Documentation / RelNotes / 2.10.0.txton commit setup_traverse_info(): stop copying oid (947208b)
   1Git 2.10 Release Notes
   2======================
   3
   4Backward compatibility notes
   5----------------------------
   6
   7Updates since v2.9
   8------------------
   9
  10UI, Workflows & Features
  11
  12 * "git pull --rebase --verify-signature" learned to warn the user
  13   that "--verify-signature" is a no-op when rebasing.
  14
  15 * An upstream project can make a recommendation to shallowly clone
  16   some submodules in the .gitmodules file it ships.
  17
  18 * "git worktree add" learned that '-' can be used as a short-hand for
  19   "@{-1}", the previous branch.
  20
  21 * Update the funcname definition to support css files.
  22
  23 * The completion script (in contrib/) learned to complete "git
  24   status" options.
  25
  26 * Messages that are generated by auto gc during "git push" on the
  27   receiving end are now passed back to the sending end in such a way
  28   that they are shown with "remote: " prefix to avoid confusing the
  29   users.
  30
  31 * "git add -i/-p" learned to honor diff.compactionHeuristic
  32   experimental knob, so that the user can work on the same hunk split
  33   as "git diff" output.
  34
  35 * "upload-pack" allows a custom "git pack-objects" replacement when
  36   responding to "fetch/clone" via the uploadpack.packObjectsHook.
  37   (merge b738396 jk/upload-pack-hook later to maint).
  38
  39 * Teach format-patch and mailsplit (hence "am") how a line that
  40   happens to begin with "From " in the e-mail message is quoted with
  41   ">", so that these lines can be restored to their original shape.
  42   (merge d9925d1 ew/mboxrd-format-am later to maint).
  43
  44 * "git repack" learned the "--keep-unreachable" option, which sends
  45   loose unreachable objects to a pack instead of leaving them loose.
  46   This helps heuristics based on the number of loose objects
  47   (e.g. "gc --auto").
  48   (merge e26a8c4 jk/repack-keep-unreachable later to maint).
  49
  50 * "log --graph --format=" learned that "%>|(N)" specifies the width
  51   relative to the terminal's left edge, not relative to the area to
  52   draw text that is to the right of the ancestry-graph section.  It
  53   also now accepts negative N that means the column limit is relative
  54   to the right border.
  55
  56 * A careless invocation of "git send-email directory/" after editing
  57   0001-change.patch with an editor often ends up sending both
  58   0001-change.patch and its backup file, 0001-change.patch~, causing
  59   embarrassment and a minor confusion.  Detect such an input and
  60   offer to skip the backup files when sending the patches out.
  61   (merge 531220b jc/send-email-skip-backup later to maint).
  62
  63 * "git submodule update" that drives many "git clone" could
  64   eventually hit flaky servers/network conditions on one of the
  65   submodules; the command learned to retry the attempt.
  66
  67 * The output coloring scheme learned two new attributes, italic and
  68   strike, in addition to existing bold, reverse, etc.
  69
  70 * "git log" learns log.showSignature configuration variable, and a
  71   command line option "--no-show-signature" to countermand it.
  72   (merge fce04c3 mj/log-show-signature-conf later to maint).
  73
  74 * More markings of messages for i18n, with updates to various tests
  75   to pass GETTEXT_POISON tests.
  76
  77 * "git archive" learned to handle files that are larger than 8GB and
  78   commits far in the future than expressible by the traditional US-TAR
  79   format.
  80   (merge 560b0e8 jk/big-and-future-archive-tar later to maint).
  81
  82
  83 * A new configuration variable core.sshCommand has been added to
  84   specify what value for GIT_SSH_COMMAND to use per repository.
  85
  86 * "git worktree prune" protected worktrees that are marked as
  87   "locked" by creating a file in a known location.  "git worktree"
  88   command learned a dedicated command pair to create and remove such
  89   a file, so that the users do not have to do this with editor.
  90
  91 * A handful of "git svn" updates.
  92
  93 * "git push" learned to accept and pass extra options to the
  94   receiving end so that hooks can read and react to them.
  95
  96 * "git status" learned to suggest "merge --abort" during a conflicted
  97   merge, just like it already suggests "rebase --abort" during a
  98   conflicted rebase.
  99
 100 * "git jump" script (in contrib/) has been updated a bit.
 101   (merge a91e692 jk/git-jump later to maint).
