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>] [--no-verify] 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, a 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 want to make 'topic' forked from branch 'master'; for example, 107because the functionality on which 'topic' depends was merged into the 108more stable 'master' branch. We want our tree to look 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--no-verify:: 236 This option bypasses the pre-rebase hook. See also linkgit:githooks[5]. 237 238-C<n>:: 239 Ensure at least <n> lines of surrounding context match before 240 and after each change. When fewer lines of surrounding 241 context exist they all must match. By default no context is 242 ever ignored. 243 244--whitespace=<nowarn|warn|error|error-all|strip>:: 245 This flag is passed to the 'git-apply' program 246 (see linkgit:git-apply[1]) that applies the patch. 247 248-i:: 249--interactive:: 250 Make a list of the commits which are about to be rebased. Let the 251 user edit that list before rebasing. This mode can also be used to 252 split commits (see SPLITTING COMMITS below). 253 254-p:: 255--preserve-merges:: 256 Instead of ignoring merges, try to recreate them. 257 258include::merge-strategies.txt[] 259 260NOTES 261----- 262 263You should understand the implications of using 'git-rebase' on a 264repository that you share. See also RECOVERING FROM UPSTREAM REBASE 265below. 266 267When the git-rebase command is run, it will first execute a "pre-rebase" 268hook if one exists. You can use this hook to do sanity checks and 269reject the rebase if it isn't appropriate. Please see the template 270pre-rebase hook script for an example. 271 272Upon completion, <branch> will be the current branch. 273 274INTERACTIVE MODE 275---------------- 276 277Rebasing interactively means that you have a chance to edit the commits 278which are rebased. You can reorder the commits, and you can 279remove them (weeding out bad or otherwise unwanted patches). 280 281The interactive mode is meant for this type of workflow: 282 2831. have a wonderful idea 2842. hack on the code 2853. prepare a series for submission 2864. submit 287 288where point 2. consists of several instances of 289 290a. regular use 291 1. finish something worthy of a commit 292 2. commit 293b. independent fixup 294 1. realize that something does not work 295 2. fix that 296 3. commit it 297 298Sometimes the thing fixed in b.2. cannot be amended to the not-quite 299perfect commit it fixes, because that commit is buried deeply in a 300patch series. That is exactly what interactive rebase is for: use it 301after plenty of "a"s and "b"s, by rearranging and editing 302commits, and squashing multiple commits into one. 303 304Start it with the last commit you want to retain as-is: 305 306 git rebase -i <after-this-commit> 307 308An editor will be fired up with all the commits in your current branch 309(ignoring merge commits), which come after the given commit. You can 310reorder the commits in this list to your heart's content, and you can 311remove them. The list looks more or less like this: 312 313------------------------------------------- 314pick deadbee The oneline of this commit 315pick fa1afe1 The oneline of the next commit 316... 317------------------------------------------- 318 319The oneline descriptions are purely for your pleasure; 'git-rebase' will 320not look at them but at the commit names ("deadbee" and "fa1afe1" in this 321example), so do not delete or edit the names. 322 323By replacing the command "pick" with the command "edit", you can tell 324'git-rebase' to stop after applying that commit, so that you can edit 325the files and/or the commit message, amend the commit, and continue 326rebasing. 327 328If you want to fold two or more commits into one, replace the command 329"pick" with "squash" for the second and subsequent commit. If the 330commits had different authors, it will attribute the squashed commit to 331the author of the first commit. 332 333In both cases, or when a "pick" does not succeed (because of merge 334errors), the loop will stop to let you fix things, and you can continue 335the loop with `git rebase --continue`. 336 337For example, if you want to reorder the last 5 commits, such that what 338was HEAD~4 becomes the new HEAD. To achieve that, you would call 339'git-rebase' like this: 340 341---------------------- 342$ git rebase -i HEAD~5 343---------------------- 344 345And move the first patch to the end of the list. 346 347You might want to preserve merges, if you have a history like this: 348 349------------------ 350 X 351 \ 352 A---M---B 353 / 354---o---O---P---Q 355------------------ 356 357Suppose you want to rebase the side branch starting at "A" to "Q". Make 358sure that the current HEAD is "B", and call 359 360----------------------------- 361$ git rebase -i -p --onto Q O 362----------------------------- 363 364 365SPLITTING COMMITS 366----------------- 367 368In interactive mode, you can mark commits with the action "edit". However, 369this does not necessarily mean that 'git-rebase' expects the result of this 370edit to be exactly one commit. Indeed, you can undo the commit, or you can 371add other commits. This can be used to split a commit into two: 372 373- Start an interactive rebase with `git rebase -i <commit>^`, where 374 <commit> is the commit you want to split. In fact, any commit range 375 will do, as long as it contains that commit. 