1git-rebase(1) 2============= 3 4NAME 5---- 6git-rebase - Forward-port local commits to the updated upstream head 7 8SYNOPSIS 9-------- 10[verse] 11'git rebase' [-i | --interactive] [-v | --verbose] [-m | --merge] 12 [-s <strategy> | --strategy=<strategy>] 13 [-C<n>] [ --whitespace=<option>] [-p | --preserve-merges] 14 [--onto <newbase>] <upstream> [<branch>] 15'git rebase' --continue | --skip | --abort 16 17DESCRIPTION 18----------- 19If <branch> is specified, 'git-rebase' will perform an automatic 20`git checkout <branch>` before doing anything else. Otherwise 21it remains on the current branch. 22 23All changes made by commits in the current branch but that are not 24in <upstream> are saved to a temporary area. This is the same set 25of commits that would be shown by `git log <upstream>..HEAD`. 26 27The current branch is reset to <upstream>, or <newbase> if the 28--onto option was supplied. This has the exact same effect as 29`git reset --hard <upstream>` (or <newbase>). ORIG_HEAD is set 30to point at the tip of the branch before the reset. 31 32The commits that were previously saved into the temporary area are 33then reapplied to the current branch, one by one, in order. Note that 34any commits in HEAD which introduce the same textual changes as a commit 35in HEAD..<upstream> are omitted (i.e., a patch already accepted upstream 36with a different commit message or timestamp will be skipped). 37 38It is possible that a merge failure will prevent this process from being 39completely automatic. You will have to resolve any such merge failure 40and run `git rebase --continue`. Another option is to bypass the commit 41that caused the merge failure with `git rebase --skip`. To restore the 42original <branch> and remove the .git/rebase-apply working files, use the 43command `git rebase --abort` instead. 44 45Assume the following history exists and the current branch is "topic": 46 47------------ 48 A---B---C topic 49 / 50 D---E---F---G master 51------------ 52 53From this point, the result of either of the following commands: 54 55 56 git rebase master 57 git rebase master topic 58 59would be: 60 61------------ 62 A'--B'--C' topic 63 / 64 D---E---F---G master 65------------ 66 67The latter form is just a short-hand of `git checkout topic` 68followed by `git rebase master`. 69 70If the upstream branch already contains a change you have made (e.g., 71because you mailed a patch which was applied upstream), then that commit 72will be skipped. For example, running `git rebase master` on the 73following history (in which A' and A introduce the same set of changes, 74but have different committer information): 75 76------------ 77 A---B---C topic 78 / 79 D---E---A'---F master 80------------ 81 82will result in: 83 84------------ 85 B'---C' topic 86 / 87 D---E---A'---F master 88------------ 89 90Here is how you would transplant a topic branch based on one 91branch to another, to pretend that you forked the topic branch 92from the latter branch, using `rebase --onto`. 93 94First let's assume your 'topic' is based on branch 'next'. 95For example feature developed in 'topic' depends on some 96functionality which is found in 'next'. 97 98------------ 99 o---o---o---o---o master 100 \ 101 o---o---o---o---o next 102 \ 103 o---o---o topic 104------------ 105 106We would want to make 'topic' forked from branch 'master', 107for example because the functionality 'topic' branch depend on 108got merged into more stable 'master' branch, like this: 109 110------------ 111 o---o---o---o---o master 112 | \ 113 | o'--o'--o' topic 114 \ 115 o---o---o---o---o next 116------------ 117 118We can get this using the following command: 119 120 git rebase --onto master next topic 121 122 123Another example of --onto option is to rebase part of a 124branch. If we have the following situation: 125 126------------ 127 H---I---J topicB 128 / 129 E---F---G topicA 130 / 131 A---B---C---D master 132------------ 133 134then the command 135 136 git rebase --onto master topicA topicB 137 138would result in: 139 140------------ 141 H'--I'--J' topicB 142 / 143 | E---F---G topicA 144 |/ 145 A---B---C---D master 146------------ 147 148This is useful when topicB does not depend on topicA. 