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[git/git.git] / Documentation / git-rebase.txt
1 git-rebase(1)
2 =============
3
4 NAME
5 ----
6 git-rebase - Reapply commits on top of another base tip
7
8 SYNOPSIS
9 --------
10 [verse]
11 'git rebase' [-i | --interactive] [<options>] [--exec <cmd>] [--onto <newbase>]
12 [<upstream> [<branch>]]
13 'git rebase' [-i | --interactive] [<options>] [--exec <cmd>] [--onto <newbase>]
14 --root [<branch>]
15 'git rebase' --continue | --skip | --abort | --quit | --edit-todo | --show-current-patch
16
17 DESCRIPTION
18 -----------
19 If <branch> is specified, 'git rebase' will perform an automatic
20 `git checkout <branch>` before doing anything else. Otherwise
21 it remains on the current branch.
22
23 If <upstream> is not specified, the upstream configured in
24 branch.<name>.remote and branch.<name>.merge options will be used (see
25 linkgit:git-config[1] for details) and the `--fork-point` option is
26 assumed. If you are currently not on any branch or if the current
27 branch does not have a configured upstream, the rebase will abort.
28
29 All changes made by commits in the current branch but that are not
30 in <upstream> are saved to a temporary area. This is the same set
31 of commits that would be shown by `git log <upstream>..HEAD`; or by
32 `git log 'fork_point'..HEAD`, if `--fork-point` is active (see the
33 description on `--fork-point` below); or by `git log HEAD`, if the
34 `--root` option is specified.
35
36 The current branch is reset to <upstream>, or <newbase> if the
37 --onto option was supplied. This has the exact same effect as
38 `git reset --hard <upstream>` (or <newbase>). ORIG_HEAD is set
39 to point at the tip of the branch before the reset.
40
41 The commits that were previously saved into the temporary area are
42 then reapplied to the current branch, one by one, in order. Note that
43 any commits in HEAD which introduce the same textual changes as a commit
44 in HEAD..<upstream> are omitted (i.e., a patch already accepted upstream
45 with a different commit message or timestamp will be skipped).
46
47 It is possible that a merge failure will prevent this process from being
48 completely automatic. You will have to resolve any such merge failure
49 and run `git rebase --continue`. Another option is to bypass the commit
50 that caused the merge failure with `git rebase --skip`. To check out the
51 original <branch> and remove the .git/rebase-apply working files, use the
52 command `git rebase --abort` instead.
53
54 Assume the following history exists and the current branch is "topic":
55
56 ------------
57 A---B---C topic
58 /
59 D---E---F---G master
60 ------------
61
62 From this point, the result of either of the following commands:
63
64
65 git rebase master
66 git rebase master topic
67
68 would be:
69
70 ------------
71 A'--B'--C' topic
72 /
73 D---E---F---G master
74 ------------
75
76 *NOTE:* The latter form is just a short-hand of `git checkout topic`
77 followed by `git rebase master`. When rebase exits `topic` will
78 remain the checked-out branch.
79
80 If the upstream branch already contains a change you have made (e.g.,
81 because you mailed a patch which was applied upstream), then that commit
82 will be skipped. For example, running `git rebase master` on the
83 following history (in which `A'` and `A` introduce the same set of changes,
84 but have different committer information):
85
86 ------------
87 A---B---C topic
88 /
89 D---E---A'---F master
90 ------------
91
92 will result in:
93
94 ------------
95 B'---C' topic
96 /
97 D---E---A'---F master
98 ------------
99
100 Here is how you would transplant a topic branch based on one
101 branch to another, to pretend that you forked the topic branch
102 from the latter branch, using `rebase --onto`.
103
104 First let's assume your 'topic' is based on branch 'next'.
105 For example, a feature developed in 'topic' depends on some
106 functionality which is found in 'next'.
107
108 ------------
109 o---o---o---o---o master
110 \
111 o---o---o---o---o next
112 \
113 o---o---o topic
114 ------------
115
116 We want to make 'topic' forked from branch 'master'; for example,
117 because the functionality on which 'topic' depends was merged into the
118 more stable 'master' branch. We want our tree to look like this:
119
120 ------------
121 o---o---o---o---o master
122 | \
123 | o'--o'--o' topic
124 \
125 o---o---o---o---o next
126 ------------
127
128 We can get this using the following command:
129
130 git rebase --onto master next topic
131
132
133 Another example of --onto option is to rebase part of a
134 branch. If we have the following situation:
135
136 ------------
137 H---I---J topicB
138 /
139 E---F---G topicA
140 /
141 A---B---C---D master
142 ------------
143
144 then the command
145
146 git rebase --onto master topicA topicB
147
148 would result in:
149
150 ------------
151 H'--I'--J' topicB
152 /
153 | E---F---G topicA
154 |/
155 A---B---C---D master
156 ------------
157
158 This is useful when topicB does not depend on topicA.
159
160 A range of commits could also be removed with rebase. If we have
161 the following situation:
162
163 ------------
164 E---F---G---H---I---J topicA
165 ------------
166
167 then the command
168
169 git rebase --onto topicA~5 topicA~3 topicA
170
171 would result in the removal of commits F and G:
172
173 ------------
174 E---H'---I'---J' topicA
175 ------------
176
177 This is useful if F and G were flawed in some way, or should not be
178 part of topicA. Note that the argument to --onto and the <upstream>
179 parameter can be any valid commit-ish.
180
181 In case of conflict, 'git rebase' will stop at the first problematic commit
182 and leave conflict markers in the tree. You can use 'git diff' to locate
183 the markers (<<<<<<) and make edits to resolve the conflict. For each
184 file you edit, you need to tell Git that the conflict has been resolved,
185 typically this would be done with
186
187
188 git add <filename>
189
190
191 After resolving the conflict manually and updating the index with the
192 desired resolution, you can continue the rebasing process with
193
194
195 git rebase --continue
196
197
198 Alternatively, you can undo the 'git rebase' with
199
200
201 git rebase --abort
202
203 CONFIGURATION
204 -------------
205
206 include::config/rebase.txt[]
207
208 OPTIONS
209 -------
210 --onto <newbase>::
211 Starting point at which to create the new commits. If the
212 --onto option is not specified, the starting point is
213 <upstream>. May be any valid commit, and not just an
214 existing branch name.
215 +
216 As a special case, you may use "A\...B" as a shortcut for the
217 merge base of A and B if there is exactly one merge base. You can
218 leave out at most one of A and B, in which case it defaults to HEAD.
219
220 <upstream>::
221 Upstream branch to compare against. May be any valid commit,
222 not just an existing branch name. Defaults to the configured
223 upstream for the current branch.
224
225 <branch>::
226 Working branch; defaults to HEAD.
227
228 --continue::
229 Restart the rebasing process after having resolved a merge conflict.
230
231 --abort::
232 Abort the rebase operation and reset HEAD to the original
233 branch. If <branch> was provided when the rebase operation was
234 started, then HEAD will be reset to <branch>. Otherwise HEAD
235 will be reset to where it was when the rebase operation was
236 started.
237
238 --quit::
239 Abort the rebase operation but HEAD is not reset back to the
240 original branch. The index and working tree are also left
241 unchanged as a result.
242
243 --keep-empty::
244 Keep the commits that do not change anything from its
245 parents in the result.
246 +
247 See also INCOMPATIBLE OPTIONS below.
248
249 --allow-empty-message::
250 By default, rebasing commits with an empty message will fail.
251 This option overrides that behavior, allowing commits with empty
252 messages to be rebased.
253 +
254 See also INCOMPATIBLE OPTIONS below.
255
256 --skip::
257 Restart the rebasing process by skipping the current patch.
258
259 --edit-todo::
260 Edit the todo list during an interactive rebase.
261
262 --show-current-patch::
263 Show the current patch in an interactive rebase or when rebase
264 is stopped because of conflicts. This is the equivalent of
265 `git show REBASE_HEAD`.
266
267 -m::
268 --merge::
269 Use merging strategies to rebase. When the recursive (default) merge
270 strategy is used, this allows rebase to be aware of renames on the
271 upstream side.
272 +
273 Note that a rebase merge works by replaying each commit from the working
274 branch on top of the <upstream> branch. Because of this, when a merge
275 conflict happens, the side reported as 'ours' is the so-far rebased
276 series, starting with <upstream>, and 'theirs' is the working branch. In
277 other words, the sides are swapped.
278 +
279 See also INCOMPATIBLE OPTIONS below.
280
281 -s <strategy>::
282 --strategy=<strategy>::
283 Use the given merge strategy.
284 If there is no `-s` option 'git merge-recursive' is used
285 instead. This implies --merge.
286 +
287 Because 'git rebase' replays each commit from the working branch
288 on top of the <upstream> branch using the given strategy, using
289 the 'ours' strategy simply empties all patches from the <branch>,
290 which makes little sense.
291 +
292 See also INCOMPATIBLE OPTIONS below.
293
294 -X <strategy-option>::
295 --strategy-option=<strategy-option>::
296 Pass the <strategy-option> through to the merge strategy.
297 This implies `--merge` and, if no strategy has been
298 specified, `-s recursive`. Note the reversal of 'ours' and
299 'theirs' as noted above for the `-m` option.
