Documentation/RelNotes/2.15.0.txt

   1 Git 2.15 Release Notes
   2 ======================
   3
   4 Backward 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 now scheduled to happen in Git v2.16,
  12    the next major release after this one.
  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 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  * "branch --set-upstream" that has been deprecated in Git 1.8 has
  22    finally been retired.
  23
  24
  25 Updates since v2.14
  26 -------------------
  27
  28 UI, Workflows & Features
  29
  30  * An example that is now obsolete has been removed from a sample hook,
  31    and an old example in it that added a sign-off manually has been
  32    improved to use the interpret-trailers command.
  33
  34  * The advice message given when "git rebase" stops for conflicting
  35    changes has been improved.
  36
  37  * The "rerere-train" script (in contrib/) learned the "--overwrite"
  38    option to allow overwriting existing recorded resolutions.
  39
  40  * "git contacts" (in contrib/) now lists the address on the
  41    "Reported-by:" trailer to its output, in addition to those on
  42    S-o-b: and other trailers, to make it easier to notify (and thank)
  43    the original bug reporter.
  44
  45  * "git rebase", especially when it is run by mistake and ends up
  46    trying to replay many changes, spent long time in silence.  The
  47    command has been taught to show progress report when it spends
  48    long time preparing these many changes to replay (which would give
  49    the user a chance to abort with ^C).
  50
  51  * "git merge" learned a "--signoff" option to add the Signed-off-by:
  52    trailer with the committer's name.
  53
  54  * "git diff" learned to optionally paint new lines that are the same
  55    as deleted lines elsewhere differently from genuinely new lines.
  56
  57  * "git interpret-trailers" learned to take the trailer specifications
  58    from the command line that overrides the configured values.
  59
  60  * "git interpret-trailers" has been taught a "--parse" and a few
  61    other options to make it easier for scripts to grab existing
  62    trailer lines from a commit log message.
  63
  64  * The "--format=%(trailers)" option "git log" and its friends take
  65    learned to take the 'unfold' and 'only' modifiers to normalize its
  66    output, e.g. "git log --format=%(trailers:only,unfold)".
  67
  68  * "gitweb" shows a link to visit the 'raw' contents of blobs in the
  69    history overview page.
  70
  71  * "[gc] rerereResolved = 5.days" used to be invalid, as the variable
  72    is defined to take an integer counting the number of days.  It now
  73    is allowed.
  74
  75  * The code to acquire a lock on a reference (e.g. while accepting a
  76    push from a client) used to immediately fail when the reference is
  77    already locked---now it waits for a very short while and retries,
  78    which can make it succeed if the lock holder was holding it during
  79    a read-only operation.
  80
  81  * "branch --set-upstream" that has been deprecated in Git 1.8 has
  82    finally been retired.
  83
  84  * The codepath to call external process filter for smudge/clean
  85    operation learned to show the progress meter.
  86
  87  * "git rev-parse" learned "--is-shallow-repository", that is to be
  88    used in a way similar to existing "--is-bare-repository" and
  89    friends.
  90
  91  * "git describe --match <pattern>" has been taught to play well with
  92    the "--all" option.
  93
  94  * "git branch" learned "-c/-C" to create a new branch by copying an
  95    existing one.
  96
  97  * Some commands (most notably "git status") makes an opportunistic
  98    update when performing a read-only operation to help optimize later
  99    operations in the same repository.  The new "--no-optional-locks"
 100    option can be passed to Git to disable them.
 101
 102  * "git for-each-ref --format=..." learned a new format element,
 103    %(trailers), to show only the commit log trailer part of the log
 104    message.
 105
 106
 107 Performance, Internal Implementation, Development Support etc.
 108
 109  * Conversion from uchar[20] to struct object_id continues.
 110
 111  * Start using selected c99 constructs in small, stable and
 112    essential part of the system to catch people who care about
 113    older compilers that do not grok them.
 114
 115  * The filter-process interface learned to allow a process with long
 116    latency give a "delayed" response.
 117
 118  * Many uses of comparison callback function the hashmap API uses
 119    cast the callback function type when registering it to
 120    hashmap_init(), which defeats the compile time type checking when
 121    the callback interface changes (e.g. gaining more parameters).
 122    The callback implementations have been updated to take "void *"
 123    pointers and cast them to the type they expect instead.
