Documentation / RelNotes / 2.2.0.txton commit Merge branch 'da/difftool' (9ce57f1)
   1Git v2.2 Release Notes
   2======================
   3
   4Updates since v2.1
   5------------------
   6
   7Ports
   8
   9 * Building on older MacOS X systems automatically sets
  10   the necessary NO_APPLE_COMMON_CRYPTO build-time option.
  11
  12 * The support to build with NO_PTHREADS has been resurrected.
  13
  14
  15UI, Workflows & Features
  16
  17 * "git archive" learned to filter what gets archived with pathspec.
  18
  19 * "git config --edit --global" starts from a skeletal per-user
  20   configuration file contents, instead of a total blank, when the
  21   user does not already have any.  This immediately reduces the
  22   need for a later "Have you forgotten setting core.user?" and we
  23   can add more to the template as we gain more experience.
  24
  25 * "git stash list -p" used to be almost always a no-op because each
  26   stash entry is represented as a merge commit.  It learned to show
  27   the difference between the base commit version and the working tree
  28   version, which is in line with what "git show" gives.
  29
  30 * Sometimes users want to report a bug they experience on their
  31   repository, but they are not at liberty to share the contents of
  32   the repository.  "fast-export" was taught an "--anonymize" option
  33   to replace blob contents, names of people and paths and log
  34   messages with bland and simple strings to help them.
  35
  36 * "log --date=iso" uses a slight variant of ISO 8601 format that is
  37   made more human readable.  A new "--date=iso-strict" option gives
  38   datetime output that is more strictly conformant.
  39
  40 * A broken reimplementation of Git could write an invalid index that
  41   records both stage #0 and higher stage entries for the same path.
  42   We now notice and reject such an index, as there is no sensible
  43   fallback (we do not know if the broken tool wanted to resolve and
  44   forgot to remove higher stage entries, or if it wanted to unresolve
  45   and forgot to remove the stage#0 entry).
  46
  47 * The temporary files "git mergetool" uses are named to avoid too
  48   many dots in them (e.g. a temporary file for "hello.c" used to be
  49   named e.g. "hello.BASE.4321.c" but now uses underscore instead,
  50   e.g. "hello_BASE_4321.c").
  51
  52 * The temporary files "git mergetools" uses can be placed in a newly
  53   creted temporary directory, instead of the current directory, by
  54   setting the mergetool.writeToTemp configuration variable.
  55
  56 * The "pre-receive" and "post-receive" hooks are no longer required
  57   to consume their input fully (not following this requirement used
  58   to result in intermittent errors in "git push").
  59
  60 * The pretty-format specifier "%d", which expanded to " (tagname)"
  61   for a tagged commit, gained a cousin "%D" that just gives the
  62   "tagname" without frills.
  63
  64 * "git push" learned "--signed" push, that allows a push (i.e.
  65   request to update the refs on the other side to point at a new
  66   history, together with the transmission of necessary objects) to be
  67   signed, so that it can be verified and audited, using the GPG
  68   signature of the person who pushed, that the tips of branches at a
  69   public repository really point the commits the pusher wanted to,
  70   without having to "trust" the server.
  71
  72 * "git interpret-trailers" is a new filter to programatically edit
  73    the tail end of the commit log messages.
  74
  75 * "git help everyday" shows the "Everyday Git in 20 commands or so"
  76   document, whose contents have been updated to more modern Git
  77   practice.
  78
  79
  80Performance, Internal Implementation, etc.
  81
  82 * The API to manipulate the "refs" has been restructured to make it
  83   more transactional, with the eventual goal to allow all-or-none
  84   atomic updates and migrating the storage to something other than
  85   the traditional filesystem based one (e.g. databases).
  86
  87 * The lockfile API and its users have been cleaned up.
  88
  89 * We no longer attempt to keep track of individual dependencies to
  90   the header files in the build procedure, relying on automated
  91   dependency generation support from modern compilers.
