Documentation/RelNotes/2.27.0.txt

   1 Git 2.27 Release Notes
   2 ======================
   3
   4 Updates since v2.26
   5 -------------------
   6
   7 Backward compatibility notes
   8
   9  * When "git describe C" finds that commit C is pointed by a signed or
  10    annotated tag, which records T as its tagname in the object, the
  11    command gives T as its answer.  Even if the user renames or moves
  12    such a tag from its natural location in the "refs/tags/" hierarchy,
  13    "git describe C" would still give T as the answer, but in such a
  14    case "git show T^0" would no longer work as expected.  There may be
  15    nothing at "refs/tags/T" or even worse there may be a different tag
  16    instead.
  17
  18    Starting from this version, "git describe" will always use the
  19    "long" version, as if the "--long" option were given, when giving
  20    its output based on such a misplaced tag to work around the problem.
  21
  22  * "git pull" issues a warning message until the pull.rebase
  23    configuration variable is explicitly given, which some existing
  24    users may find annoying---those who prefer not to rebase need to
  25    set the variable to false to squelch the warning.
  26
  27
  28 UI, Workflows & Features
  29
  30  * A handful of options to configure SSL when talking to proxies have
  31    been added.
  32
  33  * Smudge/clean conversion filters are now given more information
  34    (e.g. the object of the tree-ish in which the blob being converted
  35    appears, in addition to its path, which has already been given).
  36
  37  * When "git describe C" finds an annotated tag with tagname A to be
  38    the best name to explain commit C, and the tag is stored in a
  39    "wrong" place in the refs/tags hierarchy, e.g. refs/tags/B, the
  40    command gave a warning message but used A (not B) to describe C.
  41    If C is exactly at the tag, the describe output would be "A", but
  42    "git rev-parse A^0" would not be equal as "git rev-parse C^0".  The
  43    behavior of the command has been changed to use the "long" form
  44    i.e. A-0-gOBJECTNAME, which is correctly interpreted by rev-parse.
  45
  46  * "git pull" learned to warn when no pull.rebase configuration
  47    exists, and neither --[no-]rebase nor --ff-only is given (which
  48    would result a merge).
  49
  50  * "git p4" learned four new hooks and also "--no-verify" option to
  51    bypass them (and the existing "p4-pre-submit" hook).
  52
  53  * "git pull" shares many options with underlying "git fetch", but
  54    some of them were not documented and some of those that would make
  55    sense to pass down were not passed down.
  56
  57  * "git rebase" learned the "--no-gpg-sign" option to countermand
  58    commit.gpgSign the user may have.
  59
  60  * The output from "git format-patch" uses RFC 2047 encoding for
  61    non-ASCII letters on From: and Subject: headers, so that it can
  62    directly be fed to e-mail programs.  A new option has been added
  63    to produce these headers in raw.
  64
  65  * "git log" learned "--show-pulls" that helps pathspec limited
  66    history views; a merge commit that takes the whole change from a
  67    side branch, which is normally omitted from the output, is shown
  68    in addition to the commits that introduce real changes.
  69
  70  * The interactive input from various codepaths are consolidated and
  71    any prompt possibly issued earlier are fflush()ed before we read.
  72
  73  * Allow "git rebase" to reapply all local commits, even if the may be
  74    already in the upstream, without checking first.
  75
  76  * The 'pack.useSparse' configuration variable now defaults to 'true',
  77    enabling an optimization that has been experimental since Git 2.21.
  78
  79  * "git rebase" happens to call some hooks meant for "checkout" and
  80    "commit" by this was not a designed behaviour than historical
  81    accident.  This has been documented.
  82
  83  * "git merge" learns the "--autostash" option.
  84
  85  * "sparse-checkout" UI improvements.
  86
  87  * "git update-ref --stdin" learned a handful of new verbs to let the
  88    user control ref update transactions more explicitly, which helps
  89    as an ingredient to implement two-phase commit-style atomic
  90    ref-updates across multiple repositories.
