Documentation/RelNotes/2.2.0.txt

   1 Git v2.2 Release Notes
   2 ======================
   3
   4 Updates since v2.1
   5 ------------------
   6
   7 Ports
   8
   9  * Building on older MacOS X systems automatically sets
  10    the necessary NO_APPLE_COMMON_CRYPTO build-time option.
  11
  12  * Building with NO_PTHREADS has been resurrected.
  13
  14  * Compilation options have been updated a bit to better support the
  15    z/OS port.
  16
  17
  18 UI, Workflows & Features
  19
  20  * "git archive" learned to filter what gets archived with a pathspec.
  21
  22  * "git config --edit --global" starts from a skeletal per-user
  23    configuration file contents, instead of a total blank, when the
  24    user does not already have any global config.  This immediately
  25    reduces the need to later ask "Have you forgotten to set
  26    core.user?", and we can add more to the template as we gain
  27    more experience.
  28
  29  * "git stash list -p" used to be almost always a no-op because each
  30    stash entry is represented as a merge commit.  It learned to show
  31    the difference between the base commit version and the working tree
  32    version, which is in line with what "git stash show" gives.
  33
  34  * Sometimes users want to report a bug they experience on their
  35    repository, but they are not at liberty to share the contents of
  36    the repository.  "fast-export" was taught an "--anonymize" option
  37    to replace blob contents, names of people, paths and log
  38    messages with bland and simple strings to help them.
  39
  40  * "git difftool" learned an option to stop feeding paths to the
  41    diff backend when it exits with a non-zero status.
  42
  43  * "git grep" learned to paint (or not paint) partial matches on
  44    context lines when showing "grep -C<num>" output in color.
  45
  46  * "log --date=iso" uses a slight variant of the ISO 8601 format that is
  47    more human readable.  A new "--date=iso-strict" option gives
  48    datetime output that conforms more strictly.
  49
  50  * The logic "git prune" uses is more resilient against various corner
  51    cases.
  52
  53  * A broken reimplementation of Git could write an invalid index that
  54    records both stage #0 and higher-stage entries for the same path.
  55    We now notice and reject such an index, as there is no sensible
  56    fallback (we do not know if the broken tool wanted to resolve and
  57    forgot to remove the higher-stage entries, or if it wanted to unresolve
  58    and forgot to remove the stage #0 entry).
  59
  60  * The temporary files "git mergetool" uses are renamed to avoid too
  61    many dots in them (e.g. a temporary file for "hello.c" used to be
  62    named e.g. "hello.BASE.4321.c" but now uses underscore instead,
  63    e.g. "hello_BASE_4321.c", to allow us to have multiple variants).
  64
  65  * The temporary files "git mergetool" uses can be placed in a newly
  66    created temporary directory, instead of the current directory, by
  67    setting the mergetool.writeToTemp configuration variable.
  68
  69  * "git mergetool" understands "--tool bc" now, as version 4 of
  70    BeyondCompare can be driven the same way as its version 3 and it
  71    feels awkward to say "--tool bc3" to run version 4.
  72
  73  * The "pre-receive" and "post-receive" hooks are no longer required
  74    to consume their input fully (not following this requirement used
  75    to result in intermittent errors in "git push").
  76
  77  * The pretty-format specifier "%d", which expands to " (tagname)"
  78    for a tagged commit, gained a cousin "%D" that just gives the
  79    "tagname" without frills.
  80
  81  * "git push" learned "--signed" push, that allows a push (i.e.
  82    request to update the refs on the other side to point at a new
  83    history, together with the transmission of necessary objects) to be
  84    signed, so that it can be verified and audited, using the GPG
  85    signature of the person who pushed, that the tips of branches at a
  86    public repository really point the commits the pusher wanted to,
  87    without having to "trust" the server.
  88
  89  * "git interpret-trailers" is a new filter to programmatically edit
  90    the tail end of the commit log messages, e.g. "Signed-off-by:".
  91
  92  * "git help everyday" shows the "Everyday Git in 20 commands or so"
  93    document, whose contents have been updated to match more modern
  94    Git practice.
  95
  96  * On the "git svn" front, work progresses to reduce memory consumption and
  97    to improve handling of mergeinfo.
  98
  99
 100 Performance, Internal Implementation, Development Support etc.
 101
 102  * The API to manipulate the "refs" has been restructured to make it
 103    more transactional, with the eventual goal to allow all-or-none
 104    atomic updates and migrating the storage to something other than
 105    the traditional filesystem based one (e.g. databases).
 106
 107  * The lockfile API and its users have been cleaned up.
