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215a7ad1 JH |
1 | git-rebase(1) |
2 | ============= | |
7fc9d69f JH |
3 | |
4 | NAME | |
5 | ---- | |
b385085b | 6 | git-rebase - Reapply commits on top of another base tip |
7fc9d69f JH |
7 | |
8 | SYNOPSIS | |
9 | -------- | |
e448ff87 | 10 | [verse] |
414d924b DL |
11 | 'git rebase' [-i | --interactive] [<options>] [--exec <cmd>] |
12 | [--onto <newbase> | --keep-base] [<upstream> [<branch>]] | |
de613050 | 13 | 'git rebase' [-i | --interactive] [<options>] [--exec <cmd>] [--onto <newbase>] |
be496621 | 14 | --root [<branch>] |
437591a9 | 15 | 'git rebase' (--continue | --skip | --abort | --quit | --edit-todo | --show-current-patch) |
031321c6 | 16 | |
7fc9d69f JH |
17 | DESCRIPTION |
18 | ----------- | |
0b444cdb | 19 | If <branch> is specified, 'git rebase' will perform an automatic |
328c6cb8 | 20 | `git switch <branch>` before doing anything else. Otherwise |
5ca2db53 SP |
21 | it remains on the current branch. |
22 | ||
15a147e6 | 23 | If <upstream> is not specified, the upstream configured in |
f51a48ec SO |
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. | |
15a147e6 | 28 | |
5ca2db53 SP |
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 | |
f51a48ec SO |
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. | |
5ca2db53 SP |
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 | |
9869099b BG |
38 | `git reset --hard <upstream>` (or <newbase>). ORIG_HEAD is set |
39 | to point at the tip of the branch before the reset. | |
5ca2db53 SP |
40 | |
41 | The commits that were previously saved into the temporary area are | |
ff905462 JK |
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). | |
69a60af5 | 46 | |
031321c6 SE |
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 | |
cc120056 | 49 | and run `git rebase --continue`. Another option is to bypass the commit |
5960bc9d | 50 | that caused the merge failure with `git rebase --skip`. To check out the |
51ef1daa JS |
51 | original <branch> and remove the .git/rebase-apply working files, use the |
52 | command `git rebase --abort` instead. | |
031321c6 | 53 | |
69a60af5 CW |
54 | Assume the following history exists and the current branch is "topic": |
55 | ||
031321c6 | 56 | ------------ |
69a60af5 CW |
57 | A---B---C topic |
58 | / | |
59 | D---E---F---G master | |
031321c6 | 60 | ------------ |
69a60af5 | 61 | |
228382ae | 62 | From this point, the result of either of the following commands: |
69a60af5 | 63 | |
031321c6 | 64 | |
b1889c36 JN |
65 | git rebase master |
66 | git rebase master topic | |
69a60af5 CW |
67 | |
68 | would be: | |
69 | ||
031321c6 | 70 | ------------ |
69a60af5 CW |
71 | A'--B'--C' topic |
72 | / | |
73 | D---E---F---G master | |
031321c6 | 74 | ------------ |
69a60af5 | 75 | |
ee55703b DN |
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. | |
69a60af5 | 79 | |
ff905462 JK |
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 | |
b1889c36 | 82 | will be skipped. For example, running `git rebase master` on the |
e08bc7a9 | 83 | following history (in which `A'` and `A` introduce the same set of changes, |
ff905462 JK |
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 | ||
e52775f4 JN |
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`. | |
69a60af5 | 103 | |
e52775f4 | 104 | First let's assume your 'topic' is based on branch 'next'. |
e2b850b2 | 105 | For example, a feature developed in 'topic' depends on some |
e52775f4 | 106 | functionality which is found in 'next'. |
69a60af5 | 107 | |
031321c6 | 108 | ------------ |
e52775f4 JN |
109 | o---o---o---o---o master |
110 | \ | |
111 | o---o---o---o---o next | |
112 | \ | |
113 | o---o---o topic | |
114 | ------------ | |
115 | ||
e2b850b2 GD |
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: | |
e52775f4 JN |
119 | |
120 | ------------ | |
121 | o---o---o---o---o master | |
122 | | \ | |
123 | | o'--o'--o' topic | |
124 | \ | |
125 | o---o---o---o---o next | |
031321c6 | 126 | ------------ |
7fc9d69f | 127 | |
e52775f4 JN |
128 | We can get this using the following command: |
129 | ||
b1889c36 | 130 | git rebase --onto master next topic |
e52775f4 JN |
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 | ||
b1889c36 | 146 | git rebase --onto master topicA topicB |
e52775f4 JN |
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 | ||
ea81fcc5 SP |
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 | ||
b1889c36 | 169 | git rebase --onto topicA~5 topicA~3 topicA |
ea81fcc5 SP |
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 | ||
0b444cdb TR |
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 | |
031321c6 | 183 | the markers (<<<<<<) and make edits to resolve the conflict. For each |
2de9b711 | 184 | file you edit, you need to tell Git that the conflict has been resolved, |
031321c6 SE |
185 | typically this would be done with |
186 | ||
187 | ||
d7f078b8 | 188 | git add <filename> |
031321c6 SE |
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 | |
8978d043 | 196 | |
8978d043 | 197 | |
0b444cdb | 198 | Alternatively, you can undo the 'git rebase' with |
8978d043 | 199 | |
031321c6 SE |
200 | |
201 | git rebase --abort | |
8978d043 | 202 | |
a9c3821c TAV |
203 | CONFIGURATION |
204 | ------------- | |
205 | ||
c7245900 | 206 | include::config/rebase.txt[] |
16cf51c7 | 207 | |
7fc9d69f JH |
208 | OPTIONS |
209 | ------- | |
c2145384 | 210 | --onto <newbase>:: |
69a60af5 CW |
211 | Starting point at which to create the new commits. If the |
212 | --onto option is not specified, the starting point is | |
ea81fcc5 SP |
213 | <upstream>. May be any valid commit, and not just an |
214 | existing branch name. | |
873c3472 | 215 | + |
b9190e79 | 216 | As a special case, you may use "A\...B" as a shortcut for the |
873c3472 MG |
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. | |
69a60af5 | 219 | |
414d924b DL |
220 | --keep-base:: |
221 | Set the starting point at which to create the new commits to the | |
222 | merge base of <upstream> <branch>. Running | |
223 | 'git rebase --keep-base <upstream> <branch>' is equivalent to | |
224 | running 'git rebase --onto <upstream>... <upstream>'. | |
225 | + | |
226 | This option is useful in the case where one is developing a feature on | |
227 | top of an upstream branch. While the feature is being worked on, the | |
228 | upstream branch may advance and it may not be the best idea to keep | |
229 | rebasing on top of the upstream but to keep the base commit as-is. | |
230 | + | |
231 | Although both this option and --fork-point find the merge base between | |
232 | <upstream> and <branch>, this option uses the merge base as the _starting | |
233 | point_ on which new commits will be created, whereas --fork-point uses | |
234 | the merge base to determine the _set of commits_ which will be rebased. | |
235 | + | |
236 | See also INCOMPATIBLE OPTIONS below. | |
237 | ||
52a22d1e | 238 | <upstream>:: |
ea81fcc5 | 239 | Upstream branch to compare against. May be any valid commit, |
15a147e6 MZ |
240 | not just an existing branch name. Defaults to the configured |
241 | upstream for the current branch. | |
7fc9d69f | 242 | |
228382ae | 243 | <branch>:: |
