Documentation / RelNotes / 2.9.0.txton commit Almost ready for 2.9-rc2 (6326f19)
   1Git 2.9 Release Notes
   2=====================
   3
   4Backward compatibility notes
   5----------------------------
   6
   7The end-user facing Porcelain level commands in the "git diff" and
   8"git log" family by default enable the rename detection; you can still
   9use "diff.renames" configuration variable to disable this.
  10
  11Merging two branches that have no common ancestor with "git merge" is
  12by default forbidden now to prevent creating such an unusual merge by
  13mistake.
  14
  15The output formats of "git log" that indents the commit log message by
  164 spaces now expands HT in the log message by default.  You can use
  17the "--no-expand-tabs" option to disable this.
  18
  19"git commit-tree" plumbing command required the user to always sign
  20its result when the user sets the commit.gpgsign configuration
  21variable, which was an ancient mistake, which this release corrects.
  22A script that drives commit-tree, if it relies on this mistake, now
  23needs to read commit.gpgsign and pass the -S option as necessary.
  24
  25
  26Updates since v2.8
  27------------------
  28
  29UI, Workflows & Features
  30
  31 * Comes with git-multimail 1.3.1 (in contrib/).
  32
  33 * The end-user facing commands like "git diff" and "git log"
  34   now enable the rename detection by default.
  35
  36 * The credential.helper configuration variable is cumulative and
  37   there is no good way to override it from the command line.  As
  38   a special case, giving an empty string as its value now serves
  39   as the signal to clear the values specified in various files.
  40
  41 * A new "interactive.diffFilter" configuration can be used to
  42   customize the diff shown in "git add -i" sessions.
  43
  44 * "git p4" now allows P4 author names to be mapped to Git author
  45   names.
  46
  47 * "git rebase -x" can be used without passing "-i" option.
  48
  49 * "git -c credential.<var>=<value> submodule" can now be used to
  50   propagate configuration variables related to credential helper
  51   down to the submodules.
  52
  53 * "git tag" can create an annotated tag without explicitly given an
  54   "-a" (or "-s") option (i.e. when a tag message is given).  A new
  55   configuration variable, tag.forceSignAnnotated, can be used to tell
  56   the command to create signed tag in such a situation.
  57
  58 * "git merge" used to allow merging two branches that have no common
  59   base by default, which led to a brand new history of an existing
  60   project created and then get pulled by an unsuspecting maintainer,
  61   which allowed an unnecessary parallel history merged into the
  62   existing project.  The command has been taught not to allow this by
  63   default, with an escape hatch "--allow-unrelated-histories" option
  64   to be used in a rare event that merges histories of two projects
  65   that started their lives independently.
  66
  67 * "git pull" has been taught to pass the "--allow-unrelated-histories"
  68   option to underlying "git merge".
  69
  70 * "git apply -v" learned to report paths in the patch that were
  71   skipped via --include/--exclude mechanism or being outside the
  72   current working directory.
  73
  74 * Shell completion (in contrib/) updates.
  75
  76 * The commit object name reported when "rebase -i" stops has been
  77   shortened.
  78
  79 * "git worktree add" can be given "--no-checkout" option to only
  80   create an empty worktree without checking out the files.
  81
  82 * "git mergetools" learned to drive ExamDiff.
  83
  84 * "git pull --rebase" learned "--[no-]autostash" option, so that
  85   the rebase.autostash configuration variable set to true can be
  86   overridden from the command line.
  87
  88 * When "git log" shows the log message indented by 4-spaces, the
  89   remainder of a line after a HT does not align in the way the author
  90   originally intended.  The command now expands tabs by default to help
  91   such a case, and allows the users to override it with a new option,
  92   "--no-expand-tabs".
  93
  94 * "git send-email" now uses a more readable timestamps when
  95   formulating a message ID.
  96
  97 * "git rerere" can encounter two or more files with the same conflict
  98   signature that have to be resolved in different ways, but there was
  99   no way to record these separate resolutions.