 124
 125  * Because recent Git for Windows do come with a real msgfmt, the
 126    build procedure for git-gui has been updated to use it instead of a
 127    hand-rolled substitute.
 128
 129  * "git grep --recurse-submodules" has been reworked to give a more
 130    consistent output across submodule boundary (and do its thing
 131    without having to fork a separate process).
 132
 133  * A helper function to read a single whole line into strbuf
 134    mistakenly triggered OOM error at EOF under certain conditions,
 135    which has been fixed.
 136
 137  * The "ref-store" code reorganization continues.
 138
 139  * "git commit" used to discard the index and re-read from the filesystem
 140    just in case the pre-commit hook has updated it in the middle; this
 141    has been optimized out when we know we do not run the pre-commit hook.
 142    (merge 680ee550d7 kw/commit-keep-index-when-pre-commit-is-not-run later to maint).
 143
 144  * Updates to the HTTP layer we made recently unconditionally used
 145    features of libCurl without checking the existence of them, causing
 146    compilation errors, which has been fixed.  Also migrate the code to
 147    check feature macros, not version numbers, to cope better with
 148    libCurl that vendor ships with backported features.
 149
 150  * The API to start showing progress meter after a short delay has
 151    been simplified.
 152    (merge 8aade107dd jc/simplify-progress later to maint).
 153
 154  * Code clean-up to avoid mixing values read from the .gitmodules file
 155    and values read from the .git/config file.
 156
 157  * We used to spend more than necessary cycles allocating and freeing
 158    piece of memory while writing each index entry out.  This has been
 159    optimized.
 160
 161  * Platforms that ship with a separate sha1 with collision detection
 162    library can link to it instead of using the copy we ship as part of
 163    our source tree.
 164
 165  * Code around "notes" have been cleaned up.
 166    (merge 3964281524 mh/notes-cleanup later to maint).
 167
 168  * The long-standing rule that an in-core lockfile instance, once it
 169    is used, must not be freed, has been lifted and the lockfile and
 170    tempfile APIs have been updated to reduce the chance of programming
 171    errors.
 172
 173  * Our hashmap implementation in hashmap.[ch] is not thread-safe when
 174    adding a new item needs to expand the hashtable by rehashing; add
 175    an API to disable the automatic rehashing to work it around.
 176
 177  * Many of our programs consider that it is OK to release dynamic
 178    storage that is used throughout the life of the program by simply
 179    exiting, but this makes it harder to leak detection tools to avoid
 180    reporting false positives.  Plug many existing leaks and introduce
 181    a mechanism for developers to mark that the region of memory
 182    pointed by a pointer is not lost/leaking to help these tools.
 183
 184  * As "git commit" to conclude a conflicted "git merge" honors the
 185    commit-msg hook, "git merge" that records a merge commit that
 186    cleanly auto-merges should, but it didn't.
 187
 188  * The codepath for "git merge-recursive" has been cleaned up.
 189
 190  * Many leaks of strbuf have been fixed.
 191
 192  * "git imap-send" has our own implementation of the protocol and also
 193    can use more recent libCurl with the imap protocol support.  Update
 194    the latter so that it can use the credential subsystem, and then
 195    make it the default option to use, so that we can eventually
 196    deprecate and remove the former.
 197
 198  * "make style" runs git-clang-format to help developers by pointing
 199    out coding style issues.
 200
 201  * A test to demonstrate "git mv" failing to adjust nested submodules
 202    has been added.
 203    (merge c514167df2 hv/mv-nested-submodules-test later to maint).
 204
 205  * On Cygwin, "ulimit -s" does not report failure but it does not work
 206    at all, which causes an unexpected success of some tests that
 207    expect failures under a limited stack situation.  This has been
 208    fixed.
 209
 210  * Many codepaths have been updated to squelch -Wimplicit-fallthrough
 211    warnings from Gcc 7 (which is a good code hygiene).
 212
 213  * Add a helper for DLL loading in anticipation for its need in a
 214    future topic RSN.
 215
 216  * "git status --ignored", when noticing that a directory without any
 217    tracked path is ignored, still enumerated all the ignored paths in
 218    the directory, which is unnecessary.  The codepath has been
 219    optimized to avoid this overhead.
 220
 221  * The final batch to "git rebase -i" updates to move more code from
 222    the shell script to C has been merged.