149 150A range of commits could also be removed with rebase. If we have 151the following situation: 152 153------------ 154 E---F---G---H---I---J topicA 155------------ 156 157then the command 158 159 git rebase --onto topicA~5 topicA~3 topicA 160 161would result in the removal of commits F and G: 162 163------------ 164 E---H'---I'---J' topicA 165------------ 166 167This is useful if F and G were flawed in some way, or should not be 168part of topicA. Note that the argument to --onto and the <upstream> 169parameter can be any valid commit-ish. 170 171In case of conflict, 'git-rebase' will stop at the first problematic commit 172and leave conflict markers in the tree. You can use 'git-diff' to locate 173the markers (<<<<<<) and make edits to resolve the conflict. For each 174file you edit, you need to tell git that the conflict has been resolved, 175typically this would be done with 176 177 178 git add <filename> 179 180 181After resolving the conflict manually and updating the index with the 182desired resolution, you can continue the rebasing process with 183 184 185 git rebase --continue 186 187 188Alternatively, you can undo the 'git-rebase' with 189 190 191 git rebase --abort 192 193OPTIONS 194------- 195<newbase>:: 196 Starting point at which to create the new commits. If the 197 --onto option is not specified, the starting point is 198 <upstream>. May be any valid commit, and not just an 199 existing branch name. 200 201<upstream>:: 202 Upstream branch to compare against. May be any valid commit, 203 not just an existing branch name. 204 205<branch>:: 206 Working branch; defaults to HEAD. 207 208--continue:: 209 Restart the rebasing process after having resolved a merge conflict. 210 211--abort:: 212 Restore the original branch and abort the rebase operation. 213 214--skip:: 215 Restart the rebasing process by skipping the current patch. 216 217-m:: 218--merge:: 219 Use merging strategies to rebase. When the recursive (default) merge 220 strategy is used, this allows rebase to be aware of renames on the 221 upstream side. 222 223-s <strategy>:: 224--strategy=<strategy>:: 225 Use the given merge strategy; can be supplied more than 226 once to specify them in the order they should be tried. 227 If there is no `-s` option, a built-in list of strategies 228 is used instead ('git-merge-recursive' when merging a single 229 head, 'git-merge-octopus' otherwise). This implies --merge. 230 231-v:: 232--verbose:: 233 Display a diffstat of what changed upstream since the last rebase. 234 235-C<n>:: 236 Ensure at least <n> lines of surrounding context match before 237 and after each change. When fewer lines of surrounding 238 context exist they all must match. By default no context is 239 ever ignored. 240 241--whitespace=<nowarn|warn|error|error-all|strip>:: 242 This flag is passed to the 'git-apply' program 243 (see linkgit:git-apply[1]) that applies the patch. 244 245-i:: 246--interactive:: 247 Make a list of the commits which are about to be rebased. Let the 248 user edit that list before rebasing. This mode can also be used to 249 split commits (see SPLITTING COMMITS below). 250 251-p:: 252--preserve-merges:: 253 Instead of ignoring merges, try to recreate them. This option 254 only works in interactive mode. 255 256include::merge-strategies.txt[] 257 258NOTES 259----- 260 261You should understand the implications of using 'git-rebase' on a 262repository that you share. See also RECOVERING FROM UPSTREAM REBASE 263below. 264 265When the git-rebase command is run, it will first execute a "pre-rebase" 266hook if one exists. You can use this hook to do sanity checks and 267reject the rebase if it isn't appropriate. Please see the template 268pre-rebase hook script for an example. 269 270Upon completion, <branch> will be the current branch. 271 272INTERACTIVE MODE 273---------------- 274 275Rebasing interactively means that you have a chance to edit the commits 276which are rebased. You can reorder the commits, and you can 277remove them (weeding out bad or otherwise unwanted patches). 