 100
 101 * "git p4" learned to record P4 jobs in Git commit that imports from
 102   the history in Perforce.
 103
 104 * "git describe --contains" often made a hard-to-justify choice of
 105   tag to name a given commit, because it tried to come up
 106   with a name with smallest number of hops from a tag, causing an old
 107   commit whose close descendant that is recently tagged were not
 108   described with respect to an old tag but with a newer tag.  It did
 109   not help that its computation of "hop" count was further tweaked to
 110   penalize being on a side branch of a merge.  The logic has been
 111   updated to favor using the tag with the oldest tagger date, which
 112   is a lot easier to explain to the end users: "We describe a commit
 113   in terms of the (chronologically) oldest tag that contains the
 114   commit."
 115   (merge 7550424 js/name-rev-use-oldest-ref later to maint).
 116
 117 * "git clone" learned the "--shallow-submodules" option.
 118
 119 * HTTP transport clients learned to throw extra HTTP headers at the
 120   server, specified via http.extraHeader configuration variable.
 121
 122 * Patch output from "git diff" and friends has been tweaked to be
 123   more readable by using a blank line as a strong hint that the
 124   contents before and after it belong to logically separate units.
 125
 126 * A new configuration variable core.hooksPath allows customizing
 127   where the hook directory is.
 128
 129 * An earlier addition of "sanitize_submodule_env" with 14111fc4 (git:
 130   submodule honor -c credential.* from command line, 2016-02-29)
 131   turned out to be a convoluted no-op; implement what it wanted to do
 132   correctly, and stop filtering settings given via "git -c var=val".
 133
 134 * "git commit --dry-run" reported "No, no, you cannot commit." in one
 135   case where "git commit" would have allowed you to commit, and this
 136   improves it a little bit ("git commit --dry-run --short" still does
 137   not give you the correct answer, for example).  This is a stop-gap
 138   measure in that "commit --short --dry-run" still gives an incorrect
 139   result.
 140
 141 * The experimental "multiple worktree" feature gains more safety to
 142   forbid operations on a branch that is checked out or being actively
 143   worked on elsewhere, by noticing that e.g. it is being rebased.
 144
 145 * "git format-patch" learned a new "--base" option to record what
 146   (public, well-known) commit the original series was built on in
 147   its output.
 148
 149 * "git commit" learned to pay attention to the "commit.verbose"
 150   configuration variable and act as if the "--verbose" option
 151   was given from the command line.
 152
 153 * Updated documentation gives hints to GMail users with two-factor
 154   auth enabled that they need app-specific-password when using
 155   "git send-email".
 156
 157 * The manpage output of our documentation did not render well in
 158   terminal; typeset literals in bold by default to make them stand
 159   out more.
 160
 161 * The mark-up in the top-level README.md file has been updated to
 162   typeset CLI command names differently from the body text.
 163
 164
 165Performance, Internal Implementation, Development Support etc.
 166
 167 * The embedded args argv-array in the child process is used to build
 168   the command line to run pack-objects instead of using a separate
 169   array of strings.
 170
 171 * A test for tags has been restructured so that more parts of it can
 172   easily be run on a platform without a working GnuPG.
 173
 174 * The startup_info data, which records if we are working inside a
 175   repository (among other things), are now uniformly available to Git
 176   subcommand implementations, and Git avoids attempting to touch
 177   references when we are not in a repository.
 178
 179 * The command line argument parser for "receive-pack" has been
 180   rewritten to use parse-options.
 181
 182 * A major part of "git submodule update" has been ported to C to take
 183   advantage of the recently added framework to run download tasks in
 184   parallel.  Other updates to "git submodule" that move pieces of
 185   logic to C continues.
 186
 187 * Rename bunch of tests on "git clone" for better organization.