 223
 224  * Operations that do not touch (majority of) packed refs have been
 225    optimized by making accesses to packed-refs file lazy; we no longer
 226    pre-parse everything, and an access to a single ref in the
 227    packed-refs does not touch majority of irrelevant refs, either.
 228
 229  * Add comment to clarify that the style file is meant to be used with
 230    clang-5 and the rules are still work in progress.
 231
 232  * Many variables that points at a region of memory that will live
 233    throughout the life of the program have been marked with UNLEAK
 234    marker to help the leak checkers concentrate on real leaks..
 235
 236  * Plans for weaning us off of SHA-1 has been documented.
 237
 238  * A new "oidmap" API has been introduced and oidset API has been
 239    rewritten to use it.
 240
 241
 242 Also contains various documentation updates and code clean-ups.
 243
 244
 245 Fixes since v2.14
 246 -----------------
 247
 248  * "%C(color name)" in the pretty print format always produced ANSI
 249    color escape codes, which was an early design mistake.  They now
 250    honor the configuration (e.g. "color.ui = never") and also tty-ness
 251    of the output medium.
 252
 253  * The http.{sslkey,sslCert} configuration variables are to be
 254    interpreted as a pathname that honors "~[username]/" prefix, but
 255    weren't, which has been fixed.
 256
 257  * Numerous bugs in walking of reflogs via "log -g" and friends have
 258    been fixed.
 259
 260  * "git commit" when seeing an totally empty message said "you did not
 261    edit the message", which is clearly wrong.  The message has been
 262    corrected.
 263
 264  * When a directory is not readable, "gitweb" fails to build the
 265    project list.  Work this around by skipping such a directory.
 266
 267  * Some versions of GnuPG fails to kill gpg-agent it auto-spawned
 268    and such a left-over agent can interfere with a test.  Work it
 269    around by attempting to kill one before starting a new test.
 270
 271  * A recently added test for the "credential-cache" helper revealed
 272    that EOF detection done around the time the connection to the cache
 273    daemon is torn down were flaky.  This was fixed by reacting to
 274    ECONNRESET and behaving as if we got an EOF.
 275
 276  * "git log --tag=no-such-tag" showed log starting from HEAD, which
 277    has been fixed---it now shows nothing.
 278
 279  * The "tag.pager" configuration variable was useless for those who
 280    actually create tag objects, as it interfered with the use of an
 281    editor.  A new mechanism has been introduced for commands to enable
 282    pager depending on what operation is being carried out to fix this,
 283    and then "git tag -l" is made to run pager by default.
 284
 285  * "git push --recurse-submodules $there HEAD:$target" was not
 286    propagated down to the submodules, but now it is.
 287
 288  * Commands like "git rebase" accepted the --rerere-autoupdate option
 289    from the command line, but did not always use it.  This has been
 290    fixed.
 291
 292  * "git clone --recurse-submodules --quiet" did not pass the quiet
 293    option down to submodules.
 294
 295  * Test portability fix for OBSD.
 296
 297  * Portability fix for OBSD.
 298
 299  * "git am -s" has been taught that some input may end with a trailer
 300    block that is not Signed-off-by: and it should refrain from adding
 301    an extra blank line before adding a new sign-off in such a case.
 302
 303  * "git svn" used with "--localtime" option did not compute the tz
 304    offset for the timestamp in question and instead always used the
 305    current time, which has been corrected.
 306
 307  * Memory leak in an error codepath has been plugged.
 308
 309  * "git stash -u" used the contents of the committed version of the
 310    ".gitignore" file to decide which paths are ignored, even when the
 311    file has local changes.  The command has been taught to instead use
 312    the locally modified contents.
 313
 314  * bash 4.4 or newer gave a warning on NUL byte in command
 315    substitution done in "git stash"; this has been squelched.
 316
 317  * "git grep -L" and "git grep --quiet -L" reported different exit
 318    codes; this has been corrected.
 319
 320  * When handshake with a subprocess filter notices that the process
 321    asked for an unknown capability, Git did not report what program
 322    the offending subprocess was running.  This has been corrected.
 323
 324  * "git apply" that is used as a better "patch -p1" failed to apply a
 325    taken from a file with CRLF line endings to a file with CRLF line
 326    endings.  The root cause was because it misused convert_to_git()
 327    that tried to do "safe-crlf" processing by looking at the index
 328    entry at the same path, which is a nonsense---in that mode, "apply"
 329    is not working on the data in (or derived from) the index at all.
