Merge branch 'ew/svn-crlf'
[git/git.git] / Documentation / RelNotes / 2.16.0.txt
1 Git 2.16 Release Notes
2 ======================
3
4 Backward compatibility notes and other notable changes.
5
6 * Use of an empty string as a pathspec element that is used for
7 'everything matches' is now an error.
8
9
10 Updates since v2.15
11 -------------------
12
13 UI, Workflows & Features
14
15 * An empty string as a pathspec element that means "everything"
16 i.e. 'git add ""', is now illegal. We started this by first
17 deprecating and warning a pathspec that has such an element in
18 2.11 (Nov 2016).
19
20 * A hook script that is set unexecutable is simply ignored. Git
21 notifies when such a file is ignored, unless the message is
22 squelched via advice.ignoredHook configuration.
23
24 * "git pull" has been taught to accept "--[no-]signoff" option and
25 pass it down to "git merge".
26
27 * The "--push-option=<string>" option to "git push" now defaults to a
28 list of strings configured via push.pushOption variable.
29
30 * "gitweb" checks if a directory is searchable with Perl's "-x"
31 operator, which can be enhanced by using "filetest 'access'"
32 pragma, which now we do.
33
34 * "git stash save" has been deprecated in favour of "git stash push".
35
36 * The set of paths output from "git status --ignored" was tied
37 closely with its "--untracked=<mode>" option, but now it can be
38 controlled more flexibly. Most notably, a directory that is
39 ignored because it is listed to be ignored in the ignore/exclude
40 mechanism can be handled differently from a directory that ends up
41 to be ignored only because all files in it are ignored.
42
43 * The remote-helper for talking to MediaWiki has been updated to
44 truncate an overlong pagename so that ".mw" suffix can still be
45 added.
46
47 * The remote-helper for talking to MediaWiki has been updated to
48 work with mediawiki namespaces.
49
50 * The "--format=..." option "git for-each-ref" takes learned to show
51 the name of the 'remote' repository and the ref at the remote side
52 that is affected for 'upstream' and 'push' via "%(push:remotename)"
53 and friends.
54
55 * Doc and message updates to teach users "bisect view" is a synonym
56 for "bisect visualize".
57
58 * "git bisect run" that did not specify any command to run used to go
59 ahead and treated all commits to be tested as 'good'. This has
60 been corrected by making the command error out.
61
62 * The SubmittingPatches document has been converted to produce an
63 HTML version via AsciiDoc/Asciidoctor.
64
65 * We learned to talk to watchman to speed up "git status" and other
66 operations that need to see which paths have been modified.
67
68 * The "diff" family of commands learned to ignore differences in
69 carriage return at the end of line.
70
71 * Places that know about "sendemail.to", like documentation and shell
72 completion (in contrib/) have been taught about "sendemail.tocmd",
73 too.
74
75 * "git add --renormalize ." is a new and safer way to record the fact
76 that you are correcting the end-of-line convention and other
77 "convert_to_git()" glitches in the in-repository data.
78
79 * "git branch" and "git checkout -b" are now forbidden from creating
80 a branch whose name is "HEAD".
81
82 * "git branch --list" learned to show its output through the pager by
83 default when the output is going to a terminal, which is controlled
84 by the pager.branch configuration variable. This is similar to a
85 recent change to "git tag --list".
86
87 * "git grep -W", "git diff -W" and their friends learned a heuristic
88 to extend a pre-context beyond the line that matches the "function
89 pattern" (aka "diff.*.xfuncname") to include a comment block, if
90 exists, that immediately precedes it.
91
92 * "git config --expiry-date gc.reflogexpire" can read "2.weeks" from
93 the configuration and report it as a timestamp, just like "--int"
94 would read "1k" and report 1024, to help consumption by scripts.
95
96 * The shell completion (in contrib/) learned that "git pull" can take
97 the "--autostash" option.
98
99 * The tagnames "git log --decorate" uses to annotate the commits can
100 now be limited to subset of available refs with the two additional
101 options, --decorate-refs[-exclude]=<pattern>.
102
103 * "git grep" compiled with libpcre2 sometimes triggered a segfault,
104 which is being fixed.
105
106 * "git send-email" tries to see if the sendmail program is available
107 in /usr/lib and /usr/sbin; extend the list of locations to be
108 checked to also include directories on $PATH.
109
110 * "git diff" learned, "--anchored", a variant of the "--patience"
111 algorithm, to which the user can specify which 'unique' line to be
112 used as anchoring points.
