NONEG, apply_option_parse_include },
 		{ OPTION_CALLBACK, 'p', NULL, state, N_("num"),
 			N_("remove <num> leading slashes from traditional diff paths"),
 			0, apply_option_parse_p },
diff --git a/archive-tar.c b/archive-tar.c
index 7a535cb..a58e1a8 100644
--- a/archive-tar.c
+++ b/archive-tar.c
@@ -202,7 +202,7 @@
 			   unsigned int mode, unsigned long size)
 {
 	xsnprintf(header->mode, sizeof(header->mode), "%07o", mode & 07777);
-	xsnprintf(header->size, sizeof(header->size), "%011lo", S_ISREG(mode) ? size : 0);
+	xsnprintf(header->size, sizeof(header->size), "%011"PRIoMAX , S_ISREG(mode) ? (uintmax_t)size : (uintmax_t)0);
 	xsnprintf(header->mtime, sizeof(header->mtime), "%011lo", (unsigned long) args->time);
 
 	xsnprintf(header->uid, sizeof(header->uid), "%07o", 0);
diff --git a/attr.c b/attr.c
index 60d2847..eaece66 100644
--- a/attr.c
+++ b/attr.c
@@ -41,23 +41,17 @@
 
 struct attr_hashmap {
 	struct hashmap map;
-#ifndef NO_PTHREADS
 	pthread_mutex_t mutex;
-#endif
 };
 
 static inline void hashmap_lock(struct attr_hashmap *map)
 {
-#ifndef NO_PTHREADS
 	pthread_mutex_lock(&map->mutex);
-#endif
 }
 
 static inline void hashmap_unlock(struct attr_hashmap *map)
 {
-#ifndef NO_PTHREADS
 	pthread_mutex_unlock(&map->mutex);
-#endif
 }
 
 /*
@@ -498,23 +492,17 @@
 	size_t nr;
 	size_t alloc;
 	struct attr_check **checks;
-#ifndef NO_PTHREADS
 	pthread_mutex_t mutex;
-#endif
 } check_vector;
 
 static inline void vector_lock(void)
 {
-#ifndef NO_PTHREADS
 	pthread_mutex_lock(&check_vector.mutex);
-#endif
 }
 
 static inline void vector_unlock(void)
 {
-#ifndef NO_PTHREADS
 	pthread_mutex_unlock(&check_vector.mutex);
-#endif
 }
 
 static void check_vector_add(struct attr_check *c)
@@ -1181,8 +1169,6 @@
 
 void attr_start(void)
 {
-#ifndef NO_PTHREADS
 	pthread_mutex_init(&g_attr_hashmap.mutex, NULL);
 	pthread_mutex_init(&check_vector.mutex, NULL);
-#endif
 }
diff --git a/builtin/am.c b/builtin/am.c
index dc576a3..8f27f33 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -2113,7 +2113,9 @@
 {
 	int *opt_value = opt->value;
 
-	if (!strcmp(arg, "mbox"))
+	if (unset)
+		*opt_value = PATCH_FORMAT_UNKNOWN;
+	else if (!strcmp(arg, "mbox"))
 		*opt_value = PATCH_FORMAT_MBOX;
 	else if (!strcmp(arg, "stgit"))
 		*opt_value = PATCH_FORMAT_STGIT;
diff --git a/builtin/blame.c b/builtin/blame.c
index a443af9..06a7163 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -732,6 +732,8 @@
 {
 	int *opt = option->value;
 
+	BUG_ON_OPT_NEG(unset);
+
 	/*
 	 * -C enables copy from removed files;
 	 * -C -C enables copy from existing files, but only
@@ -754,6 +756,8 @@
 {
 	int *opt = option->value;
 
+	BUG_ON_OPT_NEG(unset);
+
 	*opt |= PICKAXE_BLAME_MOVE;
 
 	if (arg)
diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 0d403eb..2ca56fd 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -99,7 +99,7 @@
 		oi.sizep = &size;
 		if (oid_object_info_extended(the_repository, &oid, &oi, flags) < 0)
 			die("git cat-file: could not get object info");
-		printf("%lu\n", size);
+		printf("%"PRIuMAX"\n", (uintmax_t)size);
 		return 0;
 
 	case 'e':
@@ -245,7 +245,7 @@
 		if (data->mark_query)
 			data->info.sizep = &data->size;
 		else
-			strbuf_addf(sb, "%lu", data->size);
+			strbuf_addf(sb, "%"PRIuMAX , (uintmax_t)data->size);
 	} else if (is_atom("objectsize:disk", atom, len)) {
 		if (data->mark_query)
 			data->info.disk_sizep = &data->disk_size;
@@ -603,8 +603,10 @@
 {
 	struct batch_options *bo = opt->value;
 
+	BUG_ON_OPT_NEG(unset);
+
 	if (bo->enabled) {
-		return 1;
+		return error(_("only one batch option may be specified"));
 	}
 
 	bo->enabled = 1;
@@ -639,10 +641,12 @@
 		OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),
 		{ OPTION_CALLBACK, 0, "batch", &batch, "format",
 			N_("show info and content of objects fed from the standard input"),
-			PARSE_OPT_OPTARG, batch_option_callback },
+			PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
+			batch_option_callback },
 		{ OPTION_CALLBACK, 0, "batch-check", &batch, "format",
 			N_("show info about objects fed from the standard input"),
-			PARSE_OPT_OPTARG, batch_option_callback },
+			PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
+			batch_option_callback },
 		OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
 			 N_("follow in-tree symlinks (used with --batch or --batch-check)")),
 		OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
diff --git a/builtin/checkout-index.c b/builtin/checkout-index.c
index 88b86c8..eb74774 100644
--- a/builtin/checkout-index.c
+++ b/builtin/checkout-index.c
@@ -132,6 +132,8 @@
 static int option_parse_stage(const struct option *opt,
 			      const char *arg, int unset)
 {
+	BUG_ON_OPT_NEG(unset);
+
 	if (!strcmp(arg, "all")) {
 		to_tempfile = 1;
 		checkout_stage = CHECKOUT_ALL;
diff --git a/builtin/clean.c b/builtin/clean.c
index 8d9a7dc..bbcdeb2 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -140,6 +140,7 @@
 static int exclude_cb(const struct option *opt, const char *arg, int unset)
 {
 	struct string_list *exclude_list = opt->value;
+	BUG_ON_OPT_NEG(unset);
 	string_list_append(exclude_list, arg);
 	return 0;
 }
diff --git a/builtin/commit.c b/builtin/commit.c
index 96d336e..c021b11 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -161,6 +161,9 @@
 static int opt_parse_rename_score(const struct option *opt, const char *arg, int unset)
 {
 	const char **value = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+
 	if (arg != NULL && *arg == '=')
 		arg = arg + 1;
 
@@ -1335,7 +1338,7 @@
 		OPT_BOOL(0, "no-renames", &no_renames, N_("do not detect renames")),
 		{ OPTION_CALLBACK, 'M', "find-renames", &rename_score_arg,
 		  N_("n"), N_("detect renames, optionally set similarity index"),
-		  PARSE_OPT_OPTARG, opt_parse_rename_score },
+		  PARSE_OPT_OPTARG | PARSE_OPT_NONEG, opt_parse_rename_score },
 		OPT_END(),
 	};
 
diff --git a/builtin/fast-export.c b/builtin/fast-export.c
index 456797c..5790f0d 100644
--- a/builtin/fast-export.c
+++ b/builtin/fast-export.c
@@ -253,7 +253,7 @@
 
 	mark_next_object(object);
 
-	printf("blob\nmark :%"PRIu32"\ndata %lu\n", last_idnum, size);
+	printf("blob\nmark :%"PRIu32"\ndata %"PRIuMAX"\n", last_idnum, (uintmax_t)size);
 	if (size && fwrite(buf, size, 1, stdout) != 1)
 		die_errno("could not write blob '%s'", oid_to_hex(oid));
 	printf("\n");
diff --git a/builtin/fetch.c b/builtin/fetch.c
index 6ec7c07..e014032 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -98,6 +98,8 @@
 
 static int parse_refmap_arg(const struct option *opt, const char *arg, int unset)
 {
+	BUG_ON_OPT_NEG(unset);
+
 	/*
 	 * "git fetch --refmap='' origin foo"
 	 * can be used to tell the command not to store anywhere
diff --git a/builtin/grep.c b/builtin/grep.c
index 56e4a11..71df52a 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -34,7 +34,6 @@
 #define GREP_NUM_THREADS_DEFAULT 8
 static int num_threads;
 
-#ifndef NO_PTHREADS
 static pthread_t *threads;
 
 /* We use one producer thread and THREADS consumer
@@ -70,13 +69,11 @@
 
 static inline void grep_lock(void)
 {
-	assert(num_threads);
 	pthread_mutex_lock(&grep_mutex);
 }
 
 static inline void grep_unlock(void)
 {
-	assert(num_threads);
 	pthread_mutex_unlock(&grep_mutex);
 }
 
@@ -234,6 +231,9 @@
 	int hit = 0;
 	int i;
 
+	if (!HAVE_THREADS)
+		BUG("Never call this function unless you have started threads");
+
 	grep_lock();
 	all_work_added = 1;
 
@@ -265,13 +265,6 @@
 
 	return hit;
 }
-#else /* !NO_PTHREADS */
-
-static int wait_all(void)
-{
-	return 0;
-}
-#endif
 
 static int grep_cmd_config(const char *var, const char *value, void *cb)
 {
@@ -284,17 +277,15 @@
 		if (num_threads < 0)
 			die(_("invalid number of threads specified (%d) for %s"),
 			    num_threads, var);
-#ifdef NO_PTHREADS
-		else if (num_threads && num_threads != 1) {
+		else if (!HAVE_THREADS && num_threads > 1) {
 			/*
 			 * TRANSLATORS: %s is the configuration
 			 * variable for tweaking threads, currently
 			 * grep.threads
 			 */
 			warning(_("no threads support, ignoring %s"), var);
-			num_threads = 0;
+			num_threads = 1;
 		}
-#endif
 	}
 
 	if (!strcmp(var, "submodule.recurse"))
@@ -330,17 +321,14 @@
 	grep_source_init(&gs, GREP_SOURCE_OID, pathbuf.buf, path, oid);
 	strbuf_release(&pathbuf);
 
-#ifndef NO_PTHREADS
-	if (num_threads) {
+	if (num_threads > 1) {
 		/*
 		 * add_work() copies gs and thus assumes ownership of
 		 * its fields, so do not call grep_source_clear()
 		 */
 		add_work(opt, &gs);
 		return 0;
-	} else
-#endif
-	{
+	} else {
 		int hit;
 
 		hit = grep_source(opt, &gs);
@@ -363,17 +351,14 @@
 	grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename, filename);
 	strbuf_release(&buf);
 
-#ifndef NO_PTHREADS
-	if (num_threads) {
+	if (num_threads > 1) {
 		/*
 		 * add_work() copies gs and thus assumes ownership of
 		 * its fields, so do not call grep_source_clear()
 		 */
 		add_work(opt, &gs);
 		return 0;
-	} else
-#endif
-	{
+	} else {
 		int hit;
 
 		hit = grep_source(opt, &gs);
@@ -723,11 +708,14 @@
 static int file_callback(const struct option *opt, const char *arg, int unset)
 {
 	struct grep_opt *grep_opt = opt->value;
-	int from_stdin = !strcmp(arg, "-");
+	int from_stdin;
 	FILE *patterns;
 	int lno = 0;
 	struct strbuf sb = STRBUF_INIT;
 
+	BUG_ON_OPT_NEG(unset);
+
+	from_stdin = !strcmp(arg, "-");
 	patterns = from_stdin ? stdin : fopen(arg, "r");
 	if (!patterns)
 		die_errno(_("cannot open '%s'"), arg);
@@ -748,6 +736,8 @@
 static int not_callback(const struct option *opt, const char *arg, int unset)
 {
 	struct grep_opt *grep_opt = opt->value;
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
 	append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
 	return 0;
 }
@@ -755,6 +745,8 @@
 static int and_callback(const struct option *opt, const char *arg, int unset)
 {
 	struct grep_opt *grep_opt = opt->value;
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
 	append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
 	return 0;
 }
@@ -762,6 +754,8 @@
 static int open_callback(const struct option *opt, const char *arg, int unset)
 {
 	struct grep_opt *grep_opt = opt->value;
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
 	append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
 	return 0;
 }
@@ -769,6 +763,8 @@
 static int close_callback(const struct option *opt, const char *arg, int unset)
 {
 	struct grep_opt *grep_opt = opt->value;
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
 	append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
 	return 0;
 }
@@ -777,6 +773,7 @@
 			    int unset)
 {
 	struct grep_opt *grep_opt = opt->value;
+	BUG_ON_OPT_NEG(unset);
 	append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
 	return 0;
 }
@@ -1049,39 +1046,35 @@
 	pathspec.recursive = 1;
 	pathspec.recurse_submodules = !!recurse_submodules;
 
-#ifndef NO_PTHREADS
-	if (list.nr || cached || show_in_pager)
-		num_threads = 0;
-	else if (num_threads == 0)
-		num_threads = GREP_NUM_THREADS_DEFAULT;
-	else if (num_threads < 0)
-		die(_("invalid number of threads specified (%d)"), num_threads);
-	if (num_threads == 1)
-		num_threads = 0;
-#else
-	if (num_threads)
+	if (list.nr || cached || show_in_pager) {
+		if (num_threads > 1)
+			warning(_("invalid option combination, ignoring --threads"));
+		num_threads = 1;
+	} else if (!HAVE_THREADS && num_threads > 1) {
 		warning(_("no threads support, ignoring --threads"));
-	num_threads = 0;
-#endif
+		num_threads = 1;
+	} else if (num_threads < 0)
+		die(_("invalid number of threads specified (%d)"), num_threads);
+	else if (num_threads == 0)
+		num_threads = HAVE_THREADS ? GREP_NUM_THREADS_DEFAULT : 1;
 
-	if (!num_threads)
-		/*
-		 * The compiled patterns on the main path are only
-		 * used when not using threading. Otherwise
-		 * start_threads() below calls compile_grep_patterns()
-		 * for each thread.
-		 */
-		compile_grep_patterns(&opt);
-
-#ifndef NO_PTHREADS
-	if (num_threads) {
+	if (num_threads > 1) {
+		if (!HAVE_THREADS)
+			BUG("Somebody got num_threads calculation wrong!");
 		if (!(opt.name_only || opt.unmatch_name_only || opt.count)
 		    && (opt.pre_context || opt.post_context ||
 			opt.file_break || opt.funcbody))
 			skip_first_line = 1;
 		start_threads(&opt);
+	} else {
+		/*
+		 * The compiled patterns on the main path are only
+		 * used when not using threading. Otherwise
+		 * start_threads() above calls compile_grep_patterns()
+		 * for each thread.
+		 */
+		compile_grep_patterns(&opt);
 	}
-#endif
 
 	if (show_in_pager && (cached || list.nr))
 		die(_("--open-files-in-pager only works on the worktree"));
@@ -1132,7 +1125,7 @@
 		hit = grep_objects(&opt, &pathspec, &list);
 	}
 
-	if (num_threads)
+	if (num_threads > 1)
 		hit |= wait_all();
 	if (hit && show_in_pager)
 		run_pager(&opt, prefix);
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 2004e25..ac1f4ea 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -42,9 +42,7 @@
 };
 
 struct thread_local {
-#ifndef NO_PTHREADS
 	pthread_t thread;
-#endif
 	struct base_data *base_cache;
 	size_t base_cache_used;
 	int pack_fd;
@@ -98,8 +96,6 @@
 static int input_fd, output_fd;
 static const char *curr_pack;
 
-#ifndef NO_PTHREADS
-
 static struct thread_local *thread_data;
 static int nr_dispatched;
 static int threads_active;
@@ -179,26 +175,6 @@
 	free(thread_data);
 }
 
-#else
-
-#define read_lock()
-#define read_unlock()
-
-#define counter_lock()
-#define counter_unlock()
-
-#define work_lock()
-#define work_unlock()
-
-#define deepest_delta_lock()
-#define deepest_delta_unlock()
-
-#define type_cas_lock()
-#define type_cas_unlock()
-
-#endif
-
-
 static int mark_link(struct object *obj, int type, void *data, struct fsck_options *options)
 {
 	if (!obj)
@@ -364,22 +340,20 @@
 
 static inline struct thread_local *get_thread_data(void)
 {
-#ifndef NO_PTHREADS
-	if (threads_active)
-		return pthread_getspecific(key);
-	assert(!threads_active &&
-	       "This should only be reached when all threads are gone");
-#endif
+	if (HAVE_THREADS) {
+		if (threads_active)
+			return pthread_getspecific(key);
+		assert(!threads_active &&
+		       "This should only be reached when all threads are gone");
+	}
 	return &nothread_data;
 }
 
-#ifndef NO_PTHREADS
 static void set_thread_data(struct thread_local *data)
 {
 	if (threads_active)
 		pthread_setspecific(key, data);
 }
-#endif
 
 static struct base_data *alloc_base_data(void)
 {
@@ -450,7 +424,8 @@
 	int hdrlen;
 
 	if (!is_delta_type(type)) {
-		hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", type_name(type), size) + 1;
+		hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX,
+				   type_name(type),(uintmax_t)size) + 1;
 		the_hash_algo->init_fn(&c);
 		the_hash_algo->update_fn(&c, hdr, hdrlen);
 	} else
@@ -1092,7 +1067,6 @@
 	find_unresolved_deltas(base_obj);
 }
 
-#ifndef NO_PTHREADS
 static void *threaded_second_pass(void *data)
 {
 	set_thread_data(data);
@@ -1116,7 +1090,6 @@
 	}
 	return NULL;
 }
-#endif
 
 /*
  * First pass:
@@ -1213,7 +1186,6 @@
 		progress = start_progress(_("Resolving deltas"),
 					  nr_ref_deltas + nr_ofs_deltas);
 
-#ifndef NO_PTHREADS
 	nr_dispatched = 0;
 	if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
 		init_thread();
@@ -1229,7 +1201,6 @@
 		cleanup_thread();
 		return;
 	}
-#endif
 
 	for (i = 0; i < nr_objects; i++) {
 		struct object_entry *obj = &objects[i];
@@ -1531,11 +1502,10 @@
 		if (nr_threads < 0)
 			die(_("invalid number of threads specified (%d)"),
 			    nr_threads);
-#ifdef NO_PTHREADS
-		if (nr_threads != 1)
+		if (!HAVE_THREADS && nr_threads != 1) {
 			warning(_("no threads support, ignoring %s"), k);
-		nr_threads = 1;
-#endif
+			nr_threads = 1;
+		}
 		return 0;
 	}
 	return git_default_config(k, v, cb);
@@ -1628,10 +1598,10 @@
 			chain_histogram[obj_stat[i].delta_depth - 1]++;
 		if (stat_only)
 			continue;
-		printf("%s %-6s %lu %lu %"PRIuMAX,
+		printf("%s %-6s %"PRIuMAX" %"PRIuMAX" %"PRIuMAX,
 		       oid_to_hex(&obj->idx.oid),
-		       type_name(obj->real_type), obj->size,
-		       (unsigned long)(obj[1].idx.offset - obj->idx.offset),
+		       type_name(obj->real_type), (uintmax_t)obj->size,
+		       (uintmax_t)(obj[1].idx.offset - obj->idx.offset),
 		       (uintmax_t)obj->idx.offset);
 		if (is_delta_type(obj->type)) {
 			struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
@@ -1723,12 +1693,10 @@
 				nr_threads = strtoul(arg+10, &end, 0);
 				if (!arg[10] || *end || nr_threads < 0)
 					usage(index_pack_usage);
-#ifdef NO_PTHREADS
-				if (nr_threads != 1)
-					warning(_("no threads support, "
-						  "ignoring %s"), arg);
-				nr_threads = 1;
-#endif
+				if (!HAVE_THREADS && nr_threads != 1) {
+					warning(_("no threads support, ignoring %s"), arg);
+					nr_threads = 1;
+				}
 			} else if (starts_with(arg, "--pack_header=")) {
 				struct pack_header *hdr;
 				char *c;
@@ -1791,14 +1759,12 @@
 	if (strict)
 		opts.flags |= WRITE_IDX_STRICT;
 
-#ifndef NO_PTHREADS
-	if (!nr_threads) {
+	if (HAVE_THREADS && !nr_threads) {
 		nr_threads = online_cpus();
 		/* An experiment showed that more threads does not mean faster */
 		if (nr_threads > 3)
 			nr_threads = 3;
 	}
-#endif
 
 	curr_pack = open_pack_file(pack_name);
 	parse_pack_header();
diff --git a/builtin/init-db.c b/builtin/init-db.c
index 12ddda7..41faffd 100644
--- a/builtin/init-db.c
+++ b/builtin/init-db.c
@@ -451,6 +451,7 @@
 
 static int shared_callback(const struct option *opt, const char *arg, int unset)
 {
+	BUG_ON_OPT_NEG(unset);
 	*((int *) opt->value) = (arg) ? git_config_perm("arg", arg) : PERM_GROUP;
 	return 0;
 }
diff --git a/builtin/interpret-trailers.c b/builtin/interpret-trailers.c
index 4b87e0d..8ae40de 100644
--- a/builtin/interpret-trailers.c
+++ b/builtin/interpret-trailers.c
@@ -80,6 +80,8 @@
 	v->only_trailers = 1;
 	v->only_input = 1;
 	v->unfold = 1;
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
 	return 0;
 }
 
diff --git a/builtin/log.c b/builtin/log.c
index 061d4fd..5ac18e2 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -107,6 +107,8 @@
 {
 	struct line_opt_callback_data *data = option->value;
 
+	BUG_ON_OPT_NEG(unset);
+
 	if (!arg)
 		return -1;
 
@@ -1009,8 +1011,6 @@
 
 	memcpy(&opts, &rev->diffopt, sizeof(opts));
 	opts.output_format = DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
-	opts.stat_width = MAIL_DEFAULT_WRAP;
-
 	diff_setup_done(&opts);
 
 	diff_tree_oid(get_commit_tree_oid(origin),
@@ -1096,7 +1096,7 @@
 	if (rev->rdiff1) {
 		fprintf_ln(rev->diffopt.file, "%s", rev->rdiff_title);
 		show_range_diff(rev->rdiff1, rev->rdiff2,
-				rev->creation_factor, 1, &rev->diffopt);
+				rev->creation_factor, 1, NULL);
 	}
 }
 
@@ -1151,6 +1151,8 @@
 
 static int keep_callback(const struct option *opt, const char *arg, int unset)
 {
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
 	((struct rev_info *)opt->value)->total = -1;
 	keep_subject = 1;
 	return 0;
@@ -1161,6 +1163,7 @@
 static int subject_prefix_callback(const struct option *opt, const char *arg,
 			    int unset)
 {
+	BUG_ON_OPT_NEG(unset);
 	subject_prefix = 1;
 	((struct rev_info *)opt->value)->subject_prefix = arg;
 	return 0;
@@ -1168,6 +1171,8 @@
 
 static int rfc_callback(const struct option *opt, const char *arg, int unset)
 {
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
 	return subject_prefix_callback(opt, "RFC PATCH", unset);
 }
 
@@ -1176,6 +1181,7 @@
 static int numbered_callback(const struct option *opt, const char *arg,
 			     int unset)
 {
+	BUG_ON_OPT_ARG(arg);
 	*(int *)opt->value = numbered_cmdline_opt = unset ? 0 : 1;
 	if (unset)
 		auto_number =  0;
@@ -1185,6 +1191,7 @@
 static int no_numbered_callback(const struct option *opt, const char *arg,
 				int unset)
 {
+	BUG_ON_OPT_NEG(unset);
 	return numbered_callback(opt, arg, 1);
 }
 
