1Git Release Notes 2================= 3 4Backward Compatibility Notes 5---------------------------- 6 7 * "git branch -l <foo>" used to be a way to ask a reflog to be 8 created while creating a new branch, but that is no longer the 9 case. It is a short-hand for "git branch --list <foo>" now. 10 11 * "git push" into refs/tags/* hierarchy is rejected without getting 12 forced, but "git fetch" (misguidedly) used the "fast forwarding" 13 rule used for the refs/heads/* hierarchy; this has been corrected, 14 which means some fetches of tags that did not fail with older 15 version of Git will fail without "--force" with this version. 16 17 * "git help -a" now gives verbose output (same as "git help -av"). 18 Those who want the old output may say "git help --no-verbose -a".. 19 20 * "git cpn --help", when "cpn" is an alias to, say, "cherry-pick -n", 21 reported only the alias expansion of "cpn" in earlier versions of 22 Git. It now runs "git cherry-pick --help" to show the manual page 23 of the command, while sending the alias expansion to the standard 24 error stream. 25 26 * "git send-email" learned to grab address-looking string on any 27 trailer whose name ends with "-by". This is a backward-incompatible 28 change. Adding "--suppress-cc=misc-by" on the command line, or 29 setting sendemail.suppresscc configuration variable to "misc-by", 30 can be used to disable this behaviour. 31 32 33Updates since v2.19 34------------------- 35 36UI, Workflows & Features 37 38 * Running "git clone" against a project that contain two files with 39 pathnames that differ only in cases on a case insensitive 40 filesystem would result in one of the files lost because the 41 underlying filesystem is incapable of holding both at the same 42 time. An attempt is made to detect such a case and warn. 43 44 * "git checkout -b newbranch [HEAD]" should not have to do as much as 45 checking out a commit different from HEAD. An attempt is made to 46 optimize this special case. 47 48 * "git rev-list --stdin </dev/null" used to be an error; it now shows 49 no output without an error. "git rev-list --stdin --default HEAD" 50 still falls back to the given default when nothing is given on the 51 standard input. 52 53 * Lift code from GitHub to restrict delta computation so that an 54 object that exists in one fork is not made into a delta against 55 another object that does not appear in the same forked repository. 56 57 * "git format-patch" learned new "--interdiff" and "--range-diff" 58 options to explain the difference between this version and the 59 previous attempt in the cover letter (or after the tree-dashes as 60 a comment). 61 62 * "git mailinfo" used in "git am" learned to make a best-effort 63 recovery of a patch corrupted by MUA that sends text/plain with 64 format=flawed option. 65 (merge 3aa4d81f88 rs/mailinfo-format-flowed later to maint). 66 67 * The rules used by "git push" and "git fetch" to determine if a ref 68 can or cannot be updated were inconsistent; specifically, fetching 69 to update existing tags were allowed even though tags are supposed 70 to be unmoving anchoring points. "git fetch" was taught to forbid 71 updates to existing tags without the "--force" option. 72 73 * "git multi-pack-index" learned to detect corruption in the .midx 74 file it uses, and this feature has been integrated into "git fsck". 75 76 * Generation of (experimental) commit-graph files have so far been 77 fairly silent, even though it takes noticeable amount of time in a 78 meaningfully large repository. The users will now see progress 79 output. 80 81 * The minimum version of Windows supported by Windows port fo Git is 82 now set to Vista. 83 84 * The completion script (in contrib/) learned to complete a handful of 85 options "git stash list" command takes. 86 87 * The completion script (in contrib/) learned that "git fetch 88 --multiple" only takes remote names as arguments and no refspecs. 89 90 * "git status" learns to show progress bar when refreshing the index 91 takes a long time. 92 (merge ae9af12287 nd/status-refresh-progress later to maint). 