6 git-merge - Join two or more development histories together
12 'git merge' [-n] [--stat] [--no-commit] [--squash] [--[no-]edit]
13 [--no-verify] [-s <strategy>] [-X <strategy-option>] [-S[<keyid>]]
14 [--[no-]allow-unrelated-histories]
15 [--[no-]rerere-autoupdate] [-m <msg>] [-F <file>]
16 [--into-name <branch>] [<commit>...]
17 'git merge' (--continue | --abort | --quit)
21 Incorporates changes from the named commits (since the time their
22 histories diverged from the current branch) into the current
23 branch. This command is used by 'git pull' to incorporate changes
24 from another repository and can be used by hand to merge changes
25 from one branch into another.
27 Assume the following history exists and the current branch is
36 Then "`git merge topic`" will replay the changes made on the
37 `topic` branch since it diverged from `master` (i.e., `E`) until
38 its current commit (`C`) on top of `master`, and record the result
39 in a new commit along with the names of the two parent commits and
40 a log message from the user describing the changes.
45 D---E---F---G---H master
48 The second syntax ("`git merge --abort`") can only be run after the
49 merge has resulted in conflicts. 'git merge --abort' will abort the
50 merge process and try to reconstruct the pre-merge state. However,
51 if there were uncommitted changes when the merge started (and
52 especially if those changes were further modified after the merge
53 was started), 'git merge --abort' will in some cases be unable to
54 reconstruct the original (pre-merge) changes. Therefore:
56 *Warning*: Running 'git merge' with non-trivial uncommitted changes is
57 discouraged: while possible, it may leave you in a state that is hard to
58 back out of in the case of a conflict.
60 The third syntax ("`git merge --continue`") can only be run after the
61 merge has resulted in conflicts.
67 include::merge-options.txt[]
70 Set the commit message to be used for the merge commit (in
73 If `--log` is specified, a shortlog of the commits being merged
74 will be appended to the specified message.
76 The 'git fmt-merge-msg' command can be
77 used to give a good default for automated 'git merge'
78 invocations. The automated message can include the branch description.
80 --into-name <branch>::
81 Prepare the default merge message as if merging to the branch
82 `<branch>`, instead of the name of the real branch to which
87 Read the commit message to be used for the merge commit (in
90 If `--log` is specified, a shortlog of the commits being merged
91 will be appended to the specified message.
93 include::rerere-options.txt[]
96 --no-overwrite-ignore::
97 Silently overwrite ignored files from the merge result. This
98 is the default behavior. Use `--no-overwrite-ignore` to abort.
101 Abort the current conflict resolution process, and
102 try to reconstruct the pre-merge state. If an autostash entry is
103 present, apply it to the worktree.
105 If there were uncommitted worktree changes present when the merge
106 started, 'git merge --abort' will in some cases be unable to
107 reconstruct these changes. It is therefore recommended to always
108 commit or stash your changes before running 'git merge'.
110 'git merge --abort' is equivalent to 'git reset --merge' when
111 `MERGE_HEAD` is present unless `MERGE_AUTOSTASH` is also present in
112 which case 'git merge --abort' applies the stash entry to the worktree
113 whereas 'git reset --merge' will save the stashed changes in the stash
117 Forget about the current merge in progress. Leave the index
118 and the working tree as-is. If `MERGE_AUTOSTASH` is present, the
119 stash entry will be saved to the stash list.
122 After a 'git merge' stops due to conflicts you can conclude the
123 merge by running 'git merge --continue' (see "HOW TO RESOLVE
124 CONFLICTS" section below).
127 Commits, usually other branch heads, to merge into our branch.
128 Specifying more than one commit will create a merge with
129 more than two parents (affectionately called an Octopus merge).
131 If no commit is given from the command line, merge the remote-tracking
132 branches that the current branch is configured to use as its upstream.
133 See also the configuration section of this manual page.
135 When `FETCH_HEAD` (and no other commit) is specified, the branches
136 recorded in the `.git/FETCH_HEAD` file by the previous invocation
137 of `git fetch` for merging are merged to the current branch.
143 Before applying outside changes, you should get your own work in
144 good shape and committed locally, so it will not be clobbered if
145 there are conflicts. See also linkgit:git-stash[1].
146 'git pull' and 'git merge' will stop without doing anything when
147 local uncommitted changes overlap with files that 'git pull'/'git
148 merge' may need to update.