 102
 103 * "git push" and "git clone" learned to give better progress meters
 104   to the end user who is waiting on the terminal.
 105
 106 * An entry "git log --decorate" for the tip of the current branch is
 107   shown as "HEAD -> name" (where "name" is the name of the branch);
 108   the arrow is now painted in the same color as "HEAD", not in the
 109   color for commits.
 110
 111 * "git format-patch" learned format.from configuration variable to
 112   specify the default settings for its "--from" option.
 113
 114 * "git am -3" calls "git merge-recursive" when it needs to fall back
 115   to a three-way merge; this call has been turned into an internal
 116   subroutine call instead of spawning a separate subprocess.
 117
 118 * The command line completion scripts (in contrib/) now knows about
 119   "git branch --delete/--move [--remote]".
 120   (merge 2703c22 vs/completion-branch-fully-spelled-d-m-r later to maint).
 121
 122 * "git rev-parse --git-path hooks/<hook>" learned to take
 123   core.hooksPath configuration variable (introduced during 2.9 cycle)
 124   into account.
 125   (merge 9445b49 ab/hooks later to maint).
 126
 127 * "git log --show-signature" and other commands that display the
 128   verification status of PGP signature now shows the longer key-id,
 129   as 32-bit key-id is so last century.
 130
 131
 132Performance, Internal Implementation, Development Support etc.
 133
 134 * "git fast-import" learned the same performance trick to avoid
 135   creating too small a packfile as "git fetch" and "git push" have,
 136   using *.unpackLimit configuration.
 137
 138 * When "git daemon" is run without --[init-]timeout specified, a
 139   connection from a client that silently goes offline can hang around
 140   for a long time, wasting resources.  The socket-level KEEPALIVE has
 141   been enabled to allow the OS to notice such failed connections.
 142
 143 * "git upload-pack" command has been updated to use the parse-options
 144   API.
 145
 146 * The "git apply" standalone program is being libified; the first
 147   step to move many state variables into a structure that can be
 148   explicitly (re)initialized to make the machinery callable more
 149   than once has been merged.
 150
 151 * HTTP transport gained an option to produce more detailed debugging
 152   trace.
 153   (merge 73e57aa ep/http-curl-trace later to maint).
 154
 155 * Instead of taking advantage of the fact that a struct string_list
 156   that is allocated with all NULs happens to be the INIT_NODUP kind,
 157   the users of string_list structures are taught to initialize them
 158   explicitly as such, to document their behaviour better.
 159   (merge 2721ce2 jk/string-list-static-init later to maint).
 160
 161 * HTTPd tests learned to show the server error log to help diagnosing
 162   a failing tests.
 163   (merge 44f243d nd/test-lib-httpd-show-error-log-in-verbose later to maint).
 164
 165 * The ownership rule for the piece of memory that hold references to
 166   be fetched in "git fetch" was screwy, which has been cleaned up.
 167
 168 * "git bisect" makes an internal call to "git diff-tree" when
 169   bisection finds the culprit, but this call did not initialize the
 170   data structure to pass to the diff-tree API correctly.
 171
 172 * Further preparatory clean-up for "worktree" feature continues.
 173   (merge 0409e0b nd/worktree-cleanup-post-head-protection later to maint).
 174
 175 * Formats of the various data (and how to validate them) where we use
 176   GPG signature have been documented.
 177
 178 * A new run-command API function pipe_command() is introduced to
 179   sanely feed data to the standard input while capturing data from
 180   the standard output and the standard error of an external process,
 181   which is cumbersome to hand-roll correctly without deadlocking.
 182
 183 * The codepath to sign data in a prepared buffer with GPG has been
 184   updated to use this API to read from the status-fd to check for
 185   errors (instead of relying on GPG's exit status).
 186   (merge efee955 jk/gpg-interface-cleanup later to maint).
 187
 188 * Allow t/perf framework to use the features from the most recent
 189   version of Git even when testing an older installed version.
 190
 191 * The commands in the "log/diff" family have had an FILE* pointer in the
 192   data structure they pass around for a long time, but some codepaths
 193   used to always write to the standard output.  As a preparatory step
 194   to make "git format-patch" available to the internal callers, these
 195   codepaths have been updated to consistently write into that FILE*
 196   instead.
 197
 198 * Conversion from unsigned char sha1[20] to struct object_id
 199   continues.
