1GIT-MERGE(1) Git Manual GIT-MERGE(1)
2
6 git-merge - Join two or more development histories together
7
9 git merge [-n] [--stat] [--no-commit] [--squash]
10 [-s <strategy>] [-X <strategy-option>]
11 [--[no-]rerere-autoupdate] [-m <msg>] <commit>...
12 git merge <msg> HEAD <commit>...
13 git merge --abort
14
17 Incorporates changes from the named commits (since the time their
18 histories diverged from the current branch) into the current branch.
19 This command is used by git pull to incorporate changes from another
20 repository and can be used by hand to merge changes from one branch
21 into another.
22 Assume the following history exists and the current branch is "master":
24 A---B---C topic
26 /
27 D---E---F---G master
28 Then "git merge topic" will replay the changes made on the topic branch
31 since it diverged from master (i.e., E) until its current commit (C) on
32 top of master, and record the result in a new commit along with the
33 names of the two parent commits and a log message from the user
34 describing the changes.
35 A---B---C topic
37 / \
38 D---E---F---G---H master
39 The second syntax (<msg> HEAD <commit>...) is supported for historical
42 reasons. Do not use it from the command line or in new scripts. It is
43 the same as git merge -m <msg> <commit>....
44 The third syntax ("git merge --abort") can only be run after the merge
46 has resulted in conflicts. git merge --abort will abort the merge
47 process and try to reconstruct the pre-merge state. However, if there
48 were uncommitted changes when the merge started (and especially if
49 those changes were further modified after the merge was started), git
50 merge --abort will in some cases be unable to reconstruct the original
51 (pre-merge) changes. Therefore:
52 Warning: Running git merge with uncommitted changes is discouraged:
54 while possible, it leaves you in a state that is hard to back out of in
55 the case of a conflict.
56
58 --commit, --no-commit
59 Perform the merge and commit the result. This option can be used to
60 override --no-commit.
61 With --no-commit perform the merge but pretend the merge failed and
63 do not autocommit, to give the user a chance to inspect and further
64 tweak the merge result before committing.
65 --ff, --no-ff
67 Do not generate a merge commit if the merge resolved as a
68 fast-forward, only update the branch pointer. This is the default
69 behavior of git-merge.
70 With --no-ff Generate a merge commit even if the merge resolved as
72 a fast-forward.
73 --log[=<n>], --no-log
75 In addition to branch names, populate the log message with one-line
76 descriptions from at most <n> actual commits that are being merged.
77 See also git-fmt-merge-msg(1).
78 With --no-log do not list one-line descriptions from the actual
80 commits being merged.
81 --stat, -n, --no-stat
83 Show a diffstat at the end of the merge. The diffstat is also
84 controlled by the configuration option merge.stat.
85 With -n or --no-stat do not show a diffstat at the end of the
87 merge.
88 --squash, --no-squash
90 Produce the working tree and index state as if a real merge
91 happened (except for the merge information), but do not actually
92 make a commit or move the HEAD, nor record $GIT_DIR/MERGE_HEAD to
93 cause the next git commit command to create a merge commit. This
94 allows you to create a single commit on top of the current branch
95 whose effect is the same as merging another branch (or more in case
96 of an octopus).
97 With --no-squash perform the merge and commit the result. This
99 option can be used to override --squash.
100 --ff-only
102 Refuse to merge and exit with a non-zero status unless the current
103 HEAD is already up-to-date or the merge can be resolved as a
104 fast-forward.
105 -s <strategy>, --strategy=<strategy>
107 Use the given merge strategy; can be supplied more than once to
108 specify them in the order they should be tried. If there is no -s
109 option, a built-in list of strategies is used instead (git
110 merge-recursive when merging a single head, git merge-octopus
111 otherwise).
112 -X <option>, --strategy-option=<option>
114 Pass merge strategy specific option through to the merge strategy.
115 --summary, --no-summary
117 Synonyms to --stat and --no-stat; these are deprecated and will be
118 removed in the future.
119 -q, --quiet
121 Operate quietly.
122 -v, --verbose
124 Be verbose.
125 -m <msg>
127 Set the commit message to be used for the merge commit (in case one
128 is created).
129 If --log is specified, a shortlog of the commits being merged will
131 be appended to the specified message.
132 The git fmt-merge-msg command can be used to give a good default
134 for automated git merge invocations.
135 --rerere-autoupdate, --no-rerere-autoupdate
137 Allow the rerere mechanism to update the index with the result of
138 auto-conflict resolution if possible.
139 --abort
141 Abort the current conflict resolution process, and try to
142 reconstruct the pre-merge state.
