a43b4c9e4e2ce13d89902eecb21f0e81e69d9b7d
   1Git 2.16 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 now an error.
   8
   9
  10Updates since v2.15
  11-------------------
  12
  13UI, Workflows & Features
  14
  15 * An empty string as a pathspec element that means "everything"
  16   i.e. 'git add ""', is now illegal.  We started this by first
  17   deprecating and warning a pathspec that has such an element in
  18   2.11 (Nov 2016).
  19
  20 * A hook script that is set unexecutable is simply ignored.  Git
  21   notifies when such a file is ignored, unless the message is
  22   squelched via advice.ignoredHook configuration.
  23
  24 * "git pull" has been taught to accept "--[no-]signoff" option and
  25   pass it down to "git merge".
  26
  27 * The "--push-option=<string>" option to "git push" now defaults to a
  28   list of strings configured via push.pushOption variable.
  29
  30 * "gitweb" checks if a directory is searchable with Perl's "-x"
  31   operator, which can be enhanced by using "filetest 'access'"
  32   pragma, which now we do.
  33
  34 * "git stash save" has been deprecated in favour of "git stash push".
  35
  36 * The set of paths output from "git status --ignored" was tied
  37   closely with its "--untracked=<mode>" option, but now it can be
  38   controlled more flexibly.  Most notably, a directory that is
  39   ignored because it is listed to be ignored in the ignore/exclude
  40   mechanism can be handled differently from a directory that ends up
  41   to be ignored only because all files in it are ignored.
  42
  43 * The remote-helper for talking to MediaWiki has been updated to
  44   truncate an overlong pagename so that ".mw" suffix can still be
  45   added.
  46
  47 * The remote-helper for talking to MediaWiki has been updated to
  48   work with mediawiki namespaces.
  49
  50 * The "--format=..." option "git for-each-ref" takes learned to show
  51   the name of the 'remote' repository and the ref at the remote side
  52   that is affected for 'upstream' and 'push' via "%(push:remotename)"
  53   and friends.
  54
  55 * Doc and message updates to teach users "bisect view" is a synonym
  56   for "bisect visualize".
  57
  58 * "git bisect run" that did not specify any command to run used to go
  59   ahead and treated all commits to be tested as 'good'.  This has
  60   been corrected by making the command error out.
  61
  62 * The SubmittingPatches document has been converted to produce an
  63   HTML version via AsciiDoc/Asciidoctor.
  64
  65 * We learned to talk to watchman to speed up "git status" and other
  66   operations that need to see which paths have been modified.
  67
  68 * The "diff" family of commands learned to ignore differences in
  69   carriage return at the end of line.
  70
  71 * Places that know about "sendemail.to", like documentation and shell
  72   completion (in contrib/) have been taught about "sendemail.tocmd",
  73   too.
  74
  75 * "git add --renormalize ." is a new and safer way to record the fact
  76   that you are correcting the end-of-line convention and other
  77   "convert_to_git()" glitches in the in-repository data.
  78
  79 * "git branch" and "git checkout -b" are now forbidden from creating
  80   a branch whose name is "HEAD".
  81
  82 * "git branch --list" learned to show its output through the pager by
  83   default when the output is going to a terminal, which is controlled
  84   by the pager.branch configuration variable.  This is similar to a
  85   recent change to "git tag --list".
  86
  87 * "git grep -W", "git diff -W" and their friends learned a heuristic
  88   to extend a pre-context beyond the line that matches the "function
  89   pattern" (aka "diff.*.xfuncname") to include a comment block, if
  90   exists, that immediately precedes it.
  91
  92 * "git config --expiry-date gc.reflogexpire" can read "2.weeks" from
  93   the configuration and report it as a timestamp, just like "--int"
  94   would read "1k" and report 1024, to help consumption by scripts.
  95
  96 * The shell completion (in contrib/) learned that "git pull" can take
  97   the "--autostash" option.
  98
  99 * The tagnames "git log --decorate" uses to annotate the commits can
 100   now be limited to subset of available refs with the two additional
 101   options, --decorate-refs[-exclude]=<pattern>.
 102
 103 * "git grep" compiled with libpcre2 sometimes triggered a segfault,
 104   which is being fixed.
 105
 106 * "git send-email" tries to see if the sendmail program is available
 107   in /usr/lib and /usr/sbin; extend the list of locations to be
 108   checked to also include directories on $PATH.
 109
 110 * "git diff" learned, "--anchored", a variant of the "--patience"
 111   algorithm, to which the user can specify which 'unique' line to be
 112   used as anchoring points.
 113
 114 * The way "git worktree add" determines what branch to create from
 115   where and checkout in the new worktree has been updated a bit.