300 +
301 See also INCOMPATIBLE OPTIONS below.
302
303 -S[<keyid>]::
304 --gpg-sign[=<keyid>]::
305 GPG-sign commits. The `keyid` argument is optional and
306 defaults to the committer identity; if specified, it must be
307 stuck to the option without a space.
308
309 -q::
310 --quiet::
311 Be quiet. Implies --no-stat.
312
313 -v::
314 --verbose::
315 Be verbose. Implies --stat.
316
317 --stat::
318 Show a diffstat of what changed upstream since the last rebase. The
319 diffstat is also controlled by the configuration option rebase.stat.
320
321 -n::
322 --no-stat::
323 Do not show a diffstat as part of the rebase process.
324
325 --no-verify::
326 This option bypasses the pre-rebase hook. See also linkgit:githooks[5].
327
328 --verify::
329 Allows the pre-rebase hook to run, which is the default. This option can
330 be used to override --no-verify. See also linkgit:githooks[5].
331
332 -C<n>::
333 Ensure at least <n> lines of surrounding context match before
334 and after each change. When fewer lines of surrounding
335 context exist they all must match. By default no context is
336 ever ignored.
337 +
338 See also INCOMPATIBLE OPTIONS below.
339
340 --no-ff::
341 --force-rebase::
342 -f::
343 Individually replay all rebased commits instead of fast-forwarding
344 over the unchanged ones. This ensures that the entire history of
345 the rebased branch is composed of new commits.
346 +
347 You may find this helpful after reverting a topic branch merge, as this option
348 recreates the topic branch with fresh commits so it can be remerged
349 successfully without needing to "revert the reversion" (see the
350 link:howto/revert-a-faulty-merge.html[revert-a-faulty-merge How-To] for
351 details).
352
353 --fork-point::
354 --no-fork-point::
355 Use reflog to find a better common ancestor between <upstream>
356 and <branch> when calculating which commits have been
357 introduced by <branch>.
358 +
359 When --fork-point is active, 'fork_point' will be used instead of
360 <upstream> to calculate the set of commits to rebase, where
361 'fork_point' is the result of `git merge-base --fork-point <upstream>
362 <branch>` command (see linkgit:git-merge-base[1]). If 'fork_point'
363 ends up being empty, the <upstream> will be used as a fallback.
364 +
365 If either <upstream> or --root is given on the command line, then the
366 default is `--no-fork-point`, otherwise the default is `--fork-point`.
367
368 --ignore-whitespace::
369 --whitespace=<option>::
370 These flag are passed to the 'git apply' program
371 (see linkgit:git-apply[1]) that applies the patch.
372 +
373 See also INCOMPATIBLE OPTIONS below.
374
375 --committer-date-is-author-date::
376 --ignore-date::
377 These flags are passed to 'git am' to easily change the dates
378 of the rebased commits (see linkgit:git-am[1]).
379 +
380 See also INCOMPATIBLE OPTIONS below.
381
382 --signoff::
383 Add a Signed-off-by: trailer to all the rebased commits. Note
384 that if `--interactive` is given then only commits marked to be
385 picked, edited or reworded will have the trailer added.
386 +
387 See also INCOMPATIBLE OPTIONS below.
388
389 -i::
390 --interactive::
391 Make a list of the commits which are about to be rebased. Let the
392 user edit that list before rebasing. This mode can also be used to
393 split commits (see SPLITTING COMMITS below).
394 +
395 The commit list format can be changed by setting the configuration option
396 rebase.instructionFormat. A customized instruction format will automatically
397 have the long commit hash prepended to the format.
398 +
399 See also INCOMPATIBLE OPTIONS below.
400
401 -r::
402 --rebase-merges[=(rebase-cousins|no-rebase-cousins)]::
403 By default, a rebase will simply drop merge commits from the todo
404 list, and put the rebased commits into a single, linear branch.
405 With `--rebase-merges`, the rebase will instead try to preserve
406 the branching structure within the commits that are to be rebased,
407 by recreating the merge commits. Any resolved merge conflicts or
408 manual amendments in these merge commits will have to be
409 resolved/re-applied manually.
410 +
411 By default, or when `no-rebase-cousins` was specified, commits which do not
412 have `<upstream>` as direct ancestor will keep their original branch point,
413 i.e. commits that would be excluded by gitlink:git-log[1]'s
414 `--ancestry-path` option will keep their original ancestry by default. If
415 the `rebase-cousins` mode is turned on, such commits are instead rebased
416 onto `<upstream>` (or `<onto>`, if specified).
