summaryrefslogtreecommitdiff
path: root/Documentation/RelNotes/2.10.0.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/RelNotes/2.10.0.txt')
-rw-r--r--Documentation/RelNotes/2.10.0.txt609
1 files changed, 609 insertions, 0 deletions
diff --git a/Documentation/RelNotes/2.10.0.txt b/Documentation/RelNotes/2.10.0.txt
new file mode 100644
index 0000000000..4f7460be39
--- /dev/null
+++ b/Documentation/RelNotes/2.10.0.txt
@@ -0,0 +1,609 @@
+Git 2.10 Release Notes
+======================
+
+Backward compatibility notes
+----------------------------
+
+Updates since v2.9
+------------------
+
+UI, Workflows & Features
+
+ * "git pull --rebase --verify-signature" learned to warn the user
+ that "--verify-signature" is a no-op when rebasing.
+
+ * An upstream project can make a recommendation to shallowly clone
+ some submodules in the .gitmodules file it ships.
+
+ * "git worktree add" learned that '-' can be used as a short-hand for
+ "@{-1}", the previous branch.
+
+ * Update the funcname definition to support css files.
+
+ * The completion script (in contrib/) learned to complete "git
+ status" options.
+
+ * Messages that are generated by auto gc during "git push" on the
+ receiving end are now passed back to the sending end in such a way
+ that they are shown with "remote: " prefix to avoid confusing the
+ users.
+
+ * "git add -i/-p" learned to honor diff.compactionHeuristic
+ experimental knob, so that the user can work on the same hunk split
+ as "git diff" output.
+
+ * "upload-pack" allows a custom "git pack-objects" replacement when
+ responding to "fetch/clone" via the uploadpack.packObjectsHook.
+ (merge b738396 jk/upload-pack-hook later to maint).
+
+ * Teach format-patch and mailsplit (hence "am") how a line that
+ happens to begin with "From " in the e-mail message is quoted with
+ ">", so that these lines can be restored to their original shape.
+ (merge d9925d1 ew/mboxrd-format-am later to maint).
+
+ * "git repack" learned the "--keep-unreachable" option, which sends
+ loose unreachable objects to a pack instead of leaving them loose.
+ This helps heuristics based on the number of loose objects
+ (e.g. "gc --auto").
+ (merge e26a8c4 jk/repack-keep-unreachable later to maint).
+
+ * "log --graph --format=" learned that "%>|(N)" specifies the width
+ relative to the terminal's left edge, not relative to the area to
+ draw text that is to the right of the ancestry-graph section. It
+ also now accepts negative N that means the column limit is relative
+ to the right border.
+
+ * A careless invocation of "git send-email directory/" after editing
+ 0001-change.patch with an editor often ends up sending both
+ 0001-change.patch and its backup file, 0001-change.patch~, causing
+ embarrassment and a minor confusion. Detect such an input and
+ offer to skip the backup files when sending the patches out.
+ (merge 531220b jc/send-email-skip-backup later to maint).
+
+ * "git submodule update" that drives many "git clone" could
+ eventually hit flaky servers/network conditions on one of the
+ submodules; the command learned to retry the attempt.
+
+ * The output coloring scheme learned two new attributes, italic and
+ strike, in addition to existing bold, reverse, etc.
+
+ * "git log" learns log.showSignature configuration variable, and a
+ command line option "--no-show-signature" to countermand it.
+ (merge fce04c3 mj/log-show-signature-conf later to maint).
+
+ * More markings of messages for i18n, with updates to various tests
+ to pass GETTEXT_POISON tests.
+
+ * "git archive" learned to handle files that are larger than 8GB and
+ commits far in the future than expressible by the traditional US-TAR
+ format.
+ (merge 5caeeb8 jk/big-and-future-archive-tar later to maint).
+
+ * A new configuration variable core.sshCommand has been added to
+ specify what value for GIT_SSH_COMMAND to use per repository.
+
+ * "git worktree prune" protected worktrees that are marked as
+ "locked" by creating a file in a known location. "git worktree"
+ command learned a dedicated command pair to create and remove such
+ a file, so that the users do not have to do this with editor.
+
+ * A handful of "git svn" updates.
+
+ * "git push" learned to accept and pass extra options to the
+ receiving end so that hooks can read and react to them.