93 94 * "git help -a" and "git help -av" give different pieces of 95 information, and generally the "verbose" version is more friendly 96 to the new users. "git help -a" by default now uses the more 97 verbose output (with "--no-verbose", you can go back to the 98 original). Also "git help -av" now lists aliases and external 99 commands, which it did not used to. 100 101 * Unlike "grep", "git grep" by default recurses to the whole tree. 102 The command learned "git grep --recursive" option, so that "git 103 grep --no-recursive" can serve as a synonym to setting the 104 max-depth to 0. 105 106 * When pushing into a repository that borrows its objects from an 107 alternate object store, "git receive-pack" that responds to the 108 push request on the other side lists the tips of refs in the 109 alternate to reduce the amount of objects transferred. This 110 sometimes is detrimental when the number of refs in the alternate 111 is absurdly large, in which case the bandwidth saved in potentially 112 fewer objects transferred is wasted in excessively large ref 113 advertisement. The alternate refs that are advertised are now 114 configurable with a pair of configuration variables. 115 116 * "git cmd --help" when "cmd" is aliased used to only say "cmd is 117 aliased to ...". Now it shows that to the standard error stream 118 and runs "git $cmd --help" where $cmd is the first word of the 119 alias expansion. 120 121 * The documentation of "git gc" has been updated to mention that it 122 is no longer limited to "pruning away crufts" but also updates 123 ancillary files like commit-graph as a part of repository 124 optimization. 125 126 * "git p4 unshelve" improvements. 127 128 * The logic to select the default user name and e-mail on Windows has 129 been improved. 130 (merge 501afcb8b0 js/mingw-default-ident later to maint). 131 132 * The "rev-list --filter" feature learned to exclude all trees via 133 "tree:0" filter. 134 135 * "git send-email" learned to grab address-looking string on any 136 trailer whose name ends with "-by"; --suppress-cc=misc-by on the 137 command line, or setting sendemail.suppresscc configuration 138 variable to "misc-by", can be used to disable this behaviour. 139 140 * Developer builds now uses -Wunused-function compilation option. 141 142 * One of our CI tests to run with "unusual/experimental/random" 143 settings now also uses commit-graph and midx. 144 145 * "git mergetool" learned to take the "--[no-]gui" option, just like 146 "git difftool" does. 147 148 149Performance, Internal Implementation, Development Support etc. 150 151 * When there are too many packfiles in a repository (which is not 152 recommended), looking up an object in these would require 153 consulting many pack .idx files; a new mechanism to have a single 154 file that consolidates all of these .idx files is introduced. 155 156 * "git submodule update" is getting rewritten piece-by-piece into C. 157 158 * The code for computing history reachability has been shuffled, 159 obtained a bunch of new tests to cover them, and then being 160 improved. 161 162 * The unpack_trees() API used in checking out a branch and merging 163 walks one or more trees along with the index. When the cache-tree 164 in the index tells us that we are walking a tree whose flattened 165 contents is known (i.e. matches a span in the index), as linearly 166 scanning a span in the index is much more efficient than having to 167 open tree objects recursively and listing their entries, the walk 168 can be optimized, which has been done. 169 170 * When creating a thin pack, which allows objects to be made into a 171 delta against another object that is not in the resulting pack but 172 is known to be present on the receiving end, the code learned to 173 take advantage of the reachability bitmap; this allows the server 174 to send a delta against a base beyond the "boundary" commit. 175 176 * spatch transformation to replace boolean uses of !hashcmp() to 177 newly introduced oideq() is added, and applied, to regain 178 performance lost due to support of multiple hash algorithms. 