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 * "git rebase -i" learned a new insn, 'break', that the user can 149 insert in the to-do list. Upon hitting it, the command returns 150 control back to the user. 151 152 153Performance, Internal Implementation, Development Support etc. 154 155 * When there are too many packfiles in a repository (which is not 156 recommended), looking up an object in these would require 157 consulting many pack .idx files; a new mechanism to have a single 158 file that consolidates all of these .idx files is introduced. 159 160 * "git submodule update" is getting rewritten piece-by-piece into C. 161 162 * The code for computing history reachability has been shuffled, 163 obtained a bunch of new tests to cover them, and then being 164 improved. 165 166 * The unpack_trees() API used in checking out a branch and merging 167 walks one or more trees along with the index. When the cache-tree 168 in the index tells us that we are walking a tree whose flattened 169 contents is known (i.e. matches a span in the index), as linearly 170 scanning a span in the index is much more efficient than having to 171 open tree objects recursively and listing their entries, the walk 172 can be optimized, which has been done. 173 174 * When creating a thin pack, which allows objects to be made into a 175 delta against another object that is not in the resulting pack but 176 is known to be present on the receiving end, the code learned to 177 take advantage of the reachability bitmap; this allows the server 178 to send a delta against a base beyond the "boundary" commit. 179 180 * spatch transformation to replace boolean uses of !hashcmp() to 181 newly introduced oideq() is added, and applied, to regain 182 performance lost due to support of multiple hash algorithms. 183 184 * Fix a bug in which the same path could be registered under multiple 185 worktree entries if the path was missing (for instance, was removed 186 manually). Also, as a convenience, expand the number of cases in 187 which --force is applicable. 188 189 * Split Documentation/config.txt for easier maintenance. 190 (merge 6014363f0b nd/config-split later to maint). 191 192 * Test helper binaries clean-up. 193 (merge c9a1f4161f nd/test-tool later to maint). 194 195 * Various tests have been updated to make it easier to swap the 196 hash function used for object identification. 197 (merge ae0c89d41b bc/hash-independent-tests later to maint). 198 199 * Update fsck.skipList implementation and documentation. 200 (merge 371a655074 ab/fsck-skiplist later to maint). 201 202 * An alias that expands to another alias has so far been forbidden, 203 but now it is allowed to create such an alias. 204 205 * Various test scripts have been updated for style and also correct 206 handling of exit status of various commands. 207 208 * "gc --auto" ended up calling exit(-1) upon error, which has been 209 corrected to use exit(1). Also the error reporting behaviour when 210 daemonized has been updated to exit with zero status when stopping 211 due to a previously discovered error (which implies there is no 212 point running gc to improve the situation); we used to exit with 213 failure in such a case. 214 215 * Various codepaths in the core-ish part learned to work on an 216 arbitrary in-core index structure, not necessarily the default 217 instance "the_index". 218 (merge b3c7eef9b0 nd/the-index later to maint). 219 220 * Code clean-up in the internal machinery used by "git status" and 221 "git commit --dry-run". 222 (merge 73ba5d78b4 ss/wt-status-committable later to maint). 223 224 * Some environment variables that control the runtime options of Git 225 used during tests are getting renamed for consistency. 226 (merge 4231d1ba99 bp/rename-test-env-var later to maint). 227 228 * A new extension to the index file has been introduced, which allows 229 the index file to be read in parallel for performance. 230 231 * The oidset API was built on top of the oidmap API which in turn is 232 on the hashmap API. Replace the implementation to build on top of 233 the khash API and gain performance. 234 235 * Over some transports, fetching objects with an exact commit object 236 name can be done without first seeing the ref advertisements. The 237 code has been optimized to exploit this. 238 239 * In a partial clone that will lazily be hydrated from the 240 originating repository, we generally want to avoid "does this 241 object exist (locally)?" on objects that we deliberately omitted 242 when we created the clone. The cache-tree codepath (which is used 243 to write a tree object out of the index) however insisted that the 244 object exists, even for paths that are outside of the partial 245 checkout area. The code has been updated to avoid such a check. 