  92
  93 * In tests, we have been using NOT_{MINGW,CYGWIN} test prerequisites
  94   long before negated prerequisites e.g. !MINGW were invented.
  95   The former has been converted to the latter to avoid confusion.
  96
  97 * Looking up remotes configuration in a repository with very many
  98   remotes defined has been optimized.
  99
 100 * There are cases where you lock and open to write a file, close it
 101   to show the updated contents to external processes, and then have
 102   to update the file again while still holding the lock, but the
 103   lockfile API lacked support for such an access pattern.
 104
 105 * The API to allocate the structure to keep track of commit
 106   decoration has been updated to make it less cumbersome to use.
 107
 108 * An in-core caching layer to let us avoid reading the same
 109   configuration files number of times has been added.  A few commands
 110   have been converted to use this subsystem.
 111
 112 * Various code paths have been cleaned up and simplified by using
 113   "strbuf", "starts_with()", and "skip_prefix()" APIs more.
 114
 115 * A few codepaths that died when large blobs that would not fit in
 116   core are involved in their operation have been taught to punt
 117   instead, by e.g. marking too large a blob as not to be diffed.
 118
 119 * A few more code paths in "commit" and "checkout" have been taught
 120   to repopulate the cache-tree in the index, to help speed up later
 121   "write-tree" (used in "commit") and "diff-index --cached" (used in
 122   "status").
 123
 124 * A common programming mistake to assign the same short option name
 125   to two separate options is detected by parse_options() API to help
 126   developers.
 127
 128 * The code path to write out the packed-refs file has been optimized,
 129   which especially matters in a repository with a large number of
 130   refs.
 131
 132 * The check to see if a ref $F can be created by making sure no
 133   existing ref has $F/ as its prefix has been optimized, which
 134   especially matters in a repository with a large number of existing
 135   refs.
 136
 137 * "git fsck" was taught to check contents of tag objects a bit more.
 138
 139 * "git hash-object" was taught a "--literally" option to help
 140   debugging.
 141
 142 * When running a required clean filter, we do not have to mmap the
 143   original before feeding the filter.  Instead, stream the file
 144   contents directly to the filter and process its output.
 145
 146 * The scripts in the test suite can be run with "-x" option to show
 147   a shell-trace of each command run in them.
 148
 149 * The "run-command" API learned to manage the argv and environment
 150   array for child process, alleviating the need for the callers to
 151   allocate and deallocate them.
 152
 153
 154Also contains various documentation updates and code clean-ups.
 155
 156
 157Fixes since v2.1
 158----------------
 159
 160Unless otherwise noted, all the fixes since v2.1 in the maintenance
 161track are contained in this release (see the maintenance releases'
 162notes for details).
 163
 164 * "git log --pretty/format=" with an empty format string did not
 165   mean the more obvious "No output whatsoever" but "Use default
 166   format", which was counterintuitive.
 167
 168 * "git -c section.var command" and "git -c section.var= command"
 169   should pass the configuration differently (the former should be a
 170   boolean true, the latter should be an empty string).
 171
 172 * Applying a patch not generated by Git in a subdirectory used to
 173   check the whitespace breakage using the attributes for incorrect
 174   paths. Also whitespace checks were performed even for paths
 175   excluded via "git apply --exclude=<path>" mechanism.
 176
 177 * "git bundle create" with date-range specification were meant to
 178   exclude tags outside the range, but it didn't.
 179
 180 * "git add x" where x that used to be a directory has become a
 181   symbolic link to a directory misbehaved.
 182
 183 * The prompt script checked $GIT_DIR/ref/stash file to see if there
 184   is a stash, which was a no-no.
 185
 186 * Pack-protocol documentation had a minor typo.
 187
 188 * "git checkout -m" did not switch to another branch while carrying
 189   the local changes forward when a path was deleted from the index.
 190
 191 * "git daemon" (with NO_IPV6 build configuration) used to incorrectly
 192   use the hostname even when gethostbyname() reported that the given
 193   hostname is not found.