417 +
418 The `--rebase-merges` mode is similar in spirit to `--preserve-merges`, but
419 in contrast to that option works well in interactive rebases: commits can be
420 reordered, inserted and dropped at will.
421 +
422 It is currently only possible to recreate the merge commits using the
423 `recursive` merge strategy; Different merge strategies can be used only via
424 explicit `exec git merge -s <strategy> [...]` commands.
425 +
426 See also REBASING MERGES and INCOMPATIBLE OPTIONS below.
427
428 -p::
429 --preserve-merges::
430 Recreate merge commits instead of flattening the history by replaying
431 commits a merge commit introduces. Merge conflict resolutions or manual
432 amendments to merge commits are not preserved.
433 +
434 This uses the `--interactive` machinery internally, but combining it
435 with the `--interactive` option explicitly is generally not a good
436 idea unless you know what you are doing (see BUGS below).
437 +
438 See also INCOMPATIBLE OPTIONS below.
439
440 -x <cmd>::
441 --exec <cmd>::
442 Append "exec <cmd>" after each line creating a commit in the
443 final history. <cmd> will be interpreted as one or more shell
444 commands. Any command that fails will interrupt the rebase,
445 with exit code 1.
446 +
447 You may execute several commands by either using one instance of `--exec`
448 with several commands:
449 +
450 git rebase -i --exec "cmd1 && cmd2 && ..."
451 +
452 or by giving more than one `--exec`:
453 +
454 git rebase -i --exec "cmd1" --exec "cmd2" --exec ...
455 +
456 If `--autosquash` is used, "exec" lines will not be appended for
457 the intermediate commits, and will only appear at the end of each
458 squash/fixup series.
459 +
460 This uses the `--interactive` machinery internally, but it can be run
461 without an explicit `--interactive`.
462 +
463 See also INCOMPATIBLE OPTIONS below.
464
465 --root::
466 Rebase all commits reachable from <branch>, instead of
467 limiting them with an <upstream>. This allows you to rebase
468 the root commit(s) on a branch. When used with --onto, it
469 will skip changes already contained in <newbase> (instead of
470 <upstream>) whereas without --onto it will operate on every change.
471 When used together with both --onto and --preserve-merges,
472 'all' root commits will be rewritten to have <newbase> as parent
473 instead.
474 +
475 See also INCOMPATIBLE OPTIONS below.
476
477 --autosquash::
478 --no-autosquash::
479 When the commit log message begins with "squash! ..." (or
480 "fixup! ..."), and there is already a commit in the todo list that
481 matches the same `...`, automatically modify the todo list of rebase
482 -i so that the commit marked for squashing comes right after the
483 commit to be modified, and change the action of the moved commit
484 from `pick` to `squash` (or `fixup`). A commit matches the `...` if
485 the commit subject matches, or if the `...` refers to the commit's
486 hash. As a fall-back, partial matches of the commit subject work,
487 too. The recommended way to create fixup/squash commits is by using
488 the `--fixup`/`--squash` options of linkgit:git-commit[1].
489 +
490 If the `--autosquash` option is enabled by default using the
491 configuration variable `rebase.autoSquash`, this option can be
492 used to override and disable this setting.
493 +
494 See also INCOMPATIBLE OPTIONS below.
495
496 --autostash::
497 --no-autostash::
498 Automatically create a temporary stash entry before the operation
499 begins, and apply it after the operation ends. This means
500 that you can run rebase on a dirty worktree. However, use
501 with care: the final stash application after a successful
502 rebase might result in non-trivial conflicts.
503
504 INCOMPATIBLE OPTIONS
505 --------------------
506
507 git-rebase has many flags that are incompatible with each other,
508 predominantly due to the fact that it has three different underlying
509 implementations:
510
511 * one based on linkgit:git-am[1] (the default)
512 * one based on git-merge-recursive (merge backend)
513 * one based on linkgit:git-cherry-pick[1] (interactive backend)