 188
 189 * The tests that involve running httpd leaked the system-wide
 190   configuration in /etc/gitconfig to the tested environment.
 191
 192 * Build updates for MSVC.
 193
 194 * The repository set-up sequence has been streamlined (the biggest
 195   change is that there is no longer git_config_early()), so that we
 196   do not attempt to look into refs/* when we know we do not have a
 197   Git repository.
 198
 199 * Code restructuring around the "refs" API to prepare for pluggable
 200   refs backends.
 201
 202 * Sources to many test helper binaries and the generated helpers
 203   have been moved to t/helper/ subdirectory to reduce clutter at the
 204   top level of the tree.
 205
 206 * Unify internal logic between "git tag -v" and "git verify-tag"
 207   commands by making one directly call into the other.
 208
 209 * "merge-recursive" strategy incorrectly checked if a path that is
 210   involved in its internal merge exists in the working tree.
 211
 212 * The test scripts for "git p4" (but not "git p4" implementation
 213   itself) has been updated so that they would work even on a system
 214   where the installed version of Python is python 3.
 215
 216 * As nobody maintains our in-tree git.spec.in and distros use their
 217   own spec file, we stopped pretending that we support "make rpm".
 218
 219 * Move from "unsigned char[20]" to "struct object_id" continues.
 220
 221 * The code for warning_errno/die_errno has been refactored and a new
 222   error_errno() reporting helper is introduced.
 223   (merge 1da045f nd/error-errno later to maint).
 224
 225 * Running tests with '-x' option to trace the individual command
 226   executions is a useful way to debug test scripts, but some tests
 227   that capture the standard error stream and check what the command
 228   said can be broken with the trace output mixed in.  When running
 229   our tests under "bash", however, we can redirect the trace output
 230   to another file descriptor to keep the standard error of programs
 231   being tested intact.
 232   (merge d88785e jk/test-send-sh-x-trace-elsewhere later to maint).
 233
 234 * t0040 had too many unnecessary repetitions in its test data.  Teach
 235   test-parse-options program so that a caller can tell what it
 236   expects in its output, so that these repetitions can be cleaned up.
 237
 238 * Add perf test for "rebase -i".
 239
 240 * Common mistakes when writing gitlink: in our documentation are
 241   found by "make check-docs".
 242
 243 * t9xxx series has been updated primarily for readability, while
 244   fixing small bugs in it.  A few scripted Porcelain commands have
 245   also been updated to fix possible bugs around their use of
 246   "test -z" and "test -n".
 247
 248 * CI test was taught to run git-svn tests.
 249
 250 * "git cat-file --batch-all" has been sped up, by taking advantage
 251   of the fact that it does not have to read a list of objects, in two
 252   ways.
 253
 254 * test updates to make it more readable and maintainable.
 255   (merge e6273f4 es/t1500-modernize later to maint).
 256
 257 * "make DEVELOPER=1" worked as expected; setting DEVELOPER=1 in
 258   config.mak didn't.
 259   (merge 51dd3e8 mm/makefile-developer-can-be-in-config-mak later to maint).
 260
 261
 262Also contains various documentation updates and code clean-ups.
 263
 264
 265Fixes since v2.8
 266----------------
 267
 268Unless otherwise noted, all the fixes since v2.8 in the maintenance
 269track are contained in this release (see the maintenance releases'
 270notes for details).
 271
 272 * "git config --get-urlmatch", unlike other variants of the "git
 273   config --get" family, did not signal error with its exit status
 274   when there was no matching configuration.
 275
 276 * The "--local-env-vars" and "--resolve-git-dir" options of "git
 277   rev-parse" failed to work outside a repository when the command's
 278   option parsing was rewritten in 1.8.5 era.
 279
 280 * "git index-pack --keep[=<msg>] pack-$name.pack" simply did not work.
 281
 282 * Fetching of history by naming a commit object name directly didn't
 283   work across remote-curl transport.