113
114 * The way "git worktree add" determines what branch to create from
115 where and checkout in the new worktree has been updated a bit.
116
117 * Ancient part of codebase still shows dots after an abbreviated
118 object name just to show that it is not a full object name, but
119 these ellipses are confusing to people who newly discovered Git
120 who are used to seeing abbreviated object names and find them
121 confusing with the range syntax.
122
123 * With a configuration variable rebase.abbreviateCommands set,
124 "git rebase -i" produces the todo list with a single-letter
125 command names.
126
127 * "git worktree add" learned to run the post-checkout hook, just like
128 "git checkout" does, after the initial checkout.
129
130
131 Performance, Internal Implementation, Development Support etc.
132
133 * An earlier update made it possible to use an on-stack in-core
134 lockfile structure (as opposed to having to deliberately leak an
135 on-heap one). Many codepaths have been updated to take advantage
136 of this new facility.
137
138 * Calling cmd_foo() as if it is a general purpose helper function is
139 a no-no. Correct two instances of such to set an example.
140
141 * We try to see if somebody runs our test suite with a shell that
142 does not support "local" like bash/dash does.
143
144 * An early part of piece-by-piece rewrite of "git bisect" in C.
145
146 * GSoC to piece-by-piece rewrite "git submodule" in C.
147
148 * Optimize the code to find shortest unique prefix of object names.
149
150 * Pathspec-limited revision traversal was taught not to keep finding
151 unneeded differences once it knows two trees are different inside
152 given pathspec.
153
154 * Conversion from uchar[20] to struct object_id continues.
155
156 * Code cleanup.
157
158 * A single-word "unsigned flags" in the diff options is being split
159 into a structure with many bitfields.
160
161 * TravisCI build updates.
162
163 * Parts of a test to drive the long-running content filter interface
164 has been split into its own module, hopefully to eventually become
165 reusable.
166
167 * Drop (perhaps overly cautious) sanity check before using the index
168 read from the filesystem at runtime.
169
170 * The build procedure has been taught to avoid some unnecessary
171 instability in the build products.
172
173 * A new mechanism to upgrade the wire protocol in place is proposed
174 and demonstrated that it works with the older versions of Git
175 without harming them.
176
177 * An infrastructure to define what hash function is used in Git is
178 introduced, and an effort to plumb that throughout various
179 codepaths has been started.
180
181 * The code to iterate over loose object files got optimized.
182
183 * An internal function that was left for backward compatibility has
184 been removed, as there is no remaining callers.
185
186 * Historically, the diff machinery for rename detection had a
187 hardcoded limit of 32k paths; this is being lifted to allow users
188 trade cycles with a (possibly) easier to read result.
189
190 * The tracing infrastructure has been optimized for cases where no
191 tracing is requested.
192
193 * In preparation for implementing narrow/partial clone, the object
194 walking machinery has been taught a way to tell it to "filter" some
195 objects from enumeration.
196
197 * A few structures and variables that are implementation details of
198 the decorate API have been renamed and then the API got documented
199 better.
200
201 * Assorted updates for TravisCI integration.
202 (merge 4f26366679 sg/travis-fixes later to maint).
203
204 Also contains various documentation updates and code clean-ups.
205
206
207 Fixes since v2.15
208 -----------------
209
210 * "auto" as a value for the columnar output configuration ought to
211 judge "is the output consumed by humans?" with the same criteria as
212 "auto" for coloured output configuration, i.e. either the standard
213 output stream is going to tty, or a pager is in use. We forgot the
214 latter, which has been fixed.
215
216 * The experimental "color moved lines differently in diff output"
217 feature was buggy around "ignore whitespace changes" edges, which
218 has been corrected.
219
220 * Instead of using custom line comparison and hashing functions to
221 implement "moved lines" coloring in the diff output, use the pair
222 of these functions from lower-layer xdiff/ code.
223
224 * Some codepaths did not check for errors when asking what branch the
225 HEAD points at, which have been fixed.
226
227 * "git commit", after making a commit, did not check for errors when
228 asking on what branch it made the commit, which has been corrected.
229
230 * "git status --ignored -u" did not stop at a working tree of a
231 separate project that is embedded in an ignored directory and
232 listed files in that other project, instead of just showing the
233 directory itself as ignored.
234
235 * A broken access to object databases in recent update to "git grep
236 --recurse-submodules" has been fixed.
237
238 * A recent regression in "git rebase -i" that broke execution of git
239 commands from subdirectories via "exec" instruction has been fixed.
