Merge branch 'ps/t1509-chroot-test-fixup'
[git/git.git] / Documentation / git-rebase.txt
1 git-rebase(1)
2 =============
3
4 NAME
5 ----
6 git-rebase - Forward-port local commits to the updated upstream head
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 | --edit-todo
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 rebase.stat::
207 Whether to show a diffstat of what changed upstream since the last
208 rebase. False by default.
209
210 rebase.autoSquash::
211 If set to true enable '--autosquash' option by default.
212
213 rebase.autoStash::
214 If set to true enable '--autostash' option by default.
215
216 rebase.missingCommitsCheck::
217 If set to "warn", print warnings about removed commits in
218 interactive mode. If set to "error", print the warnings and
219 stop the rebase. If set to "ignore", no checking is
220 done. "ignore" by default.
221
222 rebase.instructionFormat::
223 Custom commit list format to use during an '--interactive' rebase.
224
225 OPTIONS
226 -------
227 --onto <newbase>::
228 Starting point at which to create the new commits. If the
229 --onto option is not specified, the starting point is
230 <upstream>. May be any valid commit, and not just an
231 existing branch name.
232 +
233 As a special case, you may use "A\...B" as a shortcut for the
234 merge base of A and B if there is exactly one merge base. You can
235 leave out at most one of A and B, in which case it defaults to HEAD.
236
237 <upstream>::
238 Upstream branch to compare against. May be any valid commit,
239 not just an existing branch name. Defaults to the configured
240 upstream for the current branch.
241
242 <branch>::
243 Working branch; defaults to HEAD.
244
245 --continue::
246 Restart the rebasing process after having resolved a merge conflict.
247
248 --abort::
249 Abort the rebase operation and reset HEAD to the original
250 branch. If <branch> was provided when the rebase operation was
251 started, then HEAD will be reset to <branch>. Otherwise HEAD
252 will be reset to where it was when the rebase operation was
253 started.
254
255 --keep-empty::
256 Keep the commits that do not change anything from its
257 parents in the result.
258
259 --skip::
260 Restart the rebasing process by skipping the current patch.
261
262 --edit-todo::
263 Edit the todo list during an interactive rebase.
264
265 -m::
266 --merge::
267 Use merging strategies to rebase. When the recursive (default) merge
268 strategy is used, this allows rebase to be aware of renames on the
269 upstream side.
270 +
271 Note that a rebase merge works by replaying each commit from the working
272 branch on top of the <upstream> branch. Because of this, when a merge
273 conflict happens, the side reported as 'ours' is the so-far rebased
274 series, starting with <upstream>, and 'theirs' is the working branch. In
275 other words, the sides are swapped.
276
277 -s <strategy>::
278 --strategy=<strategy>::
279 Use the given merge strategy.
280 If there is no `-s` option 'git merge-recursive' is used
281 instead. This implies --merge.
282 +
283 Because 'git rebase' replays each commit from the working branch
284 on top of the <upstream> branch using the given strategy, using
285 the 'ours' strategy simply discards all patches from the <branch>,
286 which makes little sense.
287
288 -X <strategy-option>::
289 --strategy-option=<strategy-option>::
290 Pass the <strategy-option> through to the merge strategy.
291 This implies `--merge` and, if no strategy has been
292 specified, `-s recursive`. Note the reversal of 'ours' and
293 'theirs' as noted above for the `-m` option.
294
295 -S[<keyid>]::
296 --gpg-sign[=<keyid>]::
297 GPG-sign commits.
298
299 -q::
300 --quiet::
301 Be quiet. Implies --no-stat.
302
303 -v::
304 --verbose::
305 Be verbose. Implies --stat.
306
307 --stat::
308 Show a diffstat of what changed upstream since the last rebase. The
309 diffstat is also controlled by the configuration option rebase.stat.
310
311 -n::
312 --no-stat::
313 Do not show a diffstat as part of the rebase process.
314
315 --no-verify::
316 This option bypasses the pre-rebase hook. See also linkgit:githooks[5].
317
318 --verify::
319 Allows the pre-rebase hook to run, which is the default. This option can
320 be used to override --no-verify. See also linkgit:githooks[5].
