Documentation / RelNotes / 2.9.0.txton commit Merge branch 'jk/cat-file-buffered-batch-all' (6289913)
   1Git 2.9 Release Notes
   2=====================
   3
   4Backward compatibility note
   5---------------------------
   6
   7The end-user facing Porcelain level commands in the "git diff" and
   8"git log" by default enables the rename detection; you can still use
   9"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 Porcelain level commands like "diff" and "log"
  34   now enables 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" session.
  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 --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 in
  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   (merge d9d501b068 jc/rerere-multi later to maint).
 101
 102 * "git p4" learned to record P4 jobs in Git commit that imports from
 103   the history in Perforce.
 104
 105 * "git describe --contains" often made a hard-to-justify choice of
 106   tag to give name to a given commit, because it tried to come up
 107   with a name with smallest number of hops from a tag, causing an old
 108   commit whose close descendant that is recently tagged were not
 109   described with respect to an old tag but with a newer tag.  It did
 110   not help that its computation of "hop" count was further tweaked to
 111   penalize being on a side branch of a merge.  The logic has been
 112   updated to favor using the tag with the oldest tagger date, which
 113   is a lot easier to explain to the end users: "We describe a commit
 114   in terms of the (chronologically) oldest tag that contains the
 115   commit."
 116   (merge 7550424 js/name-rev-use-oldest-ref later to maint).
 117
 118 * "git clone" learned "--shallow-submodules" option.
 119
 120 * HTTP transport clients learned to throw extra HTTP headers at the
 121   server, specified via http.extraHeader configuration variable.
 122
 123 * Patch output from "git diff" and friends has been tweaked to be
 124   more readable by using a blank line as a strong hint that the
 125   contents before and after it belong to a logically separate unit.
 126
 127 * A new configuration variable core.hooksPath allows customizing
 128   where the hook directory is.
 129
 130 * An earlier addition of "sanitize_submodule_env" with 14111fc4 (git:
 131   submodule honor -c credential.* from command line, 2016-02-29)
 132   turned out to be a convoluted no-op; implement what it wanted to do
 133   correctly, and stop filtering settings given via "git -c var=val".
 134
 135 * "git commit --dry-run" reported "No, no, you cannot commit." in one
 136   case where "git commit" would have allowed you to commit, and this
 137   improves it a little bit ("git commit --dry-run --short" still does
 138   not give you the correct answer, for example).  This is a stop-gap
 139   measure in that "commit --short --dry-run" still gives an incorrect
 140   result.
 141
 142 * The experimental "multiple worktree" feature gains more safety to
 143   forbid operations on a branch that is checked out or being actively
 144   worked on elsewhere, by noticing that e.g. it is being rebased.
 145
 146 * "git format-patch" learned a new "--base" option to record what
 147   (public, well-known) commit the original series was built on in
 148   its output.
 149
 150 * "git commit" learned to pay attention to "commit.verbose"
 151   configuration variable and act as if "--verbose" option was
 152   given from the command line.
 153
 154 * Give hints to GMail users with two-factor auth enabled that
 155   they need app-specific-password when using send-email.
 156
 157
 158Performance, Internal Implementation, Development Support etc.
 159
 160 * The embedded args argv-array in the child process is used to build
 161   the command line to run pack-objects instead of using a separate
 162   array of strings.
 163
 164 * A test for tags has been restructured so that more parts of it can
 165   easily be run on a platform without a working GnuPG.
 166
 167 * The startup_info data, which records if we are working inside a
 168   repository (among other things), are now uniformly available to Git
 169   subcommand implementations, and Git avoids attempting to touch
 170   references when we are not in a repository.
 171
 172 * The command line argument parser for "receive-pack" has been
 173   rewritten to use parse-options.
 174
 175 * A major part of "git submodule update" has been ported to C to take
 176   advantage of the recently added framework to run download tasks in
 177   parallel.
 178
 179 * Rename bunch of tests on "git clone" for better organization.
 180
 181 * The tests that involve running httpd leaked the system-wide
 182   configuration in /etc/gitconfig to the tested environment.
 183
 184 * Build updates for MSVC.
 185
 186 * The repository set-up sequence has been streamlined (the biggest
 187   change is that there is no longer git_config_early()), so that we
 188   do not attempt to look into refs/* when we know we do not have a
 189   Git repository.
 190
 191 * Code restructuring around the "refs" area to prepare for pluggable
 192   refs backends.
 193
 194 * Sources to many test helper binaries (and the generated helpers)
 195   have been moved to t/helper/ subdirectory to reduce clutter at the
 196   top level of the tree.