 284
 285 * A small memory leak in an error codepath has been plugged in xdiff
 286   code.
 287
 288 * strbuf_getwholeline() did not NUL-terminate the buffer on certain
 289   corner cases in its error codepath.
 290
 291 * "git mergetool" did not work well with conflicts that both sides
 292   deleted.
 293
 294 * "git send-email" had trouble parsing alias file in mailrc format
 295   when lines in it had trailing whitespaces on them.
 296
 297 * When "git merge --squash" stopped due to conflict, the concluding
 298   "git commit" failed to read in the SQUASH_MSG that shows the log
 299   messages from all the squashed commits.
 300
 301 * "git merge FETCH_HEAD" dereferenced NULL pointer when merging
 302   nothing into an unborn history (which is arguably unusual usage,
 303   which perhaps was the reason why nobody noticed it).
 304
 305 * When "git worktree" feature is in use, "git branch -d" allowed
 306   deletion of a branch that is checked out in another worktree,
 307   which was wrong.
 308
 309 * When "git worktree" feature is in use, "git branch -m" renamed a
 310   branch that is checked out in another worktree without adjusting
 311   the HEAD symbolic ref for the worktree.
 312
 313 * "git diff -M" used to work better when two originally identical
 314   files A and B got renamed to X/A and X/B by pairing A to X/A and B
 315   to X/B, but this was broken in the 2.0 timeframe.
 316
 317 * "git send-pack --all <there>" was broken when its command line
 318   option parsing was written in the 2.6 timeframe.
 319
 320 * "git format-patch --help" showed `-s` and `--no-patch` as if these
 321   are valid options to the command.  We already hide `--patch` option
 322   from the documentation, because format-patch is about showing the
 323   diff, and the documentation now hides these options as well.
 324
 325 * When running "git blame $path" with unnormalized data in the index
 326   for the path, the data in the working tree was blamed, even though
 327   "git add" would not have changed what is already in the index, due
 328   to "safe crlf" that disables the line-end conversion.  It has been
 329   corrected.
 330
 331 * A change back in version 2.7 to "git branch" broke display of a
 332   symbolic ref in a non-standard place in the refs/ hierarchy (we
 333   expect symbolic refs to appear in refs/remotes/*/HEAD to point at
 334   the primary branch the remote has, and as .git/HEAD to point at the
 335   branch we locally checked out).
 336
 337 * A partial rewrite of "git submodule" in the 2.7 timeframe changed
 338   the way the gitdir: pointer in the submodules point at the real
 339   repository location to use absolute paths by accident.  This has
 340   been corrected.
 341
 342 * "git commit" misbehaved in a few minor ways when an empty message
 343   is given via -m '', all of which has been corrected.
 344
 345 * Support for CRAM-MD5 authentication method in "git imap-send" did
 346   not work well.
 347
 348 * Upcoming OpenSSL 1.1.0 will break compilation by updating a few API
 349   elements we use in imap-send, which has been adjusted for the change.
 350
 351 * The socks5:// proxy support added back in 2.6.4 days was not aware
 352   that socks5h:// proxies behave differently from socks5:// proxies.
 353
 354 * "git config" had a codepath that tried to pass a NULL to
 355   printf("%s"), which nobody seems to have noticed.
 356
 357 * On Cygwin, object creation uses the "create a temporary and then
 358   rename it to the final name" pattern, not "create a temporary,
 359   hardlink it to the final name and then unlink the temporary"
 360   pattern.
 361
 362   This is necessary to use Git on Windows shared directories, and is
 363   already enabled for the MinGW and plain Windows builds.  It also
 364   has been used in Cygwin packaged versions of Git for quite a while.
 365   See http://thread.gmane.org/gmane.comp.version-control.git/291853
 366
 367 * "merge-octopus" strategy did not ensure that the index is clean
 368   when merge begins.