@@ -1192,6 +1199,7 @@
 			      int unset)
 {
 	const char **dir = (const char **)opt->value;
+	BUG_ON_OPT_NEG(unset);
 	if (*dir)
 		die(_("Two output directories?"));
 	*dir = arg;
@@ -1508,7 +1516,7 @@
 			    PARSE_OPT_NOARG, numbered_callback },
 		{ OPTION_CALLBACK, 'N', "no-numbered", &numbered, NULL,
 			    N_("use [PATCH] even with multiple patches"),
-			    PARSE_OPT_NOARG, no_numbered_callback },
+			    PARSE_OPT_NOARG | PARSE_OPT_NONEG, no_numbered_callback },
 		OPT_BOOL('s', "signoff", &do_signoff, N_("add Signed-off-by:")),
 		OPT_BOOL(0, "stdout", &use_stdout,
 			    N_("print patches to standard out")),
diff --git a/builtin/ls-files.c b/builtin/ls-files.c
index 7f9919a..c70a9c7 100644
--- a/builtin/ls-files.c
+++ b/builtin/ls-files.c
@@ -475,6 +475,8 @@
 {
 	struct string_list *exclude_list = opt->value;
 
+	BUG_ON_OPT_NEG(unset);
+
 	exc_given = 1;
 	string_list_append(exclude_list, arg);
 
@@ -486,6 +488,8 @@
 {
 	struct dir_struct *dir = opt->value;
 
+	BUG_ON_OPT_NEG(unset);
+
 	exc_given = 1;
 	add_excludes_from_file(dir, arg);
 
@@ -497,6 +501,9 @@
 {
 	struct dir_struct *dir = opt->value;
 
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
+
 	exc_given = 1;
 	setup_standard_excludes(dir);
 
@@ -548,15 +555,16 @@
 			    N_("show resolve-undo information")),
 		{ OPTION_CALLBACK, 'x', "exclude", &exclude_list, N_("pattern"),
 			N_("skip files matching pattern"),
-			0, option_parse_exclude },
+			PARSE_OPT_NONEG, option_parse_exclude },
 		{ OPTION_CALLBACK, 'X', "exclude-from", &dir, N_("file"),
 			N_("exclude patterns are read from <file>"),
-			0, option_parse_exclude_from },
+			PARSE_OPT_NONEG, option_parse_exclude_from },
 		OPT_STRING(0, "exclude-per-directory", &dir.exclude_per_dir, N_("file"),
 			N_("read additional per-directory exclude patterns in <file>")),
 		{ OPTION_CALLBACK, 0, "exclude-standard", &dir, NULL,
 			N_("add the standard git exclusions"),
-			PARSE_OPT_NOARG, option_parse_exclude_standard },
+			PARSE_OPT_NOARG | PARSE_OPT_NONEG,
+			option_parse_exclude_standard },
 		OPT_SET_INT_F(0, "full-name", &prefix_len,
 			      N_("make the output relative to the project top directory"),
 			      0, PARSE_OPT_NONEG),
diff --git a/builtin/ls-tree.c b/builtin/ls-tree.c
index fe3b952..7d581d6 100644
--- a/builtin/ls-tree.c
+++ b/builtin/ls-tree.c
@@ -100,7 +100,7 @@
 						  "BAD");
 				else
 					xsnprintf(size_text, sizeof(size_text),
-						  "%lu", size);
+						  "%"PRIuMAX, (uintmax_t)size);
 			} else
 				xsnprintf(size_text, sizeof(size_text), "-");
 			printf("%06o %s %s %7s\t", mode, type,
diff --git a/builtin/merge-file.c b/builtin/merge-file.c
index b08803e..06a2f90 100644
--- a/builtin/merge-file.c
+++ b/builtin/merge-file.c
@@ -15,6 +15,8 @@
 	static int label_count = 0;
 	const char **names = (const char **)opt->value;
 
+	BUG_ON_OPT_NEG(unset);
+
 	if (label_count >= 3)
 		return error("too many labels on the command line");
 	names[label_count++] = arg;
diff --git a/builtin/merge.c b/builtin/merge.c
index 4aa6071..c3c976d 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -224,6 +224,7 @@
 static int option_parse_n(const struct option *opt,
 			  const char *arg, int unset)
 {
+	BUG_ON_OPT_ARG(arg);
 	show_diffstat = unset;
 	return 0;
 }
@@ -1336,6 +1337,10 @@
 			die(_("%s - not something we can merge"), argv[0]);
 		if (remoteheads->next)
 			die(_("Can merge only exactly one commit into empty head"));
+
+		if (verify_signatures)
+			verify_merge_signature(remoteheads->item, verbosity);
+
 		remote_head_oid = &remoteheads->item->object.oid;
 		read_empty(remote_head_oid, 0);
 		update_ref("initial pull", "HEAD", remote_head_oid, NULL, 0,
@@ -1357,31 +1362,7 @@
 
 	if (verify_signatures) {
 		for (p = remoteheads; p; p = p->next) {
-			struct commit *commit = p->item;
-			char hex[GIT_MAX_HEXSZ + 1];
-			struct signature_check signature_check;
-			memset(&signature_check, 0, sizeof(signature_check));
-
-			check_commit_signature(commit, &signature_check);
-
-			find_unique_abbrev_r(hex, &commit->object.oid, DEFAULT_ABBREV);
-			switch (signature_check.result) {
-			case 'G':
-				break;
-			case 'U':
-				die(_("Commit %s has an untrusted GPG signature, "
-				      "allegedly by %s."), hex, signature_check.signer);
-			case 'B':
-				die(_("Commit %s has a bad GPG signature "
-				      "allegedly by %s."), hex, signature_check.signer);
-			default: /* 'N' */
-				die(_("Commit %s does not have a GPG signature."), hex);
-			}
-			if (verbosity >= 0 && signature_check.result == 'G')
-				printf(_("Commit %s has a good GPG signature by %s\n"),
-				       hex, signature_check.signer);
-
-			signature_check_clear(&signature_check);
+			verify_merge_signature(p->item, verbosity);
 		}
 	}
 
diff --git a/builtin/notes.c b/builtin/notes.c
index c05cd00..c78b7a0 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -215,6 +215,8 @@
 {
 	struct note_data *d = opt->value;
 
+	BUG_ON_OPT_NEG(unset);
+
 	strbuf_grow(&d->buf, strlen(arg) + 2);
 	if (d->buf.len)
 		strbuf_addch(&d->buf, '\n');
@@ -229,6 +231,8 @@
 {
 	struct note_data *d = opt->value;
 
+	BUG_ON_OPT_NEG(unset);
+
 	if (d->buf.len)
 		strbuf_addch(&d->buf, '\n');
 	if (!strcmp(arg, "-")) {
@@ -250,15 +254,15 @@
 	enum object_type type;
 	unsigned long len;
 
+	BUG_ON_OPT_NEG(unset);
+
 	if (d->buf.len)
 		strbuf_addch(&d->buf, '\n');
 
 	if (get_oid(arg, &object))
 		die(_("failed to resolve '%s' as a valid ref."), arg);
-	if (!(buf = read_object_file(&object, &type, &len))) {
-		free(buf);
+	if (!(buf = read_object_file(&object, &type, &len)))
 		die(_("failed to read object '%s'."), arg);
-	}
 	if (type != OBJ_BLOB) {
 		free(buf);
 		die(_("cannot read note data from non-blob object '%s'."), arg);
@@ -273,6 +277,7 @@
 static int parse_reedit_arg(const struct option *opt, const char *arg, int unset)
 {
 	struct note_data *d = opt->value;
+	BUG_ON_OPT_NEG(unset);
 	d->use_editor = 1;
 	return parse_reuse_arg(opt, arg, unset);
 }
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index c99ee79..411aefd 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -1953,8 +1953,6 @@
 	return 0;
 }
 
-#ifndef NO_PTHREADS
-
 /* Protect access to object database */
 static pthread_mutex_t read_mutex;
 #define read_lock()		pthread_mutex_lock(&read_mutex)
@@ -1979,16 +1977,6 @@
  * ahead in the list because they can be stolen and would need
  * progress_mutex for protection.
  */
-#else
-
-#define read_lock()		(void)0
-#define read_unlock()		(void)0
-#define cache_lock()		(void)0
-#define cache_unlock()		(void)0
-#define progress_lock()		(void)0
-#define progress_unlock()	(void)0
-
-#endif
 
 /*
  * Return the size of the object without doing any delta
@@ -2095,9 +2083,9 @@
 			die(_("object %s cannot be read"),
 			    oid_to_hex(&trg_entry->idx.oid));
 		if (sz != trg_size)
-			die(_("object %s inconsistent object length (%lu vs %lu)"),
-			    oid_to_hex(&trg_entry->idx.oid), sz,
-			    trg_size);
+			die(_("object %s inconsistent object length (%"PRIuMAX" vs %"PRIuMAX")"),
+			    oid_to_hex(&trg_entry->idx.oid), (uintmax_t)sz,
+			    (uintmax_t)trg_size);
 		*mem_usage += sz;
 	}
 	if (!src->data) {
@@ -2122,9 +2110,9 @@
 			    oid_to_hex(&src_entry->idx.oid));
 		}
 		if (sz != src_size)
-			die(_("object %s inconsistent object length (%lu vs %lu)"),
-			    oid_to_hex(&src_entry->idx.oid), sz,
-			    src_size);
+			die(_("object %s inconsistent object length (%"PRIuMAX" vs %"PRIuMAX")"),
+			    oid_to_hex(&src_entry->idx.oid), (uintmax_t)sz,
+			    (uintmax_t)src_size);
 		*mem_usage += sz;
 	}
 	if (!src->index) {
@@ -2347,8 +2335,6 @@
 	free(array);
 }
 
-#ifndef NO_PTHREADS
-
 static void try_to_free_from_threads(size_t size)
 {
 	read_lock();
@@ -2577,10 +2563,6 @@
 	free(p);
 }
 
-#else
-#define ll_find_deltas(l, s, w, d, p)	find_deltas(l, &s, w, d, p)
-#endif
-
 static void add_tag_chain(const struct object_id *oid)
 {
 	struct tag *tag;
@@ -2733,12 +2715,10 @@
 		if (delta_search_threads < 0)
 			die(_("invalid number of threads specified (%d)"),
 			    delta_search_threads);
-#ifdef NO_PTHREADS
-		if (delta_search_threads != 1) {
+		if (!HAVE_THREADS && delta_search_threads != 1) {
 			warning(_("no threads support, ignoring %s"), k);
 			delta_search_threads = 0;
 		}
-#endif
 		return 0;
 	}
 	if (!strcmp(k, "pack.indexversion")) {
@@ -2806,9 +2786,11 @@
 
 	if (use_delta_islands) {
 		const char *p;
-		unsigned depth = 0;
+		unsigned depth;
 		struct object_entry *ent;
 
+		/* the empty string is a root tree, which is depth 0 */
+		depth = *name ? 1 : 0;
 		for (p = strchr(name, '/'); p; p = strchr(p + 1, '/'))
 			depth++;
 
@@ -3104,6 +3086,7 @@
 	struct rev_info revs;
 	char line[1000];
 	int flags = 0;
+	int save_warning;
 
 	repo_init_revisions(the_repository, &revs, NULL);
 	save_commit_buffer = 0;
@@ -3113,6 +3096,9 @@
 	/* make sure shallows are read */
 	is_repository_shallow(the_repository);
 
+	save_warning = warn_on_object_refname_ambiguity;
+	warn_on_object_refname_ambiguity = 0;
+
 	while (fgets(line, sizeof(line), stdin) != NULL) {
 		int len = strlen(line);
 		if (len && line[len - 1] == '\n')
@@ -3139,6 +3125,8 @@
 			die(_("bad revision '%s'"), line);
 	}
 
+	warn_on_object_refname_ambiguity = save_warning;
+
 	if (use_bitmap_index && !get_object_list_from_bitmap(&revs))
 		return;
 
@@ -3207,6 +3195,9 @@
 {
 	char *c;
 	const char *val = arg;
+
+	BUG_ON_OPT_NEG(unset);
+
 	pack_idx_opts.version = strtoul(val, &c, 10);
 	if (pack_idx_opts.version > 2)
 		die(_("unsupported index version %s"), val);
@@ -3253,7 +3244,7 @@
 			 N_("similar to --all-progress when progress meter is shown")),
 		{ OPTION_CALLBACK, 0, "index-version", NULL, N_("<version>[,<offset>]"),
 		  N_("write the pack index file in the specified idx format version"),
-		  0, option_parse_index_version },
+		  PARSE_OPT_NONEG, option_parse_index_version },
 		OPT_MAGNITUDE(0, "max-pack-size", &pack_size_limit,
 			      N_("maximum size of each output pack file")),
 		OPT_BOOL(0, "local", &local,
@@ -3402,10 +3393,8 @@
 	if (!delta_search_threads)	/* --threads=0 means autodetect */
 		delta_search_threads = online_cpus();
 
-#ifdef NO_PTHREADS
-	if (delta_search_threads != 1)
+	if (!HAVE_THREADS && delta_search_threads != 1)
 		warning(_("no threads support, ignoring --threads"));
-#endif
 	if (!pack_to_stdout && !pack_size_limit)
 		pack_size_limit = pack_size_limit_cfg;
 	if (pack_to_stdout && pack_size_limit)
diff --git a/builtin/pull.c b/builtin/pull.c
index c21aa27..1b90622 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -557,6 +557,17 @@
 static int pull_into_void(const struct object_id *merge_head,
 		const struct object_id *curr_head)
 {
+	if (opt_verify_signatures) {
+		struct commit *commit;
+
+		commit = lookup_commit(the_repository, merge_head);
+		if (!commit)
+			die(_("unable to access commit %s"),
+			    oid_to_hex(merge_head));
+
+		verify_merge_signature(commit, opt_verbosity);
+	}
+
 	/*
 	 * Two-way merge: we treat the index as based on an empty tree,
 	 * and try to fast-forward to HEAD. This ensures we will not lose
diff --git a/builtin/read-tree.c b/builtin/read-tree.c
index fbbc98e..183ee8c 100644
--- a/builtin/read-tree.c
+++ b/builtin/read-tree.c
@@ -44,6 +44,7 @@
 static int index_output_cb(const struct option *opt, const char *arg,
 				 int unset)
 {
+	BUG_ON_OPT_NEG(unset);
 	set_alternate_index_output(arg);
 	return 0;
 }
@@ -54,6 +55,8 @@
 	struct dir_struct *dir;
 	struct unpack_trees_options *opts;
 
+	BUG_ON_OPT_NEG(unset);
+
 	opts = (struct unpack_trees_options *)opt->value;
 
 	if (opts->dir)
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 0ee06aa..b5c99ec 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -23,6 +23,7 @@
 #include "revision.h"
 #include "commit-reach.h"
 #include "rerere.h"
+#include "branch.h"
 
 static char const * const builtin_rebase_usage[] = {
 	N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
@@ -48,7 +49,10 @@
 {
 	struct child_process cp = CHILD_PROCESS_INIT;
 	struct strbuf out = STRBUF_INIT;
-	int ret;
+	int ret, env = git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1);
+
+	if (env != -1)
+		return env;
 
 	argv_array_pushl(&cp.args,
 			 "config", "--bool", "rebase.usebuiltin", NULL);
@@ -87,7 +91,7 @@
 		REBASE_FORCE = 1<<3,
 		REBASE_INTERACTIVE_EXPLICIT = 1<<4,
 	} flags;
-	struct strbuf git_am_opt;
+	struct argv_array git_am_opts;
 	const char *action;
 	int signoff;
 	int allow_rerere_autoupdate;
@@ -339,7 +343,7 @@
 static int run_specific_rebase(struct rebase_options *opts)
 {
 	const char *argv[] = { NULL, NULL };
-	struct strbuf script_snippet = STRBUF_INIT;
+	struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
 	int status;
 	const char *backend, *backend_func;
 
@@ -433,7 +437,9 @@
 		oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 	add_var(&script_snippet, "GIT_QUIET",
 		opts->flags & REBASE_NO_QUIET ? "" : "t");
-	add_var(&script_snippet, "git_am_opt", opts->git_am_opt.buf);
+	sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
+	add_var(&script_snippet, "git_am_opt", buf.buf);
+	strbuf_release(&buf);
 	add_var(&script_snippet, "verbose",
 		opts->flags & REBASE_VERBOSE ? "t" : "");
 	add_var(&script_snippet, "diffstat",
@@ -522,12 +528,17 @@
 
 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 
+#define RESET_HEAD_DETACH (1<<0)
+#define RESET_HEAD_HARD (1<<1)
+
 static int reset_head(struct object_id *oid, const char *action,
-		      const char *switch_to_branch, int detach_head,
+		      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;
 	struct object_id head_oid;
-	struct tree_desc desc;
+	struct tree_desc desc[2] = { { NULL }, { NULL } };
 	struct lock_file lock = LOCK_INIT;
 	struct unpack_trees_options unpack_tree_opts;
 	struct tree *tree;
@@ -536,60 +547,63 @@
 	size_t prefix_len;
 	struct object_id *orig = NULL, oid_orig,
 		*old_orig = NULL, oid_old_orig;
-	int ret = 0;
+	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)
-		return -1;
-
-	if (!oid) {
-		if (get_oid("HEAD", &head_oid)) {
-			rollback_lock_file(&lock);
-			return error(_("could not determine HEAD revision"));
-		}
-		oid = &head_oid;
+	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 = oneway_merge;
+	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) {
-		rollback_lock_file(&lock);
-		return error(_("could not read index"));
+		ret = error(_("could not read index"));
+		goto leave_reset_head;
 	}
 
-	if (!fill_tree_descriptor(&desc, oid)) {
-		error(_("failed to find tree of %s"), oid_to_hex(oid));
-		rollback_lock_file(&lock);
-		free((void *)desc.buffer);
-		return -1;
+	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 (unpack_trees(1, &desc, &unpack_tree_opts)) {
-		rollback_lock_file(&lock);
-		free((void *)desc.buffer);
-		return -1;
+	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->index, tree);
 
-	if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0)
+	if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
 		ret = error(_("could not write index"));
-	free((void *)desc.buffer);
-
-	if (ret)
-		return ret;
+		goto leave_reset_head;
+	}
 
 	reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 	strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
@@ -613,7 +627,8 @@
 		reflog_head = msg.buf;
 	}
 	if (!switch_to_branch)
-		ret = update_ref(reflog_head, "HEAD", oid, orig, REF_NO_DEREF,
+		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);
@@ -622,7 +637,11 @@
 					 UPDATE_REFS_MSG_ON_ERR);
 	}
 
+leave_reset_head:
 	strbuf_release(&msg);
+	rollback_lock_file(&lock);
+	while (nr)
+		free((void *)desc[--nr].buffer);
 	return ret;
 }
 
@@ -703,6 +722,9 @@
 {
 	struct rebase_options *opts = opt->value;
 
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
+
 	if (!is_interactive(opts))
 		opts->type = REBASE_MERGE;
 
@@ -715,6 +737,9 @@
 {
 	struct rebase_options *opts = opt->value;
 
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
+
 	opts->type = REBASE_INTERACTIVE;
 	opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
 
@@ -751,12 +776,29 @@
 	exit(1);
 }
 
+static void set_reflog_action(struct rebase_options *options)
+{
+	const char *env;
+	struct strbuf buf = STRBUF_INIT;
+
+	if (!is_interactive(options))
+		return;
+
+	env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
+	if (env && strcmp("rebase", env))
+		return; /* only override it if it is "rebase" */
+
+	strbuf_addf(&buf, "rebase -i (%s)", options->action);
+	setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
+	strbuf_release(&buf);
+}
+
 int cmd_rebase(int argc, const char **argv, const char *prefix)
 {
 	struct rebase_options options = {
 		.type = REBASE_UNSPECIFIED,
 		.flags = REBASE_NO_QUIET,
-		.git_am_opt = STRBUF_INIT,
+		.git_am_opts = ARGV_ARRAY_INIT,
 		.allow_rerere_autoupdate  = -1,
 		.allow_empty_message = 1,
 		.git_format_patch_opt = STRBUF_INIT,
@@ -777,12 +819,7 @@
 		ACTION_EDIT_TODO,
 		ACTION_SHOW_CURRENT_PATCH,
 	} action = NO_ACTION;
-	int committer_date_is_author_date = 0;
-	int ignore_date = 0;
-	int ignore_whitespace = 0;
 	const char *gpg_sign = NULL;
-	int opt_c = -1;
-	struct string_list whitespace = STRING_LIST_INIT_NODUP;
 	struct string_list exec = STRING_LIST_INIT_NODUP;
 	const char *rebase_merges = NULL;
 	int fork_point = -1;
@@ -804,15 +841,20 @@
 		{OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
 			N_("do not show diffstat of what changed upstream"),
 			PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
-		OPT_BOOL(0, "ignore-whitespace", &ignore_whitespace,
-			 N_("passed to 'git apply'")),
 		OPT_BOOL(0, "signoff", &options.signoff,
 			 N_("add a Signed-off-by: line to each commit")),
-		OPT_BOOL(0, "committer-date-is-author-date",
-			 &committer_date_is_author_date,
-			 N_("passed to 'git am'")),
-		OPT_BOOL(0, "ignore-date", &ignore_date,
-			 N_("passed to 'git am'")),
+		OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
+				  NULL, N_("passed to 'git am'"),
+				  PARSE_OPT_NOARG),
+		OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
+				  &options.git_am_opts, NULL,
+				  N_("passed to 'git am'"), PARSE_OPT_NOARG),
+		OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
+				  N_("passed to 'git am'"), PARSE_OPT_NOARG),
+		OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
+				  N_("passed to 'git apply'"), 0),
+		OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
+				  N_("action"), N_("passed to 'git apply'"), 0),
 		OPT_BIT('f', "force-rebase", &options.flags,
 			N_("cherry-pick all commits, even if unchanged"),
 			REBASE_FORCE),
@@ -846,7 +888,7 @@
 			       "them"), REBASE_PRESERVE_MERGES),
 		OPT_BOOL(0, "rerere-autoupdate",
 			 &options.allow_rerere_autoupdate,
-			 N_("allow rerere to update index  with resolved "
+			 N_("allow rerere to update index with resolved "
 			    "conflict")),
 		OPT_BOOL('k', "keep-empty", &options.keep_empty,
 			 N_("preserve empty commits during rebase")),
@@ -856,10 +898,6 @@
 		{ OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
 			N_("GPG-sign commits"),
 			PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
-		OPT_STRING_LIST(0, "whitespace", &whitespace,
-				N_("whitespace"), N_("passed to 'git apply'")),
-		OPT_SET_INT('C', NULL, &opt_c, N_("passed to 'git apply'"),
-			    REBASE_AM),
 		OPT_BOOL(0, "autostash", &options.autostash,
 			 N_("automatically stash/stash pop before and after")),
 		OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
@@ -884,6 +922,7 @@
 			 N_("rebase all reachable commits up to the root(s)")),
 		OPT_END(),
 	};
+	int i;
 
 	/*
 	 * NEEDSWORK: Once the builtin rebase has been tested enough
@@ -956,6 +995,7 @@
 
 	if (action != NO_ACTION && !in_progress)
 		die(_("No rebase in progress?"));
+	setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
 
 	if (action == ACTION_EDIT_TODO && !is_interactive(&options))
 		die(_("The --edit-todo action can only be used during "
@@ -968,6 +1008,7 @@
 		int fd;
 
 		options.action = "continue";
+		set_reflog_action(&options);
 
 		/* Sanity check */
 		if (get_oid("HEAD", &head))
@@ -996,12 +1037,15 @@
 		struct string_list merge_rr = STRING_LIST_INIT_DUP;
 
 		options.action = "skip";
+		set_reflog_action(&options);
 
 		rerere_clear(&merge_rr);
 		string_list_clear(&merge_rr, 1);
 
-		if (reset_head(NULL, "reset", NULL, 0, NULL, NULL) < 0)
+		if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
+			       NULL, NULL) < 0)
 			die(_("could not discard worktree changes"));
+		remove_branch_state();
 		if (read_basic_state(&options))
 			exit(1);
 		goto run_rebase;
@@ -1009,6 +1053,7 @@
 	case ACTION_ABORT: {
 		struct string_list merge_rr = STRING_LIST_INIT_DUP;
 		options.action = "abort";
+		set_reflog_action(&options);
 
 		rerere_clear(&merge_rr);
 		string_list_clear(&merge_rr, 1);
@@ -1016,9 +1061,11 @@
 		if (read_basic_state(&options))
 			exit(1);
 		if (reset_head(&options.orig_head, "reset",
-			       options.head_name, 0, NULL, NULL) < 0)
+			       options.head_name, RESET_HEAD_HARD,
+			       NULL, NULL) < 0)
 			die(_("could not move back to %s"),
 			    oid_to_hex(&options.orig_head));
+		remove_branch_state();
 		ret = finish_rebase(&options);
 		goto cleanup;
 	}
@@ -1064,22 +1111,27 @@
 		    state_dir_base, cmd_live_rebase, buf.buf);
 	}
 