 200
 201 * Improve the look of the way "git fetch" reports what happened to
 202   each ref that was fetched.
 203
 204 * The .c/.h sources are marked as such in our .gitattributes file so
 205   that "git diff -W" and friends would work better.
 206
 207 * Code clean-up to avoid using a variable string that compilers may
 208   feel untrustable as printf-style format given to write_file()
 209   helper function.
 210
 211 * "git p4" used a location outside $GIT_DIR/refs/ to place its
 212   temporary branches, which has been moved to refs/git-p4-tmp/.
 213
 214 * Existing autoconf generated test for the need to link with pthread
 215   library did not check all the functions from pthread libraries;
 216   recent FreeBSD has some functions in libc but not others, and we
 217   mistakenly thought linking with libc is enough when it is not.
 218
 219 * When "git fsck" reports a broken link (e.g. a tree object contains
 220   a blob that does not exist), both containing object and the object
 221   that is referred to were reported with their 40-hex object names.
 222   The command learned the "--name-objects" option to show the path to
 223   the containing object from existing refs (e.g. "HEAD~24^2:file.txt").
 224
 225 * Allow http daemon tests in Travis CI tests.
 226
 227 * Makefile assumed that -lrt is always available on platforms that
 228   want to use clock_gettime() and CLOCK_MONOTONIC, which is not a
 229   case for recent Mac OS X.  The necessary symbols are often found in
 230   libc on many modern systems and having -lrt on the command line, as
 231   long as the library exists, had no effect, but when the platform
 232   removes librt.a that is a different matter--having -lrt will break
 233   the linkage.
 234
 235   This change could be seen as a regression for those who do need to
 236   specify -lrt, as they now specifically ask for NEEDS_LIBRT when
 237   building. Hopefully they are in the minority these days.
 238
 239 * Further preparatory work on the refs API before the pluggable
 240   backend series can land.
 241
 242 * Error handling in the codepaths that updates refs has been
 243   improved.
 244
 245 * The API to iterate over all the refs (i.e. for_each_ref(), etc.)
 246   has been revamped.
 247
 248 * The handling of the "text=auto" attribute has been corrected.
 249   $ echo "* text=auto eol=crlf" >.gitattributes
 250   used to have the same effect as
 251   $ echo "* text eol=crlf" >.gitattributes
 252   i.e. declaring all files are text (ignoring "auto").  The
 253   combination has been fixed to be equivalent to doing
 254   $ git config core.autocrlf true
 255
 256 * Documentation has been updated to show better example usage
 257   of the updated "text=auto" attribute.
 258
 259 * A few tests that specifically target "git rebase -i" have been
 260   added.
 261
 262 * Dumb http transport on the client side has been optimized.
 263   (merge ecba195 ew/http-walker later to maint).
 264
 265 * Users of the parse_options_concat() API function need to allocate
 266   extra slots in advance and fill them with OPT_END() when they want
 267   to decide the set of supported options dynamically, which makes the
 268   code error-prone and hard to read.  This has been corrected by tweaking
 269   the API to allocate and return a new copy of "struct option" array.
 270
 271 * "git fetch" exchanges batched have/ack messages between the sender
 272   and the receiver, initially doubling every time and then falling
 273   back to enlarge the window size linearly.  The "smart http"
 274   transport, being an half-duplex protocol, outgrows the preset limit
 275   too quickly and becomes inefficient when interacting with a large
 276   repository.  The internal mechanism learned to grow the window size
 277   more aggressively when working with the "smart http" transport.
 278
 279 * Tests for "git svn" have been taught to reuse the lib-httpd test
 280   infrastructure when testing the subversion integration that
 281   interacts with subversion repositories served over the http://
 282   protocol.
 283   (merge a8a5d25 ew/git-svn-http-tests later to maint).
 284
 285 * "git pack-objects" has a few options that tell it not to pack
 286   objects found in certain packfiles, which require it to scan .idx
 287   files of all available packs.  The codepaths involved in these
 288   operations have been optimized for a common case of not having any
 289   non-local pack and/or any .kept pack.
 290
 291 * The t3700 test about "add --chmod=-x" have been made a bit more
 292   robust and generally cleaned up.
 293   (merge 766cdc4 ib/t3700-add-chmod-x-updates later to maint).
