Documentation / RelNotes / 2.14.0.txton commit revision.h: introduce blob/tree walking in order of the commits (ce5b6f9)
   1Git 2.14 Release Notes
   2======================
   3
   4Backward compatibility notes and other notable changes.
   5
   6 * Use of an empty string as a pathspec element that is used for
   7   'everything matches' is still warned and Git asks users to use a
   8   more explicit '.' for that instead.  The hope is that existing
   9   users will not mind this change, and eventually the warning can be
  10   turned into a hard error, upgrading the deprecation into removal of
  11   this (mis)feature.  That is not scheduled to happen in the upcoming
  12   release (yet).
  13
  14 * Git now avoids blindly falling back to ".git" when the setup
  15   sequence said we are _not_ in Git repository.  A corner case that
  16   happens to work right now may be broken by a call to die("BUG").
  17   We've tried hard to locate such cases and fixed them, but there
  18   might still be cases that need to be addressed--bug reports are
  19   greatly appreciated.
  20
  21 * The experiment to improve the hunk-boundary selection of textual
  22   diff output has finished, and the "indent heuristics" has now
  23   become the default.
  24
  25 * Git can now be built with PCRE v2 instead of v1 of the PCRE
  26   library. Replace USE_LIBPCRE=YesPlease with USE_LIBPCRE2=YesPlease
  27   in existing build scripts to build against the new version.  As the
  28   upstream PCRE maintainer has abandoned v1 maintenance for all but
  29   the most critical bug fixes, use of v2 is recommended.
  30
  31
  32Updates since v2.13
  33-------------------
  34
  35UI, Workflows & Features
  36
  37 * The colors in which "git status --short --branch" showed the names
  38   of the current branch and its remote-tracking branch are now
  39   configurable.
  40
  41 * "git clone" learned the "--no-tags" option not to fetch all tags
  42   initially, and also set up the tagopt not to follow any tags in
  43   subsequent fetches.
  44
  45 * "git archive --format=zip" learned to use zip64 extension when
  46   necessary to go beyond the 4GB limit.
  47
  48 * "git reset" learned "--recurse-submodules" option.
  49
  50 * "git diff --submodule=diff" now recurses into nested submodules.
  51
  52 * "git repack" learned to accept the --threads=<n> option and pass it
  53   to pack-objects.
  54
  55 * "git send-email" learned to run sendemail-validate hook to inspect
  56   and reject a message before sending it out.
  57
  58 * There is no good reason why "git fetch $there $sha1" should fail
  59   when the $sha1 names an object at the tip of an advertised ref,
  60   even when the other side hasn't enabled allowTipSHA1InWant.
  61
  62 * The "[includeIf "gitdir:$dir"] path=..." mechanism introduced in
  63   2.13.0 would canonicalize the path of the gitdir being matched,
  64   and did not match e.g. "gitdir:~/work/*" against a repo in
  65   "~/work/main" if "~/work" was a symlink to "/mnt/storage/work".
  66   Now we match both the resolved canonical path and what "pwd" would
  67   show. The include will happen if either one matches.
  68
  69 * The "indent" heuristics is now the default in "diff". The
  70   diff.indentHeuristic configuration variable can be set to "false"
  71   for those who do not want it.
  72
  73 * Many commands learned to pay attention to submodule.recurse
  74   configuration.
  75
  76 * The convention for a command line is to follow "git cmdname
  77   --options" with revisions followed by an optional "--"
  78   disambiguator and then finally pathspecs.  When "--" is not there,
  79   we make sure early ones are all interpretable as revs (and do not
  80   look like paths) and later ones are the other way around.  A
  81   pathspec with "magic" (e.g. ":/p/a/t/h" that matches p/a/t/h from
  82   the top-level of the working tree, no matter what subdirectory you
  83   are working from) are conservatively judged as "not a path", which
  84   required disambiguation more often.  The command line parser
  85   learned to say "it's a pathspec" a bit more often when the syntax
  86   looks like so.
  87
  88 * Update "perl-compatible regular expression" support to enable JIT
  89   and also allow linking with the newer PCRE v2 library.
  90
  91 * "filter-branch" learned a pseudo filter "--setup" that can be used
  92   to define common functions/variables that can be used by other
  93   filters.
  94
  95 * Using "git add d/i/r" when d/i/r is the top of the working tree of
  96   a separate repository would create a gitlink in the index, which
  97   would appear as a not-quite-initialized submodule to others.  We
  98   learned to give warnings when this happens.
  99
 100 * "git status" learned to optionally give how many stash entries there
 101   are in its output.