+	for (i = 0; i < options.git_am_opts.argc; i++) {
+		const char *option = options.git_am_opts.argv[i], *p;
+		if (!strcmp(option, "--committer-date-is-author-date") ||
+		    !strcmp(option, "--ignore-date") ||
+		    !strcmp(option, "--whitespace=fix") ||
+		    !strcmp(option, "--whitespace=strip"))
+			options.flags |= REBASE_FORCE;
+		else if (skip_prefix(option, "-C", &p)) {
+			while (*p)
+				if (!isdigit(*(p++)))
+					die(_("switch `C' expects a "
+					      "numerical value"));
+		} else if (skip_prefix(option, "--whitespace=", &p)) {
+			if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
+			    strcmp(p, "error") && strcmp(p, "error-all"))
+				die("Invalid whitespace option: '%s'", p);
+		}
+	}
+
 	if (!(options.flags & REBASE_NO_QUIET))
-		strbuf_addstr(&options.git_am_opt, " -q");
-
-	if (committer_date_is_author_date) {
-		strbuf_addstr(&options.git_am_opt,
-			      " --committer-date-is-author-date");
-		options.flags |= REBASE_FORCE;
-	}
-
-	if (ignore_whitespace)
-		strbuf_addstr(&options.git_am_opt, " --ignore-whitespace");
-
-	if (ignore_date) {
-		strbuf_addstr(&options.git_am_opt, " --ignore-date");
-		options.flags |= REBASE_FORCE;
-	}
+		argv_array_push(&options.git_am_opts, "-q");
 
 	if (options.keep_empty)
 		imply_interactive(&options, "--keep-empty");
@@ -1089,23 +1141,6 @@
 		options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
 	}
 
-	if (opt_c >= 0)
-		strbuf_addf(&options.git_am_opt, " -C%d", opt_c);
-
-	if (whitespace.nr) {
-		int i;
-
-		for (i = 0; i < whitespace.nr; i++) {
-			const char *item = whitespace.items[i].string;
-
-			strbuf_addf(&options.git_am_opt, " --whitespace=%s",
-				    item);
-
-			if ((!strcmp(item, "fix")) || (!strcmp(item, "strip")))
-				options.flags |= REBASE_FORCE;
-		}
-	}
-
 	if (exec.nr) {
 		int i;
 
@@ -1181,23 +1216,18 @@
 		break;
 	}
 
-	if (options.git_am_opt.len) {
-		const char *p;
-
+	if (options.git_am_opts.argc) {
 		/* all am options except -q are compatible only with --am */
-		strbuf_reset(&buf);
-		strbuf_addbuf(&buf, &options.git_am_opt);
-		strbuf_addch(&buf, ' ');
-		while ((p = strstr(buf.buf, " -q ")))
-			strbuf_splice(&buf, p - buf.buf, 4, " ", 1);
-		strbuf_trim(&buf);
+		for (i = options.git_am_opts.argc - 1; i >= 0; i--)
+			if (strcmp(options.git_am_opts.argv[i], "-q"))
+				break;
 
-		if (is_interactive(&options) && buf.len)
+		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 && buf.len)
+		if (options.type == REBASE_MERGE && i >= 0)
 			die(_("error: cannot combine merge options (--merge, "
 			      "--strategy, --strategy-option) with am options "
 			      "(%s)"), buf.buf);
@@ -1207,7 +1237,7 @@
 		if (options.type == REBASE_PRESERVE_MERGES)
 			die("cannot combine '--signoff' with "
 			    "'--preserve-merges'");
-		strbuf_addstr(&options.git_am_opt, " --signoff");
+		argv_array_push(&options.git_am_opts, "--signoff");
 		options.flags |= REBASE_FORCE;
 	}
 
@@ -1380,7 +1410,7 @@
 			write_file(autostash, "%s", oid_to_hex(&oid));
 			printf(_("Created autostash: %s\n"), buf.buf);
 			if (reset_head(&head->object.oid, "reset --hard",
-				       NULL, 0, NULL, NULL) < 0)
+				       NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
 				die(_("could not reset --hard"));
 			printf(_("HEAD is now at %s"),
 			       find_unique_abbrev(&head->object.oid,
@@ -1431,11 +1461,12 @@
 				}
 
 				strbuf_reset(&buf);
-				strbuf_addf(&buf, "rebase: checkout %s",
+				strbuf_addf(&buf, "%s: checkout %s",
+					    getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
 					    options.switch_to);
 				if (reset_head(&oid, "checkout",
 					       options.head_name, 0,
-					       NULL, NULL) < 0) {
+					       NULL, buf.buf) < 0) {
 					ret = !!error(_("could not switch to "
 							"%s"),
 						      options.switch_to);
@@ -1472,10 +1503,15 @@
 	if (options.flags & REBASE_DIFFSTAT) {
 		struct diff_options opts;
 
-		if (options.flags & REBASE_VERBOSE)
-			printf(_("Changes from %s to %s:\n"),
-				oid_to_hex(&merge_base),
-				oid_to_hex(&options.onto->object.oid));
+		if (options.flags & REBASE_VERBOSE) {
+			if (is_null_oid(&merge_base))
+				printf(_("Changes to %s:\n"),
+				       oid_to_hex(&options.onto->object.oid));
+			else
+				printf(_("Changes from %s to %s:\n"),
+				       oid_to_hex(&merge_base),
+				       oid_to_hex(&options.onto->object.oid));
+		}
 
 		/* We want color (if set), but no pager */
 		diff_setup(&opts);
@@ -1485,8 +1521,9 @@
 			DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
 		opts.detect_rename = DIFF_DETECT_RENAME;
 		diff_setup_done(&opts);
-		diff_tree_oid(&merge_base, &options.onto->object.oid,
-			      "", &opts);
+		diff_tree_oid(is_null_oid(&merge_base) ?
+			      the_hash_algo->empty_tree : &merge_base,
+			      &options.onto->object.oid, "", &opts);
 		diffcore_std(&opts);
 		diff_flush(&opts);
 	}
@@ -1499,9 +1536,10 @@
 		printf(_("First, rewinding head to replay your work on top of "
 			 "it...\n"));
 
-	strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
-	if (reset_head(&options.onto->object.oid, "checkout", NULL, 1,
-	    NULL, msg.buf))
+	strbuf_addf(&msg, "%s: checkout %s",
+		    getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
+	if (reset_head(&options.onto->object.oid, "checkout", NULL,
+		       RESET_HEAD_DETACH, NULL, msg.buf))
 		die(_("Could not detach HEAD"));
 	strbuf_release(&msg);
 
@@ -1511,7 +1549,7 @@
 	 */
 	strbuf_reset(&msg);
 	if (!oidcmp(&merge_base, &options.orig_head)) {
-		printf(_("Fast-forwarded %s to %s. \n"),
+		printf(_("Fast-forwarded %s to %s.\n"),
 			branch_name, options.onto_name);
 		strbuf_addf(&msg, "rebase finished: %s onto %s",
 			options.head_name ? options.head_name : "detached HEAD",
diff --git a/builtin/replace.c b/builtin/replace.c
index a58b9c6..affcdfb 100644
--- a/builtin/replace.c
+++ b/builtin/replace.c
@@ -495,6 +495,7 @@
 	if (!fp)
 		return -1;
 
+	advice_graft_file_deprecated = 0;
 	while (strbuf_getline(&buf, fp) != EOF) {
 		if (*buf.buf == '#')
 			continue;
diff --git a/builtin/show-branch.c b/builtin/show-branch.c
index 65f4a4c..934e514 100644
--- a/builtin/show-branch.c
+++ b/builtin/show-branch.c
@@ -604,6 +604,7 @@
 {
 	char *ep;
 	const char **base = (const char **)opt->value;
+	BUG_ON_OPT_NEG(unset);
 	if (!arg)
 		arg = "";
 	reflog = strtoul(arg, &ep, 10);
@@ -674,7 +675,7 @@
 		{ OPTION_CALLBACK, 'g', "reflog", &reflog_base, N_("<n>[,<base>]"),
 			    N_("show <n> most recent ref-log entries starting at "
 			       "base"),
-			    PARSE_OPT_OPTARG,
+			    PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
 			    parse_reflog_param },
 		OPT_END()
 	};
diff --git a/builtin/show-ref.c b/builtin/show-ref.c
index 2f13f13..ed888ff 100644
--- a/builtin/show-ref.c
+++ b/builtin/show-ref.c
@@ -151,6 +151,7 @@
 static int exclude_existing_callback(const struct option *opt, const char *arg,
 				     int unset)
 {
+	BUG_ON_OPT_NEG(unset);
 	exclude_arg = 1;
 	*(const char **)opt->value = arg;
 	return 0;
diff --git a/builtin/tag.c b/builtin/tag.c
index f623632..02f6bd1 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -338,6 +338,8 @@
 {
 	struct msg_arg *msg = opt->value;
 
+	BUG_ON_OPT_NEG(unset);
+
 	if (!arg)
 		return -1;
 	if (msg->buf.len)
@@ -390,8 +392,8 @@
 		OPT_GROUP(N_("Tag creation options")),
 		OPT_BOOL('a', "annotate", &annotate,
 					N_("annotated tag, needs a message")),
-		OPT_CALLBACK('m', "message", &msg, N_("message"),
-			     N_("tag message"), parse_msg_arg),
+		{ OPTION_CALLBACK, 'm', "message", &msg, N_("message"),
+		  N_("tag message"), PARSE_OPT_NONEG, parse_msg_arg },
 		OPT_FILENAME('F', "file", &msgfile, N_("read message from file")),
 		OPT_BOOL('e', "edit", &edit_flag, N_("force edit of tag message")),
 		OPT_BOOL('s', "sign", &opt.sign, N_("annotated and GPG-signed tag")),
diff --git a/builtin/update-index.c b/builtin/update-index.c
index 0e1dcf0..31e7cce 100644
--- a/builtin/update-index.c
+++ b/builtin/update-index.c
@@ -790,12 +790,16 @@
 static int refresh_callback(const struct option *opt,
 				const char *arg, int unset)
 {
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
 	return refresh(opt->value, 0);
 }
 
 static int really_refresh_callback(const struct option *opt,
 				const char *arg, int unset)
 {
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
 	return refresh(opt->value, REFRESH_REALLY);
 }
 
@@ -803,6 +807,7 @@
 				const char *arg, int unset)
 {
 	char *flip = opt->value;
+	BUG_ON_OPT_NEG(unset);
 	if ((arg[0] != '-' && arg[0] != '+') || arg[1] != 'x' || arg[2])
 		return error("option 'chmod' expects \"+x\" or \"-x\"");
 	*flip = arg[0];
@@ -812,6 +817,8 @@
 static int resolve_undo_clear_callback(const struct option *opt,
 				const char *arg, int unset)
 {
+	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
 	resolve_undo_clear();
 	return 0;
 }
@@ -847,6 +854,8 @@
 	unsigned int mode;
 	const char *path;
 
+	BUG_ON_OPT_NEG(unset);
+
 	if (!parse_new_style_cacheinfo(ctx->argv[1], &mode, &oid, &path)) {
 		if (add_cacheinfo(mode, &oid, path, 0))
 			die("git update-index: --cacheinfo cannot add %s", path);
@@ -869,6 +878,8 @@
 {
 	int *nul_term_line = opt->value;
 
+	BUG_ON_OPT_NEG(unset);
+
 	if (ctx->argc != 1)
 		return error("option '%s' must be the last argument", opt->long_name);
 	allow_add = allow_replace = allow_remove = 1;
@@ -881,6 +892,8 @@
 {
 	int *read_from_stdin = opt->value;
 
+	BUG_ON_OPT_NEG(unset);
+
 	if (ctx->argc != 1)
 		return error("option '%s' must be the last argument", opt->long_name);
 	*read_from_stdin = 1;
@@ -888,11 +901,13 @@
 }
 
 static int unresolve_callback(struct parse_opt_ctx_t *ctx,
-				const struct option *opt, int flags)
+				const struct option *opt, int unset)
 {
 	int *has_errors = opt->value;
 	const char *prefix = startup_info->prefix;
 
+	BUG_ON_OPT_NEG(unset);
+
 	/* consume remaining arguments. */
 	*has_errors = do_unresolve(ctx->argc, ctx->argv,
 				prefix, prefix ? strlen(prefix) : 0);
@@ -905,11 +920,13 @@
 }
 
 static int reupdate_callback(struct parse_opt_ctx_t *ctx,
-				const struct option *opt, int flags)
+				const struct option *opt, int unset)
 {
 	int *has_errors = opt->value;
 	const char *prefix = startup_info->prefix;
 
+	BUG_ON_OPT_NEG(unset);
+
 	/* consume remaining arguments. */
 	setup_work_tree();
 	*has_errors = do_reupdate(ctx->argc, ctx->argv,
diff --git a/bundle.c b/bundle.c
index 1ef584b..88c3e16 100644
--- a/bundle.c
+++ b/bundle.c
@@ -243,7 +243,7 @@
 }
 
 
-/* Write the pack data to bundle_fd, then close it if it is > 1. */
+/* Write the pack data to bundle_fd */
 static int write_pack_data(int bundle_fd, struct rev_info *revs)
 {
 	struct child_process pack_objects = CHILD_PROCESS_INIT;
@@ -256,6 +256,20 @@
 	pack_objects.in = -1;
 	pack_objects.out = bundle_fd;
 	pack_objects.git_cmd = 1;
+
+	/*
+	 * start_command() will close our descriptor if it's >1. Duplicate it
+	 * to avoid surprising the caller.
+	 */
+	if (pack_objects.out > 1) {
+		pack_objects.out = dup(pack_objects.out);
+		if (pack_objects.out < 0) {
+			error_errno(_("unable to dup bundle descriptor"));
+			child_process_clear(&pack_objects);
+			return -1;
+		}
+	}
+
 	if (start_command(&pack_objects))
 		return error(_("Could not spawn pack-objects"));
 
@@ -421,21 +435,10 @@
 	bundle_to_stdout = !strcmp(path, "-");
 	if (bundle_to_stdout)
 		bundle_fd = 1;
-	else {
+	else
 		bundle_fd = hold_lock_file_for_update(&lock, path,
 						      LOCK_DIE_ON_ERROR);
 
-		/*
-		 * write_pack_data() will close the fd passed to it,
-		 * but commit_lock_file() will also try to close the
-		 * lockfile's fd. So make a copy of the file
-		 * descriptor to avoid trying to close it twice.
-		 */
-		bundle_fd = dup(bundle_fd);
-		if (bundle_fd < 0)
-			die_errno("unable to dup file descriptor");
-	}
-
 	/* write signature */
 	write_or_die(bundle_fd, bundle_signature, strlen(bundle_signature));
 
@@ -463,10 +466,8 @@
 		goto err;
 
 	/* write pack */
-	if (write_pack_data(bundle_fd, &revs)) {
-		bundle_fd = -1; /* already closed by the above call */
+	if (write_pack_data(bundle_fd, &revs))
 		goto err;
-	}
 
 	if (!bundle_to_stdout) {
 		if (commit_lock_file(&lock))
@@ -474,11 +475,7 @@
 	}
 	return 0;
 err:
-	if (!bundle_to_stdout) {
-		if (0 <= bundle_fd)
-			close(bundle_fd);
-		rollback_lock_file(&lock);
-	}
+	rollback_lock_file(&lock);
 	return -1;
 }
 
diff --git a/ci/lib-travisci.sh b/ci/lib-travisci.sh
index 06970f7..69dff4d 100755
--- a/ci/lib-travisci.sh
+++ b/ci/lib-travisci.sh
@@ -123,7 +123,7 @@
 	# Travis CI OS X
 	export GIT_SKIP_TESTS="t9810 t9816"
 	;;
-GETTEXT_POISON)
-	export GETTEXT_POISON=YesPlease
+GIT_TEST_GETTEXT_POISON)
+	export GIT_TEST_GETTEXT_POISON=YesPlease
 	;;
 esac
diff --git a/commit.c b/commit.c
index d566d7e..d13a7bc 100644
--- a/commit.c
+++ b/commit.c
@@ -657,11 +657,10 @@
 /* count number of children that have not been emitted */
 define_commit_slab(indegree_slab, int);
 
-/* record author-date for each commit object */
 define_commit_slab(author_date_slab, timestamp_t);
 
-static void record_author_date(struct author_date_slab *author_date,
-			       struct commit *commit)
+void record_author_date(struct author_date_slab *author_date,
+			struct commit *commit)
 {
 	const char *buffer = get_commit_buffer(commit, NULL);
 	struct ident_split ident;
@@ -686,8 +685,8 @@
 	unuse_commit_buffer(commit, buffer);
 }
 
-static int compare_commits_by_author_date(const void *a_, const void *b_,
-					  void *cb_data)
+int compare_commits_by_author_date(const void *a_, const void *b_,
+				   void *cb_data)
 {
 	const struct commit *a = a_, *b = b_;
 	struct author_date_slab *author_date = cb_data;
@@ -1100,7 +1099,33 @@
 	return ret;
 }
 
+void verify_merge_signature(struct commit *commit, int verbosity)
+{
+	char hex[GIT_MAX_HEXSZ + 1];
+	struct signature_check signature_check;
+	memset(&signature_check, 0, sizeof(signature_check));
 
+	check_commit_signature(commit, &signature_check);
+
+	find_unique_abbrev_r(hex, &commit->object.oid, DEFAULT_ABBREV);
+	switch (signature_check.result) {
+	case 'G':
+		break;
+	case 'U':
+		die(_("Commit %s has an untrusted GPG signature, "
+		      "allegedly by %s."), hex, signature_check.signer);
+	case 'B':
+		die(_("Commit %s has a bad GPG signature "
+		      "allegedly by %s."), hex, signature_check.signer);
+	default: /* 'N' */
+		die(_("Commit %s does not have a GPG signature."), hex);
+	}
+	if (verbosity >= 0 && signature_check.result == 'G')
+		printf(_("Commit %s has a good GPG signature by %s\n"),
+		       hex, signature_check.signer);
+
+	signature_check_clear(&signature_check);
+}
 
 void append_merge_tag_headers(struct commit_list *parents,
 			      struct commit_extra_header ***tail)
diff --git a/commit.h b/commit.h
index 8f15cfd..9866453 100644
--- a/commit.h
+++ b/commit.h
@@ -8,6 +8,7 @@
 #include "gpg-interface.h"
 #include "string-list.h"
 #include "pretty.h"
+#include "commit-slab.h"
 
 #define COMMIT_NOT_FROM_GRAPH 0xFFFFFFFF
 #define GENERATION_NUMBER_INFINITY 0xFFFFFFFF
@@ -333,6 +334,20 @@
  */
 extern int check_commit_signature(const struct commit *commit, struct signature_check *sigc);
 
+/* record author-date for each commit object */
+struct author_date_slab;
+void record_author_date(struct author_date_slab *author_date,
+			struct commit *commit);
+
+int compare_commits_by_author_date(const void *a_, const void *b_, void *unused);
+
+/*
+ * Verify a single commit with check_commit_signature() and die() if it is not
+ * a good signature. This isn't really suitable for general use, but is a
+ * helper to implement consistent logic for pull/merge --verify-signatures.
+ */
+void verify_merge_signature(struct commit *commit, int verbose);
+
 int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused);
 int compare_commits_by_gen_then_commit_date(const void *a_, const void *b_, void *unused);
 
diff --git a/compat/mingw.c b/compat/mingw.c
index d2f4fab..34b3880 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -1028,8 +1028,8 @@
 }
 
 /*
- * See http://msdn2.microsoft.com/en-us/library/17w5ykft(vs.71).aspx
- * (Parsing C++ Command-Line Arguments)
+ * 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)
 {
@@ -2211,24 +2211,12 @@
 
 int link(const char *oldpath, const char *newpath)
 {
-	typedef BOOL (WINAPI *T)(LPCWSTR, LPCWSTR, LPSECURITY_ATTRIBUTES);
-	static T create_hard_link = NULL;
 	wchar_t woldpath[MAX_PATH], wnewpath[MAX_PATH];
 	if (xutftowcs_path(woldpath, oldpath) < 0 ||
 		xutftowcs_path(wnewpath, newpath) < 0)
 		return -1;
 
-	if (!create_hard_link) {
-		create_hard_link = (T) GetProcAddress(
-			GetModuleHandle("kernel32.dll"), "CreateHardLinkW");
-		if (!create_hard_link)
-			create_hard_link = (T)-1;
-	}
-	if (create_hard_link == (T)-1) {
-		errno = ENOSYS;
-		return -1;
-	}
-	if (!create_hard_link(wnewpath, woldpath, NULL)) {
+	if (!CreateHardLinkW(wnewpath, woldpath, NULL)) {
 		errno = err_win_to_posix(GetLastError());
 		return -1;
 	}
diff --git a/compat/win32/pthread.c b/compat/win32/pthread.c
index e18f5c6..2e7eead 100644
--- a/compat/win32/pthread.c
+++ b/compat/win32/pthread.c
@@ -56,141 +56,3 @@
 	t.tid = GetCurrentThreadId();
 	return t;
 }
-
-int pthread_cond_init(pthread_cond_t *cond, const void *unused)
-{
-	cond->waiters = 0;
-	cond->was_broadcast = 0;
-	InitializeCriticalSection(&cond->waiters_lock);
-
-	cond->sema = CreateSemaphore(NULL, 0, LONG_MAX, NULL);
-	if (!cond->sema)
-		die("CreateSemaphore() failed");
-
-	cond->continue_broadcast = CreateEvent(NULL,	/* security */
-				FALSE,			/* auto-reset */
-				FALSE,			/* not signaled */
-				NULL);			/* name */
-	if (!cond->continue_broadcast)
-		die("CreateEvent() failed");
-
-	return 0;
-}
-
-int pthread_cond_destroy(pthread_cond_t *cond)
-{
-	CloseHandle(cond->sema);
-	CloseHandle(cond->continue_broadcast);
-	DeleteCriticalSection(&cond->waiters_lock);
-	return 0;
-}
-
-int pthread_cond_wait(pthread_cond_t *cond, CRITICAL_SECTION *mutex)
-{
-	int last_waiter;
-
-	EnterCriticalSection(&cond->waiters_lock);
-	cond->waiters++;
-	LeaveCriticalSection(&cond->waiters_lock);
-
-	/*
-	 * Unlock external mutex and wait for signal.
-	 * NOTE: we've held mutex locked long enough to increment
-	 * waiters count above, so there's no problem with
-	 * leaving mutex unlocked before we wait on semaphore.
-	 */
-	LeaveCriticalSection(mutex);
-
-	/* let's wait - ignore return value */
-	WaitForSingleObject(cond->sema, INFINITE);
-
-	/*
-	 * Decrease waiters count. If we are the last waiter, then we must
-	 * notify the broadcasting thread that it can continue.
-	 * But if we continued due to cond_signal, we do not have to do that
-	 * because the signaling thread knows that only one waiter continued.
-	 */
-	EnterCriticalSection(&cond->waiters_lock);
-	cond->waiters--;
-	last_waiter = cond->was_broadcast && cond->waiters == 0;
-	LeaveCriticalSection(&cond->waiters_lock);
-
-	if (last_waiter) {
-		/*
-		 * cond_broadcast was issued while mutex was held. This means
-		 * that all other waiters have continued, but are contending
-		 * for the mutex at the end of this function because the
-		 * broadcasting thread did not leave cond_broadcast, yet.
-		 * (This is so that it can be sure that each waiter has
-		 * consumed exactly one slice of the semaphor.)
-		 * The last waiter must tell the broadcasting thread that it
-		 * can go on.
-		 */
-		SetEvent(cond->continue_broadcast);
-		/*
-		 * Now we go on to contend with all other waiters for
-		 * the mutex. Auf in den Kampf!
-		 */
-	}
-	/* lock external mutex again */
-	EnterCriticalSection(mutex);
-
-	return 0;
-}
-
-/*
- * IMPORTANT: This implementation requires that pthread_cond_signal
- * is called while the mutex is held that is used in the corresponding
- * pthread_cond_wait calls!
- */
-int pthread_cond_signal(pthread_cond_t *cond)
-{
-	int have_waiters;
-
-	EnterCriticalSection(&cond->waiters_lock);
-	have_waiters = cond->waiters > 0;
-	LeaveCriticalSection(&cond->waiters_lock);
-
-	/*
-	 * Signal only when there are waiters
-	 */
-	if (have_waiters)
-		return ReleaseSemaphore(cond->sema, 1, NULL) ?
-			0 : err_win_to_posix(GetLastError());
-	else
-		return 0;
-}
-
-/*
- * DOUBLY IMPORTANT: This implementation requires that pthread_cond_broadcast
- * is called while the mutex is held that is used in the corresponding
- * pthread_cond_wait calls!
- */
-int pthread_cond_broadcast(pthread_cond_t *cond)
-{
-	EnterCriticalSection(&cond->waiters_lock);
-
-	if ((cond->was_broadcast = cond->waiters > 0)) {
-		/* wake up all waiters */
-		ReleaseSemaphore(cond->sema, cond->waiters, NULL);
-		LeaveCriticalSection(&cond->waiters_lock);
-		/*
-		 * At this point all waiters continue. Each one takes its
-		 * slice of the semaphor. Now it's our turn to wait: Since
-		 * the external mutex is held, no thread can leave cond_wait,
-		 * yet. For this reason, we can be sure that no thread gets
-		 * a chance to eat *more* than one slice. OTOH, it means
-		 * that the last waiter must send us a wake-up.
-		 */
-		WaitForSingleObject(cond->continue_broadcast, INFINITE);
-		/*
-		 * Since the external mutex is held, no thread can enter
-		 * cond_wait, and, hence, it is safe to reset this flag
-		 * without cond->waiters_lock held.
-		 */
-		cond->was_broadcast = 0;
-	} else {
-		LeaveCriticalSection(&cond->waiters_lock);
-	}
-	return 0;
-}
diff --git a/compat/win32/pthread.h b/compat/win32/pthread.h
index 1c16408..c6cb8dd 100644
--- a/compat/win32/pthread.h
+++ b/compat/win32/pthread.h
@@ -32,27 +32,13 @@
 #define pthread_mutexattr_settype(a, t) 0
 #define PTHREAD_MUTEX_RECURSIVE 0
 