321
322 -C<n>::
323 Ensure at least <n> lines of surrounding context match before
324 and after each change. When fewer lines of surrounding
325 context exist they all must match. By default no context is
326 ever ignored.
327
328 -f::
329 --force-rebase::
330 Force a rebase even if the current branch is up-to-date and
331 the command without `--force` would return without doing anything.
332 +
333 You may find this (or --no-ff with an interactive rebase) helpful after
334 reverting a topic branch merge, as this option recreates the topic branch with
335 fresh commits so it can be remerged successfully without needing to "revert
336 the reversion" (see the
337 link:howto/revert-a-faulty-merge.html[revert-a-faulty-merge How-To] for details).
338
339 --fork-point::
340 --no-fork-point::
341 Use reflog to find a better common ancestor between <upstream>
342 and <branch> when calculating which commits have been
343 introduced by <branch>.
344 +
345 When --fork-point is active, 'fork_point' will be used instead of
346 <upstream> to calculate the set of commits to rebase, where
347 'fork_point' is the result of `git merge-base --fork-point <upstream>
348 <branch>` command (see linkgit:git-merge-base[1]). If 'fork_point'
349 ends up being empty, the <upstream> will be used as a fallback.
350 +
351 If either <upstream> or --root is given on the command line, then the
352 default is `--no-fork-point`, otherwise the default is `--fork-point`.
353
354 --ignore-whitespace::
355 --whitespace=<option>::
356 These flag are passed to the 'git apply' program
357 (see linkgit:git-apply[1]) that applies the patch.
358 Incompatible with the --interactive option.
359
360 --committer-date-is-author-date::
361 --ignore-date::
362 These flags are passed to 'git am' to easily change the dates
363 of the rebased commits (see linkgit:git-am[1]).
364 Incompatible with the --interactive option.
365
366 -i::
367 --interactive::
368 Make a list of the commits which are about to be rebased. Let the
369 user edit that list before rebasing. This mode can also be used to
370 split commits (see SPLITTING COMMITS below).
371 +
372 The commit list format can be changed by setting the configuration option
373 rebase.instructionFormat. A customized instruction format will automatically
374 have the long commit hash prepended to the format.
375
376 -p::
377 --preserve-merges::
378 Recreate merge commits instead of flattening the history by replaying
379 commits a merge commit introduces. Merge conflict resolutions or manual
380 amendments to merge commits are not preserved.
381 +
382 This uses the `--interactive` machinery internally, but combining it
383 with the `--interactive` option explicitly is generally not a good
384 idea unless you know what you are doing (see BUGS below).
385
386 -x <cmd>::
387 --exec <cmd>::
388 Append "exec <cmd>" after each line creating a commit in the
389 final history. <cmd> will be interpreted as one or more shell
390 commands.
391 +
392 This option can only be used with the `--interactive` option
393 (see INTERACTIVE MODE below).
394 +
395 You may execute several commands by either using one instance of `--exec`
396 with several commands:
397 +
398 git rebase -i --exec "cmd1 && cmd2 && ..."
399 +
400 or by giving more than one `--exec`:
401 +
402 git rebase -i --exec "cmd1" --exec "cmd2" --exec ...
403 +
404 If `--autosquash` is used, "exec" lines will not be appended for
405 the intermediate commits, and will only appear at the end of each
406 squash/fixup series.
407
408 --root::
409 Rebase all commits reachable from <branch>, instead of
410 limiting them with an <upstream>. This allows you to rebase
411 the root commit(s) on a branch. When used with --onto, it
412 will skip changes already contained in <newbase> (instead of
413 <upstream>) whereas without --onto it will operate on every change.
414 When used together with both --onto and --preserve-merges,
415 'all' root commits will be rewritten to have <newbase> as parent
416 instead.
417
418 --autosquash::
419 --no-autosquash::
420 When the commit log message begins with "squash! ..." (or
421 "fixup! ..."), and there is a commit whose title begins with
422 the same ..., automatically modify the todo list of rebase -i
423 so that the commit marked for squashing comes right after the
424 commit to be modified, and change the action of the moved
425 commit from `pick` to `squash` (or `fixup`). Ignores subsequent
426 "fixup! " or "squash! " after the first, in case you referred to an
427 earlier fixup/squash with `git commit --fixup/--squash`.