278 279The interactive mode is meant for this type of workflow: 280 2811. have a wonderful idea 2822. hack on the code 2833. prepare a series for submission 2844. submit 285 286where point 2. consists of several instances of 287 288a. regular use 289 1. finish something worthy of a commit 290 2. commit 291b. independent fixup 292 1. realize that something does not work 293 2. fix that 294 3. commit it 295 296Sometimes the thing fixed in b.2. cannot be amended to the not-quite 297perfect commit it fixes, because that commit is buried deeply in a 298patch series. That is exactly what interactive rebase is for: use it 299after plenty of "a"s and "b"s, by rearranging and editing 300commits, and squashing multiple commits into one. 301 302Start it with the last commit you want to retain as-is: 303 304 git rebase -i <after-this-commit> 305 306An editor will be fired up with all the commits in your current branch 307(ignoring merge commits), which come after the given commit. You can 308reorder the commits in this list to your heart's content, and you can 309remove them. The list looks more or less like this: 310 311------------------------------------------- 312pick deadbee The oneline of this commit 313pick fa1afe1 The oneline of the next commit 314... 315------------------------------------------- 316 317The oneline descriptions are purely for your pleasure; 'git-rebase' will 318not look at them but at the commit names ("deadbee" and "fa1afe1" in this 319example), so do not delete or edit the names. 320 321By replacing the command "pick" with the command "edit", you can tell 322'git-rebase' to stop after applying that commit, so that you can edit 323the files and/or the commit message, amend the commit, and continue 324rebasing. 325 326If you want to fold two or more commits into one, replace the command 327"pick" with "squash" for the second and subsequent commit. If the 328commits had different authors, it will attribute the squashed commit to 329the author of the first commit. 330 331In both cases, or when a "pick" does not succeed (because of merge 332errors), the loop will stop to let you fix things, and you can continue 333the loop with `git rebase --continue`. 334 335For example, if you want to reorder the last 5 commits, such that what 336was HEAD~4 becomes the new HEAD. To achieve that, you would call 337'git-rebase' like this: 338 339---------------------- 340$ git rebase -i HEAD~5 341---------------------- 342 343And move the first patch to the end of the list. 344 345You might want to preserve merges, if you have a history like this: 346 347------------------ 348 X 349 \ 350 A---M---B 351 / 352---o---O---P---Q 353------------------ 354 355Suppose you want to rebase the side branch starting at "A" to "Q". Make 356sure that the current HEAD is "B", and call 357 358----------------------------- 359$ git rebase -i -p --onto Q O 360----------------------------- 361 362 363SPLITTING COMMITS 364----------------- 365 366In interactive mode, you can mark commits with the action "edit". However, 367this does not necessarily mean that 'git-rebase' expects the result of this 368edit to be exactly one commit. Indeed, you can undo the commit, or you can 369add other commits. This can be used to split a commit into two: 370 371- Start an interactive rebase with `git rebase -i <commit>^`, where 372 <commit> is the commit you want to split. In fact, any commit range 373 will do, as long as it contains that commit. 374 375- Mark the commit you want to split with the action "edit". 376 377- When it comes to editing that commit, execute `git reset HEAD^`. The 378 effect is that the HEAD is rewound by one, and the index follows suit. 379 However, the working tree stays the same. 380 381- Now add the changes to the index that you want to have in the first 382 commit. You can use `git add` (possibly interactively) or 383 'git-gui' (or both) to do that. 384 385- Commit the now-current index with whatever commit message is appropriate 386 now. 387 388- Repeat the last two steps until your working tree is clean. 389 390- Continue the rebase with `git rebase --continue`. 391 392If you are not absolutely sure that the intermediate revisions are 393consistent (they compile, pass the testsuite, etc.) you should use 394'git-stash' to stash away the not-yet-committed changes 395after each commit, test, and amend the commit if fixes are necessary. 