  91
  92
  93 Performance, Internal Implementation, Development Support etc.
  94
  95  * The advise API has been revamped to allow more systematic enumeration of
  96    advice knobs in the future.
  97
  98  * SHA-256 transition continues.
  99
 100  * The code to interface with GnuPG has been refactored.
 101
 102  * "git stash" has kept an escape hatch to use the scripted version
 103    for a few releases, which got stale.  It has been removed.
 104
 105  * Enable tests that require GnuPG on Windows.
 106
 107  * Minor test usability improvement.
 108
 109  * Trace2 enhancement to allow logging of the environment variables.
 110
 111  * Test clean-up continues.
 112
 113  * Perf-test update.
 114
 115  * A Windows-specific test element has been made more robust against
 116    misuse from both user's environment and programmer's errors.
 117
 118  * Various tests have been updated to work around issues found with
 119    shell utilities that come with busybox etc.
 120
 121  * The config API made mixed uses of int and size_t types to represent
 122    length of various pieces of text it parsed, which has been updated
 123    to use the correct type (i.e. size_t) throughout.
 124
 125  * The "--decorate-refs" and "--decorate-refs-exclude" options "git
 126    log" takes have learned a companion configuration variable
 127    log.excludeDecoration that sits at the lowest priority in the
 128    family.
 129
 130  * A new CI job to build and run test suite on linux with musl libc
 131    has been added.
 132
 133  * Update the CI configuration to use GitHub Actions, retiring the one
 134    based on Azure Pipelines.
 135
 136  * The directory traversal code had redundant recursive calls which
 137    made its performance characteristics exponential with respect to
 138    the depth of the tree, which was corrected.
 139
 140
 141 Fixes since v2.26
 142 -----------------
 143
 144  * The real_path() convenience function can easily be misused; with a
 145    bit of code refactoring in the callers' side, its use has been
 146    eliminated.
 147    (merge 49d3c4b481 am/real-path-fix later to maint).
 148
 149  * Update "git p4" to work with Python 3.
 150    (merge 6bb40ed20a yz/p4-py3 later to maint).
 151
 152  * The mechanism to prevent "git commit" from making an empty commit
 153    or amending during an interrupted cherry-pick was broken during the
 154    rewrite of "git rebase" in C, which has been corrected.
 155    (merge 430b75f720 pw/advise-rebase-skip later to maint).
 156
 157  * Fix "git checkout --recurse-submodules" of a nested submodule
 158    hierarchy.
 159    (merge 846f34d351 pb/recurse-submodules-fix later to maint).
 160
 161  * The "--fork-point" mode of "git rebase" regressed when the command
 162    was rewritten in C back in 2.20 era, which has been corrected.
 163    (merge f08132f889 at/rebase-fork-point-regression-fix later to maint).
 164
 165  * The import-tars importer (in contrib/fast-import/) used to create
 166    phony files at the top-level of the repository when the archive
 167    contains global PAX headers, which made its own logic to detect and
 168    omit the common leading directory ineffective, which has been
 169    corrected.
 170    (merge c839fcff65 js/import-tars-do-not-make-phony-files-from-pax-headers later to maint).
 171
 172  * Simplify the commit ancestry connectedness check in a partial clone
 173    repository in which "promised" objects are assumed to be obtainable
 174    lazily on-demand from promisor remote repositories.
 175    (merge 2b98478c6f jt/connectivity-check-optim-in-partial-clone later to maint).
 176
 177  * The server-end of the v2 protocol to serve "git clone" and "git
 178    fetch" was not prepared to see a delim packets at unexpected
 179    places, which led to a crash.
 180    (merge cacae4329f jk/harden-protocol-v2-delim-handling later to maint).
 181
 182  * When fed a midx that records no objects, some codepaths tried to
 183    loop from 0 through (num_objects-1), which, due to integer
 184    arithmetic wrapping around, made it nonsense operation with out of
 185    bounds array accesses.  The code has been corrected to reject such
 186    an midx file.
 187    (merge 796d61cdc0 dr/midx-avoid-int-underflow later to maint).