-/*
- * Implement simple condition variable for Windows threads, based on ACE
- * implementation.
- *
- * See original implementation: http://bit.ly/1vkDjo
- * ACE homepage: http://www.cse.wustl.edu/~schmidt/ACE.html
- * See also: http://www.cse.wustl.edu/~schmidt/win32-cv-1.html
- */
-typedef struct {
-	LONG waiters;
-	int was_broadcast;
-	CRITICAL_SECTION waiters_lock;
-	HANDLE sema;
-	HANDLE continue_broadcast;
-} pthread_cond_t;
+#define pthread_cond_t CONDITION_VARIABLE
 
-extern int pthread_cond_init(pthread_cond_t *cond, const void *unused);
-extern int pthread_cond_destroy(pthread_cond_t *cond);
-extern int pthread_cond_wait(pthread_cond_t *cond, CRITICAL_SECTION *mutex);
-extern int pthread_cond_signal(pthread_cond_t *cond);
-extern int pthread_cond_broadcast(pthread_cond_t *cond);
+#define pthread_cond_init(a,b) InitializeConditionVariable((a))
+#define pthread_cond_destroy(a) do {} while (0)
+#define pthread_cond_wait(a,b) return_0(SleepConditionVariableCS((a), (b), INFINITE))
+#define pthread_cond_signal WakeConditionVariable
+#define pthread_cond_broadcast WakeAllConditionVariable
 
 /*
  * Simple thread creation implementation using pthread API
diff --git a/config.c b/config.c
index 2ffd39c..ff521eb 100644
--- a/config.c
+++ b/config.c
@@ -1668,6 +1668,8 @@
 
 	if (opts->commondir)
 		repo_config = mkpathdup("%s/config", opts->commondir);
+	else if (opts->git_dir)
+		BUG("git_dir without commondir");
 	else
 		repo_config = NULL;
 
@@ -2292,22 +2294,25 @@
 	return 0;
 }
 
-int git_config_get_index_threads(void)
+int git_config_get_index_threads(int *dest)
 {
-	int is_bool, val = 0;
+	int is_bool, val;
 
 	val = git_env_ulong("GIT_TEST_INDEX_THREADS", 0);
-	if (val)
-		return val;
+	if (val) {
+		*dest = val;
+		return 0;
+	}
 
 	if (!git_config_get_bool_or_int("index.threads", &is_bool, &val)) {
 		if (is_bool)
-			return val ? 0 : 1;
+			*dest = val ? 0 : 1;
 		else
-			return val;
+			*dest = val;
+		return 0;
 	}
 
-	return 0; /* auto */
+	return 1;
 }
 
 NORETURN
diff --git a/config.h b/config.h
index a06027e..ee5d3fa 100644
--- a/config.h
+++ b/config.h
@@ -246,11 +246,11 @@
 extern int git_config_get_bool_or_int(const char *key, int *is_bool, int *dest);
 extern int git_config_get_maybe_bool(const char *key, int *dest);
 extern int git_config_get_pathname(const char *key, const char **dest);
+extern int git_config_get_index_threads(int *dest);
 extern int git_config_get_untracked_cache(void);
 extern int git_config_get_split_index(void);
 extern int git_config_get_max_percent_split_change(void);
 extern int git_config_get_fsmonitor(void);
-extern int git_config_get_index_threads(void);
 
 /* This dies if the configured or default date is in the future */
 extern int git_config_get_expiry(const char *key, const char **output);
diff --git a/config.mak.uname b/config.mak.uname
index f179d7a..3ee7da0 100644
--- a/config.mak.uname
+++ b/config.mak.uname
@@ -430,8 +430,6 @@
 	NO_NSEC = YesPlease
 	NEEDS_LIBGEN =
 	NEEDS_CRYPTO_WITH_SSL = YesPlease
-	NEEDS_IDN_WITH_CURL = YesPlease
-	NEEDS_SSL_WITH_CURL = YesPlease
 	NEEDS_RESOLV =
 	NO_HSTRERROR = YesPlease
 	NO_MMAP = YesPlease
@@ -457,7 +455,6 @@
 	# Missdetected, hence commented out, see below.
 	#NO_CURL = YesPlease
 	# Added manually, see above.
-	NEEDS_SSL_WITH_CURL = YesPlease
 	HAVE_LIBCHARSET_H = YesPlease
 	HAVE_STRINGS_H = YesPlease
 	NEEDS_LIBICONV = YesPlease
diff --git a/configure.ac b/configure.ac
index e11b797..e0d0da3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -600,17 +600,14 @@
 
 if test $CURL_CONFIG != no; then
     GIT_CONF_SUBST([CURL_CONFIG])
-    if test -z "${NO_OPENSSL}"; then
-      AC_MSG_CHECKING([if Curl supports SSL])
-      if test $(curl-config --features|grep SSL) = SSL; then
-         NEEDS_SSL_WITH_CURL=YesPlease
-         AC_MSG_RESULT([yes])
-      else
-         NEEDS_SSL_WITH_CURL=
-         AC_MSG_RESULT([no])
-      fi
-      GIT_CONF_SUBST([NEEDS_SSL_WITH_CURL])
+
+    if test -z "$CURL_CONFIG_OPTS"; then
+        CURL_CONFIG_OPTS="--libs"
     fi
+
+    CURL_LDFLAGS=$($CURL_CONFIG $CURL_CONFIG_OPTS)
+    AC_MSG_NOTICE([Setting CURL_LDFLAGS to '$CURL_LDFLAGS'])
+    GIT_CONF_SUBST([CURL_LDFLAGS], [$CURL_LDFLAGS])
 fi
 
 fi
@@ -792,6 +789,12 @@
 [NO_SYS_SELECT_H=UnfortunatelyYes])
 GIT_CONF_SUBST([NO_SYS_SELECT_H])
 #
+# Define NO_POLL_H if you don't have poll.h
+AC_CHECK_HEADER([poll.h],
+[NO_POLL_H=],
+[NO_POLL_H=UnfortunatelyYes])
+GIT_CONF_SUBST([NO_POLL_H])
+#
 # Define NO_SYS_POLL_H if you don't have sys/poll.h
 AC_CHECK_HEADER([sys/poll.h],
 [NO_SYS_POLL_H=],
diff --git a/contrib/coccinelle/README b/contrib/coccinelle/README
index 9c2f887..f0e80bd 100644
--- a/contrib/coccinelle/README
+++ b/contrib/coccinelle/README
@@ -1,2 +1,43 @@
 This directory provides examples of Coccinelle (http://coccinelle.lip6.fr/)
 semantic patches that might be useful to developers.
+
+There are two types of semantic patches:
+
+ * Using the semantic transformation to check for bad patterns in the code;
+   The target 'make coccicheck' is designed to check for these patterns and
+   it is expected that any resulting patch indicates a regression.
+   The patches resulting from 'make coccicheck' are small and infrequent,
+   so once they are found, they can be sent to the mailing list as per usual.
+
+   Example for introducing new patterns:
+   67947c34ae (convert "hashcmp() != 0" to "!hasheq()", 2018-08-28)
+   b84c783882 (fsck: s/++i > 1/i++/, 2018-10-24)
+
+   Example of fixes using this approach:
+   248f66ed8e (run-command: use strbuf_addstr() for adding a string to
+               a strbuf, 2018-03-25)
+   f919ffebed (Use MOVE_ARRAY, 2018-01-22)
+
+   These types of semantic patches are usually part of testing, c.f.
+   0860a7641b (travis-ci: fail if Coccinelle static analysis found something
+               to transform, 2018-07-23)
+
+ * Using semantic transformations in large scale refactorings throughout
+   the code base.
+
+   When applying the semantic patch into a real patch, sending it to the
+   mailing list in the usual way, such a patch would be expected to have a
+   lot of textual and semantic conflicts as such large scale refactorings
+   change function signatures that are used widely in the code base.
+   A textual conflict would arise if surrounding code near any call of such
+   function changes. A semantic conflict arises when other patch series in
+   flight introduce calls to such functions.
+
+   So to aid these large scale refactorings, semantic patches can be used.
+   However we do not want to store them in the same place as the checks for
+   bad patterns, as then automated builds would fail.
+   That is why semantic patches 'contrib/coccinelle/*.pending.cocci'
+   are ignored for checks, and can be applied using 'make coccicheck-pending'.
+
+   This allows to expose plans of pending large scale refactorings without
+   impacting the bad pattern checks.
diff --git a/diff.c b/diff.c
index e38d1ec..dc9965e 100644
--- a/diff.c
+++ b/diff.c
@@ -3228,7 +3228,7 @@
 	}
 
 	if (delta && delta_size < deflate_size) {
-		char *s = xstrfmt("%lu", orig_size);
+		char *s = xstrfmt("%"PRIuMAX , (uintmax_t)orig_size);
 		emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 				 s, strlen(s), 0);
 		free(s);
diff --git a/entry.c b/entry.c
index 5d136c5..0a3c451 100644
--- a/entry.c
+++ b/entry.c
@@ -404,7 +404,7 @@
 {
 	int i, trust_ino = check_stat;
 
-#if defined(GIT_WINDOWS_NATIVE)
+#if defined(GIT_WINDOWS_NATIVE) || defined(__CYGWIN__)
 	trust_ino = 0;
 #endif
 
@@ -419,7 +419,7 @@
 		if (dup->ce_flags & (CE_MATCHED | CE_VALID | CE_SKIP_WORKTREE))
 			continue;
 
-		if ((trust_ino && dup->ce_stat_data.sd_ino == st->st_ino) ||
+		if ((trust_ino && !match_stat_data(&dup->ce_stat_data, st)) ||
 		    (!trust_ino && !fspathcmp(ce->name, dup->name))) {
 			dup->ce_flags |= CE_MATCHED;
 			break;
diff --git a/fast-import.c b/fast-import.c
index 95600c7..6988668 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -2955,8 +2955,8 @@
 		die("Object %s is a %s but a blob was expected.",
 		    oid_to_hex(oid), type_name(type));
 	strbuf_reset(&line);
-	strbuf_addf(&line, "%s %s %lu\n", oid_to_hex(oid),
-						type_name(type), size);
+	strbuf_addf(&line, "%s %s %"PRIuMAX"\n", oid_to_hex(oid),
+		    type_name(type), (uintmax_t)size);
 	cat_blob_write(line.buf, line.len);
 	strbuf_release(&line);
 	cat_blob_write(buf, size);
diff --git a/gettext.c b/gettext.c
index 7272771..d4021d6 100644
--- a/gettext.c
+++ b/gettext.c
@@ -7,6 +7,7 @@
 #include "gettext.h"
 #include "strbuf.h"
 #include "utf8.h"
+#include "config.h"
 
 #ifndef NO_GETTEXT
 #	include <locale.h>
@@ -46,15 +47,15 @@
 	return NULL;
 }
 
-#ifdef GETTEXT_POISON
 int use_gettext_poison(void)
 {
 	static int poison_requested = -1;
-	if (poison_requested == -1)
-		poison_requested = getenv("GIT_GETTEXT_POISON") ? 1 : 0;
+	if (poison_requested == -1) {
+		const char *v = getenv("GIT_TEST_GETTEXT_POISON");
+		poison_requested = v && strlen(v) ? 1 : 0;
+	}
 	return poison_requested;
 }
-#endif
 
 #ifndef NO_GETTEXT
 static int test_vsnprintf(const char *fmt, ...)
@@ -164,6 +165,8 @@
 	if (!podir)
 		podir = p = system_path(GIT_LOCALE_PATH);
 
+	use_gettext_poison(); /* getenv() reentrancy paranoia */
+
 	if (!is_directory(podir)) {
 		free(p);
 		return;
diff --git a/gettext.h b/gettext.h
index 7eee64a..71255e5 100644
--- a/gettext.h
+++ b/gettext.h
@@ -28,12 +28,15 @@
 
 #define FORMAT_PRESERVING(n) __attribute__((format_arg(n)))
 
+extern int use_gettext_poison(void);
+
 #ifndef NO_GETTEXT
 extern void git_setup_gettext(void);
 extern int gettext_width(const char *s);
 #else
 static inline void git_setup_gettext(void)
 {
+	use_gettext_poison(); /* getenv() reentrancy paranoia */
 }
 static inline int gettext_width(const char *s)
 {
@@ -41,12 +44,6 @@
 }
 #endif
 
-#ifdef GETTEXT_POISON
-extern int use_gettext_poison(void);
-#else
-#define use_gettext_poison() 0
-#endif
-
 static inline FORMAT_PRESERVING(1) const char *_(const char *msgid)
 {
 	if (!*msgid)
diff --git a/git-compat-util.h b/git-compat-util.h
index 3a08d99..09b0102 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -180,9 +180,12 @@
 #include <regex.h>
 #include <utime.h>
 #include <syslog.h>
-#ifndef NO_SYS_POLL_H
+#if !defined(NO_POLL_H)
+#include <poll.h>
+#elif !defined(NO_SYS_POLL_H)
 #include <sys/poll.h>
 #else
+/* Pull the compat stuff */
 #include <poll.h>
 #endif
 #ifdef HAVE_BSD_SYSCTL
@@ -858,6 +861,7 @@
 #define FREE_AND_NULL(p) do { free(p); (p) = NULL; } while (0)
 
 #define ALLOC_ARRAY(x, alloc) (x) = xmalloc(st_mult(sizeof(*(x)), (alloc)))
+#define CALLOC_ARRAY(x, alloc) (x) = xcalloc((alloc), sizeof(*(x)));
 #define REALLOC_ARRAY(x, alloc) (x) = xrealloc((x), st_mult(sizeof(*(x)), (alloc)))
 
 #define COPY_ARRAY(dst, src, n) copy_array((dst), (src), (n), sizeof(*(dst)) + \
diff --git a/git-legacy-rebase.sh b/git-legacy-rebase.sh
index 75a08b2..b4c7dbf 100755
--- a/git-legacy-rebase.sh
+++ b/git-legacy-rebase.sh
@@ -337,6 +337,11 @@
 		fix|strip)
 			force_rebase=t
 			;;
+		warn|nowarn|error|error-all)
+			;; # okay, known whitespace option
+		*)
+			die "fatal: Invalid whitespace option: '${1#*=}'"
+			;;
 		esac
 		;;
 	--ignore-whitespace)
@@ -352,6 +357,9 @@
 		git_am_opt="$git_am_opt $1"
 		force_rebase=t
 		;;
+	-C*[!0-9]*)
+		die "fatal: switch \`C' expects a numerical value"
+		;;
 	-C*)
 		git_am_opt="$git_am_opt $1"
 		;;
@@ -710,10 +718,16 @@
 then
 	if test -n "$verbose"
 	then
-		echo "$(eval_gettext "Changes from \$mb to \$onto:")"
+		if test -z "$mb"
+		then
+			echo "$(eval_gettext "Changes to \$onto:")"
+		else
+			echo "$(eval_gettext "Changes from \$mb to \$onto:")"
+		fi
 	fi
+	mb_tree="${mb:-$(git hash-object -t tree /dev/null)}"
 	# We want color (if set), but no pager
-	GIT_PAGER='' git diff --stat --summary "$mb" "$onto"
+	GIT_PAGER='' git diff --stat --summary "$mb_tree" "$onto"
 fi
 
 test -n "$interactive_rebase" && run_specific_rebase
diff --git a/git-sh-i18n.sh b/git-sh-i18n.sh
index 9d065fb..e1d917f 100644
--- a/git-sh-i18n.sh
+++ b/git-sh-i18n.sh
@@ -17,7 +17,7 @@
 
 # First decide what scheme to use...
 GIT_INTERNAL_GETTEXT_SH_SCHEME=fallthrough
-if test -n "$GIT_GETTEXT_POISON"
+if test -n "$GIT_TEST_GETTEXT_POISON"
 then
 	GIT_INTERNAL_GETTEXT_SH_SCHEME=poison
 elif test -n "@@USE_GETTEXT_SCHEME@@"
diff --git a/grep.c b/grep.c
index f6bd89e..4db1510 100644
--- a/grep.c
+++ b/grep.c
@@ -1513,7 +1513,6 @@
 	}
 }
 
-#ifndef NO_PTHREADS
 int grep_use_locks;
 
 /*
@@ -1539,11 +1538,6 @@
  */
 pthread_mutex_t grep_read_mutex;
 
-#else
-#define grep_attr_lock()
-#define grep_attr_unlock()
-#endif
-
 static int match_funcname(struct grep_opt *opt, struct grep_source *gs, char *bol, char *eol)
 {
 	xdemitconf_t *xecfg = opt->priv;
diff --git a/grep.h b/grep.h
index 1a57d12..fb04893 100644
--- a/grep.h
+++ b/grep.h
@@ -229,7 +229,6 @@
 extern struct grep_opt *grep_opt_dup(const struct grep_opt *opt);
 extern int grep_threads_ok(const struct grep_opt *opt);
 
-#ifndef NO_PTHREADS
 /*
  * Mutex used around access to the attributes machinery if
  * opt->use_threads.  Must be initialized/destroyed by callers!
@@ -250,9 +249,4 @@
 		pthread_mutex_unlock(&grep_read_mutex);
 }
 
-#else
-#define grep_read_lock()
-#define grep_read_unlock()
-#endif
-
 #endif
diff --git a/http-push.c b/http-push.c
index d1f52cb..cd48590 100644
--- a/http-push.c
+++ b/http-push.c
@@ -365,7 +365,7 @@
 	git_zstream stream;
 
 	unpacked = read_object_file(&request->obj->oid, &type, &len);
-	hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", type_name(type), len) + 1;
+	hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX , type_name(type), (uintmax_t)len) + 1;
 
 	/* Set it up */
 	git_deflate_init(&stream, zlib_compression_level);
diff --git a/http.c b/http.c
index 3dc8c56..eacc2a7 100644
--- a/http.c
+++ b/http.c
@@ -834,7 +834,7 @@
 #if LIBCURL_VERSION_NUM >= 0x072c00
 		curl_easy_setopt(result, CURLOPT_SSL_OPTIONS, CURLSSLOPT_NO_REVOKE);
 #else
-		warning(_("CURLSSLOPT_NO_REVOKE not suported with cURL < 7.44.0"));
+		warning(_("CURLSSLOPT_NO_REVOKE not supported with cURL < 7.44.0"));
 #endif
 	}
 
diff --git a/log-tree.c b/log-tree.c
index 7a83e99..b243779 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -762,7 +762,7 @@
 		next_commentary_block(opt, NULL);
 		fprintf_ln(opt->diffopt.file, "%s", opt->rdiff_title);
 		show_range_diff(opt->rdiff1, opt->rdiff2,
-				opt->creation_factor, 1, &opt->diffopt);
+				opt->creation_factor, 1, NULL);
 
 		memcpy(&diff_queued_diff, &dq, sizeof(diff_queued_diff));
 	}
diff --git a/midx.c b/midx.c
index a50b117..2a6a24f 100644
--- a/midx.c
+++ b/midx.c
@@ -202,7 +202,7 @@
 	struct strbuf pack_name = STRBUF_INIT;
 
 	if (pack_int_id >= m->num_packs)
-		die(_("bad pack-int-id: %u (%u total packs"),
+		die(_("bad pack-int-id: %u (%u total packs)"),
 		    pack_int_id, m->num_packs);
 
 	if (m->packs[pack_int_id])
@@ -721,12 +721,18 @@
 static size_t write_midx_large_offsets(struct hashfile *f, uint32_t nr_large_offset,
 				       struct pack_midx_entry *objects, uint32_t nr_objects)
 {
-	struct pack_midx_entry *list = objects;
+	struct pack_midx_entry *list = objects, *end = objects + nr_objects;
 	size_t written = 0;
 
 	while (nr_large_offset) {
-		struct pack_midx_entry *obj = list++;
-		uint64_t offset = obj->offset;
+		struct pack_midx_entry *obj;
+		uint64_t offset;
+
+		if (list >= end)
+			BUG("too many large-offset objects");
+
+		obj = list++;
+		offset = obj->offset;
 
 		if (!(offset >> 31))
 			continue;
diff --git a/name-hash.c b/name-hash.c
index 1fcda73..623ca69 100644
--- a/name-hash.c
+++ b/name-hash.c
@@ -7,6 +7,7 @@
  */
 #define NO_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
+#include "thread-utils.h"
 
 struct dir_entry {
 	struct hashmap_entry ent;
@@ -131,22 +132,6 @@
 static int lazy_try_threaded = 1;
 static int lazy_nr_dir_threads;
 
-#ifdef NO_PTHREADS
-
-static inline int lookup_lazy_params(struct index_state *istate)
-{
-	return 0;
-}
-
-static inline void threaded_lazy_init_name_hash(
-	struct index_state *istate)
-{
-}
-
-#else
-
-#include "thread-utils.h"
-
 /*
  * Set a minimum number of cache_entries that we will handle per
  * thread and use that to decide how many threads to run (upto
@@ -509,6 +494,7 @@
 static void threaded_lazy_init_name_hash(
 	struct index_state *istate)
 {
+	int err;
 	int nr_each;
 	int k_start;
 	int t;
@@ -516,6 +502,9 @@
 	struct lazy_dir_thread_data *td_dir;
 	struct lazy_name_thread_data *td_name;
 
+	if (!HAVE_THREADS)
+		return;
+
 	k_start = 0;
 	nr_each = DIV_ROUND_UP(istate->cache_nr, lazy_nr_dir_threads);
 
@@ -538,8 +527,9 @@
 		if (k_start > istate->cache_nr)
 			k_start = istate->cache_nr;
 		td_dir_t->k_end = k_start;
-		if (pthread_create(&td_dir_t->pthread, NULL, lazy_dir_thread_proc, td_dir_t))
-			die("unable to create lazy_dir_thread");
+		err = pthread_create(&td_dir_t->pthread, NULL, lazy_dir_thread_proc, td_dir_t);
+		if (err)
+			die(_("unable to create lazy_dir thread: %s"), strerror(err));
 	}
 	for (t = 0; t < lazy_nr_dir_threads; t++) {
 		struct lazy_dir_thread_data *td_dir_t = td_dir + t;
@@ -559,13 +549,15 @@
 	 */
 	td_name->istate = istate;
 	td_name->lazy_entries = lazy_entries;
-	if (pthread_create(&td_name->pthread, NULL, lazy_name_thread_proc, td_name))
-		die("unable to create lazy_name_thread");
+	err = pthread_create(&td_name->pthread, NULL, lazy_name_thread_proc, td_name);
+	if (err)
+		die(_("unable to create lazy_name thread: %s"), strerror(err));
 
 	lazy_update_dir_ref_counts(istate, lazy_entries);
 
