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1 Git 2.9 Release Notes
2 =====================
3
4 Backward compatibility note
5 ---------------------------
6
7 The end-user facing Porcelain level commands in the "git diff" and
8 "git log" by default enables the rename detection; you can still use
9 "diff.renames" configuration variable to disable this.
10
11 Merging two branches that have no common ancestor with "git merge" is
12 by default forbidden now to prevent creating such an unusual merge by
13 mistake.
14
15 The output formats of "git log" that indents the commit log message by
16 4 spaces now expands HT in the log message by default. You can use
17 the "--no-expand-tabs" option to disable this.
18
19
20 Updates since v2.8
21 ------------------
22
23 UI, Workflows & Features
24
25 * The end-user facing Porcelain level commands like "diff" and "log"
26 now enables the rename detection by default.
27
28 * The credential.helper configuration variable is cumulative and
29 there is no good way to override it from the command line. As
30 a special case, giving an empty string as its value now serves
31 as the signal to clear the values specified in various files.
32
33 * A new "interactive.diffFilter" configuration can be used to
34 customize the diff shown in "git add -i" session.
35
36 * "git p4" now allows P4 author names to be mapped to Git author
37 names.
38
39 * "git rebase -x" can be used without passing "-i" option.
40
41 * "git -c credential.<var>=<value> submodule" can now be used to
42 propagate configuration variables related to credential helper
43 down to the submodules.
44
45 * "git tag" can create an annotated tag without explicitly given an
46 "-a" (or "-s") option (i.e. when a tag message is given). A new
47 configuration variable, tag.forceSignAnnotated, can be used to tell
48 the command to create signed tag in such a situation.
49
50 * "git merge" used to allow merging two branches that have no common
51 base by default, which led to a brand new history of an existing
52 project created and then get pulled by an unsuspecting maintainer,
53 which allowed an unnecessary parallel history merged into the
54 existing project. The command has been taught not to allow this by
55 default, with an escape hatch "--allow-unrelated-histories" option
56 to be used in a rare event that merges histories of two projects
57 that started their lives independently.
58
59 * "git pull" has been taught to pass --allow-unrelated-histories
60 option to underlying "git merge".
61
62 * "git apply -v" learned to report paths in the patch that were
63 skipped via --include/--exclude mechanism or being outside the
64 current working directory.
65
66 * Shell completion (in contrib/) updates.
67
68 * The commit object name reported when "rebase -i" stops has been
69 shortened.
70
71 * "git worktree add" can be given "--no-checkout" option to only
72 create an empty worktree without checking out the files.
73
74 * "git mergetools" learned to drive ExamDiff.
75
76 * "git pull --rebase" learned "--[no-]autostash" option, so that
77 the rebase.autostash configuration variable set to true can be
78 overridden from the command line.
79
80 * When "git log" shows the log message indented by 4-spaces, the
81 remainder of a line after a HT does not align in the way the author
82 originally intended. The command now expands tabs by default in
83 such a case, and allows the users to override it with a new option,
84 "--no-expand-tabs".
85
86 * "git send-email" now uses a more readable timestamps when
87 formulating a message ID.
88
89 * "git rerere" can encounter two or more files with the same conflict
90 signature that have to be resolved in different ways, but there was
91 no way to record these separate resolutions.
92 (merge 890fca8 jc/rerere-multi later to maint).
93
94 * "git p4" learned to record P4 jobs in Git commit that imports from
95 the history in Perforce.
96
97 * "git describe --contains" often made a hard-to-justify choice of
98 tag to give name to a given commit, because it tried to come up
99 with a name with smallest number of hops from a tag, causing an old
100 commit whose close descendant that is recently tagged were not
101 described with respect to an old tag but with a newer tag. It did
102 not help that its computation of "hop" count was further tweaked to
103 penalize being on a side branch of a merge. The logic has been
104 updated to favor using the tag with the oldest tagger date, which
105 is a lot easier to explain to the end users: "We describe a commit
106 in terms of the (chronologically) oldest tag that contains the
107 commit."
108 (merge 7550424 js/name-rev-use-oldest-ref later to maint).
109
110 * "git clone" learned "--shallow-submodules" option.
111
112 * HTTP transport clients learned to throw extra HTTP headers at the
113 server, specified via http.extraHeader configuration variable.
114
115 * Patch output from "git diff" and friends has been tweaked to be
116 more readable by using a blank line as a strong hint that the
117 contents before and after it belong to a logically separate unit.
118
119
120 Performance, Internal Implementation, Development Support etc.
121
122 * The embedded args argv-array in the child process is used to build
123 the command line to run pack-objects instead of using a separate
124 array of strings.
125
126 * A test for tags has been restructured so that more parts of it can
127 easily be run on a platform without a working GnuPG.