 197
 198 * Unify internal logic between "git tag -v" and "git verify-tag"
 199   commands by making one directly call into the other.
 200   (merge bef234b st/verify-tag later to maint).
 201
 202 * "merge-recursive" strategy incorrectly checked if a path that is
 203   involved in its internal merge exists in the working tree.
 204
 205 * The test scripts for "git p4" (but not "git p4" implementation
 206   itself) has been updated so that they would work even on a system
 207   where the installed version of Python is python 3.
 208
 209 * As nobody maintains our in-tree git.spec.in and distros use their
 210   own spec file, we stopped pretending that we support "make rpm".
 211
 212 * Move from unsigned char[20] to struct object_id continues.
 213
 214 * Update of "git submodule" to move pieces of logic to C continues.
 215
 216 * The code for warning_errno/die_errno has been refactored and a new
 217   error_errno() reporting helper is introduced.
 218   (merge 1da045f nd/error-errno later to maint).
 219
 220 * Running tests with '-x' option to trace the individual command
 221   executions is a useful way to debug test scripts, but some tests
 222   that capture the standard error stream and check what the command
 223   said can be broken with the trace output mixed in.  When running
 224   our tests under "bash", however, we can redirect the trace output
 225   to another file descriptor to keep the standard error of programs
 226   being tested intact.
 227   (merge d88785e jk/test-send-sh-x-trace-elsewhere later to maint).
 228
 229 * t0040 had too many unnecessary repetitions in its test data.  Teach
 230   test-parse-options program so that a caller can tell what it
 231   expects in its output, so that these repetitions can be cleaned up.
 232
 233 * Add perf test for "rebase -i"
 234
 235 * Common mistakes when writing gitlink: in our documentation are
 236   found by "make check-docs".
 237
 238 * t9xxx series has been updated primarily for readability, while
 239   fixing small bugs in it.  A few scripted Porcelains have also been
 240   updated to fix possible bugs around their use of "test -z" and
 241   "test -n".
 242
 243 * CI test was taught to run git-svn tests.
 244
 245
 246Also contains various documentation updates and code clean-ups.
 247
 248
 249Fixes since v2.8
 250----------------
 251
 252Unless otherwise noted, all the fixes since v2.8 in the maintenance
 253track are contained in this release (see the maintenance releases'
 254notes for details).
 255
 256 * "git config --get-urlmatch", unlike other variants of the "git
 257   config --get" family, did not signal error with its exit status
 258   when there was no matching configuration.
 259
 260 * The "--local-env-vars" and "--resolve-git-dir" options of "git
 261   rev-parse" failed to work outside a repository when the command's
 262   option parsing was rewritten in 1.8.5 era.
 263
 264 * "git index-pack --keep[=<msg>] pack-$name.pack" simply did not work.
 265
 266 * Fetching of history by naming a commit object name directly didn't
 267   work across remote-curl transport.
 268
 269 * A small memory leak in an error codepath has been plugged in xdiff
 270   code.
 271
 272 * strbuf_getwholeline() did not NUL-terminate the buffer on certain
 273   corner cases in its error codepath.
 274
 275 * "git mergetool" did not work well with conflicts that both sides
 276   deleted.
 277
 278 * "git send-email" had trouble parsing alias file in mailrc format
 279   when lines in it had trailing whitespaces on them.
 280
 281 * When "git merge --squash" stopped due to conflict, the concluding
 282   "git commit" failed to read in the SQUASH_MSG that shows the log
 283   messages from all the squashed commits.
 284
 285 * "git merge FETCH_HEAD" dereferenced NULL pointer when merging
 286   nothing into an unborn history (which is arguably unusual usage,
 287   which perhaps was the reason why nobody noticed it).
 288
 289 * When "git worktree" feature is in use, "git branch -d" allowed
 290   deletion of a branch that is checked out in another worktree,
 291   which was wrong.
 292
 293 * When "git worktree" feature is in use, "git branch -m" renamed a
 294   branch that is checked out in another worktree without adjusting
 295   the HEAD symbolic ref for the worktree.
 296
 297 * "git diff -M" used to work better when two originally identical
 298   files A and B got renamed to X/A and X/B by pairing A to X/A and B
 299   to X/B, but this was broken in the 2.0 timeframe.
 300
 301 * "git send-pack --all <there>" was broken when its command line
 302   option parsing was written in the 2.6 timeframe.
 303
 304 * "git format-patch --help" showed `-s` and `--no-patch` as if these
 305   are valid options to the command.  We already hide `--patch` option
 306   from the documentation, because format-patch is about showing the
 307   diff, and the documentation now hides these options as well.