150 To avoid recording unrelated changes in the merge commit,
151 'git pull' and 'git merge' will also abort if there are any changes
152 registered in the index relative to the `HEAD` commit. (Special
153 narrow exceptions to this rule may exist depending on which merge
154 strategy is in use, but generally, the index must match HEAD.)
156 If all named commits are already ancestors of `HEAD`, 'git merge'
157 will exit early with the message "Already up to date."
162 Often the current branch head is an ancestor of the named commit.
163 This is the most common case especially when invoked from 'git
164 pull': you are tracking an upstream repository, you have committed
165 no local changes, and now you want to update to a newer upstream
166 revision. In this case, a new commit is not needed to store the
167 combined history; instead, the `HEAD` (along with the index) is
168 updated to point at the named commit, without creating an extra
171 This behavior can be suppressed with the `--no-ff` option.
176 Except in a fast-forward merge (see above), the branches to be
177 merged must be tied together by a merge commit that has both of them
180 A merged version reconciling the changes from all branches to be
181 merged is committed, and your `HEAD`, index, and working tree are
182 updated to it. It is possible to have modifications in the working
183 tree as long as they do not overlap; the update will preserve them.
185 When it is not obvious how to reconcile the changes, the following
188 1. The `HEAD` pointer stays the same.
189 2. The `MERGE_HEAD` ref is set to point to the other branch head.
190 3. Paths that merged cleanly are updated both in the index file and
191 in your working tree.
192 4. For conflicting paths, the index file records up to three
193 versions: stage 1 stores the version from the common ancestor,
194 stage 2 from `HEAD`, and stage 3 from `MERGE_HEAD` (you
195 can inspect the stages with `git ls-files -u`). The working
196 tree files contain the result of the "merge" program; i.e. 3-way
197 merge results with familiar conflict markers `<<<` `===` `>>>`.
198 5. No other changes are made. In particular, the local
199 modifications you had before you started merge will stay the
200 same and the index entries for them stay as they were,
201 i.e. matching `HEAD`.
203 If you tried a merge which resulted in complex conflicts and
204 want to start over, you can recover with `git merge --abort`.
209 When merging an annotated (and possibly signed) tag, Git always
210 creates a merge commit even if a fast-forward merge is possible, and
211 the commit message template is prepared with the tag message.
212 Additionally, if the tag is signed, the signature check is reported
213 as a comment in the message template. See also linkgit:git-tag[1].
215 When you want to just integrate with the work leading to the commit
216 that happens to be tagged, e.g. synchronizing with an upstream
217 release point, you may not want to make an unnecessary merge commit.
219 In such a case, you can "unwrap" the tag yourself before feeding it
220 to `git merge`, or pass `--ff-only` when you do not have any work on
226 git merge --ff-only v1.2.3
230 HOW CONFLICTS ARE PRESENTED
231 ---------------------------
233 During a merge, the working tree files are updated to reflect the result
234 of the merge. Among the changes made to the common ancestor's version,
235 non-overlapping ones (that is, you changed an area of the file while the
236 other side left that area intact, or vice versa) are incorporated in the
237 final result verbatim. When both sides made changes to the same area,
238 however, Git cannot randomly pick one side over the other, and asks you to
239 resolve it by leaving what both sides did to that area.
241 By default, Git uses the same style as the one used by the "merge" program
242 from the RCS suite to present such a conflicted hunk, like this:
245 Here are lines that are either unchanged from the common
246 ancestor, or cleanly resolved because only one side changed,
247 or cleanly resolved because both sides changed the same way.
248 <<<<<<< yours:sample.txt
249 Conflict resolution is hard;
252 Git makes conflict resolution easy.
253 >>>>>>> theirs:sample.txt
254 And here is another line that is cleanly resolved or unmodified.
257 The area where a pair of conflicting changes happened is marked with markers
258 `<<<<<<<`, `=======`, and `>>>>>>>`. The part before the `=======`
259 is typically your side, and the part afterwards is typically their side.
261 The default format does not show what the original said in the conflicting
262 area. You cannot tell how many lines are deleted and replaced with
263 Barbie's remark on your side. The only thing you can tell is that your
264 side wants to say it is hard and you'd prefer to go shopping, while the
265 other side wants to claim it is easy.