128
129 * The startup_info data, which records if we are working inside a
130 repository (among other things), are now uniformly available to Git
131 subcommand implementations, and Git avoids attempting to touch
132 references when we are not in a repository.
133
134 * The command line argument parser for "receive-pack" has been
135 rewritten to use parse-options.
136
137 * A major part of "git submodule update" has been ported to C to take
138 advantage of the recently added framework to run download tasks in
139 parallel.
140
141 * Rename bunch of tests on "git clone" for better organization.
142
143 * The tests that involve running httpd leaked the system-wide
144 configuration in /etc/gitconfig to the tested environment.
145
146 * Build updates for MSVC.
147
148 * The repository set-up sequence has been streamlined (the biggest
149 change is that there is no longer git_config_early()), so that we
150 do not attempt to look into refs/* when we know we do not have a
151 Git repository.
152
153 * Code restructuring around the "refs" area to prepare for pluggable
154 refs backends.
155
156 * Sources to many test helper binaries (and the generated helpers)
157 have been moved to t/helper/ subdirectory to reduce clutter at the
158 top level of the tree.
159
160 Note that this can break your tests if you check out revisions
161 across the merge boundary of this topic, e0b58519 (Merge branch
162 'nd/test-helpers', 2016-04-29), as bin-wrappers/test-* are not
163 rebuilt to point the underlying executables. For now, "make
164 distclean" is your friend.
165
166 * Unify internal logic between "git tag -v" and "git verify-tag"
167 commands by making one directly call into the other.
168 (merge bef234b st/verify-tag later to maint).
169
170 * "merge-recursive" strategy incorrectly checked if a path that is
171 involved in its internal merge exists in the working tree.
172
173 * The test scripts for "git p4" (but not "git p4" implementation
174 itself) has been updated so that they would work even on a system
175 where the installed version of Python is python 3.
176 (merge 1fb3fb4 ld/p4-test-py3 later to maint).
177
178 * As nobody maintains our in-tree git.spec.in and distros use their
179 own spec file, we stopped pretending that we support "make rpm".
180
181 * Move from unsigned char[20] to struct object_id continues.
182
183
184 Also contains various documentation updates and code clean-ups.
185
186
187 Fixes since v2.8
188 ----------------
189
190 Unless otherwise noted, all the fixes since v2.8 in the maintenance
191 track are contained in this release (see the maintenance releases'
192 notes for details).
193
194 * "git config --get-urlmatch", unlike other variants of the "git
195 config --get" family, did not signal error with its exit status
196 when there was no matching configuration.
197
198 * The "--local-env-vars" and "--resolve-git-dir" options of "git
199 rev-parse" failed to work outside a repository when the command's
200 option parsing was rewritten in 1.8.5 era.
201
202 * "git index-pack --keep[=<msg>] pack-$name.pack" simply did not work.
203
204 * Fetching of history by naming a commit object name directly didn't
205 work across remote-curl transport.
206
207 * A small memory leak in an error codepath has been plugged in xdiff
208 code.
209
210 * strbuf_getwholeline() did not NUL-terminate the buffer on certain
211 corner cases in its error codepath.
212
213 * "git mergetool" did not work well with conflicts that both sides
214 deleted.
215
216 * "git send-email" had trouble parsing alias file in mailrc format
217 when lines in it had trailing whitespaces on them.
218
219 * When "git merge --squash" stopped due to conflict, the concluding
220 "git commit" failed to read in the SQUASH_MSG that shows the log
221 messages from all the squashed commits.
222
223 * "git merge FETCH_HEAD" dereferenced NULL pointer when merging
224 nothing into an unborn history (which is arguably unusual usage,
225 which perhaps was the reason why nobody noticed it).
226
227 * When "git worktree" feature is in use, "git branch -d" allowed
228 deletion of a branch that is checked out in another worktree,
229 which was wrong.
230
231 * When "git worktree" feature is in use, "git branch -m" renamed a
232 branch that is checked out in another worktree without adjusting
233 the HEAD symbolic ref for the worktree.
234
235 * "git diff -M" used to work better when two originally identical
236 files A and B got renamed to X/A and X/B by pairing A to X/A and B
237 to X/B, but this was broken in the 2.0 timeframe.
238
239 * "git send-pack --all <there>" was broken when its command line
240 option parsing was written in the 2.6 timeframe.
241
242 * "git format-patch --help" showed `-s` and `--no-patch` as if these
243 are valid options to the command. We already hide `--patch` option
244 from the documentation, because format-patch is about showing the
245 diff, and the documentation now hides these options as well.
246
247 * When running "git blame $path" with unnormalized data in the index
248 for the path, the data in the working tree was blamed, even though
249 "git add" would not have changed what is already in the index, due
250 to "safe crlf" that disables the line-end conversion. It has been
251 corrected.