514
515 Flags only understood by the am backend:
516
517 * --committer-date-is-author-date
518 * --ignore-date
519 * --whitespace
520 * --ignore-whitespace
521 * -C
522
523 Flags understood by both merge and interactive backends:
524
525 * --merge
526 * --strategy
527 * --strategy-option
528 * --allow-empty-message
529
530 Flags only understood by the interactive backend:
531
532 * --[no-]autosquash
533 * --rebase-merges
534 * --preserve-merges
535 * --interactive
536 * --exec
537 * --keep-empty
538 * --autosquash
539 * --edit-todo
540 * --root when used in combination with --onto
541
542 Other incompatible flag pairs:
543
544 * --preserve-merges and --interactive
545 * --preserve-merges and --signoff
546 * --preserve-merges and --rebase-merges
547 * --rebase-merges and --strategy
548 * --rebase-merges and --strategy-option
549
550 BEHAVIORAL DIFFERENCES
551 -----------------------
552
553 There are some subtle differences how the backends behave.
554
555 Empty commits
556 ~~~~~~~~~~~~~
557
558 The am backend drops any "empty" commits, regardless of whether the
559 commit started empty (had no changes relative to its parent to
560 start with) or ended empty (all changes were already applied
561 upstream in other commits).
562
563 The merge backend does the same.
564
565 The interactive backend drops commits by default that
566 started empty and halts if it hits a commit that ended up empty.
567 The `--keep-empty` option exists for the interactive backend to allow
568 it to keep commits that started empty.
569
570 Directory rename detection
571 ~~~~~~~~~~~~~~~~~~~~~~~~~~
572
573 Directory rename heuristics are enabled in the merge and interactive
574 backends. Due to the lack of accurate tree information, directory
575 rename detection is disabled in the am backend.
576
577 include::merge-strategies.txt[]
578
579 NOTES
580 -----
581
582 You should understand the implications of using 'git rebase' on a
583 repository that you share. See also RECOVERING FROM UPSTREAM REBASE
584 below.
585
586 When the git-rebase command is run, it will first execute a "pre-rebase"
587 hook if one exists. You can use this hook to do sanity checks and
588 reject the rebase if it isn't appropriate. Please see the template
589 pre-rebase hook script for an example.
590
591 Upon completion, <branch> will be the current branch.
592
593 INTERACTIVE MODE
594 ----------------
595
596 Rebasing interactively means that you have a chance to edit the commits
597 which are rebased. You can reorder the commits, and you can
598 remove them (weeding out bad or otherwise unwanted patches).
599
600 The interactive mode is meant for this type of workflow:
601
602 1. have a wonderful idea
603 2. hack on the code
604 3. prepare a series for submission
605 4. submit
606
607 where point 2. consists of several instances of
608
609 a) regular use
610
611 1. finish something worthy of a commit
612 2. commit
613
614 b) independent fixup
615
616 1. realize that something does not work
617 2. fix that
618 3. commit it
619
620 Sometimes the thing fixed in b.2. cannot be amended to the not-quite
621 perfect commit it fixes, because that commit is buried deeply in a
622 patch series. That is exactly what interactive rebase is for: use it
623 after plenty of "a"s and "b"s, by rearranging and editing
624 commits, and squashing multiple commits into one.
625
626 Start it with the last commit you want to retain as-is:
627
628 git rebase -i <after-this-commit>
629
630 An editor will be fired up with all the commits in your current branch
631 (ignoring merge commits), which come after the given commit. You can
632 reorder the commits in this list to your heart's content, and you can
633 remove them. The list looks more or less like this:
634
635 -------------------------------------------
636 pick deadbee The oneline of this commit
637 pick fa1afe1 The oneline of the next commit
638 ...
639 -------------------------------------------
640
641 The oneline descriptions are purely for your pleasure; 'git rebase' will
642 not look at them but at the commit names ("deadbee" and "fa1afe1" in this
643 example), so do not delete or edit the names.
644
645 By replacing the command "pick" with the command "edit", you can tell
646 'git rebase' to stop after applying that commit, so that you can edit
647 the files and/or the commit message, amend the commit, and continue
648 rebasing.
649
650 To interrupt the rebase (just like an "edit" command would do, but without
651 cherry-picking any commit first), use the "break" command.
652
653 If you just want to edit the commit message for a commit, replace the
654 command "pick" with the command "reword".
655
656 To drop a commit, replace the command "pick" with "drop", or just
657 delete the matching line.
658
659 If you want to fold two or more commits into one, replace the command
660 "pick" for the second and subsequent commits with "squash" or "fixup".
661 If the commits had different authors, the folded commit will be
662 attributed to the author of the first commit. The suggested commit
663 message for the folded commit is the concatenation of the commit
664 messages of the first commit and of those with the "squash" command,
665 but omits the commit messages of commits with the "fixup" command.
666
667 'git rebase' will stop when "pick" has been replaced with "edit" or
668 when a command fails due to merge errors. When you are done editing
669 and/or resolving conflicts you can continue with `git rebase --continue`.