428 +
429 This option is only valid when the '--interactive' option is used.
430 +
431 If the '--autosquash' option is enabled by default using the
432 configuration variable `rebase.autoSquash`, this option can be
433 used to override and disable this setting.
434
435 --[no-]autostash::
436 Automatically create a temporary stash before the operation
437 begins, and apply it after the operation ends. This means
438 that you can run rebase on a dirty worktree. However, use
439 with care: the final stash application after a successful
440 rebase might result in non-trivial conflicts.
441
442 --no-ff::
443 With --interactive, cherry-pick all rebased commits instead of
444 fast-forwarding over the unchanged ones. This ensures that the
445 entire history of the rebased branch is composed of new commits.
446 +
447 Without --interactive, this is a synonym for --force-rebase.
448 +
449 You may find this helpful after reverting a topic branch merge, as this option
450 recreates the topic branch with fresh commits so it can be remerged
451 successfully without needing to "revert the reversion" (see the
452 link:howto/revert-a-faulty-merge.html[revert-a-faulty-merge How-To] for details).
453
454 include::merge-strategies.txt[]
455
456 NOTES
457 -----
458
459 You should understand the implications of using 'git rebase' on a
460 repository that you share. See also RECOVERING FROM UPSTREAM REBASE
461 below.
462
463 When the git-rebase command is run, it will first execute a "pre-rebase"
464 hook if one exists. You can use this hook to do sanity checks and
465 reject the rebase if it isn't appropriate. Please see the template
466 pre-rebase hook script for an example.
467
468 Upon completion, <branch> will be the current branch.
469
470 INTERACTIVE MODE
471 ----------------
472
473 Rebasing interactively means that you have a chance to edit the commits
474 which are rebased. You can reorder the commits, and you can
475 remove them (weeding out bad or otherwise unwanted patches).
476
477 The interactive mode is meant for this type of workflow:
478
479 1. have a wonderful idea
480 2. hack on the code
481 3. prepare a series for submission
482 4. submit
483
484 where point 2. consists of several instances of
485
486 a) regular use
487
488 1. finish something worthy of a commit
489 2. commit
490
491 b) independent fixup
492
493 1. realize that something does not work
494 2. fix that
495 3. commit it
496
497 Sometimes the thing fixed in b.2. cannot be amended to the not-quite
498 perfect commit it fixes, because that commit is buried deeply in a
499 patch series. That is exactly what interactive rebase is for: use it
500 after plenty of "a"s and "b"s, by rearranging and editing
501 commits, and squashing multiple commits into one.
502
503 Start it with the last commit you want to retain as-is:
504
505 git rebase -i <after-this-commit>
506
507 An editor will be fired up with all the commits in your current branch
508 (ignoring merge commits), which come after the given commit. You can
509 reorder the commits in this list to your heart's content, and you can
510 remove them. The list looks more or less like this:
511
512 -------------------------------------------
513 pick deadbee The oneline of this commit
514 pick fa1afe1 The oneline of the next commit
515 ...
516 -------------------------------------------
517
518 The oneline descriptions are purely for your pleasure; 'git rebase' will
519 not look at them but at the commit names ("deadbee" and "fa1afe1" in this
520 example), so do not delete or edit the names.
521
522 By replacing the command "pick" with the command "edit", you can tell
523 'git rebase' to stop after applying that commit, so that you can edit
524 the files and/or the commit message, amend the commit, and continue
525 rebasing.
526
527 If you just want to edit the commit message for a commit, replace the
528 command "pick" with the command "reword".
529
530 To drop a commit, replace the command "pick" with "drop", or just
531 delete the matching line.
532
533 If you want to fold two or more commits into one, replace the command
534 "pick" for the second and subsequent commits with "squash" or "fixup".
535 If the commits had different authors, the folded commit will be
536 attributed to the author of the first commit. The suggested commit
537 message for the folded commit is the concatenation of the commit
538 messages of the first commit and of those with the "squash" command,
539 but omits the commit messages of commits with the "fixup" command.
540
541 'git rebase' will stop when "pick" has been replaced with "edit" or
542 when a command fails due to merge errors. When you are done editing
543 and/or resolving conflicts you can continue with `git rebase --continue`.