 294
 295 * The build procedure learned PAGER_ENV knob that lists what default
 296   environment variable settings to export for popular pagers.  This
 297   mechanism is used to tweak the default settings to MORE on FreeBSD.
 298   (merge 995bc22 ew/build-time-pager-tweaks later to maint).
 299
 300 * The http-backend (the server-side component of smart-http
 301   transport) used to trickle the HTTP header one at a time.  Now
 302   these write(2)s are batched.
 303   (merge b36045c ew/http-backend-batch-headers later to maint).
 304
 305 * When "git rebase" tries to compare set of changes on the updated
 306   upstream and our own branch, it computes patch-id for all of these
 307   changes and attempts to find matches. This has been optimized by
 308   lazily computing the full patch-id (which is expensive) to be
 309   compared only for changes that touch the same set of paths.
 310   (merge ba67504 kw/patch-ids-optim later to maint).
 311
 312 * A handful of tests that were broken under gettext-poison build have
 313   been fixed.
 314
 315 * The recent i18n patch we added during this cycle did a bit too much
 316   refactoring of the messages to avoid word-legos; the repetition has
 317   been reduced to help translators.
 318
 319
 320Also contains various documentation updates and code clean-ups.
 321
 322
 323Fixes since v2.9
 324----------------
 325
 326Unless otherwise noted, all the fixes since v2.8 in the maintenance
 327track are contained in this release (see the maintenance releases'
 328notes for details).
 329
 330 * The commands in `git log` family take %C(auto) in a custom format
 331   string.  This unconditionally turned the color on, ignoring
 332   --no-color or with --color=auto when the output is not connected to
 333   a tty; this was corrected to make the format truly behave as
 334   "auto".
 335
 336 * "git rev-list --count" whose walk-length is limited with "-n"
 337   option did not work well with the counting optimized to look at the
 338   bitmap index.
 339
 340 * "git show -W" (extend hunks to cover the entire function, delimited
 341   by lines that match the "funcname" pattern) used to show the entire
 342   file when a change added an entire function at the end of the file,
 343   which has been fixed.
 344
 345 * The documentation set has been updated so that literal commands,
 346   configuration variables and environment variables are consistently
 347   typeset in fixed-width font and bold in manpages.
 348
 349 * "git svn propset" subcommand that was added in 2.3 days is
 350   documented now.
 351
 352 * The documentation tries to consistently spell "GPG"; when
 353   referring to the specific program name, "gpg" is used.
 354
 355 * "git reflog" stopped upon seeing an entry that denotes a branch
 356   creation event (aka "unborn"), which made it appear as if the
 357   reflog was truncated.
 358
 359 * The git-prompt scriptlet (in contrib/) was not friendly with those
 360   who uses "set -u", which has been fixed.
 361
 362 * compat/regex code did not cleanly compile.
 363
 364 * A codepath that used alloca(3) to place an unbounded amount of data
 365   on the stack has been updated to avoid doing so.
 366
 367 * "git update-index --add --chmod=+x file" may be usable as an escape
 368   hatch, but not a friendly thing to force for people who do need to
 369   use it regularly.  "git add --chmod=+x file" can be used instead.
 370
 371 * Build improvements for gnome-keyring (in contrib/)
 372
 373 * "git status" used to say "working directory" when it meant "working
 374   tree".
 375
 376 * Comments about misbehaving FreeBSD shells have been clarified with
 377   the version number (9.x and before are broken, newer ones are OK).
 378
 379 * "git cherry-pick A" worked on an unborn branch, but "git
 380   cherry-pick A..B" didn't.
 381
 382 * Fix an unintended regression in v2.9 that breaks "clone --depth"
 383   that recurses down to submodules by forcing the submodules to also
 384   be cloned shallowly, which many server instances that host upstream
 385   of the submodules are not prepared for.
 386
 387 * Fix unnecessarily waste in the idiomatic use of ': ${VAR=default}'
 388   to set the default value, without enclosing it in double quotes.
 389
 390 * Some platform-specific code had non-ANSI strict declarations of C
 391   functions that do not take any parameters, which has been
 392   corrected.
 393
 394 * The internal code used to show local timezone offset is not
 395   prepared to handle timestamps beyond year 2100, and gave a
 396   bogus offset value to the caller.  Use a more benign looking
 397   +0000 instead and let "git log" going in such a case, instead
 398   of aborting.