670
671 For example, if you want to reorder the last 5 commits, such that what
672 was HEAD~4 becomes the new HEAD. To achieve that, you would call
673 'git rebase' like this:
674
675 ----------------------
676 $ git rebase -i HEAD~5
677 ----------------------
678
679 And move the first patch to the end of the list.
680
681 You might want to preserve merges, if you have a history like this:
682
683 ------------------
684 X
685 \
686 A---M---B
687 /
688 ---o---O---P---Q
689 ------------------
690
691 Suppose you want to rebase the side branch starting at "A" to "Q". Make
692 sure that the current HEAD is "B", and call
693
694 -----------------------------
695 $ git rebase -i -p --onto Q O
696 -----------------------------
697
698 Reordering and editing commits usually creates untested intermediate
699 steps. You may want to check that your history editing did not break
700 anything by running a test, or at least recompiling at intermediate
701 points in history by using the "exec" command (shortcut "x"). You may
702 do so by creating a todo list like this one:
703
704 -------------------------------------------
705 pick deadbee Implement feature XXX
706 fixup f1a5c00 Fix to feature XXX
707 exec make
708 pick c0ffeee The oneline of the next commit
709 edit deadbab The oneline of the commit after
710 exec cd subdir; make test
711 ...
712 -------------------------------------------
713
714 The interactive rebase will stop when a command fails (i.e. exits with
715 non-0 status) to give you an opportunity to fix the problem. You can
716 continue with `git rebase --continue`.
717
718 The "exec" command launches the command in a shell (the one specified
719 in `$SHELL`, or the default shell if `$SHELL` is not set), so you can
720 use shell features (like "cd", ">", ";" ...). The command is run from
721 the root of the working tree.
722
723 ----------------------------------
724 $ git rebase -i --exec "make test"
725 ----------------------------------
726
727 This command lets you check that intermediate commits are compilable.
728 The todo list becomes like that:
729
730 --------------------
731 pick 5928aea one
732 exec make test
733 pick 04d0fda two
734 exec make test
735 pick ba46169 three
736 exec make test
737 pick f4593f9 four
738 exec make test
739 --------------------
740
741 SPLITTING COMMITS
742 -----------------
743
744 In interactive mode, you can mark commits with the action "edit". However,
745 this does not necessarily mean that 'git rebase' expects the result of this
746 edit to be exactly one commit. Indeed, you can undo the commit, or you can
747 add other commits. This can be used to split a commit into two:
748
749 - Start an interactive rebase with `git rebase -i <commit>^`, where
750 <commit> is the commit you want to split. In fact, any commit range
751 will do, as long as it contains that commit.
752
753 - Mark the commit you want to split with the action "edit".
754
755 - When it comes to editing that commit, execute `git reset HEAD^`. The
756 effect is that the HEAD is rewound by one, and the index follows suit.
757 However, the working tree stays the same.
758
759 - Now add the changes to the index that you want to have in the first
760 commit. You can use `git add` (possibly interactively) or
761 'git gui' (or both) to do that.
762
763 - Commit the now-current index with whatever commit message is appropriate
764 now.
765
766 - Repeat the last two steps until your working tree is clean.
767
768 - Continue the rebase with `git rebase --continue`.
769
770 If you are not absolutely sure that the intermediate revisions are
771 consistent (they compile, pass the testsuite, etc.) you should use
772 'git stash' to stash away the not-yet-committed changes
773 after each commit, test, and amend the commit if fixes are necessary.
774
775
776 RECOVERING FROM UPSTREAM REBASE
777 -------------------------------
778
779 Rebasing (or any other form of rewriting) a branch that others have
780 based work on is a bad idea: anyone downstream of it is forced to
781 manually fix their history. This section explains how to do the fix
782 from the downstream's point of view. The real fix, however, would be
783 to avoid rebasing the upstream in the first place.
784
785 To illustrate, suppose you are in a situation where someone develops a
786 'subsystem' branch, and you are working on a 'topic' that is dependent
787 on this 'subsystem'. You might end up with a history like the
788 following:
789
790 ------------
791 o---o---o---o---o---o---o---o master
792 \
793 o---o---o---o---o subsystem
794 \
795 *---*---* topic
796 ------------
797
798 If 'subsystem' is rebased against 'master', the following happens:
799
800 ------------
801 o---o---o---o---o---o---o---o master
802 \ \
803 o---o---o---o---o o'--o'--o'--o'--o' subsystem
804 \
805 *---*---* topic
806 ------------
807
808 If you now continue development as usual, and eventually merge 'topic'
809 to 'subsystem', the commits from 'subsystem' will remain duplicated forever:
810
811 ------------
812 o---o---o---o---o---o---o---o master
813 \ \
814 o---o---o---o---o o'--o'--o'--o'--o'--M subsystem
815 \ /
816 *---*---*-..........-*--* topic
817 ------------
818
819 Such duplicates are generally frowned upon because they clutter up
820 history, making it harder to follow. To clean things up, you need to
821 transplant the commits on 'topic' to the new 'subsystem' tip, i.e.,
822 rebase 'topic'. This becomes a ripple effect: anyone downstream from
823 'topic' is forced to rebase too, and so on!