 116
 117 * Ancient part of codebase still shows dots after an abbreviated
 118   object name just to show that it is not a full object name, but
 119   these ellipses are confusing to people who newly discovered Git
 120   who are used to seeing abbreviated object names and find them
 121   confusing with the range syntax.
 122
 123 * With a configuration variable rebase.abbreviateCommands set,
 124   "git rebase -i" produces the todo list with a single-letter
 125   command names.
 126
 127 * "git worktree add" learned to run the post-checkout hook, just like
 128   "git checkout" does, after the initial checkout.
 129
 130
 131Performance, Internal Implementation, Development Support etc.
 132
 133 * An earlier update made it possible to use an on-stack in-core
 134   lockfile structure (as opposed to having to deliberately leak an
 135   on-heap one).  Many codepaths have been updated to take advantage
 136   of this new facility.
 137
 138 * Calling cmd_foo() as if it is a general purpose helper function is
 139   a no-no.  Correct two instances of such to set an example.
 140
 141 * We try to see if somebody runs our test suite with a shell that
 142   does not support "local" like bash/dash does.
 143
 144 * An early part of piece-by-piece rewrite of "git bisect" in C.
 145
 146 * GSoC to piece-by-piece rewrite "git submodule" in C.
 147
 148 * Optimize the code to find shortest unique prefix of object names.
 149
 150 * Pathspec-limited revision traversal was taught not to keep finding
 151   unneeded differences once it knows two trees are different inside
 152   given pathspec.
 153
 154 * Conversion from uchar[20] to struct object_id continues.
 155
 156 * Code cleanup.
 157
 158 * A single-word "unsigned flags" in the diff options is being split
 159   into a structure with many bitfields.
 160
 161 * TravisCI build updates.
 162
 163 * Parts of a test to drive the long-running content filter interface
 164   has been split into its own module, hopefully to eventually become
 165   reusable.
 166
 167 * Drop (perhaps overly cautious) sanity check before using the index
 168   read from the filesystem at runtime.
 169
 170 * The build procedure has been taught to avoid some unnecessary
 171   instability in the build products.
 172
 173 * A new mechanism to upgrade the wire protocol in place is proposed
 174   and demonstrated that it works with the older versions of Git
 175   without harming them.
 176
 177 * An infrastructure to define what hash function is used in Git is
 178   introduced, and an effort to plumb that throughout various
 179   codepaths has been started.
 180
 181 * The code to iterate over loose object files got optimized.
 182
 183 * An internal function that was left for backward compatibility has
 184   been removed, as there is no remaining callers.
 185
 186 * Historically, the diff machinery for rename detection had a
 187   hardcoded limit of 32k paths; this is being lifted to allow users
 188   trade cycles with a (possibly) easier to read result.
 189
 190 * The tracing infrastructure has been optimized for cases where no
 191   tracing is requested.
 192
 193 * In preparation for implementing narrow/partial clone, the object
 194   walking machinery has been taught a way to tell it to "filter" some
 195   objects from enumeration.
 196
 197 * A few structures and variables that are implementation details of
 198   the decorate API have been renamed and then the API got documented
 199   better.
 200
 201 * Assorted updates for TravisCI integration.
 202   (merge 4f26366679 sg/travis-fixes later to maint).
 203
 204Also contains various documentation updates and code clean-ups.
 205
 206
 207Fixes since v2.15
 208-----------------
 209
 210 * "auto" as a value for the columnar output configuration ought to
 211   judge "is the output consumed by humans?" with the same criteria as
 212   "auto" for coloured output configuration, i.e. either the standard
 213   output stream is going to tty, or a pager is in use.  We forgot the
 214   latter, which has been fixed.
 215
 216 * The experimental "color moved lines differently in diff output"
 217   feature was buggy around "ignore whitespace changes" edges, which
 218   has been corrected.
 219
 220 * Instead of using custom line comparison and hashing functions to
 221   implement "moved lines" coloring in the diff output, use the pair
 222   of these functions from lower-layer xdiff/ code.
 223
 224 * Some codepaths did not check for errors when asking what branch the
 225   HEAD points at, which have been fixed.
 226
 227 * "git commit", after making a commit, did not check for errors when
 228   asking on what branch it made the commit, which has been corrected.
 229
 230 * "git status --ignored -u" did not stop at a working tree of a
 231   separate project that is embedded in an ignored directory and
 232   listed files in that other project, instead of just showing the
 233   directory itself as ignored.
 234
 235 * A broken access to object databases in recent update to "git grep
 236   --recurse-submodules" has been fixed.
 237
 238 * A recent regression in "git rebase -i" that broke execution of git
 239   commands from subdirectories via "exec" instruction has been fixed.
