6 git-merge - Join two or more development histories together
12 'git merge' [-n] [--stat] [--no-commit] [--squash] [--[no-]edit]
13 [-s <strategy>] [-X <strategy-option>] [-S[<keyid>]]
14 [--[no-]allow-unrelated-histories]
15 [--[no-]rerere-autoupdate] [-m <msg>] [<commit>...]
17 'git merge' --continue
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 fourth syntax ("`git merge --continue`") can only be run after the
61 merge has resulted in conflicts.
65 include::merge-options.txt[]
68 --gpg-sign[=<keyid>]::
69 GPG-sign the resulting merge commit. The `keyid` argument is
70 optional and defaults to the committer identity; if specified,
71 it must be stuck to the option without a space.
74 Set the commit message to be used for the merge commit (in
77 If `--log` is specified, a shortlog of the commits being merged
78 will be appended to the specified message.
80 The 'git fmt-merge-msg' command can be
81 used to give a good default for automated 'git merge'
82 invocations. The automated message can include the branch description.
84 --[no-]rerere-autoupdate::
85 Allow the rerere mechanism to update the index with the
86 result of auto-conflict resolution if possible.
89 Abort the current conflict resolution process, and
90 try to reconstruct the pre-merge state.
92 If there were uncommitted worktree changes present when the merge
93 started, 'git merge --abort' will in some cases be unable to
94 reconstruct these changes. It is therefore recommended to always
95 commit or stash your changes before running 'git merge'.
97 'git merge --abort' is equivalent to 'git reset --merge' when
98 `MERGE_HEAD` is present.
101 After a 'git merge' stops due to conflicts you can conclude the
102 merge by running 'git merge --continue' (see "HOW TO RESOLVE
103 CONFLICTS" section below).
106 Commits, usually other branch heads, to merge into our branch.
107 Specifying more than one commit will create a merge with
108 more than two parents (affectionately called an Octopus merge).
110 If no commit is given from the command line, merge the remote-tracking
111 branches that the current branch is configured to use as its upstream.
112 See also the configuration section of this manual page.
114 When `FETCH_HEAD` (and no other commit) is specified, the branches
115 recorded in the `.git/FETCH_HEAD` file by the previous invocation
116 of `git fetch` for merging are merged to the current branch.
122 Before applying outside changes, you should get your own work in
123 good shape and committed locally, so it will not be clobbered if
124 there are conflicts. See also linkgit:git-stash[1].
125 'git pull' and 'git merge' will stop without doing anything when
126 local uncommitted changes overlap with files that 'git pull'/'git
127 merge' may need to update.
129 To avoid recording unrelated changes in the merge commit,
130 'git pull' and 'git merge' will also abort if there are any changes
131 registered in the index relative to the `HEAD` commit. (One
132 exception is when the changed index entries are in the state that
133 would result from the merge already.)
135 If all named commits are already ancestors of `HEAD`, 'git merge'
136 will exit early with the message "Already up-to-date."
141 Often the current branch head is an ancestor of the named commit.
142 This is the most common case especially when invoked from 'git
143 pull': you are tracking an upstream repository, you have committed
144 no local changes, and now you want to update to a newer upstream
145 revision. In this case, a new commit is not needed to store the
146 combined history; instead, the `HEAD` (along with the index) is
147 updated to point at the named commit, without creating an extra
150 This behavior can be suppressed with the `--no-ff` option.
155 Except in a fast-forward merge (see above), the branches to be
156 merged must be tied together by a merge commit that has both of them
159 A merged version reconciling the changes from all branches to be
160 merged is committed, and your `HEAD`, index, and working tree are
161 updated to it. It is possible to have modifications in the working
162 tree as long as they do not overlap; the update will preserve them.
164 When it is not obvious how to reconcile the changes, the following
167 1. The `HEAD` pointer stays the same.
168 2. The `MERGE_HEAD` ref is set to point to the other branch head.
169 3. Paths that merged cleanly are updated both in the index file and
170 in your working tree.
171 4. For conflicting paths, the index file records up to three
172 versions: stage 1 stores the version from the common ancestor,
173 stage 2 from `HEAD`, and stage 3 from `MERGE_HEAD` (you
174 can inspect the stages with `git ls-files -u`). The working
175 tree files contain the result of the "merge" program; i.e. 3-way
176 merge results with familiar conflict markers `<<<` `===` `>>>`.
177 5. No other changes are made. In particular, the local
178 modifications you had before you started merge will stay the
179 same and the index entries for them stay as they were,
180 i.e. matching `HEAD`.
182 If you tried a merge which resulted in complex conflicts and
183 want to start over, you can recover with `git merge --abort`.
188 When merging an annotated (and possibly signed) tag, Git always
189 creates a merge commit even if a fast-forward merge is possible, and
190 the commit message template is prepared with the tag message.
191 Additionally, if the tag is signed, the signature check is reported
192 as a comment in the message template. See also linkgit:git-tag[1].
194 When you want to just integrate with the work leading to the commit
195 that happens to be tagged, e.g. synchronizing with an upstream
196 release point, you may not want to make an unnecessary merge commit.