 399
 400 * One among four invocations of readlink(1) in our test suite has
 401   been rewritten so that the test can run on systems without the
 402   command (others are in valgrind test framework and t9802).
 403
 404 * t/perf needs /usr/bin/time with GNU extension; the invocation of it
 405   is updated to "gtime" on Darwin.
 406
 407 * A bug, which caused "git p4" while running under verbose mode to
 408   report paths that are omitted due to branch prefix incorrectly, has
 409   been fixed; the command said "Ignoring file outside of prefix" for
 410   paths that are _inside_.
 411
 412 * The top level documentation "git help git" still pointed at the
 413   documentation set hosted at now-defunct google-code repository.
 414   Update it to point to https://git.github.io/htmldocs/git.html
 415   instead.
 416
 417 * A helper function that takes the contents of a commit object and
 418   finds its subject line did not ignore leading blank lines, as is
 419   commonly done by other codepaths.  Make it ignore leading blank
 420   lines to match.
 421
 422 * For a long time, we carried an in-code comment that said our
 423   colored output would work only when we use fprintf/fputs on
 424   Windows, which no longer is the case for the past few years.
 425
 426 * "gc.autoPackLimit" when set to 1 should not trigger a repacking
 427   when there is only one pack, but the code counted poorly and did
 428   so.
 429
 430 * Add a test to specify the desired behaviour that currently is not
 431   available in "git rebase -Xsubtree=...".
 432
 433 * More mark-up updates to typeset strings that are expected to
 434   literally typed by the end user in fixed-width font.
 435
 436 * "git commit --amend --allow-empty-message -S" for a commit without
 437   any message body could have misidentified where the header of the
 438   commit object ends.
 439
 440 * "git rebase -i --autostash" did not restore the auto-stashed change
 441   when the operation was aborted.
 442
 443 * Git does not know what the contents in the index should be for a
 444   path added with "git add -N" yet, so "git grep --cached" should not
 445   show hits (or show lack of hits, with -L) in such a path, but that
 446   logic does not apply to "git grep", i.e. searching in the working
 447   tree files.  But we did so by mistake, which has been corrected.
 448
 449 * "git blame -M" missed a single line that was moved within the file.
 450
 451 * Fix recently introduced codepaths that are involved in parallel
 452   submodule operations, which gave up on reading too early, and
 453   could have wasted CPU while attempting to write under a corner
 454   case condition.
 455
 456 * "git grep -i" has been taught to fold case in non-ascii locales
 457   correctly.
 458
 459 * A test that unconditionally used "mktemp" learned that the command
 460   is not necessarily available everywhere.
 461
 462 * There are certain house-keeping tasks that need to be performed at
 463   the very beginning of any Git program, and programs that are not
 464   built-in commands had to do them exactly the same way as "git"
 465   potty does.  It was easy to make mistakes in one-off standalone
 466   programs (like test helpers).  A common "main()" function that
 467   calls cmd_main() of individual program has been introduced to
 468   make it harder to make mistakes.
 469   (merge de61ceb jk/common-main later to maint).
 470
 471 * The test framework learned a new helper test_match_signal to
 472   check an exit code from getting killed by an expected signal.
 473
 474 * General code clean-up around a helper function to write a
 475   single-liner to a file.
 476   (merge 7eb6e10 jk/write-file later to maint).
 477
 478 * One part of "git am" had an oddball helper function that called
 479   stuff from outside "his" as opposed to calling what we have "ours",
 480   which was not gender-neutral and also inconsistent with the rest of
 481   the system where outside stuff is usuall called "theirs" in
 482   contrast to "ours".
 483
 484 * "git blame file" allowed the lineage of lines in the uncommitted,
 485   unadded contents of "file" to be inspected, but it refused when
 486   "file" did not appear in the current commit.  When "file" was
 487   created by renaming an existing file (but the change has not been
 488   committed), this restriction was unnecessarily tight.
 489
 490 * "git add -N dir/file && git write-tree" produced an incorrect tree
 491   when there are other paths in the same directory that sorts after
 492   "file".
 493
 494 * "git fetch http://user:pass@host/repo..." scrubbed the userinfo
 495   part, but "git push" didn't.
 496
 497 * "git merge" with renormalization did not work well with
 498   merge-recursive, due to "safer crlf" conversion kicking in when it
 499   shouldn't.
 500   (merge 1335d76 jc/renormalize-merge-kill-safer-crlf later to maint).