52a22d1e | 244 | Working branch; defaults to HEAD. |
7fc9d69f | 245 | |
031321c6 SE |
246 | --continue:: |
247 | Restart the rebasing process after having resolved a merge conflict. | |
248 | ||
249 | --abort:: | |
5960bc9d MZ |
250 | Abort the rebase operation and reset HEAD to the original |
251 | branch. If <branch> was provided when the rebase operation was | |
252 | started, then HEAD will be reset to <branch>. Otherwise HEAD | |
253 | will be reset to where it was when the rebase operation was | |
254 | started. | |
031321c6 | 255 | |
9512177b NTND |
256 | --quit:: |
257 | Abort the rebase operation but HEAD is not reset back to the | |
258 | original branch. The index and working tree are also left | |
9b2df3e8 | 259 | unchanged as a result. If a temporary stash entry was created |
c5e786ab | 260 | using --autostash, it will be saved to the stash list. |
9512177b | 261 | |
10cdb9f3 EN |
262 | --apply: |
263 | Use applying strategies to rebase (calling `git-am` | |
264 | internally). This option may become a no-op in the future | |
265 | once the merge backend handles everything the apply one does. | |
52eb738d EN |
266 | + |
267 | See also INCOMPATIBLE OPTIONS below. | |
268 | ||
e98c4269 EN |
269 | --empty={drop,keep,ask}:: |
270 | How to handle commits that are not empty to start and are not | |
271 | clean cherry-picks of any upstream commit, but which become | |
272 | empty after rebasing (because they contain a subset of already | |
273 | upstream changes). With drop (the default), commits that | |
274 | become empty are dropped. With keep, such commits are kept. | |
275 | With ask (implied by --interactive), the rebase will halt when | |
276 | an empty commit is applied allowing you to choose whether to | |
277 | drop it, edit files more, or just commit the empty changes. | |
278 | Other options, like --exec, will use the default of drop unless | |
279 | -i/--interactive is explicitly specified. | |
280 | + | |
b9cbd295 EN |
281 | Note that commits which start empty are kept (unless --no-keep-empty |
282 | is specified), and commits which are clean cherry-picks (as determined | |
0fcb4f6b JT |
283 | by `git log --cherry-mark ...`) are detected and dropped as a |
284 | preliminary step (unless --reapply-cherry-picks is passed). | |
e98c4269 EN |
285 | + |
286 | See also INCOMPATIBLE OPTIONS below. | |
287 | ||
b9cbd295 | 288 | --no-keep-empty:: |
90e1818f | 289 | --keep-empty:: |
b9cbd295 EN |
290 | Do not keep commits that start empty before the rebase |
291 | (i.e. that do not change anything from its parent) in the | |
292 | result. The default is to keep commits which start empty, | |
293 | since creating such commits requires passing the --allow-empty | |
294 | override flag to `git commit`, signifying that a user is very | |
295 | intentionally creating such a commit and thus wants to keep | |
296 | it. | |
297 | + | |
298 | Usage of this flag will probably be rare, since you can get rid of | |
299 | commits that start empty by just firing up an interactive rebase and | |
300 | removing the lines corresponding to the commits you don't want. This | |
301 | flag exists as a convenient shortcut, such as for cases where external | |
302 | tools generate many empty commits and you want them all removed. | |
303 | + | |
304 | For commits which do not start empty but become empty after rebasing, | |
305 | see the --empty flag. | |
5dacd4ab | 306 | + |
b9cbd295 | 307 | See also INCOMPATIBLE OPTIONS below. |
90e1818f | 308 | |
0fcb4f6b JT |
309 | --reapply-cherry-picks:: |
310 | --no-reapply-cherry-picks:: | |
311 | Reapply all clean cherry-picks of any upstream commit instead | |
312 | of preemptively dropping them. (If these commits then become | |
313 | empty after rebasing, because they contain a subset of already | |
314 | upstream changes, the behavior towards them is controlled by | |
315 | the `--empty` flag.) | |
316 | + | |
317 | By default (or if `--no-reapply-cherry-picks` is given), these commits | |
318 | will be automatically dropped. Because this necessitates reading all | |
319 | upstream commits, this can be expensive in repos with a large number | |
320 | of upstream commits that need to be read. | |
321 | + | |
322 | `--reapply-cherry-picks` allows rebase to forgo reading all upstream | |
323 | commits, potentially improving performance. | |
324 | + | |
325 | See also INCOMPATIBLE OPTIONS below. | |
326 | ||
a6c612b5 | 327 | --allow-empty-message:: |
22a69fda EN |
328 | No-op. Rebasing commits with an empty message used to fail |
329 | and this option would override that behavior, allowing commits | |
330 | with empty messages to be rebased. Now commits with an empty | |
331 | message do not cause rebasing to halt. | |
5dacd4ab EN |
332 | + |
333 | See also INCOMPATIBLE OPTIONS below. | |
a6c612b5 | 334 | |
58634dbf EW |
335 | --skip:: |
336 | Restart the rebasing process by skipping the current patch. | |
58634dbf | 337 | |
eb9a7cb4 AW |
338 | --edit-todo:: |
339 | Edit the todo list during an interactive rebase. | |
340 | ||
66335298 NTND |
341 | --show-current-patch:: |
342 | Show the current patch in an interactive rebase or when rebase | |
fbd7a232 NTND |
343 | is stopped because of conflicts. This is the equivalent of |
344 | `git show REBASE_HEAD`. | |
66335298 | 345 | |
3240240f SB |
346 | -m:: |
347 | --merge:: | |
58634dbf EW |
348 | Use merging strategies to rebase. When the recursive (default) merge |
349 | strategy is used, this allows rebase to be aware of renames on the | |
2ac0d627 | 350 | upstream side. This is the default. |
31ddd1ee TR |
351 | + |
352 | Note that a rebase merge works by replaying each commit from the working | |
353 | branch on top of the <upstream> branch. Because of this, when a merge | |
354 | conflict happens, the side reported as 'ours' is the so-far rebased | |
355 | series, starting with <upstream>, and 'theirs' is the working branch. In | |
356 | other words, the sides are swapped. | |
5dacd4ab EN |
357 | + |
358 | See also INCOMPATIBLE OPTIONS below. | |
58634dbf | 359 | |
3240240f SB |
360 | -s <strategy>:: |
361 | --strategy=<strategy>:: | |
06f39190 | 362 | Use the given merge strategy. |
0b444cdb | 363 | If there is no `-s` option 'git merge-recursive' is used |
31ddd1ee TR |
364 | instead. This implies --merge. |
365 | + | |
0b444cdb | 366 | Because 'git rebase' replays each commit from the working branch |
31ddd1ee | 367 | on top of the <upstream> branch using the given strategy, using |
5dacd4ab | 368 | the 'ours' strategy simply empties all patches from the <branch>, |
31ddd1ee | 369 | which makes little sense. |
5dacd4ab EN |
370 | + |
371 | See also INCOMPATIBLE OPTIONS below. | |
58634dbf | 372 | |
93ce190c ML |
373 | -X <strategy-option>:: |
374 | --strategy-option=<strategy-option>:: | |
375 | Pass the <strategy-option> through to the merge strategy. | |
6cf378f0 | 376 | This implies `--merge` and, if no strategy has been |
93ce190c | 377 | specified, `-s recursive`. Note the reversal of 'ours' and |
edfbbf7e | 378 | 'theirs' as noted above for the `-m` option. |
5dacd4ab EN |
379 | + |
380 | See also INCOMPATIBLE OPTIONS below. | |
93ce190c | 381 | |
aba4954c PW |
382 | --rerere-autoupdate:: |