252
253 * A change back in version 2.7 to "git branch" broke display of a
254 symbolic ref in a non-standard place in the refs/ hierarchy (we
255 expect symbolic refs to appear in refs/remotes/*/HEAD to point at
256 the primary branch the remote has, and as .git/HEAD to point at the
257 branch we locally checked out).
258
259 * A partial rewrite of "git submodule" in the 2.7 timeframe changed
260 the way the gitdir: pointer in the submodules point at the real
261 repository location to use absolute paths by accident. This has
262 been corrected.
263
264 * "git commit" misbehaved in a few minor ways when an empty message
265 is given via -m '', all of which has been corrected.
266
267 * Support for CRAM-MD5 authentication method in "git imap-send" did
268 not work well.
269
270 * Upcoming OpenSSL 1.1.0 will break compilation b updating a few APIs
271 we use in imap-send, which has been adjusted for the change.
272 (merge 1245c74 ky/imap-send-openssl-1.1.0 later to maint).
273
274 * The socks5:// proxy support added back in 2.6.4 days was not aware
275 that socks5h:// proxies behave differently.
276
277 * "git config" had a codepath that tried to pass a NULL to
278 printf("%s"), which nobody seems to have noticed.
279
280 * On Cygwin, object creation uses the "create a temporary and then
281 rename it to the final name" pattern, not "create a temporary,
282 hardlink it to the final name and then unlink the temporary"
283 pattern.
284
285 This is necessary to use Git on Windows shared directories, and is
286 already enabled for the MinGW and plain Windows builds. It also
287 has been used in Cygwin packaged versions of Git for quite a while.
288 See http://thread.gmane.org/gmane.comp.version-control.git/291853
289
290 * "merge-octopus" strategy did not ensure that the index is clean
291 when merge begins.
292
293 * When "git merge" notices that the merge can be resolved purely at
294 the tree level (without having to merge blobs) and the resulting
295 tree happens to already exist in the object store, it forgot to
296 update the index, which lead to an inconsistent state for later
297 operations.
298
299 * "git submodule" reports the paths of submodules the command
300 recurses into, but this was incorrect when the command was not run
301 from the root level of the superproject.
302 (merge 2ab5660 sb/submodule-path-misc-bugs later to maint).
303
304 * The "user.useConfigOnly" configuration variable makes it an error
305 if users do not explicitly set user.name and user.email. However,
306 its check was not done early enough and allowed another error to
307 trigger, reporting that the default value we guessed from the
308 system setting was unusable. This was a suboptimal end-user
309 experience as we want the users to set user.name/user.email without
310 relying on the auto-detection at all.
311 (merge d3c06c1 da/user-useconfigonly later to maint).
312
313 * "git mv old new" did not adjust the path for a submodule that lives
314 as a subdirectory inside old/ directory correctly.
315 (merge a127331 sb/mv-submodule-fix later to maint).
316
317 * "git replace -e" did not honour "core.editor" configuration.
318 (merge 36b1437 js/replace-edit-use-editor-configuration later to maint).
319
320 * "git push" from a corrupt repository that attempts to push a large
321 number of refs deadlocked; the thread to relay rejection notices
322 for these ref updates blocked on writing them to the main thread,
323 after the main thread at the receiving end notices that the push
324 failed and decides not to read these notices and return a failure.
325 (merge f924b52a jk/push-client-deadlock-fix later to maint).
326
327 * mmap emulation on Windows has been optimized and work better without
328 consuming paging store when not needed.
329 (merge d5425d1 js/win32-mmap later to maint).
330
331 * A question by "git send-email" to ask the identity of the sender
332 has been updated.
333 (merge 0d6b21e jd/send-email-to-whom later to maint).
334
335 * UI consistency improvements for "git mergetool".
336 (merge cce076e nf/mergetool-prompt later to maint).
337
338 * "git rebase -m" could be asked to rebase an entire branch starting
339 from the root, but failed by assuming that there always is a parent
340 commit to the first commit on the branch.
341 (merge 79f4344 bw/rebase-merge-entire-branch later to maint).
342
343 * Fix a broken "p4 lfs" test.
344 (merge 9e220fe ls/p4-lfs-test-fix-2.7.0 later to maint).
345
346 * Other minor clean-ups and documentation updates
347 (merge 8b5a3e9 kn/for-each-tag-branch later to maint).
348 (merge 99dab16 sb/misc-cleanups later to maint).
349 (merge 7a6a44c cc/apply later to maint).
350 (merge 6594883 nd/remove-unused later to maint).
351 (merge 0ff7410 sg/test-lib-simplify-expr-away later to maint).
352 (merge 060e776 jk/fix-attribute-macro-in-2.5 later to maint).
353 (merge d16df0c rt/string-list-lookup-cleanup later to maint).
354 (merge 376eb60 sb/config-exit-status-list later to maint).