+
+ * "git status" learned to suggest "merge --abort" during a conflicted
+ merge, just like it already suggests "rebase --abort" during a
+ conflicted rebase.
+
+ * "git jump" script (in contrib/) has been updated a bit.
+ (merge a91e692 jk/git-jump later to maint).
+
+ * "git push" and "git clone" learned to give better progress meters
+ to the end user who is waiting on the terminal.
+
+ * An entry "git log --decorate" for the tip of the current branch is
+ shown as "HEAD -> name" (where "name" is the name of the branch);
+ the arrow is now painted in the same color as "HEAD", not in the
+ color for commits.
+
+ * "git format-patch" learned format.from configuration variable to
+ specify the default settings for its "--from" option.
+
+ * "git am -3" calls "git merge-recursive" when it needs to fall back
+ to a three-way merge; this call has been turned into an internal
+ subroutine call instead of spawning a separate subprocess.
+
+ * The command line completion scripts (in contrib/) now knows about
+ "git branch --delete/--move [--remote]".
+ (merge 2703c22 vs/completion-branch-fully-spelled-d-m-r later to maint).
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * "git fast-import" learned the same performance trick to avoid
+ creating too small a packfile as "git fetch" and "git push" have,
+ using *.unpackLimit configuration.
+
+ * When "git daemon" is run without --[init-]timeout specified, a
+ connection from a client that silently goes offline can hang around
+ for a long time, wasting resources. The socket-level KEEPALIVE has
+ been enabled to allow the OS to notice such failed connections.
+
+ * "git upload-pack" command has been updated to use the parse-options
+ API.
+
+ * The "git apply" standalone program is being libified; the first
+ step to move many state variables into a structure that can be
+ explicitly (re)initialized to make the machinery callable more
+ than once has been merged.
+
+ * HTTP transport gained an option to produce more detailed debugging
+ trace.
+ (merge 73e57aa ep/http-curl-trace later to maint).
+
+ * Instead of taking advantage of the fact that a struct string_list
+ that is allocated with all NULs happens to be the INIT_NODUP kind,
+ the users of string_list structures are taught to initialize them
+ explicitly as such, to document their behaviour better.
+ (merge 2721ce2 jk/string-list-static-init later to maint).
+
+ * HTTPd tests learned to show the server error log to help diagnosing
+ a failing tests.
+ (merge 44f243d nd/test-lib-httpd-show-error-log-in-verbose later to maint).
+
+ * The ownership rule for the piece of memory that hold references to
+ be fetched in "git fetch" was screwy, which has been cleaned up.
+
+ * "git bisect" makes an internal call to "git diff-tree" when
+ bisection finds the culprit, but this call did not initialize the
+ data structure to pass to the diff-tree API correctly.
+
+ * Further preparatory clean-up for "worktree" feature continues.
+ (merge 0409e0b nd/worktree-cleanup-post-head-protection later to maint).
+
+ * Formats of the various data (and how to validate them) where we use
+ GPG signature have been documented.
+
+ * A new run-command API function pipe_command() is introduced to
+ sanely feed data to the standard input while capturing data from
+ the standard output and the standard error of an external process,
+ which is cumbersome to hand-roll correctly without deadlocking.
+
+ The codepath to sign data in a prepared buffer with GPG has been
+ updated to use this API to read from the status-fd to check for
+ errors (instead of relying on GPG's exit status).
+ (merge efee955 jk/gpg-interface-cleanup later to maint).
+
+ * Allow t/perf framework to use the features from the most recent
+ version of Git even when testing an older installed version.
+
+ * The commands in the "log/diff" family have had an FILE* pointer in the
+ data structure they pass around for a long time, but some codepaths
+ used to always write to the standard output. As a preparatory step
+ to make "git format-patch" available to the internal callers, these
+ codepaths have been updated to consistently write into that FILE*
+ instead.
+
+ * Conversion from unsigned char sha1[20] to struct object_id
+ continues.
+
+ * Improve the look of the way "git fetch" reports what happened to
+ each ref that was fetched.
+
+ * The .c/.h sources are marked as such in our .gitattributes file so
+ that "git diff -W" and friends would work better.
+
+ * Code clean-up to avoid using a variable string that compilers may
+ feel untrustable as printf-style format given to write_file()
+ helper function.