824
825 There are two kinds of fixes, discussed in the following subsections:
826
827 Easy case: The changes are literally the same.::
828
829 This happens if the 'subsystem' rebase was a simple rebase and
830 had no conflicts.
831
832 Hard case: The changes are not the same.::
833
834 This happens if the 'subsystem' rebase had conflicts, or used
835 `--interactive` to omit, edit, squash, or fixup commits; or
836 if the upstream used one of `commit --amend`, `reset`, or
837 `filter-branch`.
838
839
840 The easy case
841 ~~~~~~~~~~~~~
842
843 Only works if the changes (patch IDs based on the diff contents) on
844 'subsystem' are literally the same before and after the rebase
845 'subsystem' did.
846
847 In that case, the fix is easy because 'git rebase' knows to skip
848 changes that are already present in the new upstream. So if you say
849 (assuming you're on 'topic')
850 ------------
851 $ git rebase subsystem
852 ------------
853 you will end up with the fixed history
854 ------------
855 o---o---o---o---o---o---o---o master
856 \
857 o'--o'--o'--o'--o' subsystem
858 \
859 *---*---* topic
860 ------------
861
862
863 The hard case
864 ~~~~~~~~~~~~~
865
866 Things get more complicated if the 'subsystem' changes do not exactly
867 correspond to the ones before the rebase.
868
869 NOTE: While an "easy case recovery" sometimes appears to be successful
870 even in the hard case, it may have unintended consequences. For
871 example, a commit that was removed via `git rebase
872 --interactive` will be **resurrected**!
873
874 The idea is to manually tell 'git rebase' "where the old 'subsystem'
875 ended and your 'topic' began", that is, what the old merge-base
876 between them was. You will have to find a way to name the last commit
877 of the old 'subsystem', for example:
878
879 * With the 'subsystem' reflog: after 'git fetch', the old tip of
880 'subsystem' is at `subsystem@{1}`. Subsequent fetches will
881 increase the number. (See linkgit:git-reflog[1].)
882
883 * Relative to the tip of 'topic': knowing that your 'topic' has three
884 commits, the old tip of 'subsystem' must be `topic~3`.
885
886 You can then transplant the old `subsystem..topic` to the new tip by
887 saying (for the reflog case, and assuming you are on 'topic' already):
888 ------------
889 $ git rebase --onto subsystem subsystem@{1}
890 ------------
891
892 The ripple effect of a "hard case" recovery is especially bad:
893 'everyone' downstream from 'topic' will now have to perform a "hard
894 case" recovery too!
895
896 REBASING MERGES
897 ---------------
898
899 The interactive rebase command was originally designed to handle
900 individual patch series. As such, it makes sense to exclude merge
901 commits from the todo list, as the developer may have merged the
902 then-current `master` while working on the branch, only to rebase
903 all the commits onto `master` eventually (skipping the merge
904 commits).
905
906 However, there are legitimate reasons why a developer may want to
907 recreate merge commits: to keep the branch structure (or "commit
908 topology") when working on multiple, inter-related branches.
909
910 In the following example, the developer works on a topic branch that
911 refactors the way buttons are defined, and on another topic branch
912 that uses that refactoring to implement a "Report a bug" button. The
913 output of `git log --graph --format=%s -5` may look like this:
914
915 ------------
916 * Merge branch 'report-a-bug'
917 |\
918 | * Add the feedback button
919 * | Merge branch 'refactor-button'
920 |\ \
921 | |/
922 | * Use the Button class for all buttons
923 | * Extract a generic Button class from the DownloadButton one
924 ------------
925
926 The developer might want to rebase those commits to a newer `master`
927 while keeping the branch topology, for example when the first topic
928 branch is expected to be integrated into `master` much earlier than the
929 second one, say, to resolve merge conflicts with changes to the
930 DownloadButton class that made it into `master`.
931
932 This rebase can be performed using the `--rebase-merges` option.
933 It will generate a todo list looking like this:
934
935 ------------
936 label onto
937
938 # Branch: refactor-button
939 reset onto
940 pick 123456 Extract a generic Button class from the DownloadButton one
941 pick 654321 Use the Button class for all buttons
942 label refactor-button
943
944 # Branch: report-a-bug
945 reset refactor-button # Use the Button class for all buttons
946 pick abcdef Add the feedback button
947 label report-a-bug
948
949 reset onto
950 merge -C a1b2c3 refactor-button # Merge 'refactor-button'
951 merge -C 6f5e4d report-a-bug # Merge 'report-a-bug'
952 ------------
953
954 In contrast to a regular interactive rebase, there are `label`, `reset`
955 and `merge` commands in addition to `pick` ones.