 102
 103 * "git status" has long shown essentially the same message as "git
 104   commit"; the message it gives while preparing for the root commit,
 105   i.e. "Initial commit", was hard to understand for some new users.
 106   Now it says "No commits yet" to stress more on the current status
 107   (rather than the commit the user is preparing for, which is more in
 108   line with the focus of "git commit").
 109
 110 * "git send-email" now has --batch-size and --relogin-delay options
 111    which can be used to overcome limitations on SMTP servers that
 112    restrict on how many of e-mails can be sent in a single session.
 113
 114 * An old message shown in the commit log template was removed, as it
 115   has outlived its usefulness.
 116
 117 * "git pull --rebase --recurse-submodules" learns to rebase the
 118   branch in the submodules to an updated base.
 119
 120 * "git log" learned -P as a synonym for --perl-regexp, "git grep"
 121   already had such a synonym.
 122
 123 * "git log" didn't understand --regexp-ignore-case when combined with
 124   --perl-regexp. This has been fixed.
 125
 126Performance, Internal Implementation, Development Support etc.
 127
 128 * The default packed-git limit value has been raised on larger
 129   platforms to save "git fetch" from a (recoverable) failure while
 130   "gc" is running in parallel.
 131
 132 * Code to update the cache-tree has been tightened so that we won't
 133   accidentally write out any 0{40} entry in the tree object.
 134
 135 * Attempt to allow us notice "fishy" situation where we fail to
 136   remove the temporary directory used during the test.
 137
 138 * Travis CI gained a task to format the documentation with both
 139   AsciiDoc and AsciiDoctor.
 140
 141 * Some platforms have ulong that is smaller than time_t, and our
 142   historical use of ulong for timestamp would mean they cannot
 143   represent some timestamp that the platform allows.  Invent a
 144   separate and dedicated timestamp_t (so that we can distingiuish
 145   timestamps and a vanilla ulongs, which along is already a good
 146   move), and then declare uintmax_t is the type to be used as the
 147   timestamp_t.
 148
 149 * We can trigger Windows auto-build tester (credits: Dscho &
 150   Microsoft) from our existing Travis CI tester now.
 151
 152 * Conversion from uchar[20] to struct object_id continues.
 153
 154 * Simplify parse_pathspec() codepath and stop it from looking at the
 155   default in-core index.
 156
 157 * Add perf-test for wildmatch.
 158
 159 * Code from "conversion using external process" codepath has been
 160   extracted to a separate sub-process.[ch] module.
 161
 162 * When "git checkout", "git merge", etc. manipulates the in-core
 163   index, various pieces of information in the index extensions are
 164   discarded from the original state, as it is usually not the case
 165   that they are kept up-to-date and in-sync with the operation on the
 166   main index.  The untracked cache extension is copied across these
 167   operations now, which would speed up "git status" (as long as the
 168   cache is properly invalidated).
 169
 170 * The internal implementation of "git grep" has seen some clean-up.
 171
 172 * Update the C style recommendation for notes for translators, as
 173   recent versions of gettext tools can work with our style of
 174   multi-line comments.
 175
 176 * The implementation of "ref" API around the "packed refs" have been
 177   cleaned up, in preparation for further changes.
 178
 179 * The internal logic used in "git blame" has been libified to make it
 180   easier to use by cgit.
 181
 182 * Our code often opens a path to an optional file, to work on its
 183   contents when we can successfully open it.  We can ignore a failure
 184   to open if such an optional file does not exist, but we do want to
 185   report a failure in opening for other reasons (e.g. we got an I/O
 186   error, or the file is there, but we lack the permission to open).
 187
 188   The exact errors we need to ignore are ENOENT (obviously) and
 189   ENOTDIR (less obvious).  Instead of repeating comparison of errno
 190   with these two constants, introduce a helper function to do so.
 191
 192 * We often try to open a file for reading whose existence is
 193   optional, and silently ignore errors from open/fopen; report such
 194   errors if they are not due to missing files.
 195
 196 * When an existing repository is used for t/perf testing, we first
 197   create bit-for-bit copy of it, which may grab a transient state of
 198   the repository and freeze it into the repository used for testing,
 199   which then may cause Git operations to fail.  Single out "the index
 200   being locked" case and forcibly drop the lock from the copy.
 201
 202 * Three instances of the same helper function have been consolidated
 203   to one.
 204
 205 * "fast-import" uses a default pack chain depth that is consistent
 206   with other parts of the system.