383 | --no-rerere-autoupdate:: | |
384 | Allow the rerere mechanism to update the index with the | |
385 | result of auto-conflict resolution if possible. | |
386 | ||
3ee5e540 NV |
387 | -S[<keyid>]:: |
388 | --gpg-sign[=<keyid>]:: | |
c241371c | 389 | --no-gpg-sign:: |
2b594bf9 MM |
390 | GPG-sign commits. The `keyid` argument is optional and |
391 | defaults to the committer identity; if specified, it must be | |
c241371c ĐTCD |
392 | stuck to the option without a space. `--no-gpg-sign` is useful to |
393 | countermand both `commit.gpgSign` configuration variable, and | |
394 | earlier `--gpg-sign`. | |
3ee5e540 | 395 | |
0e987a12 SB |
396 | -q:: |
397 | --quiet:: | |
398 | Be quiet. Implies --no-stat. | |
399 | ||
3240240f SB |
400 | -v:: |
401 | --verbose:: | |
a9c3821c TAV |
402 | Be verbose. Implies --stat. |
403 | ||
404 | --stat:: | |
405 | Show a diffstat of what changed upstream since the last rebase. The | |
406 | diffstat is also controlled by the configuration option rebase.stat. | |
407 | ||
408 | -n:: | |
409 | --no-stat:: | |
410 | Do not show a diffstat as part of the rebase process. | |
b758789c | 411 | |
fd631d58 NS |
412 | --no-verify:: |
413 | This option bypasses the pre-rebase hook. See also linkgit:githooks[5]. | |
414 | ||
7baf9c4b MZ |
415 | --verify:: |
416 | Allows the pre-rebase hook to run, which is the default. This option can | |
417 | be used to override --no-verify. See also linkgit:githooks[5]. | |
418 | ||
67dad687 MT |
419 | -C<n>:: |
420 | Ensure at least <n> lines of surrounding context match before | |
421 | and after each change. When fewer lines of surrounding | |
422 | context exist they all must match. By default no context is | |
10cdb9f3 | 423 | ever ignored. Implies --apply. |
5dacd4ab EN |
424 | + |
425 | See also INCOMPATIBLE OPTIONS below. | |
67dad687 | 426 | |
983f464f | 427 | --no-ff:: |
5e75d56f | 428 | --force-rebase:: |
983f464f EN |
429 | -f:: |
430 | Individually replay all rebased commits instead of fast-forwarding | |
431 | over the unchanged ones. This ensures that the entire history of | |
432 | the rebased branch is composed of new commits. | |
b4995494 | 433 | + |
983f464f EN |
434 | You may find this helpful after reverting a topic branch merge, as this option |
435 | recreates the topic branch with fresh commits so it can be remerged | |
436 | successfully without needing to "revert the reversion" (see the | |
437 | link:howto/revert-a-faulty-merge.html[revert-a-faulty-merge How-To] for | |
438 | details). | |
5e75d56f | 439 | |
ad8261d2 JK |
440 | --fork-point:: |
441 | --no-fork-point:: | |
f51a48ec SO |
442 | Use reflog to find a better common ancestor between <upstream> |
443 | and <branch> when calculating which commits have been | |
444 | introduced by <branch>. | |
ad8261d2 | 445 | + |
f51a48ec SO |
446 | When --fork-point is active, 'fork_point' will be used instead of |
447 | <upstream> to calculate the set of commits to rebase, where | |
448 | 'fork_point' is the result of `git merge-base --fork-point <upstream> | |
449 | <branch>` command (see linkgit:git-merge-base[1]). If 'fork_point' | |
450 | ends up being empty, the <upstream> will be used as a fallback. | |
451 | + | |
a35413c3 EN |
452 | If <upstream> is given on the command line, then the default is |
453 | `--no-fork-point`, otherwise the default is `--fork-point`. | |
414d924b DL |
454 | + |
455 | If your branch was based on <upstream> but <upstream> was rewound and | |
456 | your branch contains commits which were dropped, this option can be used | |
457 | with `--keep-base` in order to drop those commits from your branch. | |
a35413c3 EN |
458 | + |
459 | See also INCOMPATIBLE OPTIONS below. | |
ad8261d2 | 460 | |
86c91f91 | 461 | --ignore-whitespace:: |
749485f6 | 462 | --whitespace=<option>:: |
be50c938 | 463 | These flags are passed to the 'git apply' program |
5162e697 | 464 | (see linkgit:git-apply[1]) that applies the patch. |
10cdb9f3 | 465 | Implies --apply. |
5dacd4ab EN |
466 | + |
467 | See also INCOMPATIBLE OPTIONS below. | |
059f446d | 468 | |
570ccad3 MB |
469 | --committer-date-is-author-date:: |
470 | --ignore-date:: | |
4d924528 JH |
471 | These flags are passed to 'git am' to easily change the dates |
472 | of the rebased commits (see linkgit:git-am[1]). | |
5dacd4ab EN |
473 | + |
474 | See also INCOMPATIBLE OPTIONS below. | |
570ccad3 | 475 | |
9f79524a | 476 | --signoff:: |
a852ec7f PW |
477 | Add a Signed-off-by: trailer to all the rebased commits. Note |
478 | that if `--interactive` is given then only commits marked to be | |
5dacd4ab EN |
479 | picked, edited or reworded will have the trailer added. |
480 | + | |
481 | See also INCOMPATIBLE OPTIONS below. | |
9f79524a | 482 | |
3240240f SB |
483 | -i:: |
484 | --interactive:: | |
1b1dce4b | 485 | Make a list of the commits which are about to be rebased. Let the |
f0fd889d JS |
486 | user edit that list before rebasing. This mode can also be used to |
487 | split commits (see SPLITTING COMMITS below). | |
16cf51c7 MR |
488 | + |
489 | The commit list format can be changed by setting the configuration option | |
490 | rebase.instructionFormat. A customized instruction format will automatically | |
491 | have the long commit hash prepended to the format. | |
5dacd4ab EN |
492 | + |
493 | See also INCOMPATIBLE OPTIONS below. | |
1b1dce4b | 494 | |
8f6aed71 | 495 | -r:: |
7543f6f4 | 496 | --rebase-merges[=(rebase-cousins|no-rebase-cousins)]:: |
8f6aed71 JS |
497 | By default, a rebase will simply drop merge commits from the todo |
498 | list, and put the rebased commits into a single, linear branch. | |
499 | With `--rebase-merges`, the rebase will instead try to preserve | |
500 | the branching structure within the commits that are to be rebased, | |
501 | by recreating the merge commits. Any resolved merge conflicts or | |
502 | manual amendments in these merge commits will have to be | |
503 | resolved/re-applied manually. | |
504 | + | |
7543f6f4 JS |
505 | By default, or when `no-rebase-cousins` was specified, commits which do not |
506 | have `<upstream>` as direct ancestor will keep their original branch point, | |
dbf47215 | 507 | i.e. commits that would be excluded by linkgit:git-log[1]'s |
7543f6f4 JS |
508 | `--ancestry-path` option will keep their original ancestry by default. If |
509 | the `rebase-cousins` mode is turned on, such commits are instead rebased | |
510 | onto `<upstream>` (or `<onto>`, if specified). | |
511 | + | |
427c3bd2 | 512 | The `--rebase-merges` mode is similar in spirit to the deprecated |
d3a8caeb NN |
513 | `--preserve-merges` but works with interactive rebases, |
514 | where commits can be reordered, inserted and dropped at will. | |
8f6aed71 JS |
515 | + |
516 | It is currently only possible to recreate the merge commits using the | |
517 | `recursive` merge strategy; Different merge strategies can be used only via | |
518 | explicit `exec git merge -s <strategy> [...]` commands. | |
25cff9f1 | 519 | + |
5dacd4ab | 520 | See also REBASING MERGES and INCOMPATIBLE OPTIONS below. |
8f6aed71 | 521 | |
3240240f SB |
522 | -p:: |
523 | --preserve-merges:: | |
427c3bd2 JS |
524 | [DEPRECATED: use `--rebase-merges` instead] Recreate merge commits |