 330    This has been fixed.
 331
 332  * Killing "git merge --edit" before the editor returns control left
 333    the repository in a state with MERGE_MSG but without MERGE_HEAD,
 334    which incorrectly tells the subsequent "git commit" that there was
 335    a squash merge in progress.  This has been fixed.
 336
 337  * "git archive" did not work well with pathspecs and the
 338    export-ignore attribute.
 339
 340  * In addition to "cc: <a@dd.re.ss> # cruft", "cc: a@dd.re.ss # cruft"
 341    was taught to "git send-email" as a valid way to tell it that it
 342    needs to also send a carbon copy to <a@dd.re.ss> in the trailer
 343    section.
 344
 345  * "git branch -M a b" while on a branch that is completely unrelated
 346    to either branch a or branch b misbehaved when multiple worktree
 347    was in use.  This has been fixed.
 348    (merge 31824d180d nd/worktree-kill-parse-ref later to maint).
 349
 350  * "git gc" and friends when multiple worktrees are used off of a
 351    single repository did not consider the index and per-worktree refs
 352    of other worktrees as the root for reachability traversal, making
 353    objects that are in use only in other worktrees to be subject to
 354    garbage collection.
 355
 356  * A regression to "gitk --bisect" by a recent update has been fixed.
 357
 358  * "git -c submodule.recurse=yes pull" did not work as if the
 359    "--recurse-submodules" option was given from the command line.
 360    This has been corrected.
 361
 362  * Unlike "git commit-tree < file", "git commit-tree -F file" did not
 363    pass the contents of the file verbatim and instead completed an
 364    incomplete line at the end, if exists.  The latter has been updated
 365    to match the behaviour of the former.
 366
 367  * Many codepaths did not diagnose write failures correctly when disks
 368    go full, due to their misuse of write_in_full() helper function,
 369    which have been corrected.
 370    (merge f48ecd38cb jk/write-in-full-fix later to maint).
 371
 372  * "git help co" now says "co is aliased to ...", not "git co is".
 373    (merge b3a8076e0d ks/help-alias-label later to maint).
 374
 375  * "git archive", especially when used with pathspec, stored an empty
 376    directory in its output, even though Git itself never does so.
 377    This has been fixed.
 378
 379  * API error-proofing which happens to also squelch warnings from GCC.
 380
 381  * The explanation of the cut-line in the commit log editor has been
 382    slightly tweaked.
 383    (merge 8c4b1a3593 ks/commit-do-not-touch-cut-line later to maint).
 384
 385  * "git gc" tries to avoid running two instances at the same time by
 386    reading and writing pid/host from and to a lock file; it used to
 387    use an incorrect fscanf() format when reading, which has been
 388    corrected.
 389
 390  * The scripts to drive TravisCI has been reorganized and then an
 391    optimization to avoid spending cycles on a branch whose tip is
 392    tagged has been implemented.
 393    (merge 8376eb4a8f ls/travis-scriptify later to maint).
 394
 395  * The test linter has been taught that we do not like "echo -e".
 396
 397  * Code cmp.std.c nitpick.
 398
 399  * A regression fix for 2.11 that made the code to read the list of
 400    alternate object stores overrun the end of the string.
 401    (merge f0f7bebef7 jk/info-alternates-fix later to maint).
 402
 403  * "git describe --match" learned to take multiple patterns in v2.13
 404    series, but the feature ignored the patterns after the first one
 405    and did not work at all.  This has been fixed.
 406
 407  * "git filter-branch" cannot reproduce a history with a tag without
 408    the tagger field, which only ancient versions of Git allowed to be
 409    created.  This has been corrected.
 410    (merge b2c1ca6b4b ic/fix-filter-branch-to-handle-tag-without-tagger later to maint).
 411
 412  * "git cat-file --textconv" started segfaulting recently, which
 413    has been corrected.
 414
 415  * The built-in pattern to detect the "function header" for HTML did
 416    not match <H1>..<H6> elements without any attributes, which has
 417    been fixed.
 418
 419  * "git mailinfo" was loose in decoding quoted printable and produced
 420    garbage when the two letters after the equal sign are not
 421    hexadecimal.  This has been fixed.
 422
 423  * The machinery to create xdelta used in pack files received the
 424    sizes of the data in size_t, but lost the higher bits of them by
 425    storing them in "unsigned int" during the computation, which is
 426    fixed.