 188
 189  * Utitiles run via the run_command() API were not spawned correctly
 190    on Cygwin, when the paths to them are given as a full path with
 191    backslashes.
 192    (merge 05ac8582bc ak/run-command-on-cygwin-fix later to maint).
 193
 194  * "git pull --rebase" tried to run a rebase even after noticing that
 195    the pull results in a fast-forward and no rebase is needed nor
 196    sensible, for the past few years due to a mistake nobody noticed.
 197    (merge fbae70ddc6 en/pull-do-not-rebase-after-fast-forwarding later to maint).
 198
 199  * "git rebase" with the merge backend did not work well when the
 200    rebase.abbreviateCommands configuration was set.
 201    (merge de9f1d3ef4 ag/rebase-merge-allow-ff-under-abbrev-command later to maint).
 202
 203  * The logic to auto-follow tags by "git clone --single-branch" was
 204    not careful to avoid lazy-fetching unnecessary tags, which has been
 205    corrected.
 206    (merge 167a575e2d jk/use-quick-lookup-in-clone-for-tag-following later to maint).
 207
 208  * "git rebase -i" did not leave the reflog entries correctly.
 209    (merge 1f6965f994 en/sequencer-reflog-action later to maint).
 210
 211  * The more aggressive updates to remote-tracking branches we had for
 212    the past 7 years or so were not reflected in the documentation,
 213    which has been corrected.
 214    (merge a44088435c pb/pull-fetch-doc later to maint).
 215
 216  * We've left the command line parsing of "git log :/a/b/" broken for
 217    about a full year without anybody noticing, which has been
 218    corrected.
 219    (merge 0220461071 jc/missing-ref-store-fix later to maint).
 220
 221  * Misc fixes for Windows.
 222    (merge 3efc128cd5 js/mingw-fixes later to maint).
 223
 224  * "git rebase" (again) learns to honor "--no-keep-empty", which lets
 225    the user to discard commits that are empty from the beginning (as
 226    opposed to the ones that become empty because of rebasing).  The
 227    interactive rebase also marks commits that are empty in the todo.
 228    (merge 50ed76148a en/rebase-no-keep-empty later to maint).
 229
 230  * Parsing the host part out of URL for the credential helper has been corrected.
 231    (merge 4c5971e18a jk/credential-parsing-end-of-host-in-URL later to maint).
 232
 233  * Document the recommended way to abort a failing test early (e.g. by
 234    exiting a loop), which is to say "return 1".
 235    (merge 7cc112dc95 jc/doc-test-leaving-early later to maint).
 236
 237  * The code that refreshes the last access and modified time of
 238    on-disk packfiles and loose object files have been updated.
 239    (merge 312cd76130 lr/freshen-file-fix later to maint).
 240
 241  * Validation of push certificate has been made more robust against
 242    timing attacks.
 243    (merge 719483e547 bc/constant-memequal later to maint).
 244
 245  * The custom hash function used by "git fast-import" has been
 246    replaced with the one from hashmap.c, which gave us a nice
 247    performance boost.
 248    (merge d8410a816b jk/fast-import-use-hashmap later to maint).
 249
 250  * The "git submodule" command did not initialize a few variables it
 251    internally uses and was affected by variable settings leaked from
 252    the environment.
 253    (merge 65d100c4dd lx/submodule-clear-variables later to maint).
 254
 255  * Raise the minimum required version of docbook-xsl package to 1.74,
 256    as 1.74.0 was from late 2008, which is more than 10 years old, and
 257    drop compatibility cruft from our documentation suite.
 258    (merge 3c255ad660 ma/doc-discard-docbook-xsl-1.73 later to maint).
 259
 260  * "git log" learns "--[no-]mailmap" as a synonym to "--[no-]use-mailmap"
 261    (merge 88acccda38 jc/log-no-mailmap later to maint).
 262
 263  * "git commit-graph write --expire-time=<timestamp>" did not use the
 264    given timestamp correctly, which has been corrected.
 265    (merge b09b785c78 ds/commit-graph-expiry-fix later to maint).