 501
 502 * The use of strbuf in "git rm" to build filename to remove was a bit
 503   suboptimal, which has been fixed.
 504
 505 * An age old bug that caused "git diff --ignore-space-at-eol"
 506   misbehave has been fixed.
 507
 508 * "git notes merge" had a code to see if a path exists (and fails if
 509   it does) and then open the path for writing (when it doesn't).
 510   Replace it with open with O_EXCL.
 511
 512 * "git pack-objects" and "git index-pack" mostly operate with off_t
 513   when talking about the offset of objects in a packfile, but there
 514   were a handful of places that used "unsigned long" to hold that
 515   value, leading to an unintended truncation.
 516
 517 * Recent update to "git daemon" tries to enable the socket-level
 518   KEEPALIVE, but when it is spawned via inetd, the standard input
 519   file descriptor may not necessarily be connected to a socket.
 520   Suppress an ENOTSOCK error from setsockopt().
 521
 522 * Recent FreeBSD stopped making perl available at /usr/bin/perl;
 523   switch the default the built-in path to /usr/local/bin/perl on not
 524   too ancient FreeBSD releases.
 525
 526 * "git commit --help" said "--no-verify" is only about skipping the
 527   pre-commit hook, and failed to say that it also skipped the
 528   commit-msg hook.
 529
 530 * "git merge" in Git v2.9 was taught to forbid merging an unrelated
 531   lines of history by default, but that is exactly the kind of thing
 532   the "--rejoin" mode of "git subtree" (in contrib/) wants to do.
 533   "git subtree" has been taught to use the "--allow-unrelated-histories"
 534   option to override the default.
 535
 536 * The build procedure for "git persistent-https" helper (in contrib/)
 537   has been updated so that it can be built with more recent versions
 538   of Go.
 539
 540 * There is an optimization used in "git diff $treeA $treeB" to borrow
 541   an already checked-out copy in the working tree when it is known to
 542   be the same as the blob being compared, expecting that open/mmap of
 543   such a file is faster than reading it from the object store, which
 544   involves inflating and applying delta.  This however kicked in even
 545   when the checked-out copy needs to go through the convert-to-git
 546   conversion (including the clean filter), which defeats the whole
 547   point of the optimization.  The optimization has been disabled when
 548   the conversion is necessary.
 549
 550 * "git -c grep.patternType=extended log --basic-regexp" misbehaved
 551   because the internal API to access the grep machinery was not
 552   designed well.
 553
 554 * Windows port was failing some tests in t4130, due to the lack of
 555   inum in the returned values by its lstat(2) emulation.
 556
 557 * The reflog output format is documented better, and a new format
 558   --date=unix to report the seconds-since-epoch (without timezone)
 559   has been added.
 560   (merge 442f6fd jk/reflog-date later to maint).
 561
 562 * "git difftool <paths>..." started in a subdirectory failed to
 563   interpret the paths relative to that directory, which has been
 564   fixed.
 565
 566 * The characters in the label shown for tags/refs for commits in
 567   "gitweb" output are now properly escaped for proper HTML output.
 568
 569 * FreeBSD can lie when asked mtime of a directory, which made the
 570   untracked cache code to fall back to a slow-path, which in turn
 571   caused tests in t7063 to fail because it wanted to verify the
 572   behaviour of the fast-path.
 573
 574 * Squelch compiler warnings for nedmalloc (in compat/) library.
 575
 576 * A small memory leak in the command line parsing of "git blame"
 577   has been plugged.
 578
 579 * The API documentation for hashmap was unclear if hashmap_entry
 580   can be safely discarded without any other consideration.  State
 581   that it is safe to do so.
 582
 583 * Not-so-recent rewrite of "git am" that started making internal
 584   calls into the commit machinery had an unintended regression, in
 585   that no matter how many seconds it took to apply many patches, the
 586   resulting committer timestamp for the resulting commits were all
 587   the same.
 588
 589 * "git push --force-with-lease" already had enough logic to allow
 590   ensuring that such a push results in creation of a ref (i.e. the
 591   receiving end did not have another push from sideways that would be
 592   discarded by our force-pushing), but didn't expose this possibility
 593   to the users.  It does so now.
 594   (merge 9eed4f3 jk/push-force-with-lease-creation later to maint).