376 377- Mark the commit you want to split with the action "edit". 378 379- When it comes to editing that commit, execute `git reset HEAD^`. The 380 effect is that the HEAD is rewound by one, and the index follows suit. 381 However, the working tree stays the same. 382 383- Now add the changes to the index that you want to have in the first 384 commit. You can use `git add` (possibly interactively) or 385 'git-gui' (or both) to do that. 386 387- Commit the now-current index with whatever commit message is appropriate 388 now. 389 390- Repeat the last two steps until your working tree is clean. 391 392- Continue the rebase with `git rebase --continue`. 393 394If you are not absolutely sure that the intermediate revisions are 395consistent (they compile, pass the testsuite, etc.) you should use 396'git-stash' to stash away the not-yet-committed changes 397after each commit, test, and amend the commit if fixes are necessary. 398 399 400RECOVERING FROM UPSTREAM REBASE 401------------------------------- 402 403Rebasing (or any other form of rewriting) a branch that others have 404based work on is a bad idea: anyone downstream of it is forced to 405manually fix their history. This section explains how to do the fix 406from the downstream's point of view. The real fix, however, would be 407to avoid rebasing the upstream in the first place. 408 409To illustrate, suppose you are in a situation where someone develops a 410'subsystem' branch, and you are working on a 'topic' that is dependent 411on this 'subsystem'. You might end up with a history like the 412following: 413 414------------ 415 o---o---o---o---o---o---o---o---o master 416 \ 417 o---o---o---o---o subsystem 418 \ 419 *---*---* topic 420------------ 421 422If 'subsystem' is rebased against 'master', the following happens: 423 424------------ 425 o---o---o---o---o---o---o---o master 426 \ \ 427 o---o---o---o---o o'--o'--o'--o'--o' subsystem 428 \ 429 *---*---* topic 430------------ 431 432If you now continue development as usual, and eventually merge 'topic' 433to 'subsystem', the commits from 'subsystem' will remain duplicated forever: 434 435------------ 436 o---o---o---o---o---o---o---o master 437 \ \ 438 o---o---o---o---o o'--o'--o'--o'--o'--M subsystem 439 \ / 440 *---*---*-..........-*--* topic 441------------ 442 443Such duplicates are generally frowned upon because they clutter up 444history, making it harder to follow. To clean things up, you need to 445transplant the commits on 'topic' to the new 'subsystem' tip, i.e., 446rebase 'topic'. This becomes a ripple effect: anyone downstream from 447'topic' is forced to rebase too, and so on! 448 449There are two kinds of fixes, discussed in the following subsections: 450 451Easy case: The changes are literally the same.:: 452 453 This happens if the 'subsystem' rebase was a simple rebase and 454 had no conflicts. 455 456Hard case: The changes are not the same.:: 457 458 This happens if the 'subsystem' rebase had conflicts, or used 459 `\--interactive` to omit, edit, or squash commits; or if the 460 upstream used one of `commit \--amend`, `reset`, or 461 `filter-branch`. 462 463 464The easy case 465~~~~~~~~~~~~~ 466 467Only works if the changes (patch IDs based on the diff contents) on 468'subsystem' are literally the same before and after the rebase 469'subsystem' did. 470 471In that case, the fix is easy because 'git-rebase' knows to skip 472changes that are already present in the new upstream. So if you say 473(assuming you're on 'topic') 474------------ 475 $ git rebase subsystem 476------------ 477you will end up with the fixed history 478------------ 479 o---o---o---o---o---o---o---o master 480 \ 481 o'--o'--o'--o'--o' subsystem 482 \ 483 *---*---* topic 484------------ 485 486 487The hard case 488~~~~~~~~~~~~~ 489 490Things get more complicated if the 'subsystem' changes do not exactly 491correspond to the ones before the rebase. 492 493NOTE: While an "easy case recovery" sometimes appears to be successful 494 even in the hard case, it may have unintended consequences. For 495 example, a commit that was removed via `git rebase 496 \--interactive` will be **resurrected**! 497 498The idea is to manually tell 'git-rebase' "where the old 'subsystem' 499ended and your 'topic' began", that is, what the old merge-base 500between them was. You will have to find a way to name the last commit 501of the old 'subsystem', for example: 502 503* With the 'subsystem' reflog: after 'git-fetch', the old tip of 504 'subsystem' is at `subsystem@\{1}`. Subsequent fetches will 505 increase the number. (See linkgit:git-reflog[1].) 506 507* Relative to the tip of 'topic': knowing that your 'topic' has three 508 commits, the old tip of 'subsystem' must be `topic~3`. 509 510You can then transplant the old `subsystem..topic` to the new tip by 511saying (for the reflog case, and assuming you are on 'topic' already): 512------------ 513 $ git rebase --onto subsystem subsystem@{1} 514------------ 515 516The ripple effect of a "hard case" recovery is especially bad: 517'everyone' downstream from 'topic' will now have to perform a "hard 518case" recovery too! 519 520 521Authors 522------ 523Written by Junio C Hamano <gitster@pobox.com> and 524Johannes E. Schindelin <johannes.schindelin@gmx.de> 525 526Documentation 527-------------- 528Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>. 529 530GIT 531--- 532Part of the linkgit:git[1] suite