 194   (merge 107efbe rs/daemon-fixes later to maint).
 195
 196 * With sufficiently long refnames, "git fast-import" could have
 197   overflown an on-stack buffer.
 198
 199 * After "pack-refs --prune" packed refs at the top-level, it failed
 200   to prune them.
 201
 202 * Progress output from "git gc --auto" was visible in "git fetch -q".
 203
 204 * We used to pass -1000 to poll(2), expecting it to also mean "no
 205   timeout", which should be spelled as -1.
 206
 207 * "git rebase" documentation was unclear that it is required to
 208   specify on what <upstream> the rebase is to be done when telling it
 209   to first check out <branch>.
 210   (merge 95c6826 so/rebase-doc later to maint).
 211
 212 * "git push" over HTTP transport had an artificial limit on number of
 213   refs that can be pushed imposed by the command line length.
 214   (merge 26be19b jk/send-pack-many-refspecs later to maint).
 215
 216 * When receiving an invalid pack stream that records the same object
 217   twice, multiple threads got confused due to a race.
 218   (merge ab791dd jk/index-pack-threading-races later to maint).
 219
 220 * An attempt to remove the entire tree in the "git fast-import" input
 221   stream caused it to misbehave.
 222   (merge 2668d69 mb/fast-import-delete-root later to maint).
 223
 224 * Reachability check (used in "git prune" and friends) did not add a
 225   detached HEAD as a starting point to traverse objects still in use.
 226   (merge c40fdd0 mk/reachable-protect-detached-head later to maint).
 227
 228 * "git config --add section.var val" used to lose existing
 229   section.var whose value was an empty string.
 230   (merge c1063be ta/config-add-to-empty-or-true-fix later to maint).
 231
 232 * "git fsck" failed to report that it found corrupt objects via its
 233   exit status in some cases.
 234   (merge 30d1038 jk/fsck-exit-code-fix later to maint).
 235
 236 * Use of "--verbose" option used to break "git branch --merged".
 237   (merge 12994dd jk/maint-branch-verbose-merged later to maint).
 238
 239 * Some MUAs mangled a line in a message that begins with "From " to
 240   ">From " when writing to a mailbox file and feeding such an input
 241   to "git am" used to lose such a line.
 242   (merge 85de86a jk/mbox-from-line later to maint).
 243
 244 * "rev-parse --verify --quiet $name" is meant to quietly exit with a
 245   non-zero status when $name is not a valid object name, but still
 246   gave error messages in some cases.
 247
 248 * A handful of C source files have been updated to include
 249   "git-compat-util.h" as the first thing, to conform better to our
 250   coding guidelines.
 251   (merge 1c4b660 da/include-compat-util-first-in-c later to maint).
 252
 253 * t7004 test, which tried to run Git with small stack space, has been
 254   updated to give a bit larger stack to avoid false breakage on some
 255   platforms.
 256   (merge b9a1907 sk/tag-contains-wo-recursion later to maint).
 257
 258 * A few documentation pages had example sections marked up not quite
 259   correctly, which passed AsciiDoc but failed with AsciiDoctor.
 260   (merge c30c43c bc/asciidoc-pretty-formats-fix later to maint).
 261   (merge f8a48af bc/asciidoc later to maint).
 262
 263 * "gitweb" used deprecated CGI::startfrom, which was removed from
 264   CGI.pm as of 4.04; use CGI::start_from instead.
 265   (merge 4750f4b rm/gitweb-start-form later to maint).
 266
 267 * Newer versions of 'meld' breaks the auto-detection we use to see if
 268   they are new enough to support the `--output` option.
 269   (merge b12d045 da/mergetool-meld later to maint).
 270
 271 * "git pack-objects" forgot to disable the codepath to generate
 272   object recheability bitmap when it needs to split the resulting
 273   pack.
 274   (merge 2113471 jk/pack-objects-no-bitmap-when-splitting later to maint).