525 | instead of flattening the history by replaying commits a merge commit | |
526 | introduces. Merge conflict resolutions or manual amendments to merge | |
527 | commits are not preserved. | |
cddb42d2 JN |
528 | + |
529 | This uses the `--interactive` machinery internally, but combining it | |
530 | with the `--interactive` option explicitly is generally not a good | |
531 | idea unless you know what you are doing (see BUGS below). | |
5dacd4ab EN |
532 | + |
533 | See also INCOMPATIBLE OPTIONS below. | |
cddb42d2 | 534 | |
c2145384 LK |
535 | -x <cmd>:: |
536 | --exec <cmd>:: | |
537 | Append "exec <cmd>" after each line creating a commit in the | |
538 | final history. <cmd> will be interpreted as one or more shell | |
b8c0b210 JS |
539 | commands. Any command that fails will interrupt the rebase, |
540 | with exit code 1. | |
c2145384 | 541 | + |
c2145384 LK |
542 | You may execute several commands by either using one instance of `--exec` |
543 | with several commands: | |
544 | + | |
545 | git rebase -i --exec "cmd1 && cmd2 && ..." | |
546 | + | |
547 | or by giving more than one `--exec`: | |
548 | + | |
549 | git rebase -i --exec "cmd1" --exec "cmd2" --exec ... | |
550 | + | |
551 | If `--autosquash` is used, "exec" lines will not be appended for | |
552 | the intermediate commits, and will only appear at the end of each | |
553 | squash/fixup series. | |
78ec2400 SB |
554 | + |
555 | This uses the `--interactive` machinery internally, but it can be run | |
556 | without an explicit `--interactive`. | |
5dacd4ab EN |
557 | + |
558 | See also INCOMPATIBLE OPTIONS below. | |
f09c9b8c | 559 | |
be496621 TR |
560 | --root:: |
561 | Rebase all commits reachable from <branch>, instead of | |
562 | limiting them with an <upstream>. This allows you to rebase | |
df5df20c | 563 | the root commit(s) on a branch. When used with --onto, it |
be496621 | 564 | will skip changes already contained in <newbase> (instead of |
df5df20c CW |
565 | <upstream>) whereas without --onto it will operate on every change. |
566 | When used together with both --onto and --preserve-merges, | |
567 | 'all' root commits will be rewritten to have <newbase> as parent | |
be496621 | 568 | instead. |
5dacd4ab EN |
569 | + |
570 | See also INCOMPATIBLE OPTIONS below. | |
be496621 | 571 | |
f59baa50 | 572 | --autosquash:: |
dd1e5b31 | 573 | --no-autosquash:: |
f59baa50 | 574 | When the commit log message begins with "squash! ..." (or |
c44a4c65 JS |
575 | "fixup! ..."), and there is already a commit in the todo list that |
576 | matches the same `...`, automatically modify the todo list of rebase | |
577 | -i so that the commit marked for squashing comes right after the | |
578 | commit to be modified, and change the action of the moved commit | |
579 | from `pick` to `squash` (or `fixup`). A commit matches the `...` if | |
580 | the commit subject matches, or if the `...` refers to the commit's | |
581 | hash. As a fall-back, partial matches of the commit subject work, | |
582 | too. The recommended way to create fixup/squash commits is by using | |
583 | the `--fixup`/`--squash` options of linkgit:git-commit[1]. | |
f59baa50 | 584 | + |
bcf9626a | 585 | If the `--autosquash` option is enabled by default using the |
da0005b8 | 586 | configuration variable `rebase.autoSquash`, this option can be |
dd1e5b31 | 587 | used to override and disable this setting. |
5dacd4ab EN |
588 | + |
589 | See also INCOMPATIBLE OPTIONS below. | |
b4995494 | 590 | |
82e0668c JK |
591 | --autostash:: |
592 | --no-autostash:: | |
e01db917 | 593 | Automatically create a temporary stash entry before the operation |
58794775 RR |
594 | begins, and apply it after the operation ends. This means |
595 | that you can run rebase on a dirty worktree. However, use | |
596 | with care: the final stash application after a successful | |
597 | rebase might result in non-trivial conflicts. | |
598 | ||
d421afa0 JS |
599 | --reschedule-failed-exec:: |
600 | --no-reschedule-failed-exec:: | |
601 | Automatically reschedule `exec` commands that failed. This only makes | |
602 | sense in interactive mode (or when an `--exec` option was provided). | |
603 | ||
5dacd4ab EN |
604 | INCOMPATIBLE OPTIONS |
605 | -------------------- | |
606 | ||
68aa495b | 607 | The following options: |
5dacd4ab | 608 | |
10cdb9f3 | 609 | * --apply |
4d924528 JH |
610 | * --committer-date-is-author-date |
611 | * --ignore-date | |
4d924528 | 612 | * --ignore-whitespace |
be50c938 | 613 | * --whitespace |
5dacd4ab EN |
614 | * -C |
615 | ||
68aa495b | 616 | are incompatible with the following options: |
5dacd4ab EN |
617 | |
618 | * --merge | |
619 | * --strategy | |
620 | * --strategy-option | |
621 | * --allow-empty-message | |
5dacd4ab EN |
622 | * --[no-]autosquash |
623 | * --rebase-merges | |
624 | * --preserve-merges | |
625 | * --interactive | |
626 | * --exec | |
b9cbd295 | 627 | * --no-keep-empty |
e98c4269 | 628 | * --empty= |
0fcb4f6b | 629 | * --reapply-cherry-picks |
5dacd4ab EN |
630 | * --edit-todo |
631 | * --root when used in combination with --onto | |
632 | ||
68aa495b | 633 | In addition, the following pairs of options are incompatible: |
5dacd4ab EN |
634 | |
635 | * --preserve-merges and --interactive | |
636 | * --preserve-merges and --signoff | |
637 | * --preserve-merges and --rebase-merges | |
e98c4269 | 638 | * --preserve-merges and --empty= |
414d924b DL |
639 | * --keep-base and --onto |
640 | * --keep-base and --root | |
a35413c3 | 641 | * --fork-point and --root |
5dacd4ab | 642 | |
0661e49a EN |
643 | BEHAVIORAL DIFFERENCES |
644 | ----------------------- | |
645 | ||
10cdb9f3 | 646 | git rebase has two primary backends: apply and merge. (The apply |
344420bf | 647 | backend used to be known as the 'am' backend, but the name led to |
10cdb9f3 EN |
648 | confusion as it looks like a verb instead of a noun. Also, the merge |
649 | backend used to be known as the interactive backend, but it is now | |
650 | used for non-interactive cases as well. Both were renamed based on | |
651 | lower-level functionality that underpinned each.) There are some | |
652 | subtle differences in how these two backends behave: | |
0661e49a | 653 | |
6fcbad87 JS |
654 | Empty commits |
655 | ~~~~~~~~~~~~~ | |
0661e49a | 656 | |
10cdb9f3 | 657 | The apply backend unfortunately drops intentionally empty commits, i.e. |
d48e5e21 EN |
658 | commits that started empty, though these are rare in practice. It |
659 | also drops commits that become empty and has no option for controlling | |
660 | this behavior. | |
0661e49a | 661 | |
b9cbd295 EN |
662 | The merge backend keeps intentionally empty commits by default (though |
663 | with -i they are marked as empty in the todo list editor, or they can | |
664 | be dropped automatically with --no-keep-empty). | |
665 | ||
666 | Similar to the apply backend, by default the merge backend drops | |
667 | commits that become empty unless -i/--interactive is specified (in | |
668 | which case it stops and asks the user what to do). The merge backend | |
669 | also has an --empty={drop,keep,ask} option for changing the behavior | |
670 | of handling commits that become empty. | |