+
+ * "git p4" used a location outside $GIT_DIR/refs/ to place its
+ temporary branches, which has been moved to refs/git-p4-tmp/.
+
+ * Existing autoconf generated test for the need to link with pthread
+ library did not check all the functions from pthread libraries;
+ recent FreeBSD has some functions in libc but not others, and we
+ mistakenly thought linking with libc is enough when it is not.
+
+ * When "git fsck" reports a broken link (e.g. a tree object contains
+ a blob that does not exist), both containing object and the object
+ that is referred to were reported with their 40-hex object names.
+ The command learned the "--name-objects" option to show the path to
+ the containing object from existing refs (e.g. "HEAD~24^2:file.txt").
+
+ * Allow http daemon tests in Travis CI tests.
+
+ * Makefile assumed that -lrt is always available on platforms that
+ want to use clock_gettime() and CLOCK_MONOTONIC, which is not a
+ case for recent Mac OS X. The necessary symbols are often found in
+ libc on many modern systems and having -lrt on the command line, as
+ long as the library exists, had no effect, but when the platform
+ removes librt.a that is a different matter--having -lrt will break
+ the linkage.
+
+ This change could be seen as a regression for those who do need to
+ specify -lrt, as they now specifically ask for NEEDS_LIBRT when
+ building. Hopefully they are in the minority these days.
+
+ * Further preparatory work on the refs API before the pluggable
+ backend series can land.
+
+ * Error handling in the codepaths that updates refs has been
+ improved.
+
+ * The API to iterate over all the refs (i.e. for_each_ref(), etc.)
+ has been revamped.
+
+ * The handling of the "text=auto" attribute has been corrected.
+ $ echo "* text=auto eol=crlf" >.gitattributes
+ used to have the same effect as
+ $ echo "* text eol=crlf" >.gitattributes
+ i.e. declaring all files are text (ignoring "auto"). The
+ combination has been fixed to be equivalent to doing
+ $ git config core.autocrlf true
+
+ * A few tests that specifically target "git rebase -i" have been
+ added.
+
+ * Dumb http transport on the client side has been optimized.
+ (merge ecba195 ew/http-walker later to maint).
+
+ * Users of the parse_options_concat() API function need to allocate
+ extra slots in advance and fill them with OPT_END() when they want
+ to decide the set of supported options dynamically, which makes the
+ code error-prone and hard to read. This has been corrected by tweaking
+ the API to allocate and return a new copy of "struct option" array.
+
+ * "git fetch" exchanges batched have/ack messages between the sender
+ and the receiver, initially doubling every time and then falling
+ back to enlarge the window size linearly. The "smart http"
+ transport, being an half-duplex protocol, outgrows the preset limit
+ too quickly and becomes inefficient when interacting with a large
+ repository. The internal mechanism learned to grow the window size
+ more aggressively when working with the "smart http" transport.
+
+ * Tests for "git svn" have been taught to reuse the lib-httpd test
+ infrastructure when testing the subversion integration that
+ interacts with subversion repositories served over the http://
+ protocol.
+ (merge a8a5d25 ew/git-svn-http-tests later to maint).
+
+ * "git pack-objects" has a few options that tell it not to pack
+ objects found in certain packfiles, which require it to scan .idx
+ files of all available packs. The codepaths involved in these
+ operations have been optimized for a common case of not having any
+ non-local pack and/or any .kept pack.
+
+ * The t3700 test about "add --chmod=-x" have been made a bit more
+ robust and generally cleaned up.
+ (merge 766cdc4 ib/t3700-add-chmod-x-updates later to maint).
+
+ * The build procedure learned PAGER_ENV knob that lists what default
+ environment variable settings to export for popular pagers. This
+ mechanism is used to tweak the default settings to MORE on FreeBSD.
+ (merge 995bc22 ew/build-time-pager-tweaks later to maint).
+
+ * The http-backend (the server-side component of smart-http
+ transport) used to trickle the HTTP header one at a time. Now
+ these write(2)s are batched.
+ (merge b36045c ew/http-backend-batch-headers later to maint).
+
+ * When "git rebase" tries to compare set of changes on the updated
+ upstream and our own branch, it computes patch-id for all of these
+ changes and attempts to find matches. This has been optimized by
+ lazily computing the full patch-id (which is expensive) to be
+ compared only for changes that touch the same set of paths.