-	if (pthread_join(td_name->pthread, NULL))
-		die("unable to join lazy_name_thread");
+	err = pthread_join(td_name->pthread, NULL);
+	if (err)
+		die(_("unable to join lazy_name thread: %s"), strerror(err));
 
 	cleanup_dir_mutex();
 
@@ -574,8 +566,6 @@
 	free(lazy_entries);
 }
 
-#endif
-
 static void lazy_init_name_hash(struct index_state *istate)
 {
 
diff --git a/object.h b/object.h
index 0feb90a..796792c 100644
--- a/object.h
+++ b/object.h
@@ -59,7 +59,7 @@
 
 /*
  * object flag allocation:
- * revision.h:               0---------10                              2526
+ * revision.h:               0---------10                              25----28
  * fetch-pack.c:             01
  * negotiator/default.c:       2--5
  * walker.c:                 0-2
@@ -78,7 +78,7 @@
  * builtin/show-branch.c:    0-------------------------------------------26
  * builtin/unpack-objects.c:                                 2021
  */
-#define FLAG_BITS  27
+#define FLAG_BITS  29
 
 /*
  * The object type is stored in 3 bits.
diff --git a/pack-objects.h b/pack-objects.h
index 86ee93f..dc869f2 100644
--- a/pack-objects.h
+++ b/pack-objects.h
@@ -145,9 +145,7 @@
 	struct packed_git **in_pack_by_idx;
 	struct packed_git **in_pack;
 
-#ifndef NO_PTHREADS
 	pthread_mutex_t lock;
-#endif
 
 	/*
 	 * This list contains entries for bases which we know the other side
@@ -169,15 +167,11 @@
 
 static inline void packing_data_lock(struct packing_data *pdata)
 {
-#ifndef NO_PTHREADS
 	pthread_mutex_lock(&pdata->lock);
-#endif
 }
 static inline void packing_data_unlock(struct packing_data *pdata)
 {
-#ifndef NO_PTHREADS
 	pthread_mutex_unlock(&pdata->lock);
-#endif
 }
 
 struct object_entry *packlist_alloc(struct packing_data *pdata,
@@ -418,7 +412,7 @@
 				     unsigned int tree_depth)
 {
 	if (!pack->tree_depth)
-		ALLOC_ARRAY(pack->tree_depth, pack->nr_objects);
+		CALLOC_ARRAY(pack->tree_depth, pack->nr_alloc);
 	pack->tree_depth[e - pack->objects] = tree_depth;
 }
 
@@ -435,7 +429,7 @@
 				unsigned char layer)
 {
 	if (!pack->layer)
-		ALLOC_ARRAY(pack->layer, pack->nr_objects);
+		CALLOC_ARRAY(pack->layer, pack->nr_alloc);
 	pack->layer[e - pack->objects] = layer;
 }
 
diff --git a/parse-options-cb.c b/parse-options-cb.c
index e823653..8c9edce 100644
--- a/parse-options-cb.c
+++ b/parse-options-cb.c
@@ -28,13 +28,6 @@
 	return 0;
 }
 
-int parse_opt_approxidate_cb(const struct option *opt, const char *arg,
-			     int unset)
-{
-	*(timestamp_t *)(opt->value) = approxidate(arg);
-	return 0;
-}
-
 int parse_opt_expiry_date_cb(const struct option *opt, const char *arg,
 			     int unset)
 {
@@ -65,6 +58,8 @@
 {
 	int *target = opt->value;
 
+	BUG_ON_OPT_ARG(arg);
+
 	if (unset)
 		/* --no-quiet, --no-verbose */
 		*target = 0;
@@ -87,6 +82,8 @@
 	struct object_id oid;
 	struct commit *commit;
 
+	BUG_ON_OPT_NEG(unset);
+
 	if (!arg)
 		return -1;
 	if (get_oid(arg, &oid))
@@ -117,6 +114,9 @@
 int parse_opt_tertiary(const struct option *opt, const char *arg, int unset)
 {
 	int *target = opt->value;
+
+	BUG_ON_OPT_ARG(arg);
+
 	*target = unset ? 2 : 1;
 	return 0;
 }
diff --git a/parse-options.h b/parse-options.h
index dd14911..6c4fe20 100644
--- a/parse-options.h
+++ b/parse-options.h
@@ -150,9 +150,6 @@
 				      (h), 0, &parse_opt_string_list }
 #define OPT_UYN(s, l, v, h)         { OPTION_CALLBACK, (s), (l), (v), NULL, \
 				      (h), PARSE_OPT_NOARG, &parse_opt_tertiary }
-#define OPT_DATE(s, l, v, h) \
-	{ OPTION_CALLBACK, (s), (l), (v), N_("time"),(h), 0,	\
-	  parse_opt_approxidate_cb }
 #define OPT_EXPIRY_DATE(s, l, v, h) \
 	{ OPTION_CALLBACK, (s), (l), (v), N_("expiry-date"),(h), 0,	\
 	  parse_opt_expiry_date_cb }
@@ -194,6 +191,20 @@
 #define opterror(o,r,f) (opterror((o),(r),(f)), const_error())
 #endif
 
+/*
+ * Use these assertions for callbacks that expect to be called with NONEG and
+ * NOARG respectively, and do not otherwise handle the "unset" and "arg"
+ * parameters.
+ */
+#define BUG_ON_OPT_NEG(unset) do { \
+	if ((unset)) \
+		BUG("option callback does not expect negation"); \
+} while (0)
+#define BUG_ON_OPT_ARG(arg) do { \
+	if ((arg)) \
+		BUG("option callback does not expect an argument"); \
+} while (0)
+
 /*----- incremental advanced APIs -----*/
 
 enum {
@@ -232,7 +243,6 @@
 
 /*----- some often used options -----*/
 extern int parse_opt_abbrev_cb(const struct option *, const char *, int);
-extern int parse_opt_approxidate_cb(const struct option *, const char *, int);
 extern int parse_opt_expiry_date_cb(const struct option *, const char *, int);
 extern int parse_opt_color_flag_cb(const struct option *, const char *, int);
 extern int parse_opt_verbosity_cb(const struct option *, const char *, int);
diff --git a/po/README b/po/README
index fef4c0f..aa704ff 100644
--- a/po/README
+++ b/po/README
@@ -289,16 +289,11 @@
 version of the strings, e.g. to grep some error message or other
 output.
 
-To smoke out issues like these Git can be compiled with gettext poison
-support, at the top-level:
+To smoke out issues like these, Git tested with a translation mode that
+emits gibberish on every call to gettext. To use it run the test suite
+with it, e.g.:
 
-    make GETTEXT_POISON=YesPlease
-
-That'll give you a git which emits gibberish on every call to
-gettext. It's obviously not meant to be installed, but you should run
-the test suite with it:
-
-    cd t && prove -j 9 ./t[0-9]*.sh
+    cd t && GIT_TEST_GETTEXT_POISON=YesPlease prove -j 9 ./t[0-9]*.sh
 
 If tests break with it you should inspect them manually and see if
 what you're translating is sane, i.e. that you're not translating
diff --git a/preload-index.c b/preload-index.c
index 222792c..c7dc3f2 100644
--- a/preload-index.c
+++ b/preload-index.c
@@ -7,17 +7,7 @@
 #include "fsmonitor.h"
 #include "config.h"
 #include "progress.h"
-
-#ifdef NO_PTHREADS
-void preload_index(struct index_state *index,
-			  const struct pathspec *pathspec,
-			  unsigned int refresh_flags)
-{
-	; /* nothing */
-}
-#else
-
-#include <pthread.h>
+#include "thread-utils.h"
 
 /*
  * Mostly randomly chosen maximum thread counts: we
@@ -108,7 +98,7 @@
 	struct thread_data data[MAX_PARALLEL];
 	struct progress_data pd;
 
-	if (!core_preload_index)
+	if (!HAVE_THREADS || !core_preload_index)
 		return;
 
 	threads = index->cache_nr / THREAD_COST;
@@ -131,6 +121,8 @@
 
 	for (i = 0; i < threads; i++) {
 		struct thread_data *p = data+i;
+		int err;
+
 		p->index = index;
 		if (pathspec)
 			copy_pathspec(&p->pathspec, pathspec);
@@ -139,8 +131,10 @@
 		if (pd.progress)
 			p->progress = &pd;
 		offset += work;
-		if (pthread_create(&p->pthread, NULL, preload_thread, p))
-			die("unable to create threaded lstat");
+		err = pthread_create(&p->pthread, NULL, preload_thread, p);
+
+		if (err)
+			die(_("unable to create threaded lstat: %s"), strerror(err));
 	}
 	for (i = 0; i < threads; i++) {
 		struct thread_data *p = data+i;
@@ -151,7 +145,6 @@
 
 	trace_performance_leave("preload index");
 }
-#endif
 
 int read_index_preload(struct index_state *index,
 		       const struct pathspec *pathspec,
diff --git a/prio-queue.c b/prio-queue.c
index a078451..d3f488c 100644
--- a/prio-queue.c
+++ b/prio-queue.c
@@ -85,3 +85,12 @@
 	}
 	return result;
 }
+
+void *prio_queue_peek(struct prio_queue *queue)
+{
+	if (!queue->nr)
+		return NULL;
+	if (!queue->compare)
+		return queue->array[queue->nr - 1].data;
+	return queue->array[0].data;
+}
diff --git a/prio-queue.h b/prio-queue.h
index d030ec9..682e518 100644
--- a/prio-queue.h
+++ b/prio-queue.h
@@ -46,6 +46,12 @@
  */
 extern void *prio_queue_get(struct prio_queue *);
 
+/*
+ * Gain access to the "thing" that would be returned by
+ * prio_queue_get, but do not remove it from the queue.
+ */
+extern void *prio_queue_peek(struct prio_queue *);
+
 extern void clear_prio_queue(struct prio_queue *);
 
 /* Reverse the LIFO elements */
diff --git a/range-diff.c b/range-diff.c
index 3958720..48b0e1b 100644
--- a/range-diff.c
+++ b/range-diff.c
@@ -460,8 +460,13 @@
 		struct diff_options opts;
 		struct strbuf indent = STRBUF_INIT;
 
-		memcpy(&opts, diffopt, sizeof(opts));
-		opts.output_format = DIFF_FORMAT_PATCH;
+		if (diffopt)
+			memcpy(&opts, diffopt, sizeof(opts));
+		else
+			diff_setup(&opts);
+
+		if (!opts.output_format)
+			opts.output_format = DIFF_FORMAT_PATCH;
 		opts.flags.suppress_diff_headers = 1;
 		opts.flags.dual_color_diffed_diffs = dual_color;
 		opts.output_prefix = output_prefix_cb;
diff --git a/range-diff.h b/range-diff.h
index 190593f..08a50b6 100644
--- a/range-diff.h
+++ b/range-diff.h
@@ -5,6 +5,11 @@
 
 #define RANGE_DIFF_CREATION_FACTOR_DEFAULT 60
 
+/*
+ * Compare series of commmits in RANGE1 and RANGE2, and emit to the
+ * standard output.  NULL can be passed to DIFFOPT to use the built-in
+ * default.
+ */
 int show_range_diff(const char *range1, const char *range2,
 		    int creation_factor, int dual_color,
 		    struct diff_options *diffopt);
diff --git a/read-cache.c b/read-cache.c
index 8c92450..bd45dc3 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1752,7 +1752,7 @@
 	size_t len;
 	const char *name;
 	unsigned int flags;
-	size_t copy_len;
+	size_t copy_len = 0;
 	/*
 	 * Adjacent cache entries tend to share the leading paths, so it makes
 	 * sense to only store the differences in later entries.  In the v4
@@ -1792,8 +1792,6 @@
 				die(_("malformed name field in the index, near path '%s'"),
 					previous_ce->name);
 			copy_len = previous_len - strip_len;
-		} else {
-			copy_len = 0;
 		}
 		name = (const char *)cp;
 	}
@@ -1926,19 +1924,15 @@
 	struct index_entry_offset entries[FLEX_ARRAY];
 };
 
-#ifndef NO_PTHREADS
 static struct index_entry_offset_table *read_ieot_extension(const char *mmap, size_t mmap_size, size_t offset);
 static void write_ieot_extension(struct strbuf *sb, struct index_entry_offset_table *ieot);
-#endif
 
 static size_t read_eoie_extension(const char *mmap, size_t mmap_size);
 static void write_eoie_extension(struct strbuf *sb, git_hash_ctx *eoie_context, size_t offset);
 
 struct load_index_extensions
 {
-#ifndef NO_PTHREADS
 	pthread_t pthread;
-#endif
 	struct index_state *istate;
 	const char *mmap;
 	size_t mmap_size;
@@ -2016,8 +2010,6 @@
 	return consumed;
 }
 
-#ifndef NO_PTHREADS
-
 /*
  * Mostly randomly chosen maximum thread counts: we
  * cap the parallelism to online_cpus() threads, and we want
@@ -2128,7 +2120,6 @@
 
 	return consumed;
 }
-#endif
 
 /* remember to discard_cache() before reading a different cache! */
 int do_read_index(struct index_state *istate, const char *path, int must_exist)
@@ -2141,10 +2132,8 @@
 	size_t mmap_size;
 	struct load_index_extensions p;
 	size_t extension_offset = 0;
-#ifndef NO_PTHREADS
 	int nr_threads, cpus;
 	struct index_entry_offset_table *ieot = NULL;
-#endif
 
 	if (istate->initialized)
 		return istate->cache_nr;
@@ -2187,8 +2176,8 @@
 
 	src_offset = sizeof(*hdr);
 
-#ifndef NO_PTHREADS
-	nr_threads = git_config_get_index_threads();
+	if (git_config_get_index_threads(&nr_threads))
+		nr_threads = 1;
 
 	/* TODO: does creating more threads than cores help? */
 	if (!nr_threads) {
@@ -2198,6 +2187,9 @@
 			nr_threads = cpus;
 	}
 
+	if (!HAVE_THREADS)
+		nr_threads = 1;
+
 	if (nr_threads > 1) {
 		extension_offset = read_eoie_extension(mmap, mmap_size);
 		if (extension_offset) {
@@ -2225,22 +2217,16 @@
 	} else {
 		src_offset += load_all_cache_entries(istate, mmap, mmap_size, src_offset);
 	}
-#else
-	src_offset += load_all_cache_entries(istate, mmap, mmap_size, src_offset);
-#endif
 
 	istate->timestamp.sec = st.st_mtime;
 	istate->timestamp.nsec = ST_MTIME_NSEC(st);
 
 	/* if we created a thread, join it otherwise load the extensions on the primary thread */
-#ifndef NO_PTHREADS
 	if (extension_offset) {
 		int ret = pthread_join(p.pthread, NULL);
 		if (ret)
 			die(_("unable to join load_index_extensions thread: %s"), strerror(ret));
-	}
-#endif
-	if (!extension_offset) {
+	} else {
 		p.src_offset = src_offset;
 		load_index_extensions(&p);
 	}
@@ -2704,6 +2690,36 @@
 		rollback_lock_file(lockfile);
 }
 
+static int record_eoie(void)
+{
+	int val;
+
+	if (!git_config_get_bool("index.recordendofindexentries", &val))
+		return val;
+
+	/*
+	 * As a convenience, the end of index entries extension
+	 * used for threading is written by default if the user
+	 * explicitly requested threaded index reads.
+	 */
+	return !git_config_get_index_threads(&val) && val != 1;
+}
+
+static int record_ieot(void)
+{
+	int val;
+
+	if (!git_config_get_bool("index.recordoffsettable", &val))
+		return val;
+
+	/*
+	 * As a convenience, the offset table used for threading is
+	 * written by default if the user explicitly requested
+	 * threaded index reads.
+	 */
+	return !git_config_get_index_threads(&val) && val != 1;
+}
+
 /*
  * On success, `tempfile` is closed. If it is the temporary file
  * of a `struct lock_file`, we will therefore effectively perform
@@ -2762,9 +2778,10 @@
 	if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
 		return -1;
 
-#ifndef NO_PTHREADS
-	nr_threads = git_config_get_index_threads();
-	if (nr_threads != 1) {
+	if (!HAVE_THREADS || git_config_get_index_threads(&nr_threads))
+		nr_threads = 1;
+
+	if (nr_threads != 1 && record_ieot()) {
 		int ieot_blocks, cpus;
 
 		/*
@@ -2793,7 +2810,6 @@
 			ieot_entries = DIV_ROUND_UP(entries, ieot_blocks);
 		}
 	}
-#endif
 
 	offset = lseek(newfd, 0, SEEK_CUR);
 	if (offset < 0) {
@@ -2877,7 +2893,6 @@
 	 * strip_extensions parameter as we need it when loading the shared
 	 * index.
 	 */
-#ifndef NO_PTHREADS
 	if (ieot) {
 		struct strbuf sb = STRBUF_INIT;
 
@@ -2889,7 +2904,6 @@
 		if (err)
 			return -1;
 	}
-#endif
 
 	if (!strip_extensions && istate->split_index) {
 		struct strbuf sb = STRBUF_INIT;
@@ -2951,7 +2965,7 @@
 	 * read.  Write it out regardless of the strip_extensions parameter as we need it
 	 * when loading the shared index.
 	 */
-	if (offset) {
+	if (offset && record_eoie()) {
 		struct strbuf sb = STRBUF_INIT;
 
 		write_eoie_extension(&sb, &eoie_c, offset);
@@ -3165,7 +3179,8 @@
 		struct tempfile *temp;
 		int saved_errno;
 
-		temp = mks_tempfile(git_path("sharedindex_XXXXXX"));
+		/* Same initial permissions as the main .git/index file */
+		temp = mks_tempfile_sm(git_path("sharedindex_XXXXXX"), 0, 0666);
 		if (!temp) {
 			oidclr(&si->base_oid);
 			ret = do_write_locked_index(istate, lock, flags);
@@ -3475,7 +3490,6 @@
 	strbuf_add(sb, hash, the_hash_algo->rawsz);
 }
 
-#ifndef NO_PTHREADS
 #define IEOT_VERSION	(1)
 
 static struct index_entry_offset_table *read_ieot_extension(const char *mmap, size_t mmap_size, size_t offset)
@@ -3548,4 +3562,3 @@
 	       strbuf_add(sb, &buffer, sizeof(uint32_t));
        }
 }
-#endif
diff --git a/ref-filter.c b/ref-filter.c
index 0c45ed9..5de616b 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -534,6 +534,10 @@
 	if (ARRAY_SIZE(valid_atom) <= i)
 		return strbuf_addf_ret(err, -1, _("unknown field name: %.*s"),
 				       (int)(ep-atom), atom);
+	if (valid_atom[i].source != SOURCE_NONE && !have_git_dir())
+		return strbuf_addf_ret(err, -1,
+				       _("not a git repository, but the field '%.*s' requires access to object data"),
+				       (int)(ep-atom), atom);
 
 	/* Add it in, including the deref prefix */
 	at = used_atom_cnt;
@@ -878,7 +882,7 @@
 			v->s = xstrdup(type_name(oi->type));
 		else if (!strcmp(name, "objectsize")) {
 			v->value = oi->size;
-			v->s = xstrfmt("%lu", oi->size);
+			v->s = xstrfmt("%"PRIuMAX , (uintmax_t)oi->size);
 		}
 		else if (deref)
 			grab_objectname(name, &oi->oid, v, &used_atom[i]);
@@ -2316,6 +2320,8 @@
 	struct object_id oid;
 	int no_merged = starts_with(opt->long_name, "no");
 
+	BUG_ON_OPT_NEG(unset);
+
 	if (rf->merge) {
 		if (no_merged) {
 			return opterror(opt, "is incompatible with --merged", 0);
diff --git a/refs.c b/refs.c
index 17e4307..f993635 100644
--- a/refs.c
+++ b/refs.c
@@ -217,6 +217,7 @@
 /* The argument to filter_refs */
 struct ref_filter {
 	const char *pattern;
+	const char *prefix;
 	each_ref_fn *fn;
 	void *cb_data;
 };
@@ -296,6 +297,8 @@
 
 	if (wildmatch(filter->pattern, refname, 0))
 		return 0;
+	if (filter->prefix)
+		skip_prefix(refname, filter->prefix, &refname);
 	return filter->fn(refname, oid, flags, filter->cb_data);
 }
 
@@ -458,6 +461,7 @@
 	}
 
 	filter.pattern = real_pattern.buf;
+	filter.prefix = prefix;
 	filter.fn = fn;
 	filter.cb_data = cb_data;
 	ret = for_each_ref(filter_refs, &filter);
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 9183875..dd8abe9 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -180,7 +180,8 @@
 		break;
 	case REF_TYPE_OTHER_PSEUDOREF:
 	case REF_TYPE_MAIN_PSEUDOREF:
-		return files_reflog_path_other_worktrees(refs, sb, refname);
+		files_reflog_path_other_worktrees(refs, sb, refname);
+		break;
 	case REF_TYPE_NORMAL:
 		strbuf_addf(sb, "%s/logs/%s", refs->gitcommondir, refname);
 		break;
diff --git a/remote-curl.c b/remote-curl.c
index 762a55a..1220dff 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -617,10 +617,11 @@
 	return err;
 }
 
-static curl_off_t xcurl_off_t(ssize_t len) {
-	if (len > maximum_signed_value_of_type(curl_off_t))
+static curl_off_t xcurl_off_t(size_t len) {
+	uintmax_t size = len;
+	if (size > maximum_signed_value_of_type(curl_off_t))
 		die("cannot handle pushes this big");
-	return (curl_off_t) len;
+	return (curl_off_t)size;
 }
 
 static int post_rpc(struct rpc_state *rpc)
diff --git a/revision.c b/revision.c
index bdd3e7c..13e0519 100644
--- a/revision.c
+++ b/revision.c
@@ -25,6 +25,8 @@
 #include "worktree.h"
 #include "argv-array.h"
 #include "commit-reach.h"
+#include "commit-graph.h"
+#include "prio-queue.h"
 
 volatile show_early_output_fn_t show_early_output;
 
@@ -767,8 +769,8 @@
 		*cache = new_entry;
 }
 
-static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
-		    struct commit_list **list, struct commit_list **cache_ptr)
+static int process_parents(struct rev_info *revs, struct commit *commit,
+			   struct commit_list **list, struct commit_list **cache_ptr)
 {
 	struct commit_list *parent = commit->parents;
 	unsigned left_flag;
@@ -807,7 +809,8 @@
 			if (p->object.flags & SEEN)
 				continue;
 			p->object.flags |= SEEN;
-			commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
+			if (list)
+				commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 		}
 		return 0;
 	}
@@ -846,7 +849,8 @@
 		p->object.flags |= left_flag;
 		if (!(p->object.flags & SEEN)) {
 			p->object.flags |= SEEN;
-			commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
+			if (list)
+				commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 		}
 		if (revs->first_parent_only)
 			break;
@@ -1090,7 +1094,7 @@
 
 		if (revs->max_age != -1 && (commit->date < revs->max_age))
 			obj->flags |= UNINTERESTING;
-		if (add_parents_to_list(revs, commit, &list, NULL) < 0)
+		if (process_parents(revs, commit, &list, NULL) < 0)
 			return -1;
 		if (obj->flags & UNINTERESTING) {
 			mark_parents_uninteresting(commit);
@@ -2468,7 +2472,7 @@
 	if (revs->diffopt.objfind)
 		revs->simplify_history = 0;
 