143 If there were uncommitted worktree changes present when the merge
145 started, git merge --abort will in some cases be unable to
146 reconstruct these changes. It is therefore recommended to always
147 commit or stash your changes before running git merge.
148 git merge --abort is equivalent to git reset --merge when
150 MERGE_HEAD is present.
151 <commit>...
153 Commits, usually other branch heads, to merge into our branch. You
154 need at least one <commit>. Specifying more than one <commit>
155 obviously means you are trying an Octopus.
156
158 Before applying outside changes, you should get your own work in good
159 shape and committed locally, so it will not be clobbered if there are
160 conflicts. See also git-stash(1). git pull and git merge will stop
161 without doing anything when local uncommitted changes overlap with
162 files that git pull/git merge may need to update.
163 To avoid recording unrelated changes in the merge commit, git pull and
165 git merge will also abort if there are any changes registered in the
166 index relative to the HEAD commit. (One exception is when the changed
167 index entries are in the state that would result from the merge
168 already.)
169 If all named commits are already ancestors of HEAD, git merge will exit
171 early with the message "Already up-to-date."
172
174 Often the current branch head is an ancestor of the named commit. This
175 is the most common case especially when invoked from git pull: you are
176 tracking an upstream repository, you have committed no local changes,
177 and now you want to update to a newer upstream revision. In this case,
178 a new commit is not needed to store the combined history; instead, the
179 HEAD (along with the index) is updated to point at the named commit,
180 without creating an extra merge commit.
181 This behavior can be suppressed with the --no-ff option.
183
185 Except in a fast-forward merge (see above), the branches to be merged
186 must be tied together by a merge commit that has both of them as its
187 parents.
188 A merged version reconciling the changes from all branches to be merged
190 is committed, and your HEAD, index, and working tree are updated to it.
191 It is possible to have modifications in the working tree as long as
192 they do not overlap; the update will preserve them.
193 When it is not obvious how to reconcile the changes, the following
195 happens:
196 1. The HEAD pointer stays the same.
198 2. The MERGE_HEAD ref is set to point to the other branch head.
200 3. Paths that merged cleanly are updated both in the index file and in
202 your working tree.
203 4. For conflicting paths, the index file records up to three versions:
205 stage 1 stores the version from the common ancestor, stage 2 from
206 HEAD, and stage 3 from MERGE_HEAD (you can inspect the stages with
207 git ls-files -u). The working tree files contain the result of the
208 "merge" program; i.e. 3-way merge results with familiar conflict
209 markers <<< === >>>.
210 5. No other changes are made. In particular, the local modifications
212 you had before you started merge will stay the same and the index
213 entries for them stay as they were, i.e. matching HEAD.
214 If you tried a merge which resulted in complex conflicts and want to
216 start over, you can recover with git merge --abort.
217
219 During a merge, the working tree files are updated to reflect the
220 result of the merge. Among the changes made to the common ancestor’s
221 version, non-overlapping ones (that is, you changed an area of the file
222 while the other side left that area intact, or vice versa) are
223 incorporated in the final result verbatim. When both sides made changes
224 to the same area, however, git cannot randomly pick one side over the
225 other, and asks you to resolve it by leaving what both sides did to
226 that area.
227 By default, git uses the same style as that is used by "merge" program
229 from the RCS suite to present such a conflicted hunk, like this:
230 Here are lines that are either unchanged from the common
232 ancestor, or cleanly resolved because only one side changed.
233 <<<<<<< yours:sample.txt
234 Conflict resolution is hard;
235 let's go shopping.
236 =======
237 Git makes conflict resolution easy.
238 >>>>>>> theirs:sample.txt
239 And here is another line that is cleanly resolved or unmodified.
240 The area where a pair of conflicting changes happened is marked with
243 markers <<<<<<<, =======, and >>>>>>>. The part before the ======= is
244 typically your side, and the part afterwards is typically their side.
245 The default format does not show what the original said in the
247 conflicting area. You cannot tell how many lines are deleted and
248 replaced with Barbie’s remark on your side. The only thing you can tell
249 is that your side wants to say it is hard and you’d prefer to go
250 shopping, while the other side wants to claim it is easy.
251 An alternative style can be used by setting the "merge.conflictstyle"
253 configuration variable to "diff3". In "diff3" style, the above conflict
254 may look like this:
255 Here are lines that are either unchanged from the common
257 ancestor, or cleanly resolved because only one side changed.
258 <<<<<<< yours:sample.txt
259 Conflict resolution is hard;
260 let's go shopping.