+ (merge b3dfeeb kw/patch-ids-optim later to maint).
+
+ * A handful of tests that were broken under gettext-poison build have
+ been fixed.
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.9
+----------------
+
+Unless otherwise noted, all the fixes since v2.8 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * The commands in `git log` family take %C(auto) in a custom format
+ string. This unconditionally turned the color on, ignoring
+ --no-color or with --color=auto when the output is not connected to
+ a tty; this was corrected to make the format truly behave as
+ "auto".
+
+ * "git rev-list --count" whose walk-length is limited with "-n"
+ option did not work well with the counting optimized to look at the
+ bitmap index.
+
+ * "git show -W" (extend hunks to cover the entire function, delimited
+ by lines that match the "funcname" pattern) used to show the entire
+ file when a change added an entire function at the end of the file,
+ which has been fixed.
+
+ * The documentation set has been updated so that literal commands,
+ configuration variables and environment variables are consistently
+ typeset in fixed-width font and bold in manpages.
+
+ * "git svn propset" subcommand that was added in 2.3 days is
+ documented now.
+
+ * The documentation tries to consistently spell "GPG"; when
+ referring to the specific program name, "gpg" is used.
+
+ * "git reflog" stopped upon seeing an entry that denotes a branch
+ creation event (aka "unborn"), which made it appear as if the
+ reflog was truncated.
+
+ * The git-prompt scriptlet (in contrib/) was not friendly with those
+ who uses "set -u", which has been fixed.
+
+ * compat/regex code did not cleanly compile.
+
+ * A codepath that used alloca(3) to place an unbounded amount of data
+ on the stack has been updated to avoid doing so.
+
+ * "git update-index --add --chmod=+x file" may be usable as an escape
+ hatch, but not a friendly thing to force for people who do need to
+ use it regularly. "git add --chmod=+x file" can be used instead.
+
+ * Build improvements for gnome-keyring (in contrib/)
+
+ * "git status" used to say "working directory" when it meant "working
+ tree".
+
+ * Comments about misbehaving FreeBSD shells have been clarified with
+ the version number (9.x and before are broken, newer ones are OK).
+
+ * "git cherry-pick A" worked on an unborn branch, but "git
+ cherry-pick A..B" didn't.
+
+ * Fix an unintended regression in v2.9 that breaks "clone --depth"
+ that recurses down to submodules by forcing the submodules to also
+ be cloned shallowly, which many server instances that host upstream
+ of the submodules are not prepared for.
+
+ * Fix unnecessarily waste in the idiomatic use of ': ${VAR=default}'
+ to set the default value, without enclosing it in double quotes.
+
+ * Some platform-specific code had non-ANSI strict declarations of C
+ functions that do not take any parameters, which has been
+ corrected.
+
+ * The internal code used to show local timezone offset is not
+ prepared to handle timestamps beyond year 2100, and gave a
+ bogus offset value to the caller. Use a more benign looking
+ +0000 instead and let "git log" going in such a case, instead
+ of aborting.
+
+ * One among four invocations of readlink(1) in our test suite has
+ been rewritten so that the test can run on systems without the
+ command (others are in valgrind test framework and t9802).
+
+ * t/perf needs /usr/bin/time with GNU extension; the invocation of it
+ is updated to "gtime" on Darwin.
+
+ * A bug, which caused "git p4" while running under verbose mode to
+ report paths that are omitted due to branch prefix incorrectly, has
+ been fixed; the command said "Ignoring file outside of prefix" for
+ paths that are _inside_.
+
+ * The top level documentation "git help git" still pointed at the
+ documentation set hosted at now-defunct google-code repository.
+ Update it to point to https://git.github.io/htmldocs/git.html
+ instead.
+
+ * A helper function that takes the contents of a commit object and
+ finds its subject line did not ignore leading blank lines, as is
+ commonly done by other codepaths. Make it ignore leading blank
+ lines to match.
+
+ * For a long time, we carried an in-code comment that said our
+ colored output would work only when we use fprintf/fputs on
+ Windows, which no longer is the case for the past few years.
+
+ * "gc.autoPackLimit" when set to 1 should not trigger a repacking
+ when there is only one pack, but the code counted poorly and did
+ so.
+
+ * Add a test to specify the desired behaviour that currently is not
+ available in "git rebase -Xsubtree=...".