 595
 596 * The mechanism to limit the pack window memory size, when packing is
 597   done using multiple threads (which is the default), is per-thread,
 598   but this was not documented clearly.
 599   (merge 954176c ms/document-pack-window-memory-is-per-thread later to maint).
 600
 601 * "import-tars" fast-import script (in contrib/) used to ignore a
 602   hardlink target and replaced it with an empty file, which has been
 603   corrected to record the same blob as the other file the hardlink is
 604   shared with.
 605   (merge 04e0869 js/import-tars-hardlinks later to maint).
 606
 607 * "git mv dir non-existing-dir/" did not work in some environments
 608   the same way as existing mainstream platforms.  The code now moves
 609   "dir" to "non-existing-dir", without relying on rename("A", "B/")
 610   that strips the trailing slash of '/'.
 611   (merge 189d035 js/mv-dir-to-new-directory later to maint).
 612
 613 * The "t/" hierarchy is prone to get an unusual pathname; "make test"
 614   has been taught to make sure they do not contain paths that cannot
 615   be checked out on Windows (and the mechanism can be reusable to
 616   catch pathnames that are not portable to other platforms as need
 617   arises).
 618   (merge c2cafd3 js/test-lint-pathname later to maint).
 619
 620 * When "git merge-recursive" works on history with many criss-cross
 621   merges in "verbose" mode, the names the command assigns to the
 622   virtual merge bases could have overwritten each other by unintended
 623   reuse of the same piece of memory.
 624   (merge 5447a76 rs/pull-signed-tag later to maint).
 625
 626 * "git checkout --detach <branch>" used to give the same advice
 627   message as that is issued when "git checkout <tag>" (or anything
 628   that is not a branch name) is given, but asking with "--detach" is
 629   an explicit enough sign that the user knows what is going on.  The
 630   advice message has been squelched in this case.
 631   (merge 779b88a sb/checkout-explit-detach-no-advice later to maint).
 632
 633 * "git difftool" by default ignores the error exit from the backend
 634   commands it spawns, because often they signal that they found
 635   differences by exiting with a non-zero status code just like "diff"
 636   does; the exit status codes 126 and above however are special in
 637   that they are used to signal that the command is not executable,
 638   does not exist, or killed by a signal.  "git difftool" has been
 639   taught to notice these exit status codes.
 640   (merge 45a4f5d jk/difftool-command-not-found later to maint).
 641
 642 * On Windows, help.browser configuration variable used to be ignored,
 643   which has been corrected.
 644   (merge 6db5967 js/no-html-bypass-on-windows later to maint).
 645
 646 * The "git -c var[=val] cmd" facility to append a configuration
 647   variable definition at the end of the search order was described in
 648   git(1) manual page, but not in git-config(1), which was more likely
 649   place for people to look for when they ask "can I make a one-shot
 650   override, and if so how?"
 651   (merge ae1f709 dg/document-git-c-in-git-config-doc later to maint).
 652
 653 * The tempfile (hence its user lockfile) API lets the caller to open
 654   a file descriptor to a temporary file, write into it and then
 655   finalize it by first closing the filehandle and then either
 656   removing or renaming the temporary file.  When the process spawns a
 657   subprocess after obtaining the file descriptor, and if the
 658   subprocess has not exited when the attempt to remove or rename is
 659   made, the last step fails on Windows, because the subprocess has
 660   the file descriptor still open.  Open tempfile with O_CLOEXEC flag
 661   to avoid this (on Windows, this is mapped to O_NOINHERIT).
 662   (merge 05d1ed6 bw/mingw-avoid-inheriting-fd-to-lockfile later to maint).
 663
 664 * Correct an age-old calco (is that a typo-like word for calc)
 665   in the documentation.
 666   (merge 7841c48 ls/packet-line-protocol-doc-fix later to maint).
 667
 668 * Other minor clean-ups and documentation updates
 669   (merge 02a8cfa rs/merge-add-strategies-simplification later to maint).
 670   (merge af4941d rs/merge-recursive-string-list-init later to maint).
 671   (merge 1eb47f1 rs/use-strbuf-add-unique-abbrev later to maint).
 672   (merge ddd0bfa jk/tighten-alloc later to maint).
 673   (merge ecf30b2 rs/mailinfo-lib later to maint).
 674   (merge 0eb75ce sg/reflog-past-root later to maint).
 675   (merge 4369523 hv/doc-commit-reference-style later to maint).