956
957 The `label` command associates a label with the current HEAD when that
958 command is executed. These labels are created as worktree-local refs
959 (`refs/rewritten/<label>`) that will be deleted when the rebase
960 finishes. That way, rebase operations in multiple worktrees linked to
961 the same repository do not interfere with one another. If the `label`
962 command fails, it is rescheduled immediately, with a helpful message how
963 to proceed.
964
965 The `reset` command resets the HEAD, index and worktree to the specified
966 revision. It is similar to an `exec git reset --hard <label>`, but
967 refuses to overwrite untracked files. If the `reset` command fails, it is
968 rescheduled immediately, with a helpful message how to edit the todo list
969 (this typically happens when a `reset` command was inserted into the todo
970 list manually and contains a typo).
971
972 The `merge` command will merge the specified revision(s) into whatever
973 is HEAD at that time. With `-C <original-commit>`, the commit message of
974 the specified merge commit will be used. When the `-C` is changed to
975 a lower-case `-c`, the message will be opened in an editor after a
976 successful merge so that the user can edit the message.
977
978 If a `merge` command fails for any reason other than merge conflicts (i.e.
979 when the merge operation did not even start), it is rescheduled immediately.
980
981 At this time, the `merge` command will *always* use the `recursive`
982 merge strategy for regular merges, and `octopus` for octopus merges,
983 with no way to choose a different one. To work around
984 this, an `exec` command can be used to call `git merge` explicitly,
985 using the fact that the labels are worktree-local refs (the ref
986 `refs/rewritten/onto` would correspond to the label `onto`, for example).
987
988 Note: the first command (`label onto`) labels the revision onto which
989 the commits are rebased; The name `onto` is just a convention, as a nod
990 to the `--onto` option.
991
992 It is also possible to introduce completely new merge commits from scratch
993 by adding a command of the form `merge <merge-head>`. This form will
994 generate a tentative commit message and always open an editor to let the
995 user edit it. This can be useful e.g. when a topic branch turns out to
996 address more than a single concern and wants to be split into two or
997 even more topic branches. Consider this todo list:
998
999 ------------
1000 pick 192837 Switch from GNU Makefiles to CMake
1001 pick 5a6c7e Document the switch to CMake
1002 pick 918273 Fix detection of OpenSSL in CMake
1003 pick afbecd http: add support for TLS v1.3
1004 pick fdbaec Fix detection of cURL in CMake on Windows
1005 ------------
1006
1007 The one commit in this list that is not related to CMake may very well
1008 have been motivated by working on fixing all those bugs introduced by
1009 switching to CMake, but it addresses a different concern. To split this
1010 branch into two topic branches, the todo list could be edited like this:
1011
1012 ------------
1013 label onto
1014
1015 pick afbecd http: add support for TLS v1.3
1016 label tlsv1.3
1017
1018 reset onto
1019 pick 192837 Switch from GNU Makefiles to CMake
1020 pick 918273 Fix detection of OpenSSL in CMake
1021 pick fdbaec Fix detection of cURL in CMake on Windows
1022 pick 5a6c7e Document the switch to CMake
1023 label cmake
1024
1025 reset onto
1026 merge tlsv1.3
1027 merge cmake
1028 ------------
1029
1030 BUGS
1031 ----
1032 The todo list presented by `--preserve-merges --interactive` does not
1033 represent the topology of the revision graph. Editing commits and
1034 rewording their commit messages should work fine, but attempts to
1035 reorder commits tend to produce counterintuitive results. Use
1036 `--rebase-merges` in such scenarios instead.
1037
1038 For example, an attempt to rearrange
1039 ------------
1040 1 --- 2 --- 3 --- 4 --- 5
1041 ------------
1042 to
1043 ------------
1044 1 --- 2 --- 4 --- 3 --- 5
1045 ------------
1046 by moving the "pick 4" line will result in the following history:
1047 ------------
1048 3
1049 /
1050 1 --- 2 --- 4 --- 5
1051 ------------
1052
1053 GIT
1054 ---
1055 Part of the linkgit:git[1] suite