179 180 * Fix a bug in which the same path could be registered under multiple 181 worktree entries if the path was missing (for instance, was removed 182 manually). Also, as a convenience, expand the number of cases in 183 which --force is applicable. 184 185 * Split Documentation/config.txt for easier maintenance. 186 (merge 6014363f0b nd/config-split later to maint). 187 188 * Test helper binaries clean-up. 189 (merge c9a1f4161f nd/test-tool later to maint). 190 191 * Various tests have been updated to make it easier to swap the 192 hash function used for object identification. 193 (merge ae0c89d41b bc/hash-independent-tests later to maint). 194 195 * Update fsck.skipList implementation and documentation. 196 (merge 371a655074 ab/fsck-skiplist later to maint). 197 198 * An alias that expands to another alias has so far been forbidden, 199 but now it is allowed to create such an alias. 200 201 * Various test scripts have been updated for style and also correct 202 handling of exit status of various commands. 203 204 * "gc --auto" ended up calling exit(-1) upon error, which has been 205 corrected to use exit(1). Also the error reporting behaviour when 206 daemonized has been updated to exit with zero status when stopping 207 due to a previously discovered error (which implies there is no 208 point running gc to improve the situation); we used to exit with 209 failure in such a case. 210 211 * Various codepaths in the core-ish part learned to work on an 212 arbitrary in-core index structure, not necessarily the default 213 instance "the_index". 214 (merge b3c7eef9b0 nd/the-index later to maint). 215 216 * Code clean-up in the internal machinery used by "git status" and 217 "git commit --dry-run". 218 (merge 73ba5d78b4 ss/wt-status-committable later to maint). 219 220 * Some environment variables that control the runtime options of Git 221 used during tests are getting renamed for consistency. 222 (merge 4231d1ba99 bp/rename-test-env-var later to maint). 223 224 * A new extension to the index file has been introduced, which allows 225 the index file to be read in parallel for performance. 226 227 * The oidset API was built on top of the oidmap API which in turn is 228 on the hashmap API. Replace the implementation to build on top of 229 the khash API and gain performance. 230 231 * Over some transports, fetching objects with an exact commit object 232 name can be done without first seeing the ref advertisements. The 233 code has been optimized to exploit this. 234 235 * In a partial clone that will lazily be hydrated from the 236 originating repository, we generally want to avoid "does this 237 object exist (locally)?" on objects that we deliberately omitted 238 when we created the clone. The cache-tree codepath (which is used 239 to write a tree object out of the index) however insisted that the 240 object exists, even for paths that are outside of the partial 241 checkout area. The code has been updated to avoid such a check. 242 243 * To help developers, an EditorConfig file that attempts to follow 244 the project convention has been added. 245 (merge b548d698a0 bc/editorconfig later to maint). 246 247 * The result of coverage test can be combined with "git blame" to 248 check the test coverage of code introduced recently with a new 249 'coverage-diff' tool (in contrib/). 250 (merge 783faedd65 ds/coverage-diff later to maint). 251 252 * An experiment to fuzz test a few areas, hopefully we can gain more 253 coverage to various areas. 254 255 * More codepaths are moving away from hardcoded hash sizes. 256 257 * The way the Windows port figures out the current directory has been 258 improved. 259 260 * The way DLLs are loaded on the Windows port has been improved. 261 262 * Some tests have been reorganized and renamed; "ls t/" now gives a 263 better overview of what is tested for these scripts than before. 