0661e49a | 671 | |
6fcbad87 JS |
672 | Directory rename detection |
673 | ~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
674 | ||
be50c938 EN |
675 | Due to the lack of accurate tree information (arising from |
676 | constructing fake ancestors with the limited information available in | |
10cdb9f3 | 677 | patches), directory rename detection is disabled in the apply backend. |
be50c938 EN |
678 | Disabled directory rename detection means that if one side of history |
679 | renames a directory and the other adds new files to the old directory, | |
680 | then the new files will be left behind in the old directory without | |
681 | any warning at the time of rebasing that you may want to move these | |
682 | files into the new directory. | |
683 | ||
10cdb9f3 EN |
684 | Directory rename detection works with the merge backend to provide you |
685 | warnings in such cases. | |
be50c938 EN |
686 | |
687 | Context | |
688 | ~~~~~~~ | |
689 | ||
10cdb9f3 | 690 | The apply backend works by creating a sequence of patches (by calling |
be50c938 EN |
691 | `format-patch` internally), and then applying the patches in sequence |
692 | (calling `am` internally). Patches are composed of multiple hunks, | |
693 | each with line numbers, a context region, and the actual changes. The | |
694 | line numbers have to be taken with some fuzz, since the other side | |
695 | will likely have inserted or deleted lines earlier in the file. The | |
696 | context region is meant to help find how to adjust the line numbers in | |
697 | order to apply the changes to the right lines. However, if multiple | |
698 | areas of the code have the same surrounding lines of context, the | |
699 | wrong one can be picked. There are real-world cases where this has | |
700 | caused commits to be reapplied incorrectly with no conflicts reported. | |
701 | Setting diff.context to a larger value may prevent such types of | |
702 | problems, but increases the chance of spurious conflicts (since it | |
703 | will require more lines of matching context to apply). | |
704 | ||
10cdb9f3 | 705 | The merge backend works with a full copy of each relevant file, |
be50c938 EN |
706 | insulating it from these types of problems. |
707 | ||
708 | Labelling of conflicts markers | |
709 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
710 | ||
711 | When there are content conflicts, the merge machinery tries to | |
712 | annotate each side's conflict markers with the commits where the | |
10cdb9f3 | 713 | content came from. Since the apply backend drops the original |
be50c938 EN |
714 | information about the rebased commits and their parents (and instead |
715 | generates new fake commits based off limited information in the | |
716 | generated patches), those commits cannot be identified; instead it has | |
717 | to fall back to a commit summary. Also, when merge.conflictStyle is | |
10cdb9f3 | 718 | set to diff3, the apply backend will use "constructed merge base" to |
be50c938 EN |
719 | label the content from the merge base, and thus provide no information |
720 | about the merge base commit whatsoever. | |
721 | ||
10cdb9f3 EN |
722 | The merge backend works with the full commits on both sides of history |
723 | and thus has no such limitations. | |
be50c938 EN |
724 | |
725 | Hooks | |
726 | ~~~~~ | |
727 | ||
10cdb9f3 | 728 | The apply backend has not traditionally called the post-commit hook, |
f7139e7c EN |
729 | while the merge backend has. Both have called the post-checkout hook, |
730 | though the merge backend has squelched its output. Further, both | |
731 | backends only call the post-checkout hook with the starting point | |
732 | commit of the rebase, not the intermediate commits nor the final | |
733 | commit. In each case, the calling of these hooks was by accident of | |
734 | implementation rather than by design (both backends were originally | |
735 | implemented as shell scripts and happened to invoke other commands | |
736 | like 'git checkout' or 'git commit' that would call the hooks). Both | |
737 | backends should have the same behavior, though it is not entirely | |
738 | clear which, if any, is correct. We will likely make rebase stop | |
739 | calling either of these hooks in the future. | |
be50c938 | 740 | |
2ac0d627 EN |
741 | Interruptability |
742 | ~~~~~~~~~~~~~~~~ | |
743 | ||
10cdb9f3 EN |
744 | The apply backend has safety problems with an ill-timed interrupt; if |
745 | the user presses Ctrl-C at the wrong time to try to abort the rebase, | |
746 | the rebase can enter a state where it cannot be aborted with a | |
747 | subsequent `git rebase --abort`. The merge backend does not appear to | |
2ac0d627 EN |
748 | suffer from the same shortcoming. (See |
749 | https://lore.kernel.org/git/20200207132152.GC2868@szeder.dev/ for | |
750 | details.) | |
751 | ||
120b1eb7 EN |
752 | Commit Rewording |
753 | ~~~~~~~~~~~~~~~~ | |
754 | ||
755 | When a conflict occurs while rebasing, rebase stops and asks the user | |
756 | to resolve. Since the user may need to make notable changes while | |
757 | resolving conflicts, after conflicts are resolved and the user has run | |
758 | `git rebase --continue`, the rebase should open an editor and ask the | |
759 | user to update the commit message. The merge backend does this, while | |
760 | the apply backend blindly applies the original commit message. | |
761 | ||
be50c938 EN |
762 | Miscellaneous differences |
763 | ~~~~~~~~~~~~~~~~~~~~~~~~~ | |
764 | ||
765 | There are a few more behavioral differences that most folks would | |
766 | probably consider inconsequential but which are mentioned for | |
767 | completeness: | |
768 | ||
769 | * Reflog: The two backends will use different wording when describing | |
770 | the changes made in the reflog, though both will make use of the | |
771 | word "rebase". | |
772 | ||
773 | * Progress, informational, and error messages: The two backends | |
774 | provide slightly different progress and informational messages. | |
10cdb9f3 EN |
775 | Also, the apply backend writes error messages (such as "Your files |
776 | would be overwritten...") to stdout, while the merge backend writes | |
777 | them to stderr. | |
be50c938 EN |
778 | |
779 | * State directories: The two backends keep their state in different | |
780 | directories under .git/ | |
f59baa50 | 781 | |
58634dbf EW |
782 | include::merge-strategies.txt[] |
783 | ||
031321c6 SE |
784 | NOTES |
785 | ----- | |
90d1c08e | 786 | |
0b444cdb | 787 | You should understand the implications of using 'git rebase' on a |
90d1c08e TR |
788 | repository that you share. See also RECOVERING FROM UPSTREAM REBASE |
789 | below. | |
031321c6 | 790 | |
467c0197 | 791 | When the git-rebase command is run, it will first execute a "pre-rebase" |
031321c6 SE |
792 | hook if one exists. You can use this hook to do sanity checks and |
793 | reject the rebase if it isn't appropriate. Please see the template | |
794 | pre-rebase hook script for an example. | |
795 | ||
702088af | 796 | Upon completion, <branch> will be the current branch. |
031321c6 | 797 | |
1b1dce4b JS |
798 | INTERACTIVE MODE |
799 | ---------------- | |
800 | ||