-	if (revs->topo_order)
+	if (revs->topo_order && !generation_numbers_enabled(the_repository))
 		revs->limited = 1;
 
 	if (revs->prune_data.nr) {
@@ -2907,6 +2911,217 @@
 	return 0;
 }
 
+define_commit_slab(indegree_slab, int);
+define_commit_slab(author_date_slab, timestamp_t);
+
+struct topo_walk_info {
+	uint32_t min_generation;
+	struct prio_queue explore_queue;
+	struct prio_queue indegree_queue;
+	struct prio_queue topo_queue;
+	struct indegree_slab indegree;
+	struct author_date_slab author_date;
+};
+
+static inline void test_flag_and_insert(struct prio_queue *q, struct commit *c, int flag)
+{
+	if (c->object.flags & flag)
+		return;
+
+	c->object.flags |= flag;
+	prio_queue_put(q, c);
+}
+
+static void explore_walk_step(struct rev_info *revs)
+{
+	struct topo_walk_info *info = revs->topo_walk_info;
+	struct commit_list *p;
+	struct commit *c = prio_queue_get(&info->explore_queue);
+
+	if (!c)
+		return;
+
+	if (parse_commit_gently(c, 1) < 0)
+		return;
+
+	if (revs->sort_order == REV_SORT_BY_AUTHOR_DATE)
+		record_author_date(&info->author_date, c);
+
+	if (revs->max_age != -1 && (c->date < revs->max_age))
+		c->object.flags |= UNINTERESTING;
+
+	if (process_parents(revs, c, NULL, NULL) < 0)
+		return;
+
+	if (c->object.flags & UNINTERESTING)
+		mark_parents_uninteresting(c);
+
+	for (p = c->parents; p; p = p->next)
+		test_flag_and_insert(&info->explore_queue, p->item, TOPO_WALK_EXPLORED);
+}
+
+static void explore_to_depth(struct rev_info *revs,
+			     uint32_t gen_cutoff)
+{
+	struct topo_walk_info *info = revs->topo_walk_info;
+	struct commit *c;
+	while ((c = prio_queue_peek(&info->explore_queue)) &&
+	       c->generation >= gen_cutoff)
+		explore_walk_step(revs);
+}
+
+static void indegree_walk_step(struct rev_info *revs)
+{
+	struct commit_list *p;
+	struct topo_walk_info *info = revs->topo_walk_info;
+	struct commit *c = prio_queue_get(&info->indegree_queue);
+
+	if (!c)
+		return;
+
+	if (parse_commit_gently(c, 1) < 0)
+		return;
+
+	explore_to_depth(revs, c->generation);
+
+	for (p = c->parents; p; p = p->next) {
+		struct commit *parent = p->item;
+		int *pi = indegree_slab_at(&info->indegree, parent);
+
+		if (*pi)
+			(*pi)++;
+		else
+			*pi = 2;
+
+		test_flag_and_insert(&info->indegree_queue, parent, TOPO_WALK_INDEGREE);
+
+		if (revs->first_parent_only)
+			return;
+	}
+}
+
+static void compute_indegrees_to_depth(struct rev_info *revs,
+				       uint32_t gen_cutoff)
+{
+	struct topo_walk_info *info = revs->topo_walk_info;
+	struct commit *c;
+	while ((c = prio_queue_peek(&info->indegree_queue)) &&
+	       c->generation >= gen_cutoff)
+		indegree_walk_step(revs);
+}
+
+static void init_topo_walk(struct rev_info *revs)
+{
+	struct topo_walk_info *info;
+	struct commit_list *list;
+	revs->topo_walk_info = xmalloc(sizeof(struct topo_walk_info));
+	info = revs->topo_walk_info;
+	memset(info, 0, sizeof(struct topo_walk_info));
+
+	init_indegree_slab(&info->indegree);
+	memset(&info->explore_queue, 0, sizeof(info->explore_queue));
+	memset(&info->indegree_queue, 0, sizeof(info->indegree_queue));
+	memset(&info->topo_queue, 0, sizeof(info->topo_queue));
+
+	switch (revs->sort_order) {
+	default: /* REV_SORT_IN_GRAPH_ORDER */
+		info->topo_queue.compare = NULL;
+		break;
+	case REV_SORT_BY_COMMIT_DATE:
+		info->topo_queue.compare = compare_commits_by_commit_date;
+		break;
+	case REV_SORT_BY_AUTHOR_DATE:
+		init_author_date_slab(&info->author_date);
+		info->topo_queue.compare = compare_commits_by_author_date;
+		info->topo_queue.cb_data = &info->author_date;
+		break;
+	}
+
+	info->explore_queue.compare = compare_commits_by_gen_then_commit_date;
+	info->indegree_queue.compare = compare_commits_by_gen_then_commit_date;
+
+	info->min_generation = GENERATION_NUMBER_INFINITY;
+	for (list = revs->commits; list; list = list->next) {
+		struct commit *c = list->item;
+
+		if (parse_commit_gently(c, 1))
+			continue;
+
+		test_flag_and_insert(&info->explore_queue, c, TOPO_WALK_EXPLORED);
+		test_flag_and_insert(&info->indegree_queue, c, TOPO_WALK_INDEGREE);
+
+		if (c->generation < info->min_generation)
+			info->min_generation = c->generation;
+
+		*(indegree_slab_at(&info->indegree, c)) = 1;
+
+		if (revs->sort_order == REV_SORT_BY_AUTHOR_DATE)
+			record_author_date(&info->author_date, c);
+	}
+	compute_indegrees_to_depth(revs, info->min_generation);
+
+	for (list = revs->commits; list; list = list->next) {
+		struct commit *c = list->item;
+
+		if (*(indegree_slab_at(&info->indegree, c)) == 1)
+			prio_queue_put(&info->topo_queue, c);
+	}
+
+	/*
+	 * This is unfortunate; the initial tips need to be shown
+	 * in the order given from the revision traversal machinery.
+	 */
+	if (revs->sort_order == REV_SORT_IN_GRAPH_ORDER)
+		prio_queue_reverse(&info->topo_queue);
+}
+
+static struct commit *next_topo_commit(struct rev_info *revs)
+{
+	struct commit *c;
+	struct topo_walk_info *info = revs->topo_walk_info;
+
+	/* pop next off of topo_queue */
+	c = prio_queue_get(&info->topo_queue);
+
+	if (c)
+		*(indegree_slab_at(&info->indegree, c)) = 0;
+
+	return c;
+}
+
+static void expand_topo_walk(struct rev_info *revs, struct commit *commit)
+{
+	struct commit_list *p;
+	struct topo_walk_info *info = revs->topo_walk_info;
+	if (process_parents(revs, commit, NULL, NULL) < 0) {
+		if (!revs->ignore_missing_links)
+			die("Failed to traverse parents of commit %s",
+			    oid_to_hex(&commit->object.oid));
+	}
+
+	for (p = commit->parents; p; p = p->next) {
+		struct commit *parent = p->item;
+		int *pi;
+
+		if (parse_commit_gently(parent, 1) < 0)
+			continue;
+
+		if (parent->generation < info->min_generation) {
+			info->min_generation = parent->generation;
+			compute_indegrees_to_depth(revs, info->min_generation);
+		}
+
+		pi = indegree_slab_at(&info->indegree, parent);
+
+		(*pi)--;
+		if (*pi == 1)
+			prio_queue_put(&info->topo_queue, parent);
+
+		if (revs->first_parent_only)
+			return;
+	}
+}
+
 int prepare_revision_walk(struct rev_info *revs)
 {
 	int i;
@@ -2943,11 +3158,13 @@
 		commit_list_sort_by_date(&revs->commits);
 	if (revs->no_walk)
 		return 0;
-	if (revs->limited)
+	if (revs->limited) {
 		if (limit_list(revs) < 0)
 			return -1;
-	if (revs->topo_order)
-		sort_in_topological_order(&revs->commits, revs->sort_order);
+		if (revs->topo_order)
+			sort_in_topological_order(&revs->commits, revs->sort_order);
+	} else if (revs->topo_order)
+		init_topo_walk(revs);
 	if (revs->line_level_traverse)
 		line_log_filter(revs);
 	if (revs->simplify_merges)
@@ -2964,7 +3181,7 @@
 	for (;;) {
 		struct commit *p = *pp;
 		if (!revs->limited)
-			if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
+			if (process_parents(revs, p, &revs->commits, &cache) < 0)
 				return rewrite_one_error;
 		if (p->object.flags & UNINTERESTING)
 			return rewrite_one_ok;
@@ -3272,6 +3489,8 @@
 
 		if (revs->reflog_info)
 			commit = next_reflog_entry(revs->reflog_info);
+		else if (revs->topo_walk_info)
+			commit = next_topo_commit(revs);
 		else
 			commit = pop_commit(&revs->commits);
 
@@ -3293,7 +3512,9 @@
 
 			if (revs->reflog_info)
 				try_to_simplify_commit(revs, commit);
-			else if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0) {
+			else if (revs->topo_walk_info)
+				expand_topo_walk(revs, commit);
+			else if (process_parents(revs, commit, &revs->commits, NULL) < 0) {
 				if (!revs->ignore_missing_links)
 					die("Failed to traverse parents of commit %s",
 						oid_to_hex(&commit->object.oid));
diff --git a/revision.h b/revision.h
index 0d2abc2..7987bfc 100644
--- a/revision.h
+++ b/revision.h
@@ -32,6 +32,9 @@
 #define TRACK_LINEAR	(1u<<26)
 #define ALL_REV_FLAGS	(((1u<<11)-1) | NOT_USER_GIVEN | TRACK_LINEAR)
 
+#define TOPO_WALK_EXPLORED	(1u<<27)
+#define TOPO_WALK_INDEGREE	(1u<<28)
+
 #define DECORATE_SHORT_REFS	1
 #define DECORATE_FULL_REFS	2
 
@@ -64,6 +67,8 @@
 #define REVISION_WALK_NO_WALK_SORTED 1
 #define REVISION_WALK_NO_WALK_UNSORTED 2
 
+struct topo_walk_info;
+
 struct rev_info {
 	/* Starting list */
 	struct commit_list *commits;
@@ -270,6 +275,8 @@
 	const char *break_bar;
 
 	struct revision_sources *sources;
+
+	struct topo_walk_info *topo_walk_info;
 };
 
 int ref_excluded(struct string_list *, const char *path);
diff --git a/run-command.c b/run-command.c
index d679cc2..c11ff80 100644
--- a/run-command.c
+++ b/run-command.c
@@ -1226,7 +1226,7 @@
 	{
 		int err = pthread_create(&async->tid, NULL, run_thread, async);
 		if (err) {
-			error_errno("cannot create thread");
+			error(_("cannot create async thread: %s"), strerror(err));
 			goto error;
 		}
 	}
@@ -1259,6 +1259,15 @@
 #endif
 }
 
+int async_with_fork(void)
+{
+#ifdef NO_PTHREADS
+	return 1;
+#else
+	return 0;
+#endif
+}
+
 const char *find_hook(const char *name)
 {
 	static struct strbuf path = STRBUF_INIT;
diff --git a/run-command.h b/run-command.h
index 3932420..68f5369 100644
--- a/run-command.h
+++ b/run-command.h
@@ -1,9 +1,7 @@
 #ifndef RUN_COMMAND_H
 #define RUN_COMMAND_H
 
-#ifndef NO_PTHREADS
-#include <pthread.h>
-#endif
+#include "thread-utils.h"
 
 #include "argv-array.h"
 
@@ -143,6 +141,7 @@
 int start_async(struct async *async);
 int finish_async(struct async *async);
 int in_async(void);
+int async_with_fork(void);
 void check_pipe(int err);
 
 /**
diff --git a/send-pack.c b/send-pack.c
index e920ca5..f692686 100644
--- a/send-pack.c
+++ b/send-pack.c
@@ -203,9 +203,8 @@
 static int sideband_demux(int in, int out, void *data)
 {
 	int *fd = data, ret;
-#ifdef NO_PTHREADS
-	close(fd[1]);
-#endif
+	if (async_with_fork())
+		close(fd[1]);
 	ret = recv_sideband("send-pack", fd[0], out);
 	close(out);
 	return ret;
diff --git a/sequencer.c b/sequencer.c
index 0d87b07..e1a4dd1 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -3244,10 +3244,6 @@
 	}
 
 	merge_commit = to_merge->item;
-	write_message(oid_to_hex(&merge_commit->object.oid), GIT_SHA1_HEXSZ,
-		      git_path_merge_head(the_repository), 0);
-	write_message("no-ff", 5, git_path_merge_mode(the_repository), 0);
-
 	bases = get_merge_bases(head_commit, merge_commit);
 	if (bases && oideq(&merge_commit->object.oid,
 			   &bases->item->object.oid)) {
@@ -3256,6 +3252,10 @@
 		goto leave_merge;
 	}
 
+	write_message(oid_to_hex(&merge_commit->object.oid), GIT_SHA1_HEXSZ,
+		      git_path_merge_head(the_repository), 0);
+	write_message("no-ff", 5, git_path_merge_mode(the_repository), 0);
+
 	for (j = bases; j; j = j->next)
 		commit_list_insert(j->item, &reversed);
 	free_commit_list(bases);
@@ -3512,6 +3512,7 @@
 			unlink(rebase_path_author_script());
 			unlink(rebase_path_stopped_sha());
 			unlink(rebase_path_amend());
+			unlink(git_path_merge_head(the_repository));
 			delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 
 			if (item->command == TODO_BREAK)
@@ -3882,6 +3883,7 @@
 			   opts, flags))
 		return error(_("could not commit staged changes."));
 	unlink(rebase_path_amend());
+	unlink(git_path_merge_head(the_repository));
 	if (final_fixup) {
 		unlink(rebase_path_fixup_msg());
 		unlink(rebase_path_squash_msg());
diff --git a/sha1-file.c b/sha1-file.c
index 2daf7d9..5bd11c8 100644
--- a/sha1-file.c
+++ b/sha1-file.c
@@ -833,7 +833,7 @@
 		return -1;
 
 	/* Generate the header */
-	hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", type_name(obj_type), size) + 1;
+	hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX , type_name(obj_type), (uintmax_t)size) + 1;
 
 	/* Sha1.. */
 	the_hash_algo->init_fn(&c);
@@ -1492,7 +1492,7 @@
 	git_hash_ctx c;
 
 	/* Generate the header */
-	*hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
+	*hdrlen = xsnprintf(hdr, *hdrlen, "%s %"PRIuMAX , type, (uintmax_t)len)+1;
 
 	/* Sha1.. */
 	the_hash_algo->init_fn(&c);
@@ -1758,7 +1758,7 @@
 	buf = read_object(oid->hash, &type, &len);
 	if (!buf)
 		return error(_("cannot read sha1_file for %s"), oid_to_hex(oid));
-	hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", type_name(type), len) + 1;
+	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);
 
diff --git a/t/README b/t/README
index 2424974..28711cc 100644
--- a/t/README
+++ b/t/README
@@ -302,6 +302,12 @@
 could be enabled by running the test suite with correct GIT_TEST_
 environment set.
 
+GIT_TEST_GETTEXT_POISON=<non-empty?> turns all strings marked for
+translation into gibberish if non-empty (think "test -n"). Used for
+spotting those tests that need to be marked with a C_LOCALE_OUTPUT
+prerequisite when adding more strings for translation. See "Testing
+marked strings" in po/README for details.
+
 GIT_TEST_SPLIT_INDEX=<boolean> forces split-index mode on the whole
 test suite. Accept any boolean values that are accepted by git-config.
 
@@ -339,6 +345,10 @@
 GIT_TEST_PRELOAD_INDEX=<boolean> exercises the preload-index code path
 by overriding the minimum number of cache entries required per thread.
 
+GIT_TEST_REBASE_USE_BUILTIN=<boolean>, when false, disables the
+builtin version of git-rebase. See 'rebase.useBuiltin' in
+git-config(1).
+
 GIT_TEST_INDEX_THREADS=<n> enables exercising the multi-threaded loading
 of the index for the whole test suite by bypassing the default number of
 cache entries and thread minimums. Setting this to 1 will make the
diff --git a/t/helper/test-parse-options.c b/t/helper/test-parse-options.c
index 9cb8a0e..47fee66 100644
--- a/t/helper/test-parse-options.c
+++ b/t/helper/test-parse-options.c
@@ -36,6 +36,7 @@
 
 static int number_callback(const struct option *opt, const char *arg, int unset)
 {
+	BUG_ON_OPT_NEG(unset);
 	*(int *)opt->value = strtol(arg, NULL, 10);
 	return 0;
 }
@@ -119,7 +120,6 @@
 		OPT_INTEGER('j', NULL, &integer, "get a integer, too"),
 		OPT_MAGNITUDE('m', "magnitude", &magnitude, "get a magnitude"),
 		OPT_SET_INT(0, "set23", &integer, "set integer to 23", 23),
-		OPT_DATE('t', NULL, &timestamp, "get timestamp of <time>"),
 		OPT_CALLBACK('L', "length", &integer, "str",
 			"get length of <str>", length_callback),
 		OPT_FILENAME('F', "file", &file, "set file to <file>"),
diff --git a/t/helper/test-prio-queue.c b/t/helper/test-prio-queue.c
index 9807b64..5bc9c46 100644
--- a/t/helper/test-prio-queue.c
+++ b/t/helper/test-prio-queue.c
@@ -22,14 +22,24 @@
 	struct prio_queue pq = { intcmp };
 
 	while (*++argv) {
-		if (!strcmp(*argv, "get"))
-			show(prio_queue_get(&pq));
-		else if (!strcmp(*argv, "dump")) {
-			int *v;
-			while ((v = prio_queue_get(&pq)))
-			       show(v);
-		}
-		else {
+		if (!strcmp(*argv, "get")) {
+			void *peek = prio_queue_peek(&pq);
+			void *get = prio_queue_get(&pq);
+			if (peek != get)
+				BUG("peek and get results do not match");
+			show(get);
+		} else if (!strcmp(*argv, "dump")) {
+			void *peek;
+			void *get;
+			while ((peek = prio_queue_peek(&pq))) {
+				get = prio_queue_get(&pq);
+				if (peek != get)
+					BUG("peek and get results do not match");
+				show(get);
+			}
+		} else if (!strcmp(*argv, "stack")) {
+			pq.compare = NULL;
+		} else {
 			int *v = malloc(sizeof(*v));
 			*v = atoi(*argv);
 			prio_queue_put(&pq, v);
diff --git a/t/lib-gettext.sh b/t/lib-gettext.sh
index eec757f..2139b42 100644
--- a/t/lib-gettext.sh
+++ b/t/lib-gettext.sh
@@ -10,9 +10,14 @@
 GIT_PO_PATH="$GIT_BUILD_DIR/po"
 export GIT_TEXTDOMAINDIR GIT_PO_PATH
 
-. "$GIT_BUILD_DIR"/git-sh-i18n
+if test -n "$GIT_TEST_INSTALLED"
+then
+	. "$(git --exec-path)"/git-sh-i18n
+else
+	. "$GIT_BUILD_DIR"/git-sh-i18n
+fi
 
-if test_have_prereq GETTEXT && ! test_have_prereq GETTEXT_POISON
+if test_have_prereq GETTEXT && test_have_prereq C_LOCALE_OUTPUT
 then
 	# is_IS.UTF-8 on Solaris and FreeBSD, is_IS.utf8 on Debian
 	is_IS_locale=$(locale -a 2>/dev/null |
diff --git a/t/lib-git-daemon.sh b/t/lib-git-daemon.sh
index edbea2d..f98de95 100644
--- a/t/lib-git-daemon.sh
+++ b/t/lib-git-daemon.sh
@@ -92,7 +92,7 @@
 	kill "$GIT_DAEMON_PID"
 	wait "$GIT_DAEMON_PID" >&3 2>&4
 	ret=$?
-	if test_match_signal 15 $?
+	if ! test_match_signal 15 $ret
 	then
 		error "git daemon exited with status: $ret"
 	fi
diff --git a/t/lib-gpg/keyring.gpg b/t/lib-gpg/keyring.gpg
index d4754a1..918dfce 100644
--- a/t/lib-gpg/keyring.gpg
+++ b/t/lib-gpg/keyring.gpg
@@ -30,7 +30,6 @@
 =aEiU
 -----END PGP PRIVATE KEY BLOCK-----
 -----BEGIN PGP PRIVATE KEY BLOCK-----
-Version: GnuPG v1
 
 lQOYBFFMlkcBCADJi/xnAF8yI34PHilSCbM7VtOFO17oFMkpu4cgN2QpPuM5MVjy
 cvrzKSguZFvPCDLzeAFJW1uPxL4SHaHSkisCrFhijH7OJWcOPNPSFCwu+inAoAsv
@@ -83,11 +82,43 @@
 ZKLy5nTTSy16ztqEeS7eifHLPZg1UFFyEEIQ1XW0CNDAeuWKh90ERjyl4Cg7PnWS
 Z9Ei+zj6JD5Pcdi3BJhQo9WOLOVEJ0NHmewTYqk9QVXH/0v1Hdl4LMJtgcbdbDWk
 4UTkXbg9pn3umCgkNJ3Vs8fWnIWO9Izdr2/wrFY2JvUT7Yvl+wsNIWatvOEzGy7n
-BOW78WUxzhu0YJTLKy+iKCjg5HS5dx6OC+e4aEEgfhNPCMkbvDsJjtQ=
-=hieJ
+BOW78WUxzhu0YJTLKy+iKCjg5HS5dx6OC+e4aEEgfhNPCMkbvDsJjtSdA5gEW967
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+EZXrwyDUxU7YSgKTHMKo9nFC6fIc1GeGPRalIF1gmTY32qlYJC6y5BTDhZNV5ydG
+u8QL2P/orP7XuRrJyeyK+QP/XTekr/DS6Jkct826MPA52ciIkWVgYLatH5fO4HCq
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+/HMLlcfZGiGdxS6n/vdz6wsEobJoi6STkHkA+VFNOSZmdsw6eKl3X911tpCTYfOG
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+EGEJLoW3InGJwHQgBBkBCAAdFiEE+DZKWeB//p9NYwBaZaDuoC4wytcFAlveu9wA
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+yQsGZ92EGxthsPK0+rhHV0MbaINupI1oO9gATFglSxq17o83FJatGRjaXCZau8jr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+=Iv7W
 -----END PGP PRIVATE KEY BLOCK-----
 -----BEGIN PGP PUBLIC KEY BLOCK-----
-Version: GnuPG v1
 
 mQGiBEZnyykRBACzCPjIpTYNL7Y2tQqlEGTTDlvZcWNLjF5f7ZzuyOqNOidLUgFD
 36qch1LZLSZkShdR3Gae+bsolyjxrlFuFP0eXRPMtqK20aLw7WZvPFpEV1ThMne+
@@ -137,6 +168,25 @@
 8uZ000stes7ahHku3onxyz2YNVBRchBCENV1tAjQwHrliofdBEY8peAoOz51kmfR
 Ivs4+iQ+T3HYtwSYUKPVjizlRCdDR5nsE2KpPUFVx/9L9R3ZeCzCbYHG3Ww1pOFE
 5F24PaZ97pgoJDSd1bPH1pyFjvSM3a9v8KxWNib1E+2L5fsLDSFmrbzhMxsu5wTl
-u/FlMc4btGCUyysvoigo4OR0uXcejgvnuGhBIH4TTwjJG7w7CY7U
-=iYv/
+u/FlMc4btGCUyysvoigo4OR0uXcejgvnuGhBIH4TTwjJG7w7CY7UuQENBFveu9wB
+CACo7Hk9LE0I8jd/Xzp9H88VqfPURDFFCoC4oG9NTCrrjSN3HnQWbM94aRTilXIo
+ua5XcPLn98ktzpIbdg3xz0g+DaxsyxhM0k6UNdEvDdqtA1GMMi1OgtFPB5zGZv5/
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+llEUNoB2VKkoht0DzGYmK9OHABEBAAGJAmwEGAEIACAWIQTUviIxGtMTHl7aKaRh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+=KRyT
 -----END PGP PUBLIC KEY BLOCK-----
diff --git a/t/perf/p3400-rebase.sh b/t/perf/p3400-rebase.sh
index ce271ca..d202aae 100755
--- a/t/perf/p3400-rebase.sh
+++ b/t/perf/p3400-rebase.sh
@@ -6,9 +6,9 @@
 test_perf_default_repo
 
 test_expect_success 'setup rebasing on top of a lot of changes' '
-	git checkout -f -b base &&
-	git checkout -b to-rebase &&
-	git checkout -b upstream &&
+	git checkout -f -B base &&
+	git checkout -B to-rebase &&
+	git checkout -B upstream &&
 	for i in $(seq 100)
 	do
 		# simulate huge diffs
@@ -35,8 +35,8 @@
 
 test_expect_success 'setup rebasing many changes without split-index' '
 	git config core.splitIndex false &&
-	git checkout -b upstream2 to-rebase &&
-	git checkout -b to-rebase2 upstream
+	git checkout -B upstream2 to-rebase &&
+	git checkout -B to-rebase2 upstream
 '
 
 test_perf 'rebase a lot of unrelated changes without split-index' '
diff --git a/t/t0000-basic.sh b/t/t0000-basic.sh
index 4d23373..b656600 100755
--- a/t/t0000-basic.sh
+++ b/t/t0000-basic.sh
@@ -274,7 +274,7 @@
 	EOF
 "
 