396 397 398RECOVERING FROM UPSTREAM REBASE 399------------------------------- 400 401Rebasing (or any other form of rewriting) a branch that others have 402based work on is a bad idea: anyone downstream of it is forced to 403manually fix their history. This section explains how to do the fix 404from the downstream's point of view. The real fix, however, would be 405to avoid rebasing the upstream in the first place. 406 407To illustrate, suppose you are in a situation where someone develops a 408'subsystem' branch, and you are working on a 'topic' that is dependent 409on this 'subsystem'. You might end up with a history like the 410following: 411 412------------ 413 o---o---o---o---o---o---o---o---o master 414 \ 415 o---o---o---o---o subsystem 416 \ 417 *---*---* topic 418------------ 419 420If 'subsystem' is rebased against 'master', the following happens: 421 422------------ 423 o---o---o---o---o---o---o---o master 424 \ \ 425 o---o---o---o---o o'--o'--o'--o'--o' subsystem 426 \ 427 *---*---* topic 428------------ 429 430If you now continue development as usual, and eventually merge 'topic' 431to 'subsystem', the commits from 'subsystem' will remain duplicated forever: 432 433------------ 434 o---o---o---o---o---o---o---o master 435 \ \ 436 o---o---o---o---o o'--o'--o'--o'--o'--M subsystem 437 \ / 438 *---*---*-..........-*--* topic 439------------ 440 441Such duplicates are generally frowned upon because they clutter up 442history, making it harder to follow. To clean things up, you need to 443transplant the commits on 'topic' to the new 'subsystem' tip, i.e., 444rebase 'topic'. This becomes a ripple effect: anyone downstream from 445'topic' is forced to rebase too, and so on! 446 447There are two kinds of fixes, discussed in the following subsections: 448 449Easy case: The changes are literally the same.:: 450 451 This happens if the 'subsystem' rebase was a simple rebase and 452 had no conflicts. 453 454Hard case: The changes are not the same.:: 455 456 This happens if the 'subsystem' rebase had conflicts, or used 457 `\--interactive` to omit, edit, or squash commits; or if the 458 upstream used one of `commit \--amend`, `reset`, or 459 `filter-branch`. 460 461 462The easy case 463~~~~~~~~~~~~~ 464 465Only works if the changes (patch IDs based on the diff contents) on 466'subsystem' are literally the same before and after the rebase 467'subsystem' did. 468 469In that case, the fix is easy because 'git-rebase' knows to skip 470changes that are already present in the new upstream. So if you say 471(assuming you're on 'topic') 472------------ 473 $ git rebase subsystem 474------------ 475you will end up with the fixed history 476------------ 477 o---o---o---o---o---o---o---o master 478 \ 479 o'--o'--o'--o'--o' subsystem 480 \ 481 *---*---* topic 482------------ 483 484 485The hard case 486~~~~~~~~~~~~~ 487 488Things get more complicated if the 'subsystem' changes do not exactly 489correspond to the ones before the rebase. 490 491NOTE: While an "easy case recovery" sometimes appears to be successful 492 even in the hard case, it may have unintended consequences. For 493 example, a commit that was removed via `git rebase 494 \--interactive` will be **resurrected**! 495 496The idea is to manually tell 'git-rebase' "where the old 'subsystem' 497ended and your 'topic' began", that is, what the old merge-base 498between them was. You will have to find a way to name the last commit 499of the old 'subsystem', for example: 500 501* With the 'subsystem' reflog: after 'git-fetch', the old tip of 502 'subsystem' is at `subsystem@\{1}`. Subsequent fetches will 503 increase the number. (See linkgit:git-reflog[1].) 504 505* Relative to the tip of 'topic': knowing that your 'topic' has three 506 commits, the old tip of 'subsystem' must be `topic~3`. 507 508You can then transplant the old `subsystem..topic` to the new tip by 509saying (for the reflog case, and assuming you are on 'topic' already): 510------------ 511 $ git rebase --onto subsystem subsystem@{1} 512------------ 513 514The ripple effect of a "hard case" recovery is especially bad: 515'everyone' downstream from 'topic' will now have to perform a "hard 516case" recovery too! 517 518 519Authors 520------ 521Written by Junio C Hamano <gitster@pobox.com> and 522Johannes E. Schindelin <johannes.schindelin@gmx.de> 523 524Documentation 525-------------- 526Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>. 527 528GIT 529--- 530Part of the linkgit:git[1] suite