 207
 208 * A new test to show the interaction between the pattern [^a-z]
 209   (which matches '/') and a slash in a path has been added.  The
 210   pattern should not match the slash with "pathmatch", but should
 211   with "wildmatch".
 212
 213 * The 'diff-highlight' program (in contrib/) has been restructured
 214   for easier reuse by an external project 'diff-so-fancy'.
 215
 216 * A common pattern to free a piece of memory and assign NULL to the
 217   pointer that used to point at it has been replaced with a new
 218   FREE_AND_NULL() macro.
 219
 220 * Traditionally, the default die() routine had a code to prevent it
 221   from getting called multiple times, which interacted badly when a
 222   threaded program used it (one downside is that the real error may
 223   be hidden and instead the only error message given to the user may
 224   end up being "die recursion detected", which is not very useful).
 225
 226 * Introduce a "repository" object to eventually make it easier to
 227   work in multiple repositories (the primary focus is to work with
 228   the superproject and its submodules) in a single process.
 229
 230 * Optimize "what are the object names already taken in an alternate
 231   object database?" query that is used to derive the length of prefix
 232   an object name is uniquely abbreviated to.
 233
 234 * The hashmap API has been updated so that data to customize the
 235   behaviour of the comparison function can be specified at the time a
 236   hashmap is initialized.
 237
 238 * The "collision detecting" SHA-1 implementation shipped with 2.13 is
 239   now integrated into git.git as a submodule (the first submodule to
 240   ship with git.git). Clone git.git with --recurse-submodules to get
 241   it. For now a non-submodule copy of the same code is also shipped
 242   as part of the tree.
 243
 244 * A recent update made it easier to use "-fsanitize=" option while
 245   compiling but supported only one sanitize option.  Allow more than
 246   one to be combined, joined with a comma, like "make SANITIZE=foo,bar".
 247
 248 * Use "p4 -G" to make "p4 changes" output more Python-friendly
 249   to parse.
 250
 251 * We started using "%" PRItime, imitating "%" PRIuMAX and friends, as
 252   a way to format the internal timestamp value, but this does not
 253   play well with gettext(1) i18n framework, and causes "make pot"
 254   that is run by the l10n coordinator to create a broken po/git.pot
 255   file.  This is a possible workaround for that problem.
 256
 257 * It turns out that Cygwin also needs the fopen() wrapper that
 258   returns failure when a directory is opened for reading.
 259
 260Also contains various documentation updates and code clean-ups.
 261
 262
 263Fixes since v2.13
 264-----------------
 265
 266Unless otherwise noted, all the fixes since v2.13 in the maintenance
 267track are contained in this release (see the maintenance releases'
 268notes for details).
 269
 270 * "git gc" did not interact well with "git worktree"-managed
 271   per-worktree refs.
 272
 273 * "git cherry-pick" and other uses of the sequencer machinery
 274   mishandled a trailer block whose last line is an incomplete line.
 275   This has been fixed so that an additional sign-off etc. are added
 276   after completing the existing incomplete line.
 277
 278 * The codepath in "git am" that is used when running "git rebase"
 279   leaked memory held for the log message of the commits being rebased.
 280
 281 * "git clone --config var=val" is a way to populate the
 282   per-repository configuration file of the new repository, but it did
 283   not work well when val is an empty string.  This has been fixed.
 284
 285 * Setting "log.decorate=false" in the configuration file did not take
 286   effect in v2.13, which has been corrected.
 287
 288 * A few codepaths in "checkout" and "am" working on an unborn branch
 289   tried to access an uninitialized piece of memory.
 290
 291 * The Web interface to gmane news archive is long gone, even though
 292   the articles are still accessible via NTTP.  Replace the links with
 293   ones to public-inbox.org.  Because their message identification is
 294   based on the actual message-id, it is likely that it will be easier
 295   to migrate away from it if/when necessary.
 296
 297 * The receive-pack program now makes sure that the push certificate
 298   records the same set of push options used for pushing.
 299
 300 * Tests have been updated to pass under GETTEXT_POISON (a mechanism
 301   to ensure that output strings that should not be translated are
 302   not translated by mistake), and TravisCI is told to run them.
 303
 304 * "git checkout --recurse-submodules" did not quite work with a
 305   submodule that itself has submodules.
 306
 307 * "pack-objects" can stream a slice of an existing packfile out when
 308   the pack bitmap can tell that the reachable objects are all needed
 309   in the output, without inspecting individual objects.  This
 310   strategy however would not work well when "--local" and other
 311   options are in use, and need to be disabled.
 312
 313 * Fix memory leaks pointed out by Coverity (and people).