+
+ * More mark-up updates to typeset strings that are expected to
+ literally typed by the end user in fixed-width font.
+
+ * "git commit --amend --allow-empty-message -S" for a commit without
+ any message body could have misidentified where the header of the
+ commit object ends.
+
+ * "git rebase -i --autostash" did not restore the auto-stashed change
+ when the operation was aborted.
+
+ * Git does not know what the contents in the index should be for a
+ path added with "git add -N" yet, so "git grep --cached" should not
+ show hits (or show lack of hits, with -L) in such a path, but that
+ logic does not apply to "git grep", i.e. searching in the working
+ tree files. But we did so by mistake, which has been corrected.
+
+ * "git blame -M" missed a single line that was moved within the file.
+
+ * Fix recently introduced codepaths that are involved in parallel
+ submodule operations, which gave up on reading too early, and
+ could have wasted CPU while attempting to write under a corner
+ case condition.
+
+ * "git grep -i" has been taught to fold case in non-ascii locales
+ correctly.
+
+ * A test that unconditionally used "mktemp" learned that the command
+ is not necessarily available everywhere.
+
+ * There are certain house-keeping tasks that need to be performed at
+ the very beginning of any Git program, and programs that are not
+ built-in commands had to do them exactly the same way as "git"
+ potty does. It was easy to make mistakes in one-off standalone
+ programs (like test helpers). A common "main()" function that
+ calls cmd_main() of individual program has been introduced to
+ make it harder to make mistakes.
+ (merge de61ceb jk/common-main later to maint).
+
+ * The test framework learned a new helper test_match_signal to
+ check an exit code from getting killed by an expected signal.
+
+ * General code clean-up around a helper function to write a
+ single-liner to a file.
+ (merge 7eb6e10 jk/write-file later to maint).
+
+ * One part of "git am" had an oddball helper function that called
+ stuff from outside "his" as opposed to calling what we have "ours",
+ which was not gender-neutral and also inconsistent with the rest of
+ the system where outside stuff is usuall called "theirs" in
+ contrast to "ours".
+
+ * "git blame file" allowed the lineage of lines in the uncommitted,
+ unadded contents of "file" to be inspected, but it refused when
+ "file" did not appear in the current commit. When "file" was
+ created by renaming an existing file (but the change has not been
+ committed), this restriction was unnecessarily tight.
+
+ * "git add -N dir/file && git write-tree" produced an incorrect tree
+ when there are other paths in the same directory that sorts after
+ "file".
+
+ * "git fetch http://user:pass@host/repo..." scrubbed the userinfo
+ part, but "git push" didn't.
+
+ * "git merge" with renormalization did not work well with
+ merge-recursive, due to "safer crlf" conversion kicking in when it
+ shouldn't.
+ (merge 1335d76 jc/renormalize-merge-kill-safer-crlf later to maint).
+
+ * The use of strbuf in "git rm" to build filename to remove was a bit
+ suboptimal, which has been fixed.
+
+ * An age old bug that caused "git diff --ignore-space-at-eol"
+ misbehave has been fixed.
+
+ * "git notes merge" had a code to see if a path exists (and fails if
+ it does) and then open the path for writing (when it doesn't).
+ Replace it with open with O_EXCL.
+
+ * "git pack-objects" and "git index-pack" mostly operate with off_t
+ when talking about the offset of objects in a packfile, but there
+ were a handful of places that used "unsigned long" to hold that
+ value, leading to an unintended truncation.
+
+ * Recent update to "git daemon" tries to enable the socket-level
+ KEEPALIVE, but when it is spawned via inetd, the standard input
+ file descriptor may not necessarily be connected to a socket.
+ Suppress an ENOTSOCK error from setsockopt().
+
+ * Recent FreeBSD stopped making perl available at /usr/bin/perl;
+ switch the default the built-in path to /usr/local/bin/perl on not
+ too ancient FreeBSD releases.
+
+ * "git commit --help" said "--no-verify" is only about skipping the
+ pre-commit hook, and failed to say that it also skipped the
+ commit-msg hook.
+
+ * "git merge" in Git v2.9 was taught to forbid merging an unrelated
+ lines of history by default, but that is exactly the kind of thing
+ the "--rejoin" mode of "git subtree" (in contrib/) wants to do.