240
241 * A (possibly flakey) test fix.
242
243 * "git check-ref-format --branch @{-1}" bit a "BUG()" when run
244 outside a repository for obvious reasons; clarify the documentation
245 and make sure we do not even try to expand the at-mark magic in
246 such a case, but still call the validation logic for branch names.
247
248 * "git fetch --recurse-submodules" now knows that submodules can be
249 moved around in the superproject in addition to getting updated,
250 and finds the ones that need to be fetched accordingly.
251
252 * Command line completion (in contrib/) update.
253
254 * Description of blame.{showroot,blankboundary,showemail,date}
255 configuration variables have been added to "git config --help".
256
257 * After an error from lstat(), diff_populate_filespec() function
258 sometimes still went ahead and used invalid data in struct stat,
259 which has been fixed.
260
261 * UNC paths are also relevant in Cygwin builds and they are now
262 tested just like Mingw builds.
263
264 * Correct start-up sequence so that a repository could be placed
265 immediately under the root directory again (which was broken at
266 around Git 2.13).
267
268 * The credential helper for libsecret (in contrib/) has been improved
269 to allow possibly prompting the end user to unlock secrets that are
270 currently locked (otherwise the secrets may not be loaded).
271
272 * MinGW updates.
273
274 * Error checking in "git imap-send" for empty response has been
275 improved.
276
277 * Recent update to the refs infrastructure implementation started
278 rewriting packed-refs file more often than before; this has been
279 optimized again for most trivial cases.
280
281 * Some error messages did not quote filenames shown in it, which have
282 been fixed.
283
284 * "git rebase -i" recently started misbehaving when a submodule that
285 is configured with 'submodule.<name>.ignore' is dirty; this has
286 been corrected.
287
288 * Building with NO_LIBPCRE1_JIT did not disable it, which has been fixed.
289
290 * We used to add an empty alternate object database to the system
291 that does not help anything; it has been corrected.
292
293 * Doc update around use of "format-patch --subject-prefix" etc.
294
295 * A fix for an ancient bug in "git apply --ignore-space-change" codepath.
296
297 * Clarify and enhance documentation for "merge-base --fork-point", as
298 it was clear what it computed but not why/what for.
299
300 * A few scripts (both in production and tests) incorrectly redirected
301 their error output. These have been corrected.
302
303 * "git notes" sent its error message to its standard output stream,
304 which was corrected.
305
306 * The three-way merge performed by "git cherry-pick" was confused
307 when a new submodule was added in the meantime, which has been
308 fixed (or "papered over").
309
310 * The sequencer machinery (used by "git cherry-pick A..B", and "git
311 rebase -i", among other things) would have lost a commit if stopped
312 due to an unlockable index file, which has been fixed.
313
314 * "git apply --inaccurate-eof" when used with "--ignore-space-change"
315 triggered an internal sanity check, which has been fixed.
316
317 * Command line completion (in contrib/) has been taught about the
318 "--copy" option of "git branch".
319
320 * When "git rebase" prepared an mailbox of changes and fed it to "git
321 am" to replay them, it was confused when a stray "From " happened
322 to be in the log message of one of the replayed changes. This has
323 been corrected.
324
325 * There was a recent semantic mismerge in the codepath to write out a
326 section of a configuration section, which has been corrected.
327
328 * Mentions of "git-rebase" and "git-am" (dashed form) still remained
329 in end-user visible strings emitted by the "git rebase" command;
330 they have been corrected.
331
332 * Contrary to the documentation, "git pull -4/-6 other-args" did not
333 ask the underlying "git fetch" to go over IPv4/IPv6, which has been
334 corrected.
335
336 * "git checkout --recursive" may overwrite and rewind the history of
337 the branch that happens to be checked out in submodule
338 repositories, which might not be desirable. Detach the HEAD but
339 still allow the recursive checkout to succeed in such a case.
340 (merge 57f22bf997 sb/submodule-recursive-checkout-detach-head later to maint).
341
342 * "git branch --set-upstream" has been deprecated and (sort of)
343 removed, as "--set-upstream-to" is the preferred one these days.
344 The documentation still had "--set-upstream" listed on its
345 synopsis section, which has been corrected.
346 (merge a060f3d3d8 tz/branch-doc-remove-set-upstream later to maint).