264 265 266Fixes since v2.19 267----------------- 268 269 * "git interpret-trailers" and its underlying machinery had a buggy 270 code that attempted to ignore patch text after commit log message, 271 which triggered in various codepaths that will always get the log 272 message alone and never get such an input. 273 (merge 66e83d9b41 jk/trailer-fixes later to maint). 274 275 * Malformed or crafted data in packstream can make our code attempt 276 to read or write past the allocated buffer and abort, instead of 277 reporting an error, which has been fixed. 278 279 * "git rebase -i" did not clear the state files correctly when a run 280 of "squash/fixup" is aborted and then the user manually amended the 281 commit instead, which has been corrected. 282 (merge 10d2f35436 js/rebase-i-autosquash-fix later to maint). 283 284 * When fsmonitor is in use, after operation on submodules updates 285 .gitmodules, we lost track of the fact that we did so and relied on 286 stale fsmonitor data. 287 (merge 43f1180814 bp/mv-submodules-with-fsmonitor later to maint). 288 289 * Fix for a long-standing bug that leaves the index file corrupt when 290 it shrinks during a partial commit. 291 (merge 6c003d6ffb jk/reopen-tempfile-truncate later to maint). 292 293 * Further fix for O_APPEND emulation on Windows 294 (merge eeaf7ddac7 js/mingw-o-append later to maint). 295 296 * A corner case bugfix in "git rerere" code. 297 (merge ad2bf0d9b4 en/rerere-multi-stage-1-fix later to maint). 298 299 * "git add ':(attr:foo)'" is not supported and is supposed to be 300 rejected while the command line arguments are parsed, but we fail 301 to reject such a command line upfront. 302 (merge 84d938b732 nd/attr-pathspec-fix later to maint). 303 304 * Recent update broke the reachability algorithm when refs (e.g. 305 tags) that point at objects that are not commit were involved, 306 which has been fixed. 307 308 * "git rebase" etc. in Git 2.19 fails to abort when given an empty 309 commit log message as result of editing, which has been corrected. 310 (merge a3ec9eaf38 en/sequencer-empty-edit-result-aborts later to maint). 311 312 * The code to backfill objects in lazily cloned repository did not 313 work correctly, which has been corrected. 314 (merge e68302011c jt/lazy-object-fetch-fix later to maint). 315 316 * Update error messages given by "git remote" and make them consistent. 317 (merge 5025425dff ms/remote-error-message-update later to maint). 318 319 * "git update-ref" learned to make both "--no-deref" and "--stdin" 320 work at the same time. 321 (merge d345e9fbe7 en/update-ref-no-deref-stdin later to maint). 322 323 * Recently added "range-diff" had a corner-case bug to cause it 324 segfault, which has been corrected. 325 (merge e467a90c7a tg/range-diff-corner-case-fix later to maint). 326 327 * The recently introduced commit-graph auxiliary data is incompatible 328 with mechanisms such as replace & grafts that "breaks" immutable 329 nature of the object reference relationship. Disable optimizations 330 based on its use (and updating existing commit-graph) when these 331 incompatible features are in use in the repository. 332 (merge 829a321569 ds/commit-graph-with-grafts later to maint). 333 334 * The mailmap file update. 335 (merge 255eb03edf jn/mailmap-update later to maint). 336 337 * The code in "git status" sometimes hit an assertion failure. This 338 was caused by a structure that was reused without cleaning the data 339 used for the first run, which has been corrected. 340 (merge 3e73cc62c0 en/status-multiple-renames-to-the-same-target-fix later to maint). 341 342 * "git fetch $repo $object" in a partial clone did not correctly 343 fetch the asked-for object that is referenced by an object in 344 promisor packfile, which has been fixed. 345 346 * A corner-case bugfix. 347 (merge c5cbb27cb5 sm/show-superproject-while-conflicted later to maint). 348 349 * Various fixes to "diff --color-moved-ws". 350 351 * A partial clone that is configured to lazily fetch missing objects 352 will on-demand issue a "git fetch" request to the originating 353 repository to fill not-yet-obtained objects. The request has been 354 optimized for requesting a tree object (and not the leaf blob 355 objects contained in it) by telling the originating repository that 356 no blobs are needed. 