 314
 315 * "git read-tree -m" (no tree-ish) gave a nonsense suggestion "use
 316   --empty if you want to clear the index".  With "-m", such a request
 317   will still fail anyway, as you'd need to name at least one tree-ish
 318   to be merged.
 319
 320 * Make sure our tests would pass when the sources are checked out
 321   with "platform native" line ending convention by default on
 322   Windows.  Some "text" files out tests use and the test scripts
 323   themselves that are meant to be run with /bin/sh, ought to be
 324   checked out with eol=LF even on Windows.
 325
 326 * Introduce the BUG() macro to improve die("BUG: ...").
 327
 328 * Clarify documentation for include.path and includeIf.<condition>.path
 329   configuration variables.
 330
 331 * Git sometimes gives an advice in a rhetorical question that does
 332   not require an answer, which can confuse new users and non native
 333   speakers.  Attempt to rephrase them.
 334
 335 * A few http:// links that are redirected to https:// in the
 336   documentation have been updated to https:// links.
 337
 338 * "git for-each-ref --format=..." with %(HEAD) in the format used to
 339   resolve the HEAD symref as many times as it had processed refs,
 340   which was wasteful, and "git branch" shared the same problem.
 341
 342 * Regression fix to topic recently merged to 'master'.
 343
 344 * The shell completion script (in contrib/) learned "git stash" has
 345   a new "push" subcommand.
 346
 347 * "git interpret-trailers", when used as GIT_EDITOR for "git commit
 348   -v", looked for and appended to a trailer block at the very end,
 349   i.e. at the end of the "diff" output.  The command has been
 350   corrected to pay attention to the cut-mark line "commit -v" adds to
 351   the buffer---the real trailer block should appear just before it.
 352
 353 * A test allowed both "git push" and "git receive-pack" on the other
 354   end write their traces into the same file.  This is OK on platforms
 355   that allows atomically appending to a file opened with O_APPEND,
 356   but on other platforms led to a mangled output, causing
 357   intermittent test failures.  This has been fixed by disabling
 358   traces from "receive-pack" in the test.
 359
 360 * Tag objects, which are not reachable from any ref, that point at
 361   missing objects were mishandled by "git gc" and friends (they
 362   should silently be ignored instead)
 363
 364 * "git describe --contains" penalized light-weight tags so much that
 365   they were almost never considered.  Instead, give them about the
 366   same chance to be considered as an annotated tag that is the same
 367   age as the underlying commit would.
 368
 369 * The "run-command" API implementation has been made more robust
 370   against dead-locking in a threaded environment.
 371
 372 * A recent update to t5545-push-options.sh started skipping all the
 373   tests in the script when a web server testing is disabled or
 374   unavailable, not just the ones that require a web server.  Non HTTP
 375   tests have been salvaged to always run in this script.
 376
 377 * "git send-email" now uses Net::SMTP::SSL, which is obsolete, only
 378   when needed.  Recent versions of Net::SMTP can do TLS natively.
 379
 380 * "foo\bar\baz" in "git fetch foo\bar\baz", even though there is no
 381   slashes in it, cannot be a nickname for a remote on Windows, as
 382   that is likely to be a pathname on a local filesystem.
 383
 384 * "git clean -d" used to clean directories that has ignored files,
 385   even though the command should not lose ignored ones without "-x".
 386   "git status --ignored"  did not list ignored and untracked files
 387   without "-uall".  These have been corrected.
 388
 389 * The result from "git diff" that compares two blobs, e.g. "git diff
 390   $commit1:$path $commit2:$path", used to be shown with the full
 391   object name as given on the command line, but it is more natural to
 392   use the $path in the output and use it to look up .gitattributes.
 393
 394 * The "collision detecting" SHA-1 implementation shipped with 2.13
 395   was quite broken on some big-endian platforms and/or platforms that
 396   do not like unaligned fetches.  Update to the upstream code which
 397   has already fixed these issues.
 398
 399 * "git am -h" triggered a BUG().
 400
 401 * The interaction of "url.*.insteadOf" and custom URL scheme's
 402   whitelisting is now documented better.
 403
 404 * The timestamp of the index file is now taken after the file is
 405   closed, to help Windows, on which a stale timestamp is reported by
 406   fstat() on a file that is opened for writing and data was written
 407   but not yet closed.
 408
 409 * "git pull --rebase --autostash" didn't auto-stash when the local history
 410   fast-forwards to the upstream.
 411
 412 * A flaky test has been corrected.