347
348 * Internally we use 0{40} as a placeholder object name to signal the
349 codepath that there is no such object (e.g. the fast-forward check
350 while "git fetch" stores a new remote-tracking ref says "we know
351 there is no 'old' thing pointed at by the ref, as we are creating
352 it anew" by passing 0{40} for the 'old' side), and expect that a
353 codepath to locate an in-core object to return NULL as a sign that
354 the object does not exist. A look-up for an object that does not
355 exist however is quite costly with a repository with large number
356 of packfiles. This access pattern has been optimized.
357 (merge 87b5e236a1 jk/fewer-pack-rescan later to maint).
358
359 * In addition to "git stash -m message", the command learned to
360 accept "git stash -mmessage" form.
361 (merge 5675473fcb ph/stash-save-m-option-fix later to maint).
362
363 * @{-N} in "git checkout @{-N}" may refer to a detached HEAD state,
364 but the documentation was not clear about it, which has been fixed.
365 (merge 75ce149575 ks/doc-checkout-previous later to maint).
366
367 * A regression in the progress eye-candy was fixed.
368 (merge 9c5951cacf jk/progress-delay-fix later to maint).
369
370 * The code internal to the recursive merge strategy was not fully
371 prepared to see a path that is renamed to try overwriting another
372 path that is only different in case on case insensitive systems.
373 This does not matter in the current code, but will start to matter
374 once the rename detection logic starts taking hints from nearby
375 paths moving to some directory and moves a new path along with them.
376 (merge 4cba2b0108 en/merge-recursive-icase-removal later to maint).
377
378 * An v2.12-era regression in pathspec match logic, which made it look
379 into submodule tree even when it is not desired, has been fixed.
380 (merge eef3df5a93 bw/pathspec-match-submodule-boundary later to maint).
381
382 * Amending commits in git-gui broke the author name that is non-ascii
383 due to incorrect enconding conversion.
384
385 * Recent update to the submodule configuration code broke "diff-tree"
386 by accidentally stopping to read from the index upfront.
387 (merge fd66bcc31f bw/submodule-config-cleanup later to maint).
388
389 * Git shows a message to tell the user that it is waiting for the
390 user to finish editing when spawning an editor, in case the editor
391 opens to a hidden window or somewhere obscure and the user gets
392 lost.
393 (merge abfb04d0c7 ls/editor-waiting-message later to maint).
394
395 * The "safe crlf" check incorrectly triggered for contents that does
396 not use CRLF as line endings, which has been corrected.
397 (merge 649f1f0948 tb/check-crlf-for-safe-crlf later to maint).
398
399 * "git clone --shared" to borrow from a (secondary) worktree did not
400 work, even though "git clone --local" did. Both are now accepted.
401 (merge b3b05971c1 es/clone-shared-worktree later to maint).
402
403 * The build procedure now allows not just the repositories but also
404 the refs to be used to take pre-formatted manpages and html
405 documents to install.
406 (merge 65289e9dcd rb/quick-install-doc later to maint).
407
408 * Other minor doc, test and build updates and code cleanups.
409 (merge 1a1fc2d5b5 rd/man-prune-progress later to maint).
410 (merge 0ba014035a rd/man-reflog-add-n later to maint).
411 (merge e54b63359f rd/doc-notes-prune-fix later to maint).
412 (merge ff4c9b413a sp/doc-info-attributes later to maint).
413 (merge 7db2cbf4f1 jc/receive-pack-hook-doc later to maint).
414 (merge 5a0526264b tg/t-readme-updates later to maint).
415 (merge 5e83cca0b8 jk/no-optional-locks later to maint).
416 (merge 826c778f7c js/hashmap-update-sample later to maint).
417 (merge 176b2d328c sg/setup-doc-update later to maint).
418 (merge 1b09073514 rs/am-builtin-leakfix later to maint).
419 (merge addcf6cfde rs/fmt-merge-msg-string-leak-fix later to maint).
420 (merge c3ff8f6c14 rs/strbuf-read-once-reset-length later to maint).
421 (merge 6b0eb884f9 db/doc-workflows-neuter-the-maintainer later to maint).
422 (merge 8c87bdfb21 jk/cvsimport-quoting later to maint).
423 (merge 176cb979fe rs/fmt-merge-msg-leakfix later to maint).
424 (merge 5a03360e73 tb/delimit-pretty-trailers-args-with-comma later to maint).
425 (merge d0e6326026 ot/pretty later to maint).
426 (merge 44103f4197 sb/test-helper-excludes later to maint).
427 (merge 170078693f jt/transport-no-more-rsync later to maint).