261 |||||||
262 Conflict resolution is hard.
263 =======
264 Git makes conflict resolution easy.
265 >>>>>>> theirs:sample.txt
266 And here is another line that is cleanly resolved or unmodified.
267 In addition to the <<<<<<<, =======, and >>>>>>> markers, it uses
270 another ||||||| marker that is followed by the original text. You can
271 tell that the original just stated a fact, and your side simply gave in
272 to that statement and gave up, while the other side tried to have a
273 more positive attitude. You can sometimes come up with a better
274 resolution by viewing the original.
275
277 After seeing a conflict, you can do two things:
278 · Decide not to merge. The only clean-ups you need are to reset the
280 index file to the HEAD commit to reverse 2. and to clean up working
281 tree changes made by 2. and 3.; git merge --abort can be used for
282 this.
283 · Resolve the conflicts. Git will mark the conflicts in the working
285 tree. Edit the files into shape and git add them to the index. Use
286 git commit to seal the deal.
287 You can work through the conflict with a number of tools:
289 · Use a mergetool. git mergetool to launch a graphical mergetool
291 which will work you through the merge.
292 · Look at the diffs. git diff will show a three-way diff,
294 highlighting changes from both the HEAD and MERGE_HEAD versions.
295 · Look at the diffs from each branch. git log --merge -p <path> will
297 show diffs first for the HEAD version and then the MERGE_HEAD
298 version.
299 · Look at the originals. git show :1:filename shows the common
301 ancestor, git show :2:filename shows the HEAD version, and git show
302 :3:filename shows the MERGE_HEAD version.
303
305 · Merge branches fixes and enhancements on top of the current branch,
306 making an octopus merge:
307 $ git merge fixes enhancements
309 · Merge branch obsolete into the current branch, using ours merge
312 strategy:
313 $ git merge -s ours obsolete
315 · Merge branch maint into the current branch, but do not make a new
318 commit automatically:
319 $ git merge --no-commit maint
321 This can be used when you want to include further changes to the
323 merge, or want to write your own merge commit message.
324 You should refrain from abusing this option to sneak substantial
326 changes into a merge commit. Small fixups like bumping
327 release/version name would be acceptable.
328
330 The merge mechanism (git-merge and git-pull commands) allows the
331 backend merge strategies to be chosen with -s option. Some strategies
332 can also take their own options, which can be passed by giving
333 -X<option> arguments to git-merge and/or git-pull.
334 resolve
336 This can only resolve two heads (i.e. the current branch and
337 another branch you pulled from) using a 3-way merge algorithm. It
338 tries to carefully detect criss-cross merge ambiguities and is
339 considered generally safe and fast.
340 recursive
342 This can only resolve two heads using a 3-way merge algorithm. When
343 there is more than one common ancestor that can be used for 3-way
344 merge, it creates a merged tree of the common ancestors and uses
345 that as the reference tree for the 3-way merge. This has been
346 reported to result in fewer merge conflicts without causing
347 mis-merges by tests done on actual merge commits taken from Linux
348 2.6 kernel development history. Additionally this can detect and
349 handle merges involving renames. This is the default merge strategy
350 when pulling or merging one branch.
351 The recursive strategy can take the following options:
353 ours
355 This option forces conflicting hunks to be auto-resolved
356 cleanly by favoring our version. Changes from the other tree
357 that do not conflict with our side are reflected to the merge
358 result.
359 This should not be confused with the ours merge strategy, which
361 does not even look at what the other tree contains at all. It
362 discards everything the other tree did, declaring our history
363 contains all that happened in it.
364 theirs
366 This is opposite of ours.
367 patience
369 With this option, merge-recursive spends a little extra time to
370 avoid mismerges that sometimes occur due to unimportant
371 matching lines (e.g., braces from distinct functions). Use this
372 when the branches to be merged have diverged wildly. See also
373 git-diff(1) --patience.
374 ignore-space-change, ignore-all-space, ignore-space-at-eol
376 Treats lines with the indicated type of whitespace change as
377 unchanged for the sake of a three-way merge. Whitespace changes
378 mixed with other changes to a line are not ignored. See also
379 git-diff(1) -b, -w, and --ignore-space-at-eol.
380 · If their version only introduces whitespace changes to a
382 line, our version is used;
383 · If our version introduces whitespace changes but their
385 version includes a substantial change, their version is
386 used;
387 · Otherwise, the merge proceeds in the usual way.
389 renormalize
391 This runs a virtual check-out and check-in of all three stages
392 of a file when resolving a three-way merge. This option is
393 meant to be used when merging branches with different clean
394 filters or end-of-line normalization rules. See "Merging
395 branches with differing checkin/checkout attributes" in
396 gitattributes(5) for details.