 308
 309 * When running "git blame $path" with unnormalized data in the index
 310   for the path, the data in the working tree was blamed, even though
 311   "git add" would not have changed what is already in the index, due
 312   to "safe crlf" that disables the line-end conversion.  It has been
 313   corrected.
 314
 315 * A change back in version 2.7 to "git branch" broke display of a
 316   symbolic ref in a non-standard place in the refs/ hierarchy (we
 317   expect symbolic refs to appear in refs/remotes/*/HEAD to point at
 318   the primary branch the remote has, and as .git/HEAD to point at the
 319   branch we locally checked out).
 320
 321 * A partial rewrite of "git submodule" in the 2.7 timeframe changed
 322   the way the gitdir: pointer in the submodules point at the real
 323   repository location to use absolute paths by accident.  This has
 324   been corrected.
 325
 326 * "git commit" misbehaved in a few minor ways when an empty message
 327   is given via -m '', all of which has been corrected.
 328
 329 * Support for CRAM-MD5 authentication method in "git imap-send" did
 330   not work well.
 331
 332 * Upcoming OpenSSL 1.1.0 will break compilation b updating a few APIs
 333   we use in imap-send, which has been adjusted for the change.
 334
 335 * The socks5:// proxy support added back in 2.6.4 days was not aware
 336   that socks5h:// proxies behave differently.
 337
 338 * "git config" had a codepath that tried to pass a NULL to
 339   printf("%s"), which nobody seems to have noticed.
 340
 341 * On Cygwin, object creation uses the "create a temporary and then
 342   rename it to the final name" pattern, not "create a temporary,
 343   hardlink it to the final name and then unlink the temporary"
 344   pattern.
 345
 346   This is necessary to use Git on Windows shared directories, and is
 347   already enabled for the MinGW and plain Windows builds.  It also
 348   has been used in Cygwin packaged versions of Git for quite a while.
 349   See http://thread.gmane.org/gmane.comp.version-control.git/291853
 350
 351 * "merge-octopus" strategy did not ensure that the index is clean
 352   when merge begins.
 353
 354 * When "git merge" notices that the merge can be resolved purely at
 355   the tree level (without having to merge blobs) and the resulting
 356   tree happens to already exist in the object store, it forgot to
 357   update the index, which lead to an inconsistent state for later
 358   operations.
 359
 360 * "git submodule" reports the paths of submodules the command
 361   recurses into, but this was incorrect when the command was not run
 362   from the root level of the superproject.
 363
 364 * The "user.useConfigOnly" configuration variable makes it an error
 365   if users do not explicitly set user.name and user.email.  However,
 366   its check was not done early enough and allowed another error to
 367   trigger, reporting that the default value we guessed from the
 368   system setting was unusable.  This was a suboptimal end-user
 369   experience as we want the users to set user.name/user.email without
 370   relying on the auto-detection at all.
 371
 372 * "git mv old new" did not adjust the path for a submodule that lives
 373   as a subdirectory inside old/ directory correctly.
 374
 375 * "git replace -e" did not honour "core.editor" configuration.
 376
 377 * "git push" from a corrupt repository that attempts to push a large
 378   number of refs deadlocked; the thread to relay rejection notices
 379   for these ref updates blocked on writing them to the main thread,
 380   after the main thread at the receiving end notices that the push
 381   failed and decides not to read these notices and return a failure.
 382
 383 * mmap emulation on Windows has been optimized and work better without
 384   consuming paging store when not needed.
 385
 386 * A question by "git send-email" to ask the identity of the sender
 387   has been updated.
 388
 389 * UI consistency improvements for "git mergetool".
 390
 391 * "git rebase -m" could be asked to rebase an entire branch starting
 392   from the root, but failed by assuming that there always is a parent
 393   commit to the first commit on the branch.
 394   (merge 79f4344 bw/rebase-merge-entire-branch later to maint).
 395
 396 * Fix a broken "p4 lfs" test.
 397
 398 * Recent update to Git LFS broke "git p4" by changing the output from
 399   its "lfs pointer" subcommand.
 400
 401 * "git fetch" test t5510 was flaky while running a (forced) automagic
 402   garbage collection.
 403
 404 * Documentation updates to help contributors setting up Travis CI
 405   test for their patches.
 406
 407 * Some multi-byte encoding can have a backslash byte as a later part
 408   of one letter, which would confuse "highlight" filter used in
 409   gitweb.