544
545 For example, if you want to reorder the last 5 commits, such that what
546 was HEAD~4 becomes the new HEAD. To achieve that, you would call
547 'git rebase' like this:
548
549 ----------------------
550 $ git rebase -i HEAD~5
551 ----------------------
552
553 And move the first patch to the end of the list.
554
555 You might want to preserve merges, if you have a history like this:
556
557 ------------------
558 X
559 \
560 A---M---B
561 /
562 ---o---O---P---Q
563 ------------------
564
565 Suppose you want to rebase the side branch starting at "A" to "Q". Make
566 sure that the current HEAD is "B", and call
567
568 -----------------------------
569 $ git rebase -i -p --onto Q O
570 -----------------------------
571
572 Reordering and editing commits usually creates untested intermediate
573 steps. You may want to check that your history editing did not break
574 anything by running a test, or at least recompiling at intermediate
575 points in history by using the "exec" command (shortcut "x"). You may
576 do so by creating a todo list like this one:
577
578 -------------------------------------------
579 pick deadbee Implement feature XXX
580 fixup f1a5c00 Fix to feature XXX
581 exec make
582 pick c0ffeee The oneline of the next commit
583 edit deadbab The oneline of the commit after
584 exec cd subdir; make test
585 ...
586 -------------------------------------------
587
588 The interactive rebase will stop when a command fails (i.e. exits with
589 non-0 status) to give you an opportunity to fix the problem. You can
590 continue with `git rebase --continue`.
591
592 The "exec" command launches the command in a shell (the one specified
593 in `$SHELL`, or the default shell if `$SHELL` is not set), so you can
594 use shell features (like "cd", ">", ";" ...). The command is run from
595 the root of the working tree.
596
597 ----------------------------------
598 $ git rebase -i --exec "make test"
599 ----------------------------------
600
601 This command lets you check that intermediate commits are compilable.
602 The todo list becomes like that:
603
604 --------------------
605 pick 5928aea one
606 exec make test
607 pick 04d0fda two
608 exec make test
609 pick ba46169 three
610 exec make test
611 pick f4593f9 four
612 exec make test
613 --------------------
614
615 SPLITTING COMMITS
616 -----------------
617
618 In interactive mode, you can mark commits with the action "edit". However,
619 this does not necessarily mean that 'git rebase' expects the result of this
620 edit to be exactly one commit. Indeed, you can undo the commit, or you can
621 add other commits. This can be used to split a commit into two:
622
623 - Start an interactive rebase with `git rebase -i <commit>^`, where
624 <commit> is the commit you want to split. In fact, any commit range
625 will do, as long as it contains that commit.
626
627 - Mark the commit you want to split with the action "edit".
628
629 - When it comes to editing that commit, execute `git reset HEAD^`. The
630 effect is that the HEAD is rewound by one, and the index follows suit.
631 However, the working tree stays the same.
632
633 - Now add the changes to the index that you want to have in the first
634 commit. You can use `git add` (possibly interactively) or
635 'git gui' (or both) to do that.
636
637 - Commit the now-current index with whatever commit message is appropriate
638 now.
639
640 - Repeat the last two steps until your working tree is clean.
641
642 - Continue the rebase with `git rebase --continue`.
643
644 If you are not absolutely sure that the intermediate revisions are
645 consistent (they compile, pass the testsuite, etc.) you should use
646 'git stash' to stash away the not-yet-committed changes
647 after each commit, test, and amend the commit if fixes are necessary.
648
649
650 RECOVERING FROM UPSTREAM REBASE
651 -------------------------------
652
653 Rebasing (or any other form of rewriting) a branch that others have
654 based work on is a bad idea: anyone downstream of it is forced to
655 manually fix their history. This section explains how to do the fix
656 from the downstream's point of view. The real fix, however, would be
657 to avoid rebasing the upstream in the first place.