267 An alternative style can be used by setting the "merge.conflictStyle"
268 configuration variable to either "diff3" or "zdiff3". In "diff3"
269 style, the above conflict may look like this:
272 Here are lines that are either unchanged from the common
273 ancestor, or cleanly resolved because only one side changed,
274 <<<<<<< yours:sample.txt
275 or cleanly resolved because both sides changed the same way.
276 Conflict resolution is hard;
278 ||||||| base:sample.txt
279 or cleanly resolved because both sides changed identically.
280 Conflict resolution is hard.
282 or cleanly resolved because both sides changed the same way.
283 Git makes conflict resolution easy.
284 >>>>>>> theirs:sample.txt
285 And here is another line that is cleanly resolved or unmodified.
288 while in "zdiff3" style, it may look like this:
291 Here are lines that are either unchanged from the common
292 ancestor, or cleanly resolved because only one side changed,
293 or cleanly resolved because both sides changed the same way.
294 <<<<<<< yours:sample.txt
295 Conflict resolution is hard;
297 ||||||| base:sample.txt
298 or cleanly resolved because both sides changed identically.
299 Conflict resolution is hard.
301 Git makes conflict resolution easy.
302 >>>>>>> theirs:sample.txt
303 And here is another line that is cleanly resolved or unmodified.
306 In addition to the `<<<<<<<`, `=======`, and `>>>>>>>` markers, it uses
307 another `|||||||` marker that is followed by the original text. You can
308 tell that the original just stated a fact, and your side simply gave in to
309 that statement and gave up, while the other side tried to have a more
310 positive attitude. You can sometimes come up with a better resolution by
311 viewing the original.
314 HOW TO RESOLVE CONFLICTS
315 ------------------------
317 After seeing a conflict, you can do two things:
319 * Decide not to merge. The only clean-ups you need are to reset
320 the index file to the `HEAD` commit to reverse 2. and to clean
321 up working tree changes made by 2. and 3.; `git merge --abort`
322 can be used for this.
324 * Resolve the conflicts. Git will mark the conflicts in
325 the working tree. Edit the files into shape and
326 'git add' them to the index. Use 'git commit' or
327 'git merge --continue' to seal the deal. The latter command
328 checks whether there is a (interrupted) merge in progress
329 before calling 'git commit'.
331 You can work through the conflict with a number of tools:
333 * Use a mergetool. `git mergetool` to launch a graphical
334 mergetool which will work you through the merge.
336 * Look at the diffs. `git diff` will show a three-way diff,
337 highlighting changes from both the `HEAD` and `MERGE_HEAD`
340 * Look at the diffs from each branch. `git log --merge -p <path>`
341 will show diffs first for the `HEAD` version and then the
342 `MERGE_HEAD` version.
344 * Look at the originals. `git show :1:filename` shows the
345 common ancestor, `git show :2:filename` shows the `HEAD`
346 version, and `git show :3:filename` shows the `MERGE_HEAD`
353 * Merge branches `fixes` and `enhancements` on top of
354 the current branch, making an octopus merge:
356 ------------------------------------------------
357 $ git merge fixes enhancements
358 ------------------------------------------------
360 * Merge branch `obsolete` into the current branch, using `ours`
363 ------------------------------------------------
364 $ git merge -s ours obsolete
365 ------------------------------------------------
367 * Merge branch `maint` into the current branch, but do not make
368 a new commit automatically:
370 ------------------------------------------------
371 $ git merge --no-commit maint
372 ------------------------------------------------
374 This can be used when you want to include further changes to the
375 merge, or want to write your own merge commit message.
377 You should refrain from abusing this option to sneak substantial
378 changes into a merge commit. Small fixups like bumping
379 release/version name would be acceptable.
382 include::merge-strategies.txt[]
387 branch.<name>.mergeOptions::
388 Sets default options for merging into branch <name>. The syntax and
389 supported options are the same as those of 'git merge', but option
390 values containing whitespace characters are currently not supported.
392 include::includes/cmd-config-section-rest.txt[]
394 include::config/merge.txt[]
398 linkgit:git-fmt-merge-msg[1], linkgit:git-pull[1],
399 linkgit:gitattributes[5],
400 linkgit:git-reset[1],
401 linkgit:git-diff[1], linkgit:git-ls-files[1],
402 linkgit:git-add[1], linkgit:git-rm[1],
403 linkgit:git-mergetool[1]
407 Part of the linkgit:git[1] suite