 240
 241 * A (possibly flakey) test fix.
 242
 243 * "git check-ref-format --branch @{-1}" bit a "BUG()" when run
 244   outside a repository for obvious reasons; clarify the documentation
 245   and make sure we do not even try to expand the at-mark magic in
 246   such a case, but still call the validation logic for branch names.
 247
 248 * "git fetch --recurse-submodules" now knows that submodules can be
 249   moved around in the superproject in addition to getting updated,
 250   and finds the ones that need to be fetched accordingly.
 251
 252 * Command line completion (in contrib/) update.
 253
 254 * Description of blame.{showroot,blankboundary,showemail,date}
 255   configuration variables have been added to "git config --help".
 256
 257 * After an error from lstat(), diff_populate_filespec() function
 258   sometimes still went ahead and used invalid data in struct stat,
 259   which has been fixed.
 260
 261 * UNC paths are also relevant in Cygwin builds and they are now
 262   tested just like Mingw builds.
 263
 264 * Correct start-up sequence so that a repository could be placed
 265   immediately under the root directory again (which was broken at
 266   around Git 2.13).
 267
 268 * The credential helper for libsecret (in contrib/) has been improved
 269   to allow possibly prompting the end user to unlock secrets that are
 270   currently locked (otherwise the secrets may not be loaded).
 271
 272 * MinGW updates.
 273
 274 * Error checking in "git imap-send" for empty response has been
 275   improved.
 276
 277 * Recent update to the refs infrastructure implementation started
 278   rewriting packed-refs file more often than before; this has been
 279   optimized again for most trivial cases.
 280
 281 * Some error messages did not quote filenames shown in it, which have
 282   been fixed.
 283
 284 * "git rebase -i" recently started misbehaving when a submodule that
 285   is configured with 'submodule.<name>.ignore' is dirty; this has
 286   been corrected.
 287
 288 * Building with NO_LIBPCRE1_JIT did not disable it, which has been fixed.
 289
 290 * We used to add an empty alternate object database to the system
 291   that does not help anything; it has been corrected.
 292
 293 * Doc update around use of "format-patch --subject-prefix" etc.
 294
 295 * A fix for an ancient bug in "git apply --ignore-space-change" codepath.
 296
 297 * Clarify and enhance documentation for "merge-base --fork-point", as
 298   it was clear what it computed but not why/what for.
 299
 300 * A few scripts (both in production and tests) incorrectly redirected
 301   their error output.  These have been corrected.
 302
 303 * "git notes" sent its error message to its standard output stream,
 304   which was corrected.
 305
 306 * The three-way merge performed by "git cherry-pick" was confused
 307   when a new submodule was added in the meantime, which has been
 308   fixed (or "papered over").
 309
 310 * The sequencer machinery (used by "git cherry-pick A..B", and "git
 311   rebase -i", among other things) would have lost a commit if stopped
 312   due to an unlockable index file, which has been fixed.
 313
 314 * "git apply --inaccurate-eof" when used with "--ignore-space-change"
 315   triggered an internal sanity check, which has been fixed.
 316
 317 * Command line completion (in contrib/) has been taught about the
 318   "--copy" option of "git branch".
 319
 320 * When "git rebase" prepared an mailbox of changes and fed it to "git
 321   am" to replay them, it was confused when a stray "From " happened
 322   to be in the log message of one of the replayed changes.  This has
 323   been corrected.
 324
 325 * There was a recent semantic mismerge in the codepath to write out a
 326   section of a configuration section, which has been corrected.
 327
 328 * Mentions of "git-rebase" and "git-am" (dashed form) still remained
 329   in end-user visible strings emitted by the "git rebase" command;
 330   they have been corrected.
 331
 332 * Contrary to the documentation, "git pull -4/-6 other-args" did not
 333   ask the underlying "git fetch" to go over IPv4/IPv6, which has been
 334   corrected.
 335
 336 * "git checkout --recursive" may overwrite and rewind the history of
 337   the branch that happens to be checked out in submodule
 338   repositories, which might not be desirable.  Detach the HEAD but
 339   still allow the recursive checkout to succeed in such a case.
 340   (merge 57f22bf997 sb/submodule-recursive-checkout-detach-head later to maint).
 341
 342 * "git branch --set-upstream" has been deprecated and (sort of)
 343   removed, as "--set-upstream-to" is the preferred one these days.
 344   The documentation still had "--set-upstream" listed on its
 345   synopsis section, which has been corrected.
 346   (merge a060f3d3d8 tz/branch-doc-remove-set-upstream later to maint).