801 | Rebasing interactively means that you have a chance to edit the commits | |
802 | which are rebased. You can reorder the commits, and you can | |
803 | remove them (weeding out bad or otherwise unwanted patches). | |
804 | ||
805 | The interactive mode is meant for this type of workflow: | |
806 | ||
807 | 1. have a wonderful idea | |
808 | 2. hack on the code | |
809 | 3. prepare a series for submission | |
810 | 4. submit | |
811 | ||
812 | where point 2. consists of several instances of | |
813 | ||
d3f2475c NBL |
814 | a) regular use |
815 | ||
1b1dce4b JS |
816 | 1. finish something worthy of a commit |
817 | 2. commit | |
d3f2475c NBL |
818 | |
819 | b) independent fixup | |
820 | ||
1b1dce4b JS |
821 | 1. realize that something does not work |
822 | 2. fix that | |
823 | 3. commit it | |
824 | ||
825 | Sometimes the thing fixed in b.2. cannot be amended to the not-quite | |
826 | perfect commit it fixes, because that commit is buried deeply in a | |
827 | patch series. That is exactly what interactive rebase is for: use it | |
828 | after plenty of "a"s and "b"s, by rearranging and editing | |
829 | commits, and squashing multiple commits into one. | |
830 | ||
831 | Start it with the last commit you want to retain as-is: | |
832 | ||
833 | git rebase -i <after-this-commit> | |
834 | ||
835 | An editor will be fired up with all the commits in your current branch | |
836 | (ignoring merge commits), which come after the given commit. You can | |
837 | reorder the commits in this list to your heart's content, and you can | |
838 | remove them. The list looks more or less like this: | |
839 | ||
840 | ------------------------------------------- | |
841 | pick deadbee The oneline of this commit | |
842 | pick fa1afe1 The oneline of the next commit | |
843 | ... | |
844 | ------------------------------------------- | |
845 | ||
0b444cdb | 846 | The oneline descriptions are purely for your pleasure; 'git rebase' will |
1b1dce4b JS |
847 | not look at them but at the commit names ("deadbee" and "fa1afe1" in this |
848 | example), so do not delete or edit the names. | |
849 | ||
850 | By replacing the command "pick" with the command "edit", you can tell | |
0b444cdb | 851 | 'git rebase' to stop after applying that commit, so that you can edit |
1b1dce4b JS |
852 | the files and/or the commit message, amend the commit, and continue |
853 | rebasing. | |
854 | ||
71f82465 JS |
855 | To interrupt the rebase (just like an "edit" command would do, but without |
856 | cherry-picking any commit first), use the "break" command. | |
857 | ||
6741aa6c BG |
858 | If you just want to edit the commit message for a commit, replace the |
859 | command "pick" with the command "reword". | |
860 | ||
c9266d58 GR |
861 | To drop a commit, replace the command "pick" with "drop", or just |
862 | delete the matching line. | |
863 | ||
1b1dce4b | 864 | If you want to fold two or more commits into one, replace the command |
0205e72f MH |
865 | "pick" for the second and subsequent commits with "squash" or "fixup". |
866 | If the commits had different authors, the folded commit will be | |
867 | attributed to the author of the first commit. The suggested commit | |
868 | message for the folded commit is the concatenation of the commit | |
869 | messages of the first commit and of those with the "squash" command, | |
870 | but omits the commit messages of commits with the "fixup" command. | |
1b1dce4b | 871 | |
0b444cdb | 872 | 'git rebase' will stop when "pick" has been replaced with "edit" or |
6741aa6c BG |
873 | when a command fails due to merge errors. When you are done editing |
874 | and/or resolving conflicts you can continue with `git rebase --continue`. | |
1b1dce4b JS |
875 | |
876 | For example, if you want to reorder the last 5 commits, such that what | |
877 | was HEAD~4 becomes the new HEAD. To achieve that, you would call | |
0b444cdb | 878 | 'git rebase' like this: |
1b1dce4b JS |
879 | |
880 | ---------------------- | |
881 | $ git rebase -i HEAD~5 | |
882 | ---------------------- | |
883 | ||
884 | And move the first patch to the end of the list. | |
885 | ||
7948b49a JS |
886 | You might want to recreate merge commits, e.g. if you have a history |
887 | like this: | |
f09c9b8c JS |
888 | |
889 | ------------------ | |
890 | X | |
891 | \ | |
892 | A---M---B | |
893 | / | |
894 | ---o---O---P---Q | |
895 | ------------------ | |
896 | ||
897 | Suppose you want to rebase the side branch starting at "A" to "Q". Make | |
898 | sure that the current HEAD is "B", and call | |
899 | ||
900 | ----------------------------- | |
7948b49a | 901 | $ git rebase -i -r --onto Q O |
f09c9b8c JS |
902 | ----------------------------- |
903 | ||
cd035b1c MM |
904 | Reordering and editing commits usually creates untested intermediate |
905 | steps. You may want to check that your history editing did not break | |
906 | anything by running a test, or at least recompiling at intermediate | |
907 | points in history by using the "exec" command (shortcut "x"). You may | |
908 | do so by creating a todo list like this one: | |
909 | ||
910 | ------------------------------------------- | |
911 | pick deadbee Implement feature XXX | |
912 | fixup f1a5c00 Fix to feature XXX | |
913 | exec make | |
914 | pick c0ffeee The oneline of the next commit | |
915 | edit deadbab The oneline of the commit after | |
916 | exec cd subdir; make test | |
917 | ... | |
918 | ------------------------------------------- | |
919 | ||
920 | The interactive rebase will stop when a command fails (i.e. exits with | |
921 | non-0 status) to give you an opportunity to fix the problem. You can | |
922 | continue with `git rebase --continue`. | |
923 | ||
924 | The "exec" command launches the command in a shell (the one specified | |
925 | in `$SHELL`, or the default shell if `$SHELL` is not set), so you can | |
926 | use shell features (like "cd", ">", ";" ...). The command is run from | |
927 | the root of the working tree. | |
f0fd889d | 928 | |
c2145384 LK |
929 | ---------------------------------- |
930 | $ git rebase -i --exec "make test" | |
931 | ---------------------------------- | |
932 | ||
933 | This command lets you check that intermediate commits are compilable. | |
934 | The todo list becomes like that: | |
935 | ||
936 | -------------------- | |
937 | pick 5928aea one | |
938 | exec make test | |
939 | pick 04d0fda two | |
940 | exec make test | |
941 | pick ba46169 three | |
942 | exec make test | |
943 | pick f4593f9 four | |
944 | exec make test | |
945 | -------------------- | |
946 | ||
f0fd889d JS |
947 | SPLITTING COMMITS |
948 | ----------------- | |
949 | ||
950 | In interactive mode, you can mark commits with the action "edit". However, | |
0b444cdb | 951 | this does not necessarily mean that 'git rebase' expects the result of this |
f0fd889d JS |
952 | edit to be exactly one commit. Indeed, you can undo the commit, or you can |
953 | add other commits. This can be used to split a commit into two: | |
954 | ||
483bc4f0 | 955 | - Start an interactive rebase with `git rebase -i <commit>^`, where |
f0fd889d JS |
956 | <commit> is the commit you want to split. In fact, any commit range |
957 | will do, as long as it contains that commit. | |