246 247 * To help developers, an EditorConfig file that attempts to follow 248 the project convention has been added. 249 (merge b548d698a0 bc/editorconfig later to maint). 250 251 * The result of coverage test can be combined with "git blame" to 252 check the test coverage of code introduced recently with a new 253 'coverage-diff' tool (in contrib/). 254 (merge 783faedd65 ds/coverage-diff later to maint). 255 256 * An experiment to fuzz test a few areas, hopefully we can gain more 257 coverage to various areas. 258 259 * More codepaths are moving away from hardcoded hash sizes. 260 261 * The way the Windows port figures out the current directory has been 262 improved. 263 264 * The way DLLs are loaded on the Windows port has been improved. 265 266 * Some tests have been reorganized and renamed; "ls t/" now gives a 267 better overview of what is tested for these scripts than before. 268 269 * "git rebase" and "git rebase -i" have been reimplemented in C. 270 271 272Fixes since v2.19 273----------------- 274 275 * "git interpret-trailers" and its underlying machinery had a buggy 276 code that attempted to ignore patch text after commit log message, 277 which triggered in various codepaths that will always get the log 278 message alone and never get such an input. 279 (merge 66e83d9b41 jk/trailer-fixes later to maint). 280 281 * Malformed or crafted data in packstream can make our code attempt 282 to read or write past the allocated buffer and abort, instead of 283 reporting an error, which has been fixed. 284 285 * "git rebase -i" did not clear the state files correctly when a run 286 of "squash/fixup" is aborted and then the user manually amended the 287 commit instead, which has been corrected. 288 (merge 10d2f35436 js/rebase-i-autosquash-fix later to maint). 289 290 * When fsmonitor is in use, after operation on submodules updates 291 .gitmodules, we lost track of the fact that we did so and relied on 292 stale fsmonitor data. 293 (merge 43f1180814 bp/mv-submodules-with-fsmonitor later to maint). 294 295 * Fix for a long-standing bug that leaves the index file corrupt when 296 it shrinks during a partial commit. 297 (merge 6c003d6ffb jk/reopen-tempfile-truncate later to maint). 298 299 * Further fix for O_APPEND emulation on Windows 300 (merge eeaf7ddac7 js/mingw-o-append later to maint). 301 302 * A corner case bugfix in "git rerere" code. 303 (merge ad2bf0d9b4 en/rerere-multi-stage-1-fix later to maint). 304 305 * "git add ':(attr:foo)'" is not supported and is supposed to be 306 rejected while the command line arguments are parsed, but we fail 307 to reject such a command line upfront. 308 (merge 84d938b732 nd/attr-pathspec-fix later to maint). 309 310 * Recent update broke the reachability algorithm when refs (e.g. 311 tags) that point at objects that are not commit were involved, 312 which has been fixed. 313 314 * "git rebase" etc. in Git 2.19 fails to abort when given an empty 315 commit log message as result of editing, which has been corrected. 316 (merge a3ec9eaf38 en/sequencer-empty-edit-result-aborts later to maint). 317 318 * The code to backfill objects in lazily cloned repository did not 319 work correctly, which has been corrected. 320 (merge e68302011c jt/lazy-object-fetch-fix later to maint). 321 322 * Update error messages given by "git remote" and make them consistent. 323 (merge 5025425dff ms/remote-error-message-update later to maint). 324 325 * "git update-ref" learned to make both "--no-deref" and "--stdin" 326 work at the same time. 327 (merge d345e9fbe7 en/update-ref-no-deref-stdin later to maint). 328 329 * Recently added "range-diff" had a corner-case bug to cause it 330 segfault, which has been corrected. 331 (merge e467a90c7a tg/range-diff-corner-case-fix later to maint). 332 333 * The recently introduced commit-graph auxiliary data is incompatible 334 with mechanisms such as replace & grafts that "breaks" immutable 335 nature of the object reference relationship. Disable optimizations 336 based on its use (and updating existing commit-graph) when these 337 incompatible features are in use in the repository. 338 (merge 829a321569 ds/commit-graph-with-grafts later to maint). 339 340 * The mailmap file update. 341 (merge 255eb03edf jn/mailmap-update later to maint). 342 343 * The code in "git status" sometimes hit an assertion failure. This 344 was caused by a structure that was reused without cleaning the data 345 used for the first run, which has been corrected. 346 (merge 3e73cc62c0 en/status-multiple-renames-to-the-same-target-fix later to maint). 