198 In such a case, you can "unwrap" the tag yourself before feeding it
199 to `git merge`, or pass `--ff-only` when you do not have any work on
205 git merge --ff-only v1.2.3
209 HOW CONFLICTS ARE PRESENTED
210 ---------------------------
212 During a merge, the working tree files are updated to reflect the result
213 of the merge. Among the changes made to the common ancestor's version,
214 non-overlapping ones (that is, you changed an area of the file while the
215 other side left that area intact, or vice versa) are incorporated in the
216 final result verbatim. When both sides made changes to the same area,
217 however, Git cannot randomly pick one side over the other, and asks you to
218 resolve it by leaving what both sides did to that area.
220 By default, Git uses the same style as the one used by the "merge" program
221 from the RCS suite to present such a conflicted hunk, like this:
224 Here are lines that are either unchanged from the common
225 ancestor, or cleanly resolved because only one side changed.
226 <<<<<<< yours:sample.txt
227 Conflict resolution is hard;
230 Git makes conflict resolution easy.
231 >>>>>>> theirs:sample.txt
232 And here is another line that is cleanly resolved or unmodified.
235 The area where a pair of conflicting changes happened is marked with markers
236 `<<<<<<<`, `=======`, and `>>>>>>>`. The part before the `=======`
237 is typically your side, and the part afterwards is typically their side.
239 The default format does not show what the original said in the conflicting
240 area. You cannot tell how many lines are deleted and replaced with
241 Barbie's remark on your side. The only thing you can tell is that your
242 side wants to say it is hard and you'd prefer to go shopping, while the
243 other side wants to claim it is easy.
245 An alternative style can be used by setting the "merge.conflictStyle"
246 configuration variable to "diff3". In "diff3" style, the above conflict
250 Here are lines that are either unchanged from the common
251 ancestor, or cleanly resolved because only one side changed.
252 <<<<<<< yours:sample.txt
253 Conflict resolution is hard;
256 Conflict resolution is hard.
258 Git makes conflict resolution easy.
259 >>>>>>> theirs:sample.txt
260 And here is another line that is cleanly resolved or unmodified.
263 In addition to the `<<<<<<<`, `=======`, and `>>>>>>>` markers, it uses
264 another `|||||||` marker that is followed by the original text. You can
265 tell that the original just stated a fact, and your side simply gave in to
266 that statement and gave up, while the other side tried to have a more
267 positive attitude. You can sometimes come up with a better resolution by
268 viewing the original.
271 HOW TO RESOLVE CONFLICTS
272 ------------------------
274 After seeing a conflict, you can do two things:
276 * Decide not to merge. The only clean-ups you need are to reset
277 the index file to the `HEAD` commit to reverse 2. and to clean
278 up working tree changes made by 2. and 3.; `git merge --abort`
279 can be used for this.
281 * Resolve the conflicts. Git will mark the conflicts in
282 the working tree. Edit the files into shape and
283 'git add' them to the index. Use 'git commit' to seal the deal.
285 You can work through the conflict with a number of tools:
287 * Use a mergetool. `git mergetool` to launch a graphical
288 mergetool which will work you through the merge.
290 * Look at the diffs. `git diff` will show a three-way diff,
291 highlighting changes from both the `HEAD` and `MERGE_HEAD`
294 * Look at the diffs from each branch. `git log --merge -p <path>`
295 will show diffs first for the `HEAD` version and then the
296 `MERGE_HEAD` version.
298 * Look at the originals. `git show :1:filename` shows the
299 common ancestor, `git show :2:filename` shows the `HEAD`
300 version, and `git show :3:filename` shows the `MERGE_HEAD`
307 * Merge branches `fixes` and `enhancements` on top of
308 the current branch, making an octopus merge:
310 ------------------------------------------------
311 $ git merge fixes enhancements
312 ------------------------------------------------
314 * Merge branch `obsolete` into the current branch, using `ours`
317 ------------------------------------------------
318 $ git merge -s ours obsolete
319 ------------------------------------------------
321 * Merge branch `maint` into the current branch, but do not make
322 a new commit automatically:
324 ------------------------------------------------
325 $ git merge --no-commit maint
326 ------------------------------------------------
328 This can be used when you want to include further changes to the
329 merge, or want to write your own merge commit message.
331 You should refrain from abusing this option to sneak substantial
332 changes into a merge commit. Small fixups like bumping
333 release/version name would be acceptable.
336 include::merge-strategies.txt[]
340 include::merge-config.txt[]
342 branch.<name>.mergeOptions::
343 Sets default options for merging into branch <name>. The syntax and
344 supported options are the same as those of 'git merge', but option
345 values containing whitespace characters are currently not supported.
349 linkgit:git-fmt-merge-msg[1], linkgit:git-pull[1],
350 linkgit:gitattributes[5],
351 linkgit:git-reset[1],
352 linkgit:git-diff[1], linkgit:git-ls-files[1],
353 linkgit:git-add[1], linkgit:git-rm[1],
354 linkgit:git-mergetool[1]
358 Part of the linkgit:git[1] suite
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