658
659 To illustrate, suppose you are in a situation where someone develops a
660 'subsystem' branch, and you are working on a 'topic' that is dependent
661 on this 'subsystem'. You might end up with a history like the
662 following:
663
664 ------------
665 o---o---o---o---o---o---o---o---o master
666 \
667 o---o---o---o---o subsystem
668 \
669 *---*---* topic
670 ------------
671
672 If 'subsystem' is rebased against 'master', the following happens:
673
674 ------------
675 o---o---o---o---o---o---o---o master
676 \ \
677 o---o---o---o---o o'--o'--o'--o'--o' subsystem
678 \
679 *---*---* topic
680 ------------
681
682 If you now continue development as usual, and eventually merge 'topic'
683 to 'subsystem', the commits from 'subsystem' will remain duplicated forever:
684
685 ------------
686 o---o---o---o---o---o---o---o master
687 \ \
688 o---o---o---o---o o'--o'--o'--o'--o'--M subsystem
689 \ /
690 *---*---*-..........-*--* topic
691 ------------
692
693 Such duplicates are generally frowned upon because they clutter up
694 history, making it harder to follow. To clean things up, you need to
695 transplant the commits on 'topic' to the new 'subsystem' tip, i.e.,
696 rebase 'topic'. This becomes a ripple effect: anyone downstream from
697 'topic' is forced to rebase too, and so on!
698
699 There are two kinds of fixes, discussed in the following subsections:
700
701 Easy case: The changes are literally the same.::
702
703 This happens if the 'subsystem' rebase was a simple rebase and
704 had no conflicts.
705
706 Hard case: The changes are not the same.::
707
708 This happens if the 'subsystem' rebase had conflicts, or used
709 `--interactive` to omit, edit, squash, or fixup commits; or
710 if the upstream used one of `commit --amend`, `reset`, or
711 `filter-branch`.
712
713
714 The easy case
715 ~~~~~~~~~~~~~
716
717 Only works if the changes (patch IDs based on the diff contents) on
718 'subsystem' are literally the same before and after the rebase
719 'subsystem' did.
720
721 In that case, the fix is easy because 'git rebase' knows to skip
722 changes that are already present in the new upstream. So if you say
723 (assuming you're on 'topic')
724 ------------
725 $ git rebase subsystem
726 ------------
727 you will end up with the fixed history
728 ------------
729 o---o---o---o---o---o---o---o master
730 \
731 o'--o'--o'--o'--o' subsystem
732 \
733 *---*---* topic
734 ------------
735
736
737 The hard case
738 ~~~~~~~~~~~~~
739
740 Things get more complicated if the 'subsystem' changes do not exactly
741 correspond to the ones before the rebase.
742
743 NOTE: While an "easy case recovery" sometimes appears to be successful
744 even in the hard case, it may have unintended consequences. For
745 example, a commit that was removed via `git rebase
746 --interactive` will be **resurrected**!
747
748 The idea is to manually tell 'git rebase' "where the old 'subsystem'
749 ended and your 'topic' began", that is, what the old merge-base
750 between them was. You will have to find a way to name the last commit
751 of the old 'subsystem', for example:
752
753 * With the 'subsystem' reflog: after 'git fetch', the old tip of
754 'subsystem' is at `subsystem@{1}`. Subsequent fetches will
755 increase the number. (See linkgit:git-reflog[1].)
756
757 * Relative to the tip of 'topic': knowing that your 'topic' has three
758 commits, the old tip of 'subsystem' must be `topic~3`.
759
760 You can then transplant the old `subsystem..topic` to the new tip by
761 saying (for the reflog case, and assuming you are on 'topic' already):
762 ------------
763 $ git rebase --onto subsystem subsystem@{1}
764 ------------
765
766 The ripple effect of a "hard case" recovery is especially bad:
767 'everyone' downstream from 'topic' will now have to perform a "hard
768 case" recovery too!
769
770 BUGS
771 ----
772 The todo list presented by `--preserve-merges --interactive` does not
773 represent the topology of the revision graph. Editing commits and
774 rewording their commit messages should work fine, but attempts to
775 reorder commits tend to produce counterintuitive results.
776
777 For example, an attempt to rearrange
778 ------------
779 1 --- 2 --- 3 --- 4 --- 5
780 ------------
781 to
782 ------------
783 1 --- 2 --- 4 --- 3 --- 5
784 ------------
785 by moving the "pick 4" line will result in the following history:
786 ------------
787 3
788 /
789 1 --- 2 --- 4 --- 5
790 ------------
791
792 GIT
793 ---
794 Part of the linkgit:git[1] suite