-test_expect_success 'test --verbose' '
+test_expect_success C_LOCALE_OUTPUT 'test --verbose' '
 	test_must_fail run_sub_test_lib_test \
 		test-verbose "test verbose" --verbose <<-\EOF &&
 	test_expect_success "passing test" true
diff --git a/t/t0009-prio-queue.sh b/t/t0009-prio-queue.sh
index e56dfce6..3941ad2 100755
--- a/t/t0009-prio-queue.sh
+++ b/t/t0009-prio-queue.sh
@@ -47,4 +47,18 @@
 	test_cmp expect actual
 '
 
+cat >expect <<'EOF'
+3
+2
+6
+4
+5
+1
+8
+EOF
+test_expect_success 'stack order' '
+	test-tool prio-queue stack 8 1 5 4 6 2 3 dump >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t0040-parse-options.sh b/t/t0040-parse-options.sh
index 17d0c18..f5b1086 100755
--- a/t/t0040-parse-options.sh
+++ b/t/t0040-parse-options.sh
@@ -23,7 +23,6 @@
     -j <n>                get a integer, too
     -m, --magnitude <n>   get a magnitude
     --set23               set integer to 23
-    -t <time>             get timestamp of <time>
     -L, --length <str>    get length of <str>
     -F, --file <file>     set file to <file>
 
@@ -246,27 +245,6 @@
 '
 
 cat >expect <<\EOF
-boolean: 0
-integer: 0
-magnitude: 0
-timestamp: 1
-string: (not set)
-abbrev: 7
-verbose: -1
-quiet: 1
-dry run: no
-file: (not set)
-arg 00: foo
-EOF
-
-test_expect_success 'OPT_DATE() works' '
-	test-tool parse-options -t "1970-01-01 00:00:01 +0000" \
-		foo -q >output 2>output.err &&
-	test_must_be_empty output.err &&
-	test_cmp expect output
-'
-
-cat >expect <<\EOF
 Callback: "four", 0
 boolean: 5
 integer: 4
diff --git a/t/t0205-gettext-poison.sh b/t/t0205-gettext-poison.sh
index 438e778..a06269f 100755
--- a/t/t0205-gettext-poison.sh
+++ b/t/t0205-gettext-poison.sh
@@ -5,13 +5,15 @@
 
 test_description='Gettext Shell poison'
 
+GIT_TEST_GETTEXT_POISON=YesPlease
+export GIT_TEST_GETTEXT_POISON
 . ./lib-gettext.sh
 
-test_expect_success GETTEXT_POISON 'sanity: $GIT_INTERNAL_GETTEXT_SH_SCHEME" is poison' '
+test_expect_success 'sanity: $GIT_INTERNAL_GETTEXT_SH_SCHEME" is poison' '
     test "$GIT_INTERNAL_GETTEXT_SH_SCHEME" = "poison"
 '
 
-test_expect_success GETTEXT_POISON 'gettext: our gettext() fallback has poison semantics' '
+test_expect_success 'gettext: our gettext() fallback has poison semantics' '
     printf "# GETTEXT POISON #" >expect &&
     gettext "test" >actual &&
     test_cmp expect actual &&
@@ -20,7 +22,7 @@
     test_cmp expect actual
 '
 
-test_expect_success GETTEXT_POISON 'eval_gettext: our eval_gettext() fallback has poison semantics' '
+test_expect_success 'eval_gettext: our eval_gettext() fallback has poison semantics' '
     printf "# GETTEXT POISON #" >expect &&
     eval_gettext "test" >actual &&
     test_cmp expect actual &&
diff --git a/t/t1700-split-index.sh b/t/t1700-split-index.sh
index 2ac47aa..4667e1a 100755
--- a/t/t1700-split-index.sh
+++ b/t/t1700-split-index.sh
@@ -25,14 +25,17 @@
 	git update-index --split-index &&
 	test-tool dump-split-index .git/index >actual &&
 	indexversion=$(test-tool index-version <.git/index) &&
+
+	# NEEDSWORK: Stop hard-coding checksums.
 	if test "$indexversion" = "4"
 	then
-		own=3527df833c6c100d3d1d921a9a782d62a8be4b58
-		base=746f7ab2ed44fb839efdfbffcf399d0b113fb4cb
+		own=432ef4b63f32193984f339431fd50ca796493569
+		base=508851a7f0dfa8691e9f69c7f055865389012491
 	else
-		own=5e9b60117ece18da410ddecc8b8d43766a0e4204
-		base=4370042739b31cd17a5c5cd6043a77c9a00df113
+		own=8299b0bcd1ac364e5f1d7768efb62fa2da79a339
+		base=39d890139ee5356c7ef572216cebcd27aa41f9df
 	fi &&
+
 	cat >expect <<-EOF &&
 	own $own
 	base $base
@@ -381,6 +384,26 @@
 	test $(ls .git/sharedindex.* | wc -l) -le 2
 '
 
+test_expect_success POSIXPERM 'same mode for index & split index' '
+	git init same-mode &&
+	(
+		cd same-mode &&
+		test_commit A &&
+		test_modebits .git/index >index_mode &&
+		test_must_fail git config core.sharedRepository &&
+		git -c core.splitIndex=true status &&
+		shared=$(ls .git/sharedindex.*) &&
+		case "$shared" in
+		*" "*)
+			# we have more than one???
+			false ;;
+		*)
+			test_modebits "$shared" >split_index_mode &&
+			test_cmp index_mode split_index_mode ;;
+		esac
+	)
+'
+
 while read -r mode modebits
 do
 	test_expect_success POSIXPERM "split index respects core.sharedrepository $mode" '
diff --git a/t/t3206-range-diff.sh b/t/t3206-range-diff.sh
index 6aae364..e497c13 100755
--- a/t/t3206-range-diff.sh
+++ b/t/t3206-range-diff.sh
@@ -122,6 +122,36 @@
 	test_cmp expected actual
 '
 
+test_expect_success 'changed commit with --no-patch diff option' '
+	git range-diff --no-color --no-patch topic...changed >actual &&
+	cat >expected <<-EOF &&
+	1:  4de457d = 1:  a4b3333 s/5/A/
+	2:  fccce22 = 2:  f51d370 s/4/A/
+	3:  147e64e ! 3:  0559556 s/11/B/
+	4:  a63e992 ! 4:  d966c5c s/12/B/
+	EOF
+	test_cmp expected actual
+'
+
+test_expect_success 'changed commit with --stat diff option' '
+	git range-diff --no-color --stat topic...changed >actual &&
+	cat >expected <<-EOF &&
+	1:  4de457d = 1:  a4b3333 s/5/A/
+	     a => b | 0
+	     1 file changed, 0 insertions(+), 0 deletions(-)
+	2:  fccce22 = 2:  f51d370 s/4/A/
+	     a => b | 0
+	     1 file changed, 0 insertions(+), 0 deletions(-)
+	3:  147e64e ! 3:  0559556 s/11/B/
+	     a => b | 0
+	     1 file changed, 0 insertions(+), 0 deletions(-)
+	4:  a63e992 ! 4:  d966c5c s/12/B/
+	     a => b | 0
+	     1 file changed, 0 insertions(+), 0 deletions(-)
+	EOF
+	test_cmp expected actual
+'
+
 test_expect_success 'changed commit with sm config' '
 	git range-diff --no-color --submodule=log topic...changed >actual &&
 	cat >expected <<-EOF &&
diff --git a/t/t3406-rebase-message.sh b/t/t3406-rebase-message.sh
index 0392e36..f64b130 100755
--- a/t/t3406-rebase-message.sh
+++ b/t/t3406-rebase-message.sh
@@ -77,11 +77,54 @@
 #     "Does not point to a valid commit: invalid-ref"
 #
 # NEEDSWORK: This "grep" is fine in real non-C locales, but
-# GETTEXT_POISON poisons the refname along with the enclosing
+# GIT_TEST_GETTEXT_POISON poisons the refname along with the enclosing
 # error message.
 test_expect_success 'rebase --onto outputs the invalid ref' '
 	test_must_fail git rebase --onto invalid-ref HEAD HEAD 2>err &&
 	test_i18ngrep "invalid-ref" err
 '
 
+test_expect_success 'error out early upon -C<n> or --whitespace=<bad>' '
+	test_must_fail git rebase -Cnot-a-number HEAD 2>err &&
+	test_i18ngrep "numerical value" err &&
+	test_must_fail git rebase --whitespace=bad HEAD 2>err &&
+	test_i18ngrep "Invalid whitespace option" err
+'
+
+test_expect_success 'GIT_REFLOG_ACTION' '
+	git checkout start &&
+	test_commit reflog-onto &&
+	git checkout -b reflog-topic start &&
+	test_commit reflog-to-rebase &&
+
+	git rebase reflog-onto &&
+	git log -g --format=%gs -3 >actual &&
+	cat >expect <<-\EOF &&
+	rebase finished: returning to refs/heads/reflog-topic
+	rebase: reflog-to-rebase
+	rebase: checkout reflog-onto
+	EOF
+	test_cmp expect actual &&
+
+	git checkout -b reflog-prefix reflog-to-rebase &&
+	GIT_REFLOG_ACTION=change-the-reflog git rebase reflog-onto &&
+	git log -g --format=%gs -3 >actual &&
+	cat >expect <<-\EOF &&
+	rebase finished: returning to refs/heads/reflog-prefix
+	change-the-reflog: reflog-to-rebase
+	change-the-reflog: checkout reflog-onto
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'rebase -i onto unrelated history' '
+	git init unrelated &&
+	test_commit -C unrelated 1 &&
+	git -C unrelated remote add -f origin "$PWD" &&
+	git -C unrelated branch --set-upstream-to=origin/master &&
+	git -C unrelated -c core.editor=true rebase -i -v --stat >actual &&
+	test_i18ngrep "Changes to " actual &&
+	test_i18ngrep "5 files changed" actual
+'
+
 test_done
diff --git a/t/t3420-rebase-autostash.sh b/t/t3420-rebase-autostash.sh
index f355c68..4c7494c 100755
--- a/t/t3420-rebase-autostash.sh
+++ b/t/t3420-rebase-autostash.sh
@@ -361,4 +361,12 @@
 	git rebase -i --autostash HEAD
 '
 
+test_expect_success 'branch is left alone when possible' '
+	git checkout -b unchanged-branch &&
+	echo changed >file0 &&
+	git rebase --autostash unchanged-branch &&
+	test changed = "$(cat file0)" &&
+	test unchanged-branch = "$(git rev-parse --abbrev-ref HEAD)"
+'
+
 test_done
diff --git a/t/t3430-rebase-merges.sh b/t/t3430-rebase-merges.sh
index aa7bfc8..cc56468 100755
--- a/t/t3430-rebase-merges.sh
+++ b/t/t3430-rebase-merges.sh
@@ -396,4 +396,20 @@
 	grep "G: +G" actual
 '
 
+test_expect_success '--continue after resolving conflicts after a merge' '
+	git checkout -b already-has-g E &&
+	git cherry-pick E..G &&
+	test_commit H2 &&
+
+	git checkout -b conflicts-in-merge H &&
+	test_commit H2 H2.t conflicts H2-conflict &&
+	test_must_fail git rebase -r already-has-g &&
+	grep conflicts H2.t &&
+	echo resolved >H2.t &&
+	git add -u &&
+	git rebase --continue &&
+	test_must_fail git rev-parse --verify HEAD^2 &&
+	test_path_is_missing .git/MERGE_HEAD
+'
+
 test_done
diff --git a/t/t4052-stat-output.sh b/t/t4052-stat-output.sh
index 6e2cf93..28c0538 100755
--- a/t/t4052-stat-output.sh
+++ b/t/t4052-stat-output.sh
@@ -44,42 +44,50 @@
 log -1 --stat
 EOF
 
-while read cmd args
+cat >expect.60 <<-'EOF'
+ ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1 +
+EOF
+cat >expect.6030 <<-'EOF'
+ ...aaaaaaaaaaaaaaaaaaaaaaaaaaa | 1 +
+EOF
+cat >expect2.60 <<-'EOF'
+ ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1 +
+ ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1 +
+EOF
+cat >expect2.6030 <<-'EOF'
+ ...aaaaaaaaaaaaaaaaaaaaaaaaaaa | 1 +
+ ...aaaaaaaaaaaaaaaaaaaaaaaaaaa | 1 +
+EOF
+while read expect cmd args
 do
-	cat >expect <<-'EOF'
-	 ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaa | 1 +
-	EOF
 	test_expect_success "$cmd --stat=width: a long name is given more room when the bar is short" '
 		git $cmd $args --stat=40 >output &&
 		grep " | " output >actual &&
-		test_cmp expect actual
+		test_cmp $expect.60 actual
 	'
 
 	test_expect_success "$cmd --stat-width=width with long name" '
 		git $cmd $args --stat-width=40 >output &&
 		grep " | " output >actual &&
-		test_cmp expect actual
+		test_cmp $expect.60 actual
 	'
 
-	cat >expect <<-'EOF'
-	 ...aaaaaaaaaaaaaaaaaaaaaaaaaaa | 1 +
-	EOF
 	test_expect_success "$cmd --stat=...,name-width with long name" '
 		git $cmd $args --stat=60,30 >output &&
 		grep " | " output >actual &&
-		test_cmp expect actual
+		test_cmp $expect.6030 actual
 	'
 
 	test_expect_success "$cmd --stat-name-width with long name" '
 		git $cmd $args --stat-name-width=30 >output &&
 		grep " | " output >actual &&
-		test_cmp expect actual
+		test_cmp $expect.6030 actual
 	'
 done <<\EOF
-format-patch -1 --stdout
-diff HEAD^ HEAD --stat
-show --stat
-log -1 --stat
+expect2 format-patch --cover-letter -1 --stdout
+expect diff HEAD^ HEAD --stat
+expect show --stat
+expect log -1 --stat
 EOF
 
 
@@ -97,6 +105,16 @@
 
 cat >expect72 <<'EOF'
  abcd | 1000 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ abcd | 1000 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+EOF
+test_expect_success "format-patch --cover-letter ignores COLUMNS (big change)" '
+	COLUMNS=200 git format-patch -1 --stdout --cover-letter >output &&
+	grep " | " output >actual &&
+	test_cmp expect72 actual
+'
+
+cat >expect72 <<'EOF'
+ abcd | 1000 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 EOF
 cat >expect72-graph <<'EOF'
 |  abcd | 1000 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
diff --git a/t/t4136-apply-check.sh b/t/t4136-apply-check.sh
index 6d92872..4c3f264 100755
--- a/t/t4136-apply-check.sh
+++ b/t/t4136-apply-check.sh
@@ -29,6 +29,18 @@
 	test_must_fail git apply --check input
 '
 
+test_expect_success '`apply --recount` allows no-op patch' '
+	echo 1 >1 &&
+	git apply --recount --check <<-\EOF
+	diff --get a/1 b/1
+	index 6696ea4..606eddd 100644
+	--- a/1
+	+++ b/1
+	@@ -1,1 +1,1 @@
+	 1
+	EOF
+'
+
 test_expect_success 'invalid combination: create and copy' '
 	test_must_fail git apply --check - <<-\EOF
 	diff --git a/1 b/2
diff --git a/t/t5512-ls-remote.sh b/t/t5512-ls-remote.sh
index 91ee684..32e722d 100755
--- a/t/t5512-ls-remote.sh
+++ b/t/t5512-ls-remote.sh
@@ -302,6 +302,12 @@
 	nongit git ls-remote dst.git
 '
 
+test_expect_success 'ls-remote --sort fails gracefully outside repository' '
+	# Use a sort key that requires access to the referenced objects.
+	nongit test_must_fail git ls-remote --sort=authordate "$TRASH_DIRECTORY" 2>err &&
+	test_i18ngrep "^fatal: not a git repository, but the field '\''authordate'\'' requires access to object data" err
+'
+
 test_expect_success 'ls-remote patterns work with all protocol versions' '
 	git for-each-ref --format="%(objectname)	%(refname)" \
 		refs/heads/master refs/remotes/origin/master >expect &&
diff --git a/t/t5562-http-backend-content-length.sh b/t/t5562-http-backend-content-length.sh
index b24d8b0..90d890d 100755
--- a/t/t5562-http-backend-content-length.sh
+++ b/t/t5562-http-backend-content-length.sh
@@ -31,6 +31,7 @@
 		PATH_TRANSLATED="$PWD/.git/git-$handler_type-pack" \
 		GIT_HTTP_EXPORT_ALL=TRUE \
 		REQUEST_METHOD=POST \
+		"$PERL_PATH" \
 		"$TEST_DIRECTORY"/t5562/invoke-with-content-length.pl \
 		    "$request_body" git http-backend >act.out 2>act.err
 }
diff --git a/t/t5562/invoke-with-content-length.pl b/t/t5562/invoke-with-content-length.pl
old mode 100755
new mode 100644
index 6c2aae7..0943474
--- a/t/t5562/invoke-with-content-length.pl
+++ b/t/t5562/invoke-with-content-length.pl
@@ -1,4 +1,3 @@
-#!/usr/bin/perl
 use 5.008;
 use strict;
 use warnings;
diff --git a/t/t5573-pull-verify-signatures.sh b/t/t5573-pull-verify-signatures.sh
index 747775c..3e9876e 100755
--- a/t/t5573-pull-verify-signatures.sh
+++ b/t/t5573-pull-verify-signatures.sh
@@ -78,4 +78,11 @@
 	git pull --ff-only --no-verify-signatures bad 2>pullerror
 '
 
+test_expect_success GPG 'pull unsigned commit into unborn branch' '
+	git init empty-repo &&
+	test_must_fail \
+		git -C empty-repo pull --verify-signatures ..  2>pullerror &&
+	test_i18ngrep "does not have a GPG signature" pullerror
+'
+
 test_done
diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index f1a49e9..8bbc706 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -628,7 +628,7 @@
 	)
 '
 
-test_expect_success !MINGW,!CYGWIN,CASE_INSENSITIVE_FS 'colliding file detection' '
+test_expect_success CASE_INSENSITIVE_FS 'colliding file detection' '
 	grep X icasefs/warning &&
 	grep x icasefs/warning &&
 	test_i18ngrep "the following paths have collided" icasefs/warning
diff --git a/t/t5607-clone-bundle.sh b/t/t5607-clone-bundle.sh
index 348d9b3..cf39e9e 100755
--- a/t/t5607-clone-bundle.sh
+++ b/t/t5607-clone-bundle.sh
@@ -71,4 +71,10 @@
 	git bundle verify bundle
 '
 
+test_expect_success 'failed bundle creation does not leave cruft' '
+	# This fails because the bundle would be empty.
+	test_must_fail git bundle create fail.bundle master..master &&
+	test_path_is_missing fail.bundle.lock
+'
+
 test_done
diff --git a/t/t6012-rev-list-simplify.sh b/t/t6012-rev-list-simplify.sh
index b5a1190..a10f0df 100755
--- a/t/t6012-rev-list-simplify.sh
+++ b/t/t6012-rev-list-simplify.sh
@@ -12,6 +12,22 @@
 	git name-rev --tags --stdin | sed -e "s|$OID_REGEX (tags/\([^)]*\)) |\1 |g"
 }
 
+#
+# Create a test repo with interesting commit graph:
+#
+# A--B----------G--H--I--K--L
+#  \  \           /     /
+#   \  \         /     /
+#    C------E---F     J
+#        \_/
+#
+# The commits are laid out from left-to-right starting with
+# the root commit A and terminating at the tip commit L.
+#
+# There are a few places where we adjust the commit date or
+# author date to make the --topo-order, --date-order, and
+# --author-date-order flags produce different output.
+
 test_expect_success setup '
 	echo "Hi there" >file &&
 	echo "initial" >lost &&
@@ -21,10 +37,18 @@
 
 	git branch other-branch &&
 
+	git symbolic-ref HEAD refs/heads/unrelated &&
+	git rm -f "*" &&
+	echo "Unrelated branch" >side &&
+	git add side &&
+	test_tick && git commit -m "Side root" &&
+	note J &&
+	git checkout master &&
+
 	echo "Hello" >file &&
 	echo "second" >lost &&
 	git add file lost &&
-	test_tick && git commit -m "Modified file and lost" &&
+	test_tick && GIT_AUTHOR_DATE=$(($test_tick + 120)) git commit -m "Modified file and lost" &&
 	note B &&
 
 	git checkout other-branch &&
@@ -63,13 +87,6 @@
 	test_tick && git commit -a -m "Final change" &&
 	note I &&
 
-	git symbolic-ref HEAD refs/heads/unrelated &&
-	git rm -f "*" &&
-	echo "Unrelated branch" >side &&
-	git add side &&
-	test_tick && git commit -m "Side root" &&
-	note J &&
-
 	git checkout master &&
 	test_tick && git merge --allow-unrelated-histories -m "Coolest" unrelated &&
 	note K &&
@@ -103,14 +120,24 @@
 	check_outcome success "$@"
 }
 
-check_result 'L K J I H G F E D C B A' --full-history
+check_result 'L K J I H F E D C G B A' --full-history --topo-order
+check_result 'L K I H G F E D C B J A' --full-history
+check_result 'L K I H G F E D C B J A' --full-history --date-order
+check_result 'L K I H G F E D B C J A' --full-history --author-date-order
 check_result 'K I H E C B A' --full-history -- file
 check_result 'K I H E C B A' --full-history --topo-order -- file
 check_result 'K I H E C B A' --full-history --date-order -- file
+check_result 'K I H E B C A' --full-history --author-date-order -- file
 check_result 'I E C B A' --simplify-merges -- file
+check_result 'I E C B A' --simplify-merges --topo-order -- file
+check_result 'I E C B A' --simplify-merges --date-order -- file
+check_result 'I E B C A' --simplify-merges --author-date-order -- file
 check_result 'I B A' -- file
 check_result 'I B A' --topo-order -- file
+check_result 'I B A' --date-order -- file
+check_result 'I B A' --author-date-order -- file
 check_result 'H' --first-parent -- another-file
+check_result 'H' --first-parent --topo-order -- another-file
 
 check_result 'E C B A' --full-history E -- lost
 test_expect_success 'full history simplification without parent' '
diff --git a/t/t6018-rev-list-glob.sh b/t/t6018-rev-list-glob.sh
index 270e579..bb5aeac 100755
--- a/t/t6018-rev-list-glob.sh
+++ b/t/t6018-rev-list-glob.sh
@@ -36,7 +36,13 @@
 	git tag foo/bar master &&
 	commit master3 &&
 	git update-ref refs/remotes/foo/baz master &&
-	commit master4
+	commit master4 &&
+	git update-ref refs/remotes/upstream/one subspace/one &&
+	git update-ref refs/remotes/upstream/two subspace/two &&
+	git update-ref refs/remotes/upstream/x subspace-x &&
+	git tag qux/one subspace/one &&
+	git tag qux/two subspace/two &&
+	git tag qux/x subspace-x
 '
 
 test_expect_success 'rev-parse --glob=refs/heads/subspace/*' '
@@ -153,6 +159,54 @@
 	compare rev-parse "--exclude=* --all --all" "--all"
 '
 