 413
 414 * "git $cmd -h" for builtin commands calls the implementation of the
 415   command (i.e. cmd_$cmd() function) without doing any repository
 416   set-up, and the commands that expect RUN_SETUP is done by the Git
 417   potty needs to be prepared to show the help text without barfing.
 418   (merge d691551192 jk/consistent-h later to maint).
 419
 420 * Help contributors that visit us at GitHub.
 421
 422 * "git stash push <pathspec>" did not work from a subdirectory at all.
 423   Bugfix for a topic in v2.13
 424
 425 * As there is no portable way to pass timezone information to
 426   strftime, some output format from "git log" and friends are
 427   impossible to produce.  Teach our own strbuf_addftime to replace %z
 428   and %Z with caller-supplied values to help working around this.
 429   (merge 6eced3ec5e rs/strbuf-addftime-zZ later to maint).
 430
 431 * "git mergetool" learned to work around a wrapper MacOS X adds
 432   around underlying meld.
 433
 434 * An example in documentation that does not work in multi worktree
 435   configuration has been corrected.
 436
 437 * The pretty-format specifiers like '%h', '%t', etc. had an
 438   optimization that no longer works correctly.  In preparation/hope
 439   of getting it correctly implemented, first discard the optimization
 440   that is broken.
 441
 442 * The code to pick up and execute command alias definition from the
 443   configuration used to switch to the top of the working tree and
 444   then come back when the expanded alias was executed, which was
 445   unnecessarilyl complex.  Attempt to simplify the logic by using the
 446   early-config mechanism that does not chdir around.
 447
 448 * Fix configuration codepath to pay proper attention to commondir
 449   that is used in multi-worktree situation, and isolate config API
 450   into its own header file.
 451   (merge dc8441fdb4 bw/config-h later to maint).
 452
 453 * "git add -p" were updated in 2.12 timeframe to cope with custom
 454   core.commentchar but the implementation was buggy and a
 455   metacharacter like $ and * did not work.
 456
 457 * A recent regression in "git rebase -i" has been fixed and tests
 458   that would have caught it and others have been added.
 459
 460 * An unaligned 32-bit access in pack-bitmap code has been corrected.
 461
 462 * Tighten error checks for invalid "git apply" input.
 463
 464 * The split index code did not honor core.sharedRepository setting
 465   correctly.
 466
 467 * The Makefile rule in contrib/subtree for building documentation
 468   learned to honour USE_ASCIIDOCTOR just like the main documentation
 469   set does.
 470
 471 * Code clean-up to fix possible buffer over-reading.
 472
 473 * A few tests that tried to verify the contents of push certificates
 474   did not use 'git rev-parse' to formulate the line to look for in
 475   the certificate correctly.
 476
 477 * Update the character width tables.
 478
 479 * After "git branch --move" of the currently checked out branch, the
 480   code to walk the reflog of HEAD via "log -g" and friends
 481   incorrectly stopped at the reflog entry that records the renaming
 482   of the branch.
 483
 484 * The rewrite of "git branch --list" using for-each-ref's internals
 485   that happened in v2.13 regressed its handling of color.branch.local;
 486   this has been fixed.
 487
 488 * The build procedure has been improved to allow building and testing
 489   Git with address sanitizer more easily.
 490   (merge 425ca6710b jk/build-with-asan later to maint).
 491
 492 * On Cygwin, similar to Windows, "git push //server/share/repository"
 493   ought to mean a repository on a network share that can be accessed
 494   locally, but this did not work correctly due to stripping the double
 495   slashes at the beginning.
 496
 497 * The progress meter did not give a useful output when we haven't had
 498   0.5 seconds to measure the throughput during the interval.  Instead
 499   show the overall throughput rate at the end, which is a much more
 500   useful number.
 501
 502 * Code clean-up, that makes us in sync with Debian by one patch.
 503
 504 * We run an early part of "git gc" that deals with refs before
 505   daemonising (and not under lock) even when running a background
 506   auto-gc, which caused multiple gc processes attempting to run the
 507   early part at the same time.  This is now prevented by running the
 508   early part also under the GC lock.
 509
 510 * A recent update broke an alias that contained an uppercase letter.
 511
 512 * Other minor doc, test and build updates and code cleanups.
 513   (merge 5053313562 rs/urlmatch-cleanup later to maint).
 514   (merge 42c78a216e rs/use-div-round-up later to maint).
 515   (merge 5e8d2729ae rs/wt-status-cleanup later to maint).
 516   (merge bc9b7e207f as/diff-options-grammofix later to maint).
 517   (merge ac05222b31 ah/patch-id-doc later to maint).