397 no-renormalize
399 Disables the renormalize option. This overrides the
400 merge.renormalize configuration variable.
401 rename-threshold=<n>
403 Controls the similarity threshold used for rename detection.
404 See also git-diff(1) -M.
405 subtree[=<path>]
407 This option is a more advanced form of subtree strategy, where
408 the strategy makes a guess on how two trees must be shifted to
409 match with each other when merging. Instead, the specified path
410 is prefixed (or stripped from the beginning) to make the shape
411 of two trees to match.
412 octopus
414 This resolves cases with more than two heads, but refuses to do a
415 complex merge that needs manual resolution. It is primarily meant
416 to be used for bundling topic branch heads together. This is the
417 default merge strategy when pulling or merging more than one
418 branch.
419 ours
421 This resolves any number of heads, but the resulting tree of the
422 merge is always that of the current branch head, effectively
423 ignoring all changes from all other branches. It is meant to be
424 used to supersede old development history of side branches. Note
425 that this is different from the -Xours option to the recursive
426 merge strategy.
427 subtree
429 This is a modified recursive strategy. When merging trees A and B,
430 if B corresponds to a subtree of A, B is first adjusted to match
431 the tree structure of A, instead of reading the trees at the same
432 level. This adjustment is also done to the common ancestor tree.
433
435 merge.conflictstyle
436 Specify the style in which conflicted hunks are written out to
437 working tree files upon merge. The default is "merge", which shows
438 a <<<<<<< conflict marker, changes made by one side, a =======
439 marker, changes made by the other side, and then a >>>>>>> marker.
440 An alternate style, "diff3", adds a ||||||| marker and the original
441 text before the ======= marker.
442 merge.log
444 In addition to branch names, populate the log message with at most
445 the specified number of one-line descriptions from the actual
446 commits that are being merged. Defaults to false, and true is a
447 synonym for 20.
448 merge.renameLimit
450 The number of files to consider when performing rename detection
451 during a merge; if not specified, defaults to the value of
452 diff.renameLimit.
453 merge.renormalize
455 Tell git that canonical representation of files in the repository
456 has changed over time (e.g. earlier commits record text files with
457 CRLF line endings, but recent ones use LF line endings). In such a
458 repository, git can convert the data recorded in commits to a
459 canonical form before performing a merge to reduce unnecessary
460 conflicts. For more information, see section "Merging branches with
461 differing checkin/checkout attributes" in gitattributes(5).
462 merge.stat
464 Whether to print the diffstat between ORIG_HEAD and the merge
465 result at the end of the merge. True by default.
466 merge.tool
468 Controls which merge resolution program is used by git-
469 mergetool(1). Valid built-in values are: "kdiff3", "tkdiff",
470 "meld", "xxdiff", "emerge", "vimdiff", "gvimdiff", "diffuse",
471 "ecmerge", "tortoisemerge", "p4merge", "araxis" and "opendiff". Any
472 other value is treated is custom merge tool and there must be a
473 corresponding mergetool.<tool>.cmd option.
474 merge.verbosity
476 Controls the amount of output shown by the recursive merge
477 strategy. Level 0 outputs nothing except a final error message if
478 conflicts were detected. Level 1 outputs only conflicts, 2 outputs
479 conflicts and file changes. Level 5 and above outputs debugging
480 information. The default is level 2. Can be overridden by the
481 GIT_MERGE_VERBOSITY environment variable.
482 merge.<driver>.name
484 Defines a human-readable name for a custom low-level merge driver.
485 See gitattributes(5) for details.
486 merge.<driver>.driver
488 Defines the command that implements a custom low-level merge
489 driver. See gitattributes(5) for details.
490 merge.<driver>.recursive
492 Names a low-level merge driver to be used when performing an
493 internal merge between common ancestors. See gitattributes(5) for
494 details.
495 branch.<name>.mergeoptions
497 Sets default options for merging into branch <name>. The syntax and
498 supported options are the same as those of git merge, but option
499 values containing whitespace characters are currently not
500 supported.
501
503 git-fmt-merge-msg(1), git-pull(1), gitattributes(5), git-reset(1), git-
504 diff(1), git-ls-files(1), git-add(1), git-rm(1), git-mergetool(1)
505
507 Written by Junio C Hamano <gitster@pobox.com[1]>
508
510 Documentation by Junio C Hamano and the git-list
511 <git@vger.kernel.org[2]>.
512
514 Part of the git(1) suite
515
517 1. gitster@pobox.com
518 mailto:gitster@pobox.com
519 2. git@vger.kernel.org
521 mailto:git@vger.kernel.org
522Git 1.7.4.4 04/11/2011 GIT-MERGE(1)