+test_expect_success 'rev-parse --exclude=glob with --branches=glob' '
+	compare rev-parse "--exclude=subspace-* --branches=sub*" "subspace/one subspace/two"
+'
+
+test_expect_success 'rev-parse --exclude=glob with --tags=glob' '
+	compare rev-parse "--exclude=qux/? --tags=qux/*" "qux/one qux/two"
+'
+
+test_expect_success 'rev-parse --exclude=glob with --remotes=glob' '
+	compare rev-parse "--exclude=upstream/? --remotes=upstream/*" "upstream/one upstream/two"
+'
+
+test_expect_success 'rev-parse --exclude=ref with --branches=glob' '
+	compare rev-parse "--exclude=subspace-x --branches=sub*" "subspace/one subspace/two"
+'
+
+test_expect_success 'rev-parse --exclude=ref with --tags=glob' '
+	compare rev-parse "--exclude=qux/x --tags=qux/*" "qux/one qux/two"
+'
+
+test_expect_success 'rev-parse --exclude=ref with --remotes=glob' '
+	compare rev-parse "--exclude=upstream/x --remotes=upstream/*" "upstream/one upstream/two"
+'
+
+test_expect_success 'rev-list --exclude=glob with --branches=glob' '
+	compare rev-list "--exclude=subspace-* --branches=sub*" "subspace/one subspace/two"
+'
+
+test_expect_success 'rev-list --exclude=glob with --tags=glob' '
+	compare rev-list "--exclude=qux/? --tags=qux/*" "qux/one qux/two"
+'
+
+test_expect_success 'rev-list --exclude=glob with --remotes=glob' '
+	compare rev-list "--exclude=upstream/? --remotes=upstream/*" "upstream/one upstream/two"
+'
+
+test_expect_success 'rev-list --exclude=ref with --branches=glob' '
+	compare rev-list "--exclude=subspace-x --branches=sub*" "subspace/one subspace/two"
+'
+
+test_expect_success 'rev-list --exclude=ref with --tags=glob' '
+	compare rev-list "--exclude=qux/x --tags=qux/*" "qux/one qux/two"
+'
+
+test_expect_success 'rev-list --exclude=ref with --remotes=glob' '
+	compare rev-list "--exclude=upstream/x --remotes=upstream/*" "upstream/one upstream/two"
+'
+
 test_expect_success 'rev-list --glob=refs/heads/subspace/*' '
 
 	compare rev-list "subspace/one subspace/two" "--glob=refs/heads/subspace/*"
@@ -245,7 +299,7 @@
 
 test_expect_success 'rev-list --tags' '
 
-	compare rev-list "foo/bar" "--tags"
+	compare rev-list "foo/bar qux/x qux/two qux/one" "--tags"
 
 '
 
@@ -304,7 +358,7 @@
 	  "master other/three someref subspace-x subspace/one subspace/two" \
 	  "--glob=heads/*" &&
 	compare shortlog foo/bar --tags=foo &&
-	compare shortlog foo/bar --tags &&
+	compare shortlog "foo/bar qux/one qux/two qux/x" --tags &&
 	compare shortlog foo/baz --remotes=foo
 
 '
diff --git a/t/t6050-replace.sh b/t/t6050-replace.sh
index 86374a9..5d6d318 100755
--- a/t/t6050-replace.sh
+++ b/t/t6050-replace.sh
@@ -461,7 +461,10 @@
 	printf "%s\n%s %s\n\n# comment\n%s\n" \
 		$(git rev-parse HEAD^^ HEAD^ HEAD^^ HEAD^2) \
 		>.git/info/grafts &&
-	git replace --convert-graft-file &&
+	git status 2>stderr &&
+	test_i18ngrep "hint:.*grafts is deprecated" stderr &&
+	git replace --convert-graft-file 2>stderr &&
+	test_i18ngrep ! "hint:.*grafts is deprecated" stderr &&
 	test_path_is_missing .git/info/grafts &&
 
 	: verify that the history is now "grafted" &&
diff --git a/t/t6600-test-reach.sh b/t/t6600-test-reach.sh
index a0c64e6..b24d850 100755
--- a/t/t6600-test-reach.sh
+++ b/t/t6600-test-reach.sh
@@ -56,18 +56,22 @@
 	git config core.commitGraph true
 '
 
-test_three_modes () {
+run_three_modes () {
 	test_when_finished rm -rf .git/objects/info/commit-graph &&
-	test-tool reach $1 <input >actual &&
+	"$@" <input >actual &&
 	test_cmp expect actual &&
 	cp commit-graph-full .git/objects/info/commit-graph &&
-	test-tool reach $1 <input >actual &&
+	"$@" <input >actual &&
 	test_cmp expect actual &&
 	cp commit-graph-half .git/objects/info/commit-graph &&
-	test-tool reach $1 <input >actual &&
+	"$@" <input >actual &&
 	test_cmp expect actual
 }
 
+test_three_modes () {
+	run_three_modes test-tool reach "$@"
+}
+
 test_expect_success 'ref_newer:miss' '
 	cat >input <<-\EOF &&
 	A:commit-5-7
@@ -265,6 +269,90 @@
 	test_three_modes commit_contains --tag
 '
 
+test_expect_success 'rev-list: basic topo-order' '
+	git rev-parse \
+		commit-6-6 commit-5-6 commit-4-6 commit-3-6 commit-2-6 commit-1-6 \
+		commit-6-5 commit-5-5 commit-4-5 commit-3-5 commit-2-5 commit-1-5 \
+		commit-6-4 commit-5-4 commit-4-4 commit-3-4 commit-2-4 commit-1-4 \
+		commit-6-3 commit-5-3 commit-4-3 commit-3-3 commit-2-3 commit-1-3 \
+		commit-6-2 commit-5-2 commit-4-2 commit-3-2 commit-2-2 commit-1-2 \
+		commit-6-1 commit-5-1 commit-4-1 commit-3-1 commit-2-1 commit-1-1 \
+	>expect &&
+	run_three_modes git rev-list --topo-order commit-6-6
+'
+
+test_expect_success 'rev-list: first-parent topo-order' '
+	git rev-parse \
+		commit-6-6 \
+		commit-6-5 \
+		commit-6-4 \
+		commit-6-3 \
+		commit-6-2 \
+		commit-6-1 commit-5-1 commit-4-1 commit-3-1 commit-2-1 commit-1-1 \
+	>expect &&
+	run_three_modes git rev-list --first-parent --topo-order commit-6-6
+'
+
+test_expect_success 'rev-list: range topo-order' '
+	git rev-parse \
+		commit-6-6 commit-5-6 commit-4-6 commit-3-6 commit-2-6 commit-1-6 \
+		commit-6-5 commit-5-5 commit-4-5 commit-3-5 commit-2-5 commit-1-5 \
+		commit-6-4 commit-5-4 commit-4-4 commit-3-4 commit-2-4 commit-1-4 \
+		commit-6-3 commit-5-3 commit-4-3 \
+		commit-6-2 commit-5-2 commit-4-2 \
+		commit-6-1 commit-5-1 commit-4-1 \
+	>expect &&
+	run_three_modes git rev-list --topo-order commit-3-3..commit-6-6
+'
+
+test_expect_success 'rev-list: range topo-order' '
+	git rev-parse \
+		commit-6-6 commit-5-6 commit-4-6 \
+		commit-6-5 commit-5-5 commit-4-5 \
+		commit-6-4 commit-5-4 commit-4-4 \
+		commit-6-3 commit-5-3 commit-4-3 \
+		commit-6-2 commit-5-2 commit-4-2 \
+		commit-6-1 commit-5-1 commit-4-1 \
+	>expect &&
+	run_three_modes git rev-list --topo-order commit-3-8..commit-6-6
+'
+
+test_expect_success 'rev-list: first-parent range topo-order' '
+	git rev-parse \
+		commit-6-6 \
+		commit-6-5 \
+		commit-6-4 \
+		commit-6-3 \
+		commit-6-2 \
+		commit-6-1 commit-5-1 commit-4-1 \
+	>expect &&
+	run_three_modes git rev-list --first-parent --topo-order commit-3-8..commit-6-6
+'
+
+test_expect_success 'rev-list: ancestry-path topo-order' '
+	git rev-parse \
+		commit-6-6 commit-5-6 commit-4-6 commit-3-6 \
+		commit-6-5 commit-5-5 commit-4-5 commit-3-5 \
+		commit-6-4 commit-5-4 commit-4-4 commit-3-4 \
+		commit-6-3 commit-5-3 commit-4-3 \
+	>expect &&
+	run_three_modes git rev-list --topo-order --ancestry-path commit-3-3..commit-6-6
+'
+
+test_expect_success 'rev-list: symmetric difference topo-order' '
+	git rev-parse \
+		commit-6-6 commit-5-6 commit-4-6 \
+		commit-6-5 commit-5-5 commit-4-5 \
+		commit-6-4 commit-5-4 commit-4-4 \
+		commit-6-3 commit-5-3 commit-4-3 \
+		commit-6-2 commit-5-2 commit-4-2 \
+		commit-6-1 commit-5-1 commit-4-1 \
+		commit-3-8 commit-2-8 commit-1-8 \
+		commit-3-7 commit-2-7 commit-1-7 \
+	>expect &&
+	run_three_modes git rev-list --topo-order commit-3-8...commit-6-6
+'
+
 test_expect_success 'get_reachable_subset:all' '
 	cat >input <<-\EOF &&
 	X:commit-9-1
diff --git a/t/t7201-co.sh b/t/t7201-co.sh
index 826987c..72b9b37 100755
--- a/t/t7201-co.sh
+++ b/t/t7201-co.sh
@@ -254,9 +254,9 @@
 test_expect_success 'checkout to detach HEAD' '
 	git config advice.detachedHead true &&
 	git checkout -f renamer && git clean -f &&
-	git checkout renamer^ 2>messages &&
-	test_i18ngrep "HEAD is now at 7329388" messages &&
-	(test_line_count -gt 1 messages || test -n "$GETTEXT_POISON") &&
+	GIT_TEST_GETTEXT_POISON= git checkout renamer^ 2>messages &&
+	grep "HEAD is now at 7329388" messages &&
+	test_line_count -gt 1 messages &&
 	H=$(git rev-parse --verify HEAD) &&
 	M=$(git show-ref -s --verify refs/heads/master) &&
 	test "z$H" = "z$M" &&
diff --git a/t/t7510-signed-commit.sh b/t/t7510-signed-commit.sh
index 19ccae2..86d3f93 100755
--- a/t/t7510-signed-commit.sh
+++ b/t/t7510-signed-commit.sh
@@ -176,8 +176,9 @@
 	13B6F51ECDDE430D
 	C O Mitter <committer@example.com>
 	73D758744BE721698EC54E8713B6F51ECDDE430D
+	73D758744BE721698EC54E8713B6F51ECDDE430D
 	EOF
-	git log -1 --format="%G?%n%GK%n%GS%n%GF" sixth-signed >actual &&
+	git log -1 --format="%G?%n%GK%n%GS%n%GF%n%GP" sixth-signed >actual &&
 	test_cmp expect actual
 '
 
@@ -187,30 +188,33 @@
 	13B6F51ECDDE430D
 	C O Mitter <committer@example.com>
 
+
 	EOF
-	git log -1 --format="%G?%n%GK%n%GS%n%GF" $(cat forged1.commit) >actual &&
+	git log -1 --format="%G?%n%GK%n%GS%n%GF%n%GP" $(cat forged1.commit) >actual &&
 	test_cmp expect actual
 '
 
 test_expect_success GPG 'show untrusted signature with custom format' '
 	cat >expect <<-\EOF &&
 	U
-	61092E85B7227189
+	65A0EEA02E30CAD7
 	Eris Discordia <discord@example.net>
+	F8364A59E07FFE9F4D63005A65A0EEA02E30CAD7
 	D4BE22311AD3131E5EDA29A461092E85B7227189
 	EOF
-	git log -1 --format="%G?%n%GK%n%GS%n%GF" eighth-signed-alt >actual &&
+	git log -1 --format="%G?%n%GK%n%GS%n%GF%n%GP" eighth-signed-alt >actual &&
 	test_cmp expect actual
 '
 
 test_expect_success GPG 'show unknown signature with custom format' '
 	cat >expect <<-\EOF &&
 	E
-	61092E85B7227189
+	65A0EEA02E30CAD7
+
 
 
 	EOF
-	GNUPGHOME="$GNUPGHOME_NOT_USED" git log -1 --format="%G?%n%GK%n%GS%n%GF" eighth-signed-alt >actual &&
+	GNUPGHOME="$GNUPGHOME_NOT_USED" git log -1 --format="%G?%n%GK%n%GS%n%GF%n%GP" eighth-signed-alt >actual &&
 	test_cmp expect actual
 '
 
@@ -220,8 +224,9 @@
 
 
 
+
 	EOF
-	git log -1 --format="%G?%n%GK%n%GS%n%GF" seventh-unsigned >actual &&
+	git log -1 --format="%G?%n%GK%n%GS%n%GF%n%GP" seventh-unsigned >actual &&
 	test_cmp expect actual
 '
 
@@ -261,8 +266,9 @@
 
 
 
+
 	EOF
-	git log -1 --format="%G?%n%GK%n%GS%n%GF" $(cat double-commit.commit) >actual &&
+	git log -1 --format="%G?%n%GK%n%GS%n%GF%n%GP" $(cat double-commit.commit) >actual &&
 	test_cmp expect actual
 '
 
diff --git a/t/t7612-merge-verify-signatures.sh b/t/t7612-merge-verify-signatures.sh
index e2b1df8..d99218a 100755
--- a/t/t7612-merge-verify-signatures.sh
+++ b/t/t7612-merge-verify-signatures.sh
@@ -103,4 +103,11 @@
 	git merge --no-verify-signatures $(cat forged.commit)
 '
 
+test_expect_success GPG 'merge unsigned commit into unborn branch' '
+	test_when_finished "git checkout initial" &&
+	git checkout --orphan unborn &&
+	test_must_fail git merge --verify-signatures side-unsigned 2>mergeerror &&
+	test_i18ngrep "does not have a GPG signature" mergeerror
+'
+
 test_done
diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
index 175f83d..3c6b185 100755
--- a/t/t9902-completion.sh
+++ b/t/t9902-completion.sh
@@ -1697,7 +1697,8 @@
 	verbose test -z "$__git_all_commands"
 '
 
-test_expect_success !GETTEXT_POISON 'sourcing the completion script clears cached merge strategies' '
+test_expect_success 'sourcing the completion script clears cached merge strategies' '
+	GIT_TEST_GETTEXT_POISON= &&
 	__git_compute_merge_strategies &&
 	verbose test -n "$__git_merge_strategies" &&
 	. "$GIT_BUILD_DIR/contrib/completion/git-completion.bash" &&
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index d158c8d..b4e3915 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -778,16 +778,16 @@
 
 # Use this instead of test_cmp to compare files that contain expected and
 # actual output from git commands that can be translated.  When running
-# under GETTEXT_POISON this pretends that the command produced expected
+# under GIT_TEST_GETTEXT_POISON this pretends that the command produced expected
 # results.
 test_i18ncmp () {
-	test -n "$GETTEXT_POISON" || test_cmp "$@"
+	! test_have_prereq C_LOCALE_OUTPUT || test_cmp "$@"
 }
 
 # Use this instead of "grep expected-string actual" to see if the
 # output from a git command that can be translated either contains an
 # expected string, or does not contain an unwanted one.  When running
-# under GETTEXT_POISON this pretends that the command produced expected
+# under GIT_TEST_GETTEXT_POISON this pretends that the command produced expected
 # results.
 test_i18ngrep () {
 	eval "last_arg=\${$#}"
@@ -802,7 +802,7 @@
 		error "bug in the test script: too few parameters to test_i18ngrep"
 	fi
 
-	if test -n "$GETTEXT_POISON"
+	if test_have_prereq !C_LOCALE_OUTPUT
 	then
 		# pretend success
 		return 0
@@ -923,7 +923,8 @@
 	mkdir -p "$repo"
 	(
 		cd "$repo" || error "Cannot setup test environment"
-		"$GIT_EXEC_PATH/git-init" "--template=$GIT_BUILD_DIR/templates/blt/" >&3 2>&4 ||
+		"${GIT_TEST_INSTALLED:-$GIT_EXEC_PATH}/git$X" init \
+			"--template=$GIT_BUILD_DIR/templates/blt/" >&3 2>&4 ||
 		error "cannot run git init -- have you built things yet?"
 		mv .git/hooks .git/hooks-disabled
 	) || exit
diff --git a/t/test-lib.sh b/t/test-lib.sh
index aba66ca..6c6c0af 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -49,18 +49,28 @@
 : ${LSAN_OPTIONS=abort_on_error=1}
 export LSAN_OPTIONS
 
-################################################################
-# It appears that people try to run tests without building...
-"$GIT_BUILD_DIR/git" >/dev/null
-if test $? != 1
+if test ! -f "$GIT_BUILD_DIR"/GIT-BUILD-OPTIONS
 then
-	echo >&2 'error: you do not seem to have built git yet.'
+	echo >&2 'error: GIT-BUILD-OPTIONS missing (has Git been built?).'
 	exit 1
 fi
-
 . "$GIT_BUILD_DIR"/GIT-BUILD-OPTIONS
 export PERL_PATH SHELL_PATH
 
+################################################################
+# It appears that people try to run tests without building...
+"${GIT_TEST_INSTALLED:-$GIT_BUILD_DIR}/git$X" >/dev/null
+if test $? != 1
+then
+	if test -n "$GIT_TEST_INSTALLED"
+	then
+		echo >&2 "error: there is no working Git at '$GIT_TEST_INSTALLED'"
+	else
+		echo >&2 'error: you do not seem to have built git yet.'
+	fi
+	exit 1
+fi
+
 # if --tee was passed, write the output not only to the terminal, but
 # additionally to the file test-results/$BASENAME.out, too.
 case "$GIT_TEST_TEE_STARTED, $* " in
@@ -95,6 +105,16 @@
 TZ=UTC
 export LANG LC_ALL PAGER TZ
 EDITOR=:
+
+# GIT_TEST_GETTEXT_POISON should not influence git commands executed
+# during initialization of test-lib and the test repo. Back it up,
+# unset and then restore after initialization is finished.
+if test -n "$GIT_TEST_GETTEXT_POISON"
+then
+	GIT_TEST_GETTEXT_POISON_ORIG=$GIT_TEST_GETTEXT_POISON
+	unset GIT_TEST_GETTEXT_POISON
+fi
+
 # A call to "unset" with no arguments causes at least Solaris 10
 # /usr/xpg4/bin/sh and /bin/ksh to bail out.  So keep the unsets
 # deriving from the command substitution clustered with the other
@@ -957,7 +977,7 @@
 then
 	GIT_EXEC_PATH=$($GIT_TEST_INSTALLED/git --exec-path)  ||
 	error "Cannot run git from $GIT_TEST_INSTALLED."
-	PATH=$GIT_TEST_INSTALLED:$GIT_BUILD_DIR:$PATH
+	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"
@@ -1104,13 +1124,15 @@
 test -n "$USE_LIBPCRE2" && test_set_prereq LIBPCRE2
 test -z "$NO_GETTEXT" && test_set_prereq GETTEXT
 
-# Can we rely on git's output in the C locale?
-if test -n "$GETTEXT_POISON"
+if test -n "$GIT_TEST_GETTEXT_POISON_ORIG"
 then
-	GIT_GETTEXT_POISON=YesPlease
-	export GIT_GETTEXT_POISON
-	test_set_prereq GETTEXT_POISON
-else
+	GIT_TEST_GETTEXT_POISON=$GIT_TEST_GETTEXT_POISON_ORIG
+	unset GIT_TEST_GETTEXT_POISON_ORIG
+fi
+
+# Can we rely on git's output in the C locale?
+if test -z "$GIT_TEST_GETTEXT_POISON"
+then
 	test_set_prereq C_LOCALE_OUTPUT
 fi
 
diff --git a/thread-utils.c b/thread-utils.c
index a2135e0..5329845 100644
--- a/thread-utils.c
+++ b/thread-utils.c
@@ -20,6 +20,9 @@
 
 int online_cpus(void)
 {
+#ifdef NO_PTHREADS
+	return 1;
+#else
 #ifdef _SC_NPROCESSORS_ONLN
 	long ncpus;
 #endif
@@ -59,10 +62,12 @@
 #endif
 
 	return 1;
+#endif
 }
 
 int init_recursive_mutex(pthread_mutex_t *m)
 {
+#ifndef NO_PTHREADS
 	pthread_mutexattr_t a;
 	int ret;
 
@@ -74,4 +79,47 @@
 		pthread_mutexattr_destroy(&a);
 	}
 	return ret;
+#else
+	return 0;
+#endif
 }
+
+#ifdef NO_PTHREADS
+int dummy_pthread_create(pthread_t *pthread, const void *attr,
+			 void *(*fn)(void *), void *data)
+{
+	/*
+	 * Do nothing.
+	 *
+	 * The main purpose of this function is to break compiler's
+	 * flow analysis and avoid -Wunused-variable false warnings.
+	 */
+	return ENOSYS;
+}
+
+int dummy_pthread_init(void *data)
+{
+	/*
+	 * Do nothing.
+	 *
+	 * The main purpose of this function is to break compiler's
+	 * flow analysis or it may realize that functions like
+	 * pthread_mutex_init() is no-op, which means the (static)
+	 * variable is not used/initialized at all and trigger
+	 * -Wunused-variable
+	 */
+	return ENOSYS;
+}
+
+int dummy_pthread_join(pthread_t pthread, void **retval)
+{
+	/*
+	 * Do nothing.
+	 *
+	 * The main purpose of this function is to break compiler's
+	 * flow analysis and avoid -Wunused-variable false warnings.
+	 */
+	return ENOSYS;
+}
+
+#endif
diff --git a/thread-utils.h b/thread-utils.h
index d9a769d..4961487 100644
--- a/thread-utils.h
+++ b/thread-utils.h
@@ -4,12 +4,54 @@
 #ifndef NO_PTHREADS
 #include <pthread.h>
 
-extern int online_cpus(void);
-extern int init_recursive_mutex(pthread_mutex_t*);
+#define HAVE_THREADS 1
 
 #else
 
-#define online_cpus() 1
+#define HAVE_THREADS 0
+
+/*
+ * macros instead of typedefs because pthread definitions may have
+ * been pulled in by some system dependencies even though the user
+ * wants to disable pthread.
+ */
+#define pthread_t int
+#define pthread_mutex_t int
+#define pthread_cond_t int
+#define pthread_key_t int
+
+#define pthread_mutex_init(mutex, attr) dummy_pthread_init(mutex)
+#define pthread_mutex_lock(mutex)
+#define pthread_mutex_unlock(mutex)
+#define pthread_mutex_destroy(mutex)
+
+#define pthread_cond_init(cond, attr) dummy_pthread_init(cond)
+#define pthread_cond_wait(cond, mutex)
+#define pthread_cond_signal(cond)
+#define pthread_cond_broadcast(cond)
+#define pthread_cond_destroy(cond)
+
+#define pthread_key_create(key, attr) dummy_pthread_init(key)
+#define pthread_key_delete(key)
+
+#define pthread_create(thread, attr, fn, data) \
+	dummy_pthread_create(thread, attr, fn, data)
+#define pthread_join(thread, retval) \
+	dummy_pthread_join(thread, retval)
+
+#define pthread_setspecific(key, data)
+#define pthread_getspecific(key) NULL
+
+int dummy_pthread_create(pthread_t *pthread, const void *attr,
+			 void *(*fn)(void *), void *data);
+int dummy_pthread_join(pthread_t pthread, void **retval);
+
+int dummy_pthread_init(void *);
 
 #endif
+
+int online_cpus(void);
+int init_recursive_mutex(pthread_mutex_t*);
+
+
 #endif /* THREAD_COMPAT_H */
diff --git a/transport-helper.c b/transport-helper.c
index 7213fa0..bf225c6 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -573,7 +573,7 @@
 			fprintf(stderr, "Debug: Falling back to dumb "
 				"transport.\n");
 	} else {
-		die(_(_("unknown response to connect: %s")),
+		die(_("unknown response to connect: %s"),
 		    cmdbuf->buf);
 	}
 
diff --git a/wt-status.c b/wt-status.c
index 187568a..a247113 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -1559,6 +1559,7 @@
 	struct object_id oid;
 
 	if (!stat(git_path_merge_head(the_repository), &st)) {
+		wt_status_check_rebase(NULL, state);
 		state->merge_in_progress = 1;
 	} else if (wt_status_check_rebase(NULL, state)) {
 		;		/* all set */
@@ -1583,9 +1584,13 @@
 	const char *state_color = color(WT_STATUS_HEADER, s);
 	struct wt_status_state *state = &s->state;
 
-	if (state->merge_in_progress)
+	if (state->merge_in_progress) {
+		if (state->rebase_interactive_in_progress) {
+			show_rebase_information(s, state_color);
+			fputs("\n", s->fp);
+		}
 		show_merge_in_progress(s, state_color);
-	else if (state->am_in_progress)
+	} else if (state->am_in_progress)
 		show_am_in_progress(s, state_color);
 	else if (state->rebase_in_progress || state->rebase_interactive_in_progress)
 		show_rebase_in_progress(s, state_color);