958 | ||
959 | - Mark the commit you want to split with the action "edit". | |
960 | ||
483bc4f0 | 961 | - When it comes to editing that commit, execute `git reset HEAD^`. The |
f0fd889d JS |
962 | effect is that the HEAD is rewound by one, and the index follows suit. |
963 | However, the working tree stays the same. | |
964 | ||
965 | - Now add the changes to the index that you want to have in the first | |
483bc4f0 | 966 | commit. You can use `git add` (possibly interactively) or |
0b444cdb | 967 | 'git gui' (or both) to do that. |
f0fd889d JS |
968 | |
969 | - Commit the now-current index with whatever commit message is appropriate | |
970 | now. | |
971 | ||
972 | - Repeat the last two steps until your working tree is clean. | |
973 | ||
483bc4f0 | 974 | - Continue the rebase with `git rebase --continue`. |
f0fd889d JS |
975 | |
976 | If you are not absolutely sure that the intermediate revisions are | |
977 | consistent (they compile, pass the testsuite, etc.) you should use | |
0b444cdb | 978 | 'git stash' to stash away the not-yet-committed changes |
f0fd889d JS |
979 | after each commit, test, and amend the commit if fixes are necessary. |
980 | ||
981 | ||
90d1c08e TR |
982 | RECOVERING FROM UPSTREAM REBASE |
983 | ------------------------------- | |
984 | ||
985 | Rebasing (or any other form of rewriting) a branch that others have | |
986 | based work on is a bad idea: anyone downstream of it is forced to | |
987 | manually fix their history. This section explains how to do the fix | |
988 | from the downstream's point of view. The real fix, however, would be | |
989 | to avoid rebasing the upstream in the first place. | |
990 | ||
991 | To illustrate, suppose you are in a situation where someone develops a | |
992 | 'subsystem' branch, and you are working on a 'topic' that is dependent | |
993 | on this 'subsystem'. You might end up with a history like the | |
994 | following: | |
995 | ||
996 | ------------ | |
01826066 | 997 | o---o---o---o---o---o---o---o master |
90d1c08e TR |
998 | \ |
999 | o---o---o---o---o subsystem | |
1000 | \ | |
1001 | *---*---* topic | |
1002 | ------------ | |
1003 | ||
1004 | If 'subsystem' is rebased against 'master', the following happens: | |
1005 | ||
1006 | ------------ | |
1007 | o---o---o---o---o---o---o---o master | |
1008 | \ \ | |
1009 | o---o---o---o---o o'--o'--o'--o'--o' subsystem | |
1010 | \ | |
1011 | *---*---* topic | |
1012 | ------------ | |
1013 | ||
1014 | If you now continue development as usual, and eventually merge 'topic' | |
1015 | to 'subsystem', the commits from 'subsystem' will remain duplicated forever: | |
1016 | ||
1017 | ------------ | |
1018 | o---o---o---o---o---o---o---o master | |
1019 | \ \ | |
1020 | o---o---o---o---o o'--o'--o'--o'--o'--M subsystem | |
1021 | \ / | |
1022 | *---*---*-..........-*--* topic | |
1023 | ------------ | |
1024 | ||
1025 | Such duplicates are generally frowned upon because they clutter up | |
1026 | history, making it harder to follow. To clean things up, you need to | |
1027 | transplant the commits on 'topic' to the new 'subsystem' tip, i.e., | |
1028 | rebase 'topic'. This becomes a ripple effect: anyone downstream from | |
1029 | 'topic' is forced to rebase too, and so on! | |
1030 | ||
1031 | There are two kinds of fixes, discussed in the following subsections: | |
1032 | ||
1033 | Easy case: The changes are literally the same.:: | |
1034 | ||
1035 | This happens if the 'subsystem' rebase was a simple rebase and | |
1036 | had no conflicts. | |
1037 | ||
1038 | Hard case: The changes are not the same.:: | |
1039 | ||
1040 | This happens if the 'subsystem' rebase had conflicts, or used | |
6cf378f0 JK |
1041 | `--interactive` to omit, edit, squash, or fixup commits; or |
1042 | if the upstream used one of `commit --amend`, `reset`, or | |
9df53c5d EN |
1043 | a full history rewriting command like |
1044 | https://github.com/newren/git-filter-repo[`filter-repo`]. | |
90d1c08e TR |
1045 | |
1046 | ||
1047 | The easy case | |
1048 | ~~~~~~~~~~~~~ | |
1049 | ||
1050 | Only works if the changes (patch IDs based on the diff contents) on | |
1051 | 'subsystem' are literally the same before and after the rebase | |
1052 | 'subsystem' did. | |
1053 | ||
0b444cdb | 1054 | In that case, the fix is easy because 'git rebase' knows to skip |
0fcb4f6b JT |
1055 | changes that are already present in the new upstream (unless |
1056 | `--reapply-cherry-picks` is given). So if you say | |
90d1c08e TR |
1057 | (assuming you're on 'topic') |
1058 | ------------ | |
1059 | $ git rebase subsystem | |
1060 | ------------ | |
1061 | you will end up with the fixed history | |
1062 | ------------ | |
1063 | o---o---o---o---o---o---o---o master | |
1064 | \ | |
1065 | o'--o'--o'--o'--o' subsystem | |
1066 | \ | |
1067 | *---*---* topic | |
1068 | ------------ | |
1069 | ||
1070 | ||
1071 | The hard case | |
1072 | ~~~~~~~~~~~~~ | |
1073 | ||
1074 | Things get more complicated if the 'subsystem' changes do not exactly | |
1075 | correspond to the ones before the rebase. | |
1076 | ||
1077 | NOTE: While an "easy case recovery" sometimes appears to be successful | |
1078 | even in the hard case, it may have unintended consequences. For | |
1079 | example, a commit that was removed via `git rebase | |
6cf378f0 | 1080 | --interactive` will be **resurrected**! |
90d1c08e | 1081 | |
0b444cdb | 1082 | The idea is to manually tell 'git rebase' "where the old 'subsystem' |
414d924b | 1083 | ended and your 'topic' began", that is, what the old merge base |
90d1c08e TR |
1084 | between them was. You will have to find a way to name the last commit |
1085 | of the old 'subsystem', for example: | |
1086 | ||
0b444cdb | 1087 | * With the 'subsystem' reflog: after 'git fetch', the old tip of |
6cf378f0 | 1088 | 'subsystem' is at `subsystem@{1}`. Subsequent fetches will |
90d1c08e TR |
1089 | increase the number. (See linkgit:git-reflog[1].) |
1090 | ||
1091 | * Relative to the tip of 'topic': knowing that your 'topic' has three | |
1092 | commits, the old tip of 'subsystem' must be `topic~3`. | |
1093 | ||
1094 | You can then transplant the old `subsystem..topic` to the new tip by | |
1095 | saying (for the reflog case, and assuming you are on 'topic' already): | |
1096 | ------------ | |
1097 | $ git rebase --onto subsystem subsystem@{1} | |
1098 | ------------ | |
1099 | ||
1100 | The ripple effect of a "hard case" recovery is especially bad: | |
1101 | 'everyone' downstream from 'topic' will now have to perform a "hard | |
1102 | case" recovery too! | |
1103 | ||
25cff9f1 | 1104 | REBASING MERGES |
81d395cc | 1105 | --------------- |
25cff9f1 JS |
1106 | |
1107 | The interactive rebase command was originally designed to handle | |
1108 | individual patch series. As such, it makes sense to exclude merge | |
1109 | commits from the todo list, as the developer may have merged the | |
1110 | then-current `master` while working on the branch, only to rebase | |
1111 | all the commits onto `master` eventually (skipping the merge | |
1112 | commits). | |
1113 | ||
1114 | However, there are legitimate reasons why a developer may want to | |
1115 | recreate merge commits: to keep the branch structure (or "commit | |
