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