 266
 267  * Tests update to use "test-chmtime" instead of "touch -t".
 268    (merge e892a56845 ds/t5319-touch-fix later to maint).
 269
 270  * "git diff" in a partial clone learned to avoid lazy loading blob
 271    objects in more casese when they are not needed.
 272    (merge 95acf11a3d jt/avoid-prefetch-when-able-in-diff later to maint).
 273
 274  * "git push --atomic" used to show failures for refs that weren't
 275    even pushed, which has been corrected.
 276    (merge dfe1b7f19c jx/atomic-push later to maint).
 277
 278  * Code in builtin/*, i.e. those can only be called from within
 279    built-in subcommands, that implements bulk of a couple of
 280    subcommands have been moved to libgit.a so that they could be used
 281    by others.
 282    (merge 9460fd48b5 dl/libify-a-few later to maint).
 283
 284  * Allowing the user to split a patch hunk while "git stash -p" does
 285    not work well; a band-aid has been added to make this (partially)
 286    work better.
 287
 288  * "git diff-tree --pretty --notes" used to hit an assertion failure,
 289    as it forgot to initialize the notes subsystem.
 290    (merge 5778b22b3d tb/diff-tree-with-notes later to maint).
 291
 292  * "git range-diff" fixes.
 293    (merge 8d1675eb7f vd/range-diff-with-custom-pretty-format-fix later to maint).
 294
 295  * "git grep" did not quote a path with unusual character like other
 296    commands (like "git diff", "git status") do, but did quote when run
 297    from a subdirectory, both of which has been corrected.
 298    (merge 45115d8490 mt/grep-cquote-path later to maint).
 299
 300  * GNU/Hurd is also among the ones that need the fopen() wrapper.
 301    (merge 274a1328fb jc/gnu-hurd-lets-fread-read-dirs later to maint).
 302
 303  * Those fetching over protocol v2 from linux-next and other kernel
 304    repositories are reporting that v2 often fetches way too much than
 305    needed.
 306    (merge 11c7f2a30b jn/demote-proto2-from-default later to maint).
 307
 308  * Other code cleanup, docfix, build fix, etc.
 309    (merge 564956f358 jc/maintain-doc later to maint).
 310    (merge 7422b2a0a1 sg/commit-slab-clarify-peek later to maint).
 311    (merge 9c688735f6 rs/doc-passthru-fetch-options later to maint).
 312    (merge 757c2ba3e2 en/oidset-uninclude-hashmap later to maint).
 313    (merge 8312aa7d74 jc/config-tar later to maint).
 314    (merge d00a5bdd50 ss/submodule-foreach-cb later to maint).
 315    (merge 64d1022e14 ar/test-style-fixes later to maint).
 316    (merge 4a465443a6 ds/doc-clone-filter later to maint).
 317    (merge bb2dbe301b jk/t3419-drop-expensive-tests later to maint).
 318    (merge d3507cc712 js/test-junit-finalization-fix later to maint).
 319    (merge 2149b6748f bc/faq later to maint).
 320    (merge 12dc0879f1 jk/test-cleanup later to maint).
 321    (merge 344420bf0f pb/rebase-doc-typofix later to maint).
 322    (merge 7cd54d37dc dl/wrapper-fix-indentation later to maint).
 323    (merge 78725ebda9 jc/allow-strlen-substitution-in-shell-scripts later to maint).
 324    (merge 2ecfcdecc6 jm/gitweb-fastcgi-utf8 later to maint).
 325    (merge 0740d0a5d3 jk/oid-array-cleanups later to maint).
 326    (merge a1aba0c95c js/t0007-typofix later to maint).
 327    (merge 76ba7fa225 ma/config-doc-fix later to maint).
 328    (merge 826f0c0df2 js/subtree-doc-update-to-asciidoctor-2 later to maint).
 329    (merge 88eaf361e0 eb/mboxrd-doc later to maint).
 330    (merge 051cc54941 tm/zsh-complete-switch-restore later to maint).
 331    (merge 39102cf4fe ms/doc-revision-illustration-fix later to maint).