 369
 370 * When "git merge" notices that the merge can be resolved purely at
 371   the tree level (without having to merge blobs) and the resulting
 372   tree happens to already exist in the object store, it forgot to
 373   update the index, which left an inconsistent state that would
 374   break later operations.
 375
 376 * "git submodule" reports the paths of submodules the command
 377   recurses into, but these paths were incorrectly reported when
 378   the command was not run from the root level of the superproject.
 379
 380 * The "user.useConfigOnly" configuration variable makes it an error
 381   if users do not explicitly set user.name and user.email.  However,
 382   its check was not done early enough and allowed another error to
 383   trigger, reporting that the default value we guessed from the
 384   system setting was unusable.  This was a suboptimal end-user
 385   experience as we want the users to set user.name/user.email without
 386   relying on the auto-detection at all.
 387
 388 * "git mv old new" did not adjust the path for a submodule that lives
 389   as a subdirectory inside old/ directory correctly.
 390
 391 * "git replace -e" did not honour "core.editor" configuration.
 392
 393 * "git push" from a corrupt repository that attempts to push a large
 394   number of refs deadlocked; the thread to relay rejection notices
 395   for these ref updates blocked on writing them to the main thread,
 396   after the main thread at the receiving end notices that the push
 397   failed and decides not to read these notices and return a failure.
 398
 399 * mmap emulation on Windows has been optimized and work better without
 400   consuming paging store when not needed.
 401
 402 * A question by "git send-email" to ask the identity of the sender
 403   has been updated.
 404
 405 * UI consistency improvements for "git mergetool".
 406
 407 * "git rebase -m" could be asked to rebase an entire branch starting
 408   from the root, but failed by assuming that there always is a parent
 409   commit to the first commit on the branch.
 410
 411 * Fix a broken "p4 lfs" test.
 412
 413 * Recent update to Git LFS broke "git p4" by changing the output from
 414   its "lfs pointer" subcommand.
 415
 416 * "git fetch" test t5510 was flaky while running a (forced) automagic
 417   garbage collection.
 418
 419 * Documentation updates to help contributors setting up Travis CI
 420   test for their patches.
 421
 422 * Some multi-byte encoding can have a backslash byte as a later part
 423   of one letter, which would confuse "highlight" filter used in
 424   gitweb.
 425
 426 * "git commit-tree" plumbing command required the user to always sign
 427   its result when the user sets the commit.gpgsign configuration
 428   variable, which was an ancient mistake.  Rework "git rebase" that
 429   relied on this mistake so that it reads commit.gpgsign and pass (or
 430   not pass) the -S option to "git commit-tree" to keep the end-user
 431   expectation the same, while teaching "git commit-tree" to ignore
 432   the configuration variable.  This will stop requiring the users to
 433   sign commit objects used internally as an implementation detail of
 434   "git stash".
 435
 436 * "http.cookieFile" configuration variable clearly wants a pathname,
 437   but we forgot to treat it as such by e.g. applying tilde expansion.
 438   (merge e5a39ad bn/http-cookiefile-config later to maint).
 439
 440 * Consolidate description of tilde-expansion that is done to
 441   configuration variables that take pathname to a single place.
 442   (merge dca83ab jc/config-pathname-type later to maint).
 443
 444 * Correct faulty recommendation to use "git submodule deinit ." when
 445   de-initialising all submodules, which would result in a strange
 446   error message in a pathological corner case.
 447   (merge f6a5279 sb/submodule-deinit-all later to maint).
 448
 449 * Many 'linkgit:<git documentation page>' references were broken,
 450   which are all fixed with this.
 451   (merge 1cca17d jc/linkgit-fix later to maint).
 452
 453 * "git rerere" can get confused by conflict markers deliberately left
 454   by the inner merge step, because they are indistinguishable from
 455   the real conflict markers left by the outermost merge which are
 456   what the end user and "rerere" need to look at.  This was fixed by
 457   making the conflict markers left by the inner merges a bit longer.