+ "git subtree" has been taught to use the "--allow-unrelated-histories"
+ option to override the default.
+
+ * The build procedure for "git persistent-https" helper (in contrib/)
+ has been updated so that it can be built with more recent versions
+ of Go.
+
+ * There is an optimization used in "git diff $treeA $treeB" to borrow
+ an already checked-out copy in the working tree when it is known to
+ be the same as the blob being compared, expecting that open/mmap of
+ such a file is faster than reading it from the object store, which
+ involves inflating and applying delta. This however kicked in even
+ when the checked-out copy needs to go through the convert-to-git
+ conversion (including the clean filter), which defeats the whole
+ point of the optimization. The optimization has been disabled when
+ the conversion is necessary.
+
+ * "git -c grep.patternType=extended log --basic-regexp" misbehaved
+ because the internal API to access the grep machinery was not
+ designed well.
+
+ * Windows port was failing some tests in t4130, due to the lack of
+ inum in the returned values by its lstat(2) emulation.
+
+ * The reflog output format is documented better, and a new format
+ --date=unix to report the seconds-since-epoch (without timezone)
+ has been added.
+ (merge 442f6fd jk/reflog-date later to maint).
+
+ * "git difftool <paths>..." started in a subdirectory failed to
+ interpret the paths relative to that directory, which has been
+ fixed.
+
+ * The characters in the label shown for tags/refs for commits in
+ "gitweb" output are now properly escaped for proper HTML output.
+
+ * FreeBSD can lie when asked mtime of a directory, which made the
+ untracked cache code to fall back to a slow-path, which in turn
+ caused tests in t7063 to fail because it wanted to verify the
+ behaviour of the fast-path.
+
+ * Squelch compiler warnings for netmalloc (in compat/) library.
+
+ * A small memory leak in the command line parsing of "git blame"
+ has been plugged.
+
+ * The API documentation for hashmap was unclear if hashmap_entry
+ can be safely discarded without any other consideration. State
+ that it is safe to do so.
+
+ * Not-so-recent rewrite of "git am" that started making internal
+ calls into the commit machinery had an unintended regression, in
+ that no matter how many seconds it took to apply many patches, the
+ resulting committer timestamp for the resulting commits were all
+ the same.
+
+ * "git push --force-with-lease" already had enough logic to allow
+ ensuring that such a push results in creation of a ref (i.e. the
+ receiving end did not have another push from sideways that would be
+ discarded by our force-pushing), but didn't expose this possibility
+ to the users. It does so now.
+ (merge 9eed4f3 jk/push-force-with-lease-creation later to maint).
+
+ * The mechanism to limit the pack window memory size, when packing is
+ done using multiple threads (which is the default), is per-thread,
+ but this was not documented clearly.
+ (merge 954176c ms/document-pack-window-memory-is-per-thread later to maint).
+
+ * "import-tars" fast-import script (in contrib/) used to ignore a
+ hardlink target and replaced it with an empty file, which has been
+ corrected to record the same blob as the other file the hardlink is
+ shared with.
+ (merge 04e0869 js/import-tars-hardlinks later to maint).
+
+ * "git mv dir non-existing-dir/" did not work in some environments
+ the same way as existing mainstream platforms. The code now moves
+ "dir" to "non-existing-dir", without relying on rename("A", "B/")
+ that strips the trailing slash of '/'.
+ (merge 189d035 js/mv-dir-to-new-directory later to maint).
+
+ * The "t/" hierarchy is prone to get an unusual pathname; "make test"
+ has been taught to make sure they do not contain paths that cannot
+ be checked out on Windows (and the mechanism can be reusable to
+ catch pathnames that are not portable to other platforms as need
+ arises).
+ (merge c2cafd3 js/test-lint-pathname later to maint).
+
+ * Other minor clean-ups and documentation updates
+ (merge 02a8cfa rs/merge-add-strategies-simplification later to maint).
+ (merge af4941d rs/merge-recursive-string-list-init later to maint).
+ (merge 1eb47f1 rs/use-strbuf-add-unique-abbrev later to maint).
+ (merge ddd0bfa jk/tighten-alloc later to maint).
+ (merge ecf30b2 rs/mailinfo-lib later to maint).
+ (merge 0eb75ce sg/reflog-past-root later to maint).