 410
 411 * "git commit-tree" plumbing command required the user to always sign
 412   its result when the user sets the commit.gpgsign configuration
 413   variable, which was an ancient mistake.  Rework "git rebase" that
 414   relied on this mistake so that it reads commit.gpgsign and pass (or
 415   not pass) the -S option to "git commit-tree" to keep the end-user
 416   expectation the same, while teaching "git commit-tree" to ignore
 417   the configuration variable.  This will stop requiring the users to
 418   sign commit objects used internally as an implementation detail of
 419   "git stash".
 420   (merge 6694856 jc/commit-tree-ignore-commit-gpgsign later to maint).
 421
 422 * "http.cookieFile" configuration variable clearly wants a pathname,
 423   but we forgot to treat it as such by e.g. applying tilde expansion.
 424   (merge e5a39ad bn/http-cookiefile-config later to maint).
 425
 426 * Consolidate description of tilde-expansion that is done to
 427   configuration variables that take pathname to a single place.
 428   (merge dca83ab jc/config-pathname-type later to maint).
 429
 430 * Correct faulty recommendation to use "git submodule deinit ." when
 431   de-initialising all submodules, which would result in a strange
 432   error message in a pathological corner case.
 433   (merge f6a5279 sb/submodule-deinit-all later to maint).
 434
 435 * Many 'linkgit:<git documentation page>' references were broken,
 436   which are all fixed with this.
 437   (merge 1cca17d jc/linkgit-fix later to maint).
 438
 439 * "git rerere" can get confused by conflict markers deliberately left
 440   by the inner merge step, because they are indistinguishable from
 441   the real conflict markers left by the outermost merge which are
 442   what the end user and "rerere" need to look at.  This was fixed by
 443   making the conflict markers left by the inner merges a bit longer.
 444   (merge 0f9fd5c jc/ll-merge-internal later to maint).
 445
 446 * CI test was taught to build documentation pages.
 447   (merge b98712b ls/travis-build-doc later to maint).
 448
 449 * "git fsck" learned to catch NUL byte in a commit object as
 450   potential error and warn.
 451   (merge 6d2d780 jc/fsck-nul-in-commit later to maint).
 452
 453 * Portability enhancement for "rebase -i" to help platforms whose
 454   shell does not like "for i in <empty>" (which is not POSIX-kosher).
 455   (merge 8e98b35 jk/rebase-interative-eval-fix later to maint).
 456
 457 * On Windows, .git and optionally any files whose name starts with a
 458   dot are now marked as hidden, with a core.hideDotFiles knob to
 459   customize this behaviour.
 460   (merge ebf31e7 js/windows-dotgit later to maint).
 461
 462 * Documentation for "git merge --verify-signatures" has been updated
 463   to clarify that the signature of only the commit at the tip is
 464   verified.  Also the phrasing used for signature and key validity is
 465   adjusted to align with that used by OpenPGP.
 466   (merge 05a5869 kf/gpg-sig-verification-doc later to maint).
 467
 468 * A couple of bugs around core.autocrlf have been fixed.
 469   (merge caa47ad tb/core-eol-fix later to maint).
 470
 471 * Many commands normalize command line arguments from NFD to NFC
 472   variant of UTF-8 on OSX, but commands in the "diff" family did
 473   not, causing "git diff $path" to complain that no such path is
 474   known to Git.  They have been taught to do the normalization.
 475   (merge 90a78b8 ar/diff-args-osx-precompose later to maint).
 476
 477 * "git difftool" learned to handle unmerged paths correctly in
 478   dir-diff mode.
 479   (merge 366f9ce da/difftool later to maint).
 480
 481 * The "are we talking with TTY, doing an interactive session?"
 482   detection has been updated to work better for "Git for Windows".
 483   (merge f7f90e0 kb/msys2-tty later to maint).
 484
 485 * We forgot to add "git log --decorate=auto" to documentation when we
 486   added the feature back in v2.1.0 timeframe.
 487   (merge 462cbb4 rj/log-decorate-auto later to maint).
 488
 489 * Other minor clean-ups and documentation updates
 490   (merge 832c0e5 lp/typofixes later to maint).
 491   (merge f5ee54a sb/z-is-gnutar-ism later to maint).
 492   (merge 2e3926b va/i18n-misc-updates later to maint).
 493   (merge f212dcc bn/config-doc-tt-varnames later to maint).
 494   (merge f54bea4 nd/remote-plural-ours-plus-theirs later to maint).
 495   (merge 2bb0518 ak/t4151-ls-files-could-be-empty later to maint).
 496   (merge 4df4313 jc/test-seq later to maint).
 497   (merge a75a308 tb/t5601-sed-fix later to maint).
 498   (merge 6c1fbe1 va/i18n-remote-comment-to-align later to maint).
 499   (merge dee2303 va/mailinfo-doc-typofix later to maint).