 458   (merge 0f9fd5c jc/ll-merge-internal later to maint).
 459
 460 * CI test was taught to build documentation pages.
 461   (merge b98712b ls/travis-build-doc later to maint).
 462
 463 * "git fsck" learned to catch NUL byte in a commit object as
 464   potential error and warn.
 465   (merge 6d2d780 jc/fsck-nul-in-commit later to maint).
 466
 467 * Portability enhancement for "rebase -i" to help platforms whose
 468   shell does not like "for i in <empty>" (which is not POSIX-kosher).
 469   (merge 8e98b35 jk/rebase-interactive-eval-fix later to maint).
 470
 471 * On Windows, .git and optionally any files whose name starts with a
 472   dot are now marked as hidden, with a core.hideDotFiles knob to
 473   customize this behaviour.
 474   (merge ebf31e7 js/windows-dotgit later to maint).
 475
 476 * Documentation for "git merge --verify-signatures" has been updated
 477   to clarify that the signature of only the commit at the tip is
 478   verified.  Also the phrasing used for signature and key validity is
 479   adjusted to align with that used by OpenPGP.
 480   (merge 05a5869 kf/gpg-sig-verification-doc later to maint).
 481
 482 * A couple of bugs around core.autocrlf have been fixed.
 483   (merge caa47ad tb/core-eol-fix later to maint).
 484
 485 * Many commands normalize command line arguments from NFD to NFC
 486   variant of UTF-8 on OSX, but commands in the "diff" family did
 487   not, causing "git diff $path" to complain that no such path is
 488   known to Git.  They have been taught to do the normalization.
 489   (merge 90a78b8 ar/diff-args-osx-precompose later to maint).
 490
 491 * "git difftool" learned to handle unmerged paths correctly in
 492   dir-diff mode.
 493   (merge 366f9ce da/difftool later to maint).
 494
 495 * The "are we talking with TTY, doing an interactive session?"
 496   detection has been updated to work better for "Git for Windows".
 497   (merge f7f90e0 kb/msys2-tty later to maint).
 498
 499 * We forgot to add "git log --decorate=auto" to documentation when we
 500   added the feature back in v2.1.0 timeframe.
 501   (merge 462cbb4 rj/log-decorate-auto later to maint).
 502
 503 * "git fast-import --export-marks" would overwrite the existing marks
 504   file even when it makes a dump from its custom die routine.
 505   Prevent it from doing so when we have an import-marks file but
 506   haven't finished reading it.
 507   (merge f4beed6 fc/fast-import-broken-marks-file later to maint).
 508
 509 * "git rebase -i", after it fails to auto-resolve the conflict, had
 510   an unnecessary call to "git rerere" from its very early days, which
 511   was spotted recently; the call has been removed.
 512   (merge 7063693 js/rebase-i-dedup-call-to-rerere later to maint).
 513
 514 * Other minor clean-ups and documentation updates
 515   (merge 832c0e5 lp/typofixes later to maint).
 516   (merge f5ee54a sb/z-is-gnutar-ism later to maint).
 517   (merge 2e3926b va/i18n-misc-updates later to maint).
 518   (merge f212dcc bn/config-doc-tt-varnames later to maint).
 519   (merge f54bea4 nd/remote-plural-ours-plus-theirs later to maint).
 520   (merge 2bb0518 ak/t4151-ls-files-could-be-empty later to maint).
 521   (merge 4df4313 jc/test-seq later to maint).
 522   (merge a75a308 tb/t5601-sed-fix later to maint).
 523   (merge 6c1fbe1 va/i18n-remote-comment-to-align later to maint).
 524   (merge dee2303 va/mailinfo-doc-typofix later to maint).
 525   (merge cd82b7a pa/cherry-pick-doc-typo later to maint).
 526   (merge 2bb73ae rs/patch-id-use-skip-prefix later to maint).
 527   (merge aa20cbc rs/apply-name-terminate later to maint).