 427
 428  * The delta format used in the packfile cannot reference data at
 429    offset larger than what can be expressed in 4-byte, but the
 430    generator for the data failed to make sure the offset does not
 431    overflow.  This has been corrected.
 432
 433  * The documentation for '-X<option>' for merges was misleadingly
 434    written to suggest that "-s theirs" exists, which is not the case.
 435
 436  * "git fast-export" with -M/-C option issued "copy" instruction on a
 437    path that is simultaneously modified, which was incorrect.
 438    (merge b3e8ca89cf jt/fast-export-copy-modify-fix later to maint).
 439
 440  * Many codepaths have been updated to squelch -Wsign-compare
 441    warnings.
 442    (merge 071bcaab64 rj/no-sign-compare later to maint).
 443
 444  * Memory leaks in various codepaths have been plugged.
 445    (merge 4d01a7fa65 ma/leakplugs later to maint).
 446
 447  * Recent versions of "git rev-parse --parseopt" did not parse the
 448    option specification that does not have the optional flags (*=?!)
 449    correctly, which has been corrected.
 450    (merge a6304fa4c2 bc/rev-parse-parseopt-fix later to maint).
 451
 452  * The checkpoint command "git fast-import" did not flush updates to
 453    refs and marks unless at least one object was created since the
 454    last checkpoint, which has been corrected, as these things can
 455    happen without any new object getting created.
 456    (merge 30e215a65c er/fast-import-dump-refs-on-checkpoint later to maint).
 457
 458  * Spell the name of our system as "Git" in the output from
 459    request-pull script.
 460
 461  * Fixes for a handful memory access issues identified by valgrind.
 462
 463  * Backports a moral equivalent of 2015 fix to the poll() emulation
 464    from the upstream gnulib to fix occasional breakages on HPE NonStop.
 465
 466  * Users with "color.ui = always" in their configuration were broken
 467    by a recent change that made plumbing commands to pay attention to
 468    them as the patch created internally by "git add -p" were colored
 469    (heh) and made unusable.  This has been fixed by reverting the
 470    offending change.
 471
 472  * In the "--format=..." option of the "git for-each-ref" command (and
 473    its friends, i.e. the listing mode of "git branch/tag"), "%(atom:)"
 474    (e.g. "%(refname:)", "%(body:)" used to error out.  Instead, treat
 475    them as if the colon and an empty string that follows it were not
 476    there.
 477
 478  * An ancient bug that made Git misbehave with creation/renaming of
 479    refs has been fixed.
 480
 481  * "git fetch <there> <src>:<dst>" allows an object name on the <src>
 482    side when the other side accepts such a request since Git v2.5, but
 483    the documentation was left stale.
 484    (merge 83558a412a jc/fetch-refspec-doc-update later to maint).
 485
 486  * Update the documentation for "git filter-branch" so that the filter
 487    options are listed in the same order as they are applied, as
 488    described in an earlier part of the doc.
 489    (merge 07c4984508 dg/filter-branch-filter-order-doc later to maint).
 490
 491  * A possible oom error is now caught as a fatal error, instead of
 492    continuing and dereferencing NULL.
 493    (merge 55d7d15847 ao/path-use-xmalloc later to maint).
 494
 495  * Other minor doc, test and build updates and code cleanups.
 496    (merge f094b89a4d ma/parse-maybe-bool later to maint).
 497    (merge 6cdf8a7929 ma/ts-cleanups later to maint).
 498    (merge 7560f547e6 ma/up-to-date later to maint).
 499    (merge 0db3dc75f3 rs/apply-epoch later to maint).
 500    (merge 276d0e35c0 ma/split-symref-update-fix later to maint).
 501    (merge f777623514 ks/branch-tweak-error-message-for-extra-args later to maint).
 502    (merge 33f3c683ec ks/verify-filename-non-option-error-message-tweak later to maint).
 503    (merge 7cbbf9d6a2 ls/filter-process-delayed later to maint).
 504    (merge 488aa65c8f wk/merge-options-gpg-sign-doc later to maint).
 505    (merge e61cb19a27 jc/branch-force-doc-readability-fix later to maint).
 506    (merge 32fceba3fd np/config-path-doc later to maint).
 507    (merge e38c681fb7 sb/rev-parse-show-superproject-root later to maint).
 508    (merge 4f851dc883 sg/rev-list-doc-reorder-fix later to maint).