 108
 109  * We no longer attempt to keep track of individual dependencies to
 110    the header files in the build procedure, relying instead on automated
 111    dependency generation support from modern compilers.
 112
 113  * In tests, we have been using NOT_{MINGW,CYGWIN} test prerequisites
 114    long before negated prerequisites e.g. !MINGW were invented.
 115    The former has been converted to the latter to avoid confusion.
 116
 117  * Optimized looking up a remote's configuration in a repository with very many
 118    remotes defined.
 119
 120  * There are cases where you lock and open to write a file, close it
 121    to show the updated contents to an external processes, and then have
 122    to update the file again while still holding the lock; now the
 123    lockfile API has support for such an access pattern.
 124
 125  * The API to allocate the structure to keep track of commit
 126    decoration has been updated to make it less cumbersome to use.
 127
 128  * An in-core caching layer to let us avoid reading the same
 129    configuration files several times has been added.  A few commands
 130    have been converted to use this subsystem.
 131
 132  * Various code paths have been cleaned up and simplified by using
 133    the "strbuf", "starts_with()", and "skip_prefix()" APIs more.
 134
 135  * A few codepaths that died when large blobs that would not fit in
 136    core are involved in their operation have been taught to punt
 137    instead, by e.g. marking a too-large blob as not to be diffed.
 138
 139  * A few more code paths in "commit" and "checkout" have been taught
 140    to repopulate the cache-tree in the index, to help speed up later
 141    "write-tree" (used in "commit") and "diff-index --cached" (used in
 142    "status").
 143
 144  * A common programming mistake to assign the same short option name
 145    to two separate options is detected by the parse_options() API to help
 146    developers.
 147
 148  * The code path to write out the packed-refs file has been optimized,
 149    which especially matters in a repository with a large number of
 150    refs.
 151
 152  * The check to see if a ref $F can be created by making sure no
 153    existing ref has $F/ as its prefix has been optimized, which
 154    especially matters in a repository with a large number of existing
 155    refs.
 156
 157  * "git fsck" was taught to check the contents of tag objects a bit more.
 158
 159  * "git hash-object" was taught a "--literally" option to help
 160    debugging.
 161
 162  * When running a required clean filter, we do not have to mmap the
 163    original before feeding the filter.  Instead, stream the file
 164    contents directly to the filter and process its output.
 165
 166  * The scripts in the test suite can be run with the "-x" option to show
 167    a shell-trace of each command they run.
 168
 169  * The "run-command" API learned to manage the argv and environment
 170    arrays for child process, alleviating the need for the callers to
 171    allocate and deallocate them.
 172
 173  * Some people use AsciiDoctor, instead of AsciiDoc, to format our
 174    documentation set; the documentation has been adjusted to be usable
 175    by both, as AsciiDoctor is pickier than AsciiDoc about its input
 176    mark-up.
 177
 178
 179 Also contains various documentation updates and code clean-ups.
 180
 181
 182 Fixes since v2.1
 183 ----------------
 184
 185 Unless otherwise noted, all the fixes since v2.1 in the maintenance
 186 track are contained in this release (see the maintenance releases'
 187 notes for details).
 188
 189  * "git log --pretty/format=" with an empty format string did not
 190    mean the more obvious "No output whatsoever" but "Use default
 191    format", which was counterintuitive.
 192
 193  * "git -c section.var command" and "git -c section.var= command"
 194    should pass the configuration value differently (the former should be a
 195    boolean true, the latter should be an empty string).
 196
 197  * Applying a patch not generated by Git in a subdirectory used to
 198    check for whitespace breakage using the attributes of incorrect
 199    paths. Also whitespace checks were performed even for paths
 200    excluded via the "git apply --exclude=<path>" mechanism.
 201
 202  * "git bundle create" with a date-range specification was meant to
 203    exclude tags outside the range, but it didn't.
 204
 205  * "git add x" where x used to be a directory and is now a
 206    symbolic link to a directory misbehaved.
 207
 208  * The prompt script checked the $GIT_DIR/ref/stash file to see if there
 209    is a stash, which was a no-no.
 210
 211  * Pack-protocol documentation had a minor typo.
 212
 213  * "git checkout -m" did not switch to another branch while carrying
 214    the local changes forward when a path was deleted from the index.
 215
 216  * "git daemon" (with NO_IPV6 build configuration) used to incorrectly
 217    use the hostname even when gethostbyname() reported that the given
 218    hostname is not found.
 219    (merge 107efbe rs/daemon-fixes later to maint).