357 (merge 4c7f9567ea jt/non-blob-lazy-fetch later to maint). 358 359 * The codepath to support the experimental split-index mode had 360 remaining "racily clean" issues fixed. 361 (merge 4c490f3d32 sg/split-index-racefix later to maint). 362 363 * "git log --graph" showing an octopus merge sometimes miscounted the 364 number of display columns it is consuming to show the merge and its 365 parent commits, which has been corrected. 366 (merge 04005834ed np/log-graph-octopus-fix later to maint). 367 368 * "git range-diff" did not work well when the compared ranges had 369 changes in submodules and the "--submodule=log" was used. 370 371 * The implementation of run_command() API on the UNIX platforms had a 372 bug that caused a command not on $PATH to be found in the current 373 directory. 374 (merge f67b980771 jk/run-command-notdot later to maint). 375 376 * A mutex used in "git pack-objects" were not correctly initialized 377 and this caused "git repack" to dump core on Windows. 378 (merge 34204c8166 js/pack-objects-mutex-init-fix later to maint). 379 380 * Under certain circumstances, "git diff D:/a/b/c D:/a/b/d" on 381 Windows would strip initial parts from the paths because they 382 were not recognized as absolute, which has been corrected. 383 (merge ffd04e92e2 js/diff-notice-has-drive-prefix later to maint). 384 385 * The receive.denyCurrentBranch=updateInstead codepath kicked in even 386 when the push should have been rejected due to other reasons, such 387 as it does not fast-forward or the update-hook rejects it, which 388 has been corrected. 389 (merge b072a25fad jc/receive-deny-current-branch-fix later to maint). 390 391 * Code cleanup, docfix, build fix, etc. 392 (merge 96a7501aad ts/doc-build-manpage-xsl-quietly later to maint). 393 (merge b9b07efdb2 tg/conflict-marker-size later to maint). 394 (merge fa0aeea770 sg/doc-trace-appends later to maint). 395 (merge d64324cb60 tb/void-check-attr later to maint). 396 (merge c3b9bc94b9 en/double-semicolon-fix later to maint). 397 (merge 79336116f5 sg/t3701-tighten-trace later to maint). 398 (merge 801fa63a90 jk/dev-build-format-security later to maint). 399 (merge 0597dd62ba sb/string-list-remove-unused later to maint). 400 (merge db2d36fad8 bw/protocol-v2 later to maint). 401 (merge 456d7cd3a9 sg/split-index-test later to maint). 402 (merge 7b6057c852 tq/refs-internal-comment-fix later to maint). 403 (merge 29e8dc50ad tg/t5551-with-curl-7.61.1 later to maint). 404 (merge 55f6bce2c9 fe/doc-updates later to maint). 405 (merge 7987d2232d jk/check-everything-connected-is-long-gone later to maint). 406 (merge 4ba3c9be47 dz/credential-doc-url-matching-rules later to maint). 407 (merge 4c399442f7 ma/commit-graph-docs later to maint). 408 (merge fc0503b04e ma/t1400-undebug-test later to maint). 409 (merge e56b53553a nd/packobjectshook-doc-fix later to maint). 410 (merge c56170a0c4 ma/mailing-list-address-in-git-help later to maint). 411 (merge 6e8fc70fce rs/sequencer-oidset-insert-avoids-dups later to maint). 412 (merge ad0b8f9575 mw/doc-typofixes later to maint). 413 (merge d9f079ad1a jc/how-to-document-api later to maint). 414 (merge b1492bf315 ma/t7005-bash-workaround later to maint). 415 (merge ac1f98a0df du/rev-parse-is-plumbing later to maint). 416 (merge ca8ed443a5 mm/doc-no-dashed-git later to maint). 417 (merge ce366a8144 du/get-tar-commit-id-is-plumbing later to maint). 418 (merge 61018fe9e0 du/cherry-is-plumbing later to maint). 419 (merge c7e5fe79b9 sb/strbuf-h-update later to maint). 420 (merge 8d2008196b tq/branch-create-wo-branch-get later to maint). 421 (merge 2e3c894f4b tq/branch-style-fix later to maint). 422 (merge c5d844af9c sg/doc-show-branch-typofix later to maint). 423 (merge 081d91618b ah/doc-updates later to maint). 424 (merge b84c783882 jc/cocci-preincr later to maint). 425 (merge 5e495f8122 uk/merge-subtree-doc-update later to maint). 426 (merge aaaa881822 jk/uploadpack-packobjectshook-fix later to maint).