 347
 348 * Internally we use 0{40} as a placeholder object name to signal the
 349   codepath that there is no such object (e.g. the fast-forward check
 350   while "git fetch" stores a new remote-tracking ref says "we know
 351   there is no 'old' thing pointed at by the ref, as we are creating
 352   it anew" by passing 0{40} for the 'old' side), and expect that a
 353   codepath to locate an in-core object to return NULL as a sign that
 354   the object does not exist.  A look-up for an object that does not
 355   exist however is quite costly with a repository with large number
 356   of packfiles.  This access pattern has been optimized.
 357   (merge 87b5e236a1 jk/fewer-pack-rescan later to maint).
 358
 359 * In addition to "git stash -m message", the command learned to
 360   accept "git stash -mmessage" form.
 361   (merge 5675473fcb ph/stash-save-m-option-fix later to maint).
 362
 363 * @{-N} in "git checkout @{-N}" may refer to a detached HEAD state,
 364   but the documentation was not clear about it, which has been fixed.
 365   (merge 75ce149575 ks/doc-checkout-previous later to maint).
 366
 367 * A regression in the progress eye-candy was fixed.
 368   (merge 9c5951cacf jk/progress-delay-fix later to maint).
 369
 370 * The code internal to the recursive merge strategy was not fully
 371   prepared to see a path that is renamed to try overwriting another
 372   path that is only different in case on case insensitive systems.
 373   This does not matter in the current code, but will start to matter
 374   once the rename detection logic starts taking hints from nearby
 375   paths moving to some directory and moves a new path along with them.
 376   (merge 4cba2b0108 en/merge-recursive-icase-removal later to maint).
 377
 378 * An v2.12-era regression in pathspec match logic, which made it look
 379   into submodule tree even when it is not desired, has been fixed.
 380   (merge eef3df5a93 bw/pathspec-match-submodule-boundary later to maint).
 381
 382 * Amending commits in git-gui broke the author name that is non-ascii
 383   due to incorrect enconding conversion.
 384
 385 * Recent update to the submodule configuration code broke "diff-tree"
 386   by accidentally stopping to read from the index upfront.
 387   (merge fd66bcc31f bw/submodule-config-cleanup later to maint).
 388
 389 * Git shows a message to tell the user that it is waiting for the
 390   user to finish editing when spawning an editor, in case the editor
 391   opens to a hidden window or somewhere obscure and the user gets
 392   lost.
 393   (merge abfb04d0c7 ls/editor-waiting-message later to maint).
 394
 395 * The "safe crlf" check incorrectly triggered for contents that does
 396   not use CRLF as line endings, which has been corrected.
 397   (merge 649f1f0948 tb/check-crlf-for-safe-crlf later to maint).
 398
 399 * "git clone --shared" to borrow from a (secondary) worktree did not
 400   work, even though "git clone --local" did.  Both are now accepted.
 401   (merge b3b05971c1 es/clone-shared-worktree later to maint).
 402
 403 * The build procedure now allows not just the repositories but also
 404   the refs to be used to take pre-formatted manpages and html
 405   documents to install.
 406   (merge 65289e9dcd rb/quick-install-doc later to maint).
 407
 408 * Other minor doc, test and build updates and code cleanups.
 409   (merge 1a1fc2d5b5 rd/man-prune-progress later to maint).
 410   (merge 0ba014035a rd/man-reflog-add-n later to maint).
 411   (merge e54b63359f rd/doc-notes-prune-fix later to maint).
 412   (merge ff4c9b413a sp/doc-info-attributes later to maint).
 413   (merge 7db2cbf4f1 jc/receive-pack-hook-doc later to maint).
 414   (merge 5a0526264b tg/t-readme-updates later to maint).
 415   (merge 5e83cca0b8 jk/no-optional-locks later to maint).
 416   (merge 826c778f7c js/hashmap-update-sample later to maint).
 417   (merge 176b2d328c sg/setup-doc-update later to maint).
 418   (merge 1b09073514 rs/am-builtin-leakfix later to maint).
 419   (merge addcf6cfde rs/fmt-merge-msg-string-leak-fix later to maint).
 420   (merge c3ff8f6c14 rs/strbuf-read-once-reset-length later to maint).
 421   (merge 6b0eb884f9 db/doc-workflows-neuter-the-maintainer later to maint).
 422   (merge 8c87bdfb21 jk/cvsimport-quoting later to maint).
 423   (merge 176cb979fe rs/fmt-merge-msg-leakfix later to maint).
 424   (merge 5a03360e73 tb/delimit-pretty-trailers-args-with-comma later to maint).
 425   (merge d0e6326026 ot/pretty later to maint).
 426   (merge 44103f4197 sb/test-helper-excludes later to maint).
 427   (merge 170078693f jt/transport-no-more-rsync later to maint).