347 348 * "git fetch $repo $object" in a partial clone did not correctly 349 fetch the asked-for object that is referenced by an object in 350 promisor packfile, which has been fixed. 351 352 * A corner-case bugfix. 353 (merge c5cbb27cb5 sm/show-superproject-while-conflicted later to maint). 354 355 * Various fixes to "diff --color-moved-ws". 356 357 * A partial clone that is configured to lazily fetch missing objects 358 will on-demand issue a "git fetch" request to the originating 359 repository to fill not-yet-obtained objects. The request has been 360 optimized for requesting a tree object (and not the leaf blob 361 objects contained in it) by telling the originating repository that 362 no blobs are needed. 363 (merge 4c7f9567ea jt/non-blob-lazy-fetch later to maint). 364 365 * The codepath to support the experimental split-index mode had 366 remaining "racily clean" issues fixed. 367 (merge 4c490f3d32 sg/split-index-racefix later to maint). 368 369 * "git log --graph" showing an octopus merge sometimes miscounted the 370 number of display columns it is consuming to show the merge and its 371 parent commits, which has been corrected. 372 (merge 04005834ed np/log-graph-octopus-fix later to maint). 373 374 * "git range-diff" did not work well when the compared ranges had 375 changes in submodules and the "--submodule=log" was used. 376 377 * The implementation of run_command() API on the UNIX platforms had a 378 bug that caused a command not on $PATH to be found in the current 379 directory. 380 (merge f67b980771 jk/run-command-notdot later to maint). 381 382 * A mutex used in "git pack-objects" were not correctly initialized 383 and this caused "git repack" to dump core on Windows. 384 (merge 34204c8166 js/pack-objects-mutex-init-fix later to maint). 385 386 * Under certain circumstances, "git diff D:/a/b/c D:/a/b/d" on 387 Windows would strip initial parts from the paths because they 388 were not recognized as absolute, which has been corrected. 389 (merge ffd04e92e2 js/diff-notice-has-drive-prefix later to maint). 390 391 * The receive.denyCurrentBranch=updateInstead codepath kicked in even 392 when the push should have been rejected due to other reasons, such 393 as it does not fast-forward or the update-hook rejects it, which 394 has been corrected. 395 (merge b072a25fad jc/receive-deny-current-branch-fix later to maint). 396 397 * Code cleanup, docfix, build fix, etc. 398 (merge 96a7501aad ts/doc-build-manpage-xsl-quietly later to maint). 399 (merge b9b07efdb2 tg/conflict-marker-size later to maint). 400 (merge fa0aeea770 sg/doc-trace-appends later to maint). 401 (merge d64324cb60 tb/void-check-attr later to maint). 402 (merge c3b9bc94b9 en/double-semicolon-fix later to maint). 403 (merge 79336116f5 sg/t3701-tighten-trace later to maint). 404 (merge 801fa63a90 jk/dev-build-format-security later to maint). 405 (merge 0597dd62ba sb/string-list-remove-unused later to maint). 406 (merge db2d36fad8 bw/protocol-v2 later to maint). 407 (merge 456d7cd3a9 sg/split-index-test later to maint). 408 (merge 7b6057c852 tq/refs-internal-comment-fix later to maint). 409 (merge 29e8dc50ad tg/t5551-with-curl-7.61.1 later to maint). 410 (merge 55f6bce2c9 fe/doc-updates later to maint). 411 (merge 7987d2232d jk/check-everything-connected-is-long-gone later to maint). 412 (merge 4ba3c9be47 dz/credential-doc-url-matching-rules later to maint). 413 (merge 4c399442f7 ma/commit-graph-docs later to maint). 414 (merge fc0503b04e ma/t1400-undebug-test later to maint). 415 (merge e56b53553a nd/packobjectshook-doc-fix later to maint). 416 (merge c56170a0c4 ma/mailing-list-address-in-git-help later to maint). 417 (merge 6e8fc70fce rs/sequencer-oidset-insert-avoids-dups later to maint). 418 (merge ad0b8f9575 mw/doc-typofixes later to maint). 419 (merge d9f079ad1a jc/how-to-document-api later to maint). 420 (merge b1492bf315 ma/t7005-bash-workaround later to maint). 421 (merge ac1f98a0df du/rev-parse-is-plumbing later to maint). 422 (merge ca8ed443a5 mm/doc-no-dashed-git later to maint). 423 (merge ce366a8144 du/get-tar-commit-id-is-plumbing later to maint). 424 (merge 61018fe9e0 du/cherry-is-plumbing later to maint). 425 (merge c7e5fe79b9 sb/strbuf-h-update later to maint). 426 (merge 8d2008196b tq/branch-create-wo-branch-get later to maint). 427 (merge 2e3c894f4b tq/branch-style-fix later to maint). 428 (merge c5d844af9c sg/doc-show-branch-typofix later to maint). 429 (merge 081d91618b ah/doc-updates later to maint). 430 (merge b84c783882 jc/cocci-preincr later to maint). 431 (merge 5e495f8122 uk/merge-subtree-doc-update later to maint). 432 (merge aaaa881822 jk/uploadpack-packobjectshook-fix later to maint).