 220
 221  * With sufficiently long refnames, "git fast-import" could have
 222    overflowed an on-stack buffer.
 223
 224  * After "pack-refs --prune" packed refs at the top-level, it failed
 225    to prune them.
 226
 227  * Progress output from "git gc --auto" was visible in "git fetch -q".
 228
 229  * We used to pass -1000 to poll(2), expecting it to also mean "no
 230    timeout", which should be spelled as -1.
 231
 232  * "git rebase" documentation was unclear that it is required to
 233    specify on what <upstream> the rebase is to be done when telling it
 234    to first check out <branch>.
 235    (merge 95c6826 so/rebase-doc later to maint).
 236
 237  * "git push" over HTTP transport had an artificial limit on the number of
 238    refs that can be pushed, imposed by the command line length.
 239    (merge 26be19b jk/send-pack-many-refspecs later to maint).
 240
 241  * When receiving an invalid pack stream that records the same object
 242    twice, multiple threads got confused due to a race.
 243    (merge ab791dd jk/index-pack-threading-races later to maint).
 244
 245  * An attempt to remove the entire tree in the "git fast-import" input
 246    stream caused it to misbehave.
 247    (merge 2668d69 mb/fast-import-delete-root later to maint).
 248
 249  * Reachability check (used in "git prune" and friends) did not add a
 250    detached HEAD as a starting point to traverse objects still in use.
 251    (merge c40fdd0 mk/reachable-protect-detached-head later to maint).
 252
 253  * "git config --add section.var val" when section.var already has an
 254    empty-string value used to lose the empty-string value.
 255    (merge c1063be ta/config-add-to-empty-or-true-fix later to maint).
 256
 257  * "git fsck" failed to report that it found corrupt objects via its
 258    exit status in some cases.
 259    (merge 30d1038 jk/fsck-exit-code-fix later to maint).
 260
 261  * Use of the "--verbose" option used to break "git branch --merged".
 262    (merge 12994dd jk/maint-branch-verbose-merged later to maint).
 263
 264  * Some MUAs mangle a line in a message that begins with "From " to
 265    ">From " when writing to a mailbox file, and feeding such an input
 266    to "git am" used to lose such a line.
 267    (merge 85de86a jk/mbox-from-line later to maint).
 268
 269  * "rev-parse --verify --quiet $name" is meant to quietly exit with a
 270    non-zero status when $name is not a valid object name, but still
 271    gave error messages in some cases.
 272
 273  * A handful of C source files have been updated to include
 274    "git-compat-util.h" as the first thing, to conform better to our
 275    coding guidelines.
 276    (merge 1c4b660 da/include-compat-util-first-in-c later to maint).
 277
 278  * The t7004 test, which tried to run Git with small stack space, has been
 279    updated to use a bit larger stack to avoid false breakage on some
 280    platforms.
 281    (merge b9a1907 sk/tag-contains-wo-recursion later to maint).
 282
 283  * A few documentation pages had example sections marked up not quite
 284    correctly, which passed AsciiDoc but failed with AsciiDoctor.
 285    (merge c30c43c bc/asciidoc-pretty-formats-fix later to maint).
 286    (merge f8a48af bc/asciidoc later to maint).
 287
 288  * "gitweb" used deprecated CGI::startfrom, which was removed from
 289    CGI.pm as of 4.04; use CGI::start_from instead.
 290    (merge 4750f4b rm/gitweb-start-form later to maint).
 291
 292  * Newer versions of 'meld' break the auto-detection we use to see if
 293    they are new enough to support the `--output` option.
 294    (merge b12d045 da/mergetool-meld later to maint).
 295
 296  * "git pack-objects" forgot to disable the codepath to generate the
 297    object reachability bitmap when it needs to split the resulting
 298    pack.
 299    (merge 2113471 jk/pack-objects-no-bitmap-when-splitting later to maint).
 300
 301  * The code to use cache-tree trusted the on-disk data too much and
 302    fell into an infinite loop upon seeing an incorrectly recorded
 303    index file.
 304    (merge 729dbbd jk/cache-tree-protect-from-broken-libgit2 later to maint).
 305
 306  * "git fetch" into a repository where branch B was deleted earlier,
 307    back when it had reflog enabled, and then branch B/C is fetched
 308    into it without reflog enabled, which is arguably an unlikely
 309    corner case, unnecessarily failed.
 310    (merge aae828b jk/fetch-reflog-df-conflict later to maint).
 311
 312  * "git log --first-parent -L..." used to crash.
 313    (merge a8787c5 tm/line-log-first-parent later to maint).