1116 | topology") when working on multiple, inter-related branches. | |
1117 | ||
1118 | In the following example, the developer works on a topic branch that | |
1119 | refactors the way buttons are defined, and on another topic branch | |
1120 | that uses that refactoring to implement a "Report a bug" button. The | |
1121 | output of `git log --graph --format=%s -5` may look like this: | |
1122 | ||
1123 | ------------ | |
1124 | * Merge branch 'report-a-bug' | |
1125 | |\ | |
1126 | | * Add the feedback button | |
1127 | * | Merge branch 'refactor-button' | |
1128 | |\ \ | |
1129 | | |/ | |
1130 | | * Use the Button class for all buttons | |
1131 | | * Extract a generic Button class from the DownloadButton one | |
1132 | ------------ | |
1133 | ||
1134 | The developer might want to rebase those commits to a newer `master` | |
1135 | while keeping the branch topology, for example when the first topic | |
1136 | branch is expected to be integrated into `master` much earlier than the | |
1137 | second one, say, to resolve merge conflicts with changes to the | |
1138 | DownloadButton class that made it into `master`. | |
1139 | ||
1140 | This rebase can be performed using the `--rebase-merges` option. | |
1141 | It will generate a todo list looking like this: | |
1142 | ||
1143 | ------------ | |
1144 | label onto | |
1145 | ||
1146 | # Branch: refactor-button | |
1147 | reset onto | |
1148 | pick 123456 Extract a generic Button class from the DownloadButton one | |
1149 | pick 654321 Use the Button class for all buttons | |
1150 | label refactor-button | |
1151 | ||
1152 | # Branch: report-a-bug | |
1153 | reset refactor-button # Use the Button class for all buttons | |
1154 | pick abcdef Add the feedback button | |
1155 | label report-a-bug | |
1156 | ||
1157 | reset onto | |
1158 | merge -C a1b2c3 refactor-button # Merge 'refactor-button' | |
1159 | merge -C 6f5e4d report-a-bug # Merge 'report-a-bug' | |
1160 | ------------ | |
1161 | ||
1162 | In contrast to a regular interactive rebase, there are `label`, `reset` | |
1163 | and `merge` commands in addition to `pick` ones. | |
1164 | ||
1165 | The `label` command associates a label with the current HEAD when that | |
1166 | command is executed. These labels are created as worktree-local refs | |
1167 | (`refs/rewritten/<label>`) that will be deleted when the rebase | |
1168 | finishes. That way, rebase operations in multiple worktrees linked to | |
1169 | the same repository do not interfere with one another. If the `label` | |
1170 | command fails, it is rescheduled immediately, with a helpful message how | |
1171 | to proceed. | |
1172 | ||
1173 | The `reset` command resets the HEAD, index and worktree to the specified | |
ad0b8f95 | 1174 | revision. It is similar to an `exec git reset --hard <label>`, but |
25cff9f1 JS |
1175 | refuses to overwrite untracked files. If the `reset` command fails, it is |
1176 | rescheduled immediately, with a helpful message how to edit the todo list | |
1177 | (this typically happens when a `reset` command was inserted into the todo | |
1178 | list manually and contains a typo). | |
1179 | ||
caafecfc JS |
1180 | The `merge` command will merge the specified revision(s) into whatever |
1181 | is HEAD at that time. With `-C <original-commit>`, the commit message of | |
25cff9f1 JS |
1182 | the specified merge commit will be used. When the `-C` is changed to |
1183 | a lower-case `-c`, the message will be opened in an editor after a | |
1184 | successful merge so that the user can edit the message. | |
1185 | ||
1186 | If a `merge` command fails for any reason other than merge conflicts (i.e. | |
1187 | when the merge operation did not even start), it is rescheduled immediately. | |
1188 | ||
1189 | At this time, the `merge` command will *always* use the `recursive` | |
caafecfc | 1190 | merge strategy for regular merges, and `octopus` for octopus merges, |
57e9dcaa | 1191 | with no way to choose a different one. To work around |
25cff9f1 JS |
1192 | this, an `exec` command can be used to call `git merge` explicitly, |
1193 | using the fact that the labels are worktree-local refs (the ref | |
1194 | `refs/rewritten/onto` would correspond to the label `onto`, for example). | |
1195 | ||
1196 | Note: the first command (`label onto`) labels the revision onto which | |
1197 | the commits are rebased; The name `onto` is just a convention, as a nod | |
1198 | to the `--onto` option. | |
1199 | ||
1200 | It is also possible to introduce completely new merge commits from scratch | |
1201 | by adding a command of the form `merge <merge-head>`. This form will | |
1202 | generate a tentative commit message and always open an editor to let the | |
1203 | user edit it. This can be useful e.g. when a topic branch turns out to | |
1204 | address more than a single concern and wants to be split into two or | |
1205 | even more topic branches. Consider this todo list: | |
1206 | ||
1207 | ------------ | |
1208 | pick 192837 Switch from GNU Makefiles to CMake | |
1209 | pick 5a6c7e Document the switch to CMake | |
1210 | pick 918273 Fix detection of OpenSSL in CMake | |
1211 | pick afbecd http: add support for TLS v1.3 | |
1212 | pick fdbaec Fix detection of cURL in CMake on Windows | |
1213 | ------------ | |
1214 | ||
1215 | The one commit in this list that is not related to CMake may very well | |
1216 | have been motivated by working on fixing all those bugs introduced by | |
1217 | switching to CMake, but it addresses a different concern. To split this | |
1218 | branch into two topic branches, the todo list could be edited like this: | |
1219 | ||
1220 | ------------ | |
1221 | label onto | |
1222 | ||
1223 | pick afbecd http: add support for TLS v1.3 | |
1224 | label tlsv1.3 | |
1225 | ||
1226 | reset onto | |
1227 | pick 192837 Switch from GNU Makefiles to CMake | |
1228 | pick 918273 Fix detection of OpenSSL in CMake | |
1229 | pick fdbaec Fix detection of cURL in CMake on Windows | |
1230 | pick 5a6c7e Document the switch to CMake | |
1231 | label cmake | |
1232 | ||
1233 | reset onto | |
1234 | merge tlsv1.3 | |
1235 | merge cmake | |
1236 | ------------ | |
1237 | ||
cddb42d2 JN |
1238 | BUGS |
1239 | ---- | |
427c3bd2 JS |
1240 | The todo list presented by the deprecated `--preserve-merges --interactive` |
1241 | does not represent the topology of the revision graph (use `--rebase-merges` | |
1242 | instead). Editing commits and rewording their commit messages should work | |
1243 | fine, but attempts to reorder commits tend to produce counterintuitive results. | |
1244 | Use `--rebase-merges` in such scenarios instead. | |
cddb42d2 JN |
1245 | |
1246 | For example, an attempt to rearrange | |
1247 | ------------ | |
1248 | 1 --- 2 --- 3 --- 4 --- 5 | |
1249 | ------------ | |
1250 | to | |
1251 | ------------ | |
1252 | 1 --- 2 --- 4 --- 3 --- 5 | |
1253 | ------------ | |
1254 | by moving the "pick 4" line will result in the following history: | |
1255 | ------------ | |
1256 | 3 | |
1257 | / | |
1258 | 1 --- 2 --- 4 --- 5 | |
1259 | ------------ | |
1260 | ||
7fc9d69f JH |
1261 | GIT |
1262 | --- | |
9e1f0a85 | 1263 | Part of the linkgit:git[1] suite |