2005-09-09 10:15:47 +02:00
|
|
|
git-merge(1)
|
|
|
|
|
============
|
|
|
|
|
|
|
|
|
|
NAME
|
|
|
|
|
----
|
2007-01-19 00:53:37 +01:00
|
|
|
git-merge - Join two or more development histories together
|
2005-09-09 10:15:47 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
SYNOPSIS
|
|
|
|
|
--------
|
2006-11-20 10:06:09 +01:00
|
|
|
[verse]
|
2007-05-23 23:01:29 +02:00
|
|
|
'git-merge' [-n] [--summary] [--no-commit] [--squash] [-s <strategy>]...
|
2007-02-05 12:37:27 +01:00
|
|
|
[-m <msg>] <remote> <remote>...
|
2005-09-09 10:15:47 +02:00
|
|
|
|
|
|
|
|
DESCRIPTION
|
|
|
|
|
-----------
|
2006-11-20 10:06:09 +01:00
|
|
|
This is the top-level interface to the merge machinery
|
2005-09-09 10:15:47 +02:00
|
|
|
which drives multiple merge strategy scripts.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
OPTIONS
|
|
|
|
|
-------
|
2005-11-07 06:30:56 +01:00
|
|
|
include::merge-options.txt[]
|
2005-09-09 10:15:47 +02:00
|
|
|
|
2005-11-01 21:45:55 +01:00
|
|
|
<msg>::
|
|
|
|
|
The commit message to be used for the merge commit (in case
|
|
|
|
|
it is created). The `git-fmt-merge-msg` script can be used
|
|
|
|
|
to give a good default for automated `git-merge` invocations.
|
|
|
|
|
|
2005-09-09 10:15:47 +02:00
|
|
|
<head>::
|
2006-11-20 10:06:09 +01:00
|
|
|
Our branch head commit. This has to be `HEAD`, so new
|
|
|
|
|
syntax does not require it
|
2005-09-09 10:15:47 +02:00
|
|
|
|
|
|
|
|
<remote>::
|
2006-11-20 10:06:09 +01:00
|
|
|
Other branch head merged into our branch. You need at
|
2005-09-09 10:15:47 +02:00
|
|
|
least one <remote>. Specifying more than one <remote>
|
|
|
|
|
obviously means you are trying an Octopus.
|
|
|
|
|
|
2005-11-06 17:26:07 +01:00
|
|
|
include::merge-strategies.txt[]
|
|
|
|
|
|
2005-09-09 10:15:47 +02:00
|
|
|
|
2005-12-17 03:23:33 +01:00
|
|
|
If you tried a merge which resulted in a complex conflicts and
|
|
|
|
|
would want to start over, you can recover with
|
|
|
|
|
gitlink:git-reset[1].
|
|
|
|
|
|
|
|
|
|
|
2005-11-29 07:54:30 +01:00
|
|
|
HOW MERGE WORKS
|
|
|
|
|
---------------
|
|
|
|
|
|
|
|
|
|
A merge is always between the current `HEAD` and one or more
|
|
|
|
|
remote branch heads, and the index file must exactly match the
|
|
|
|
|
tree of `HEAD` commit (i.e. the contents of the last commit) when
|
|
|
|
|
it happens. In other words, `git-diff --cached HEAD` must
|
|
|
|
|
report no changes.
|
|
|
|
|
|
|
|
|
|
[NOTE]
|
|
|
|
|
This is a bit of lie. In certain special cases, your index are
|
|
|
|
|
allowed to be different from the tree of `HEAD` commit. The most
|
|
|
|
|
notable case is when your `HEAD` commit is already ahead of what
|
|
|
|
|
is being merged, in which case your index can have arbitrary
|
|
|
|
|
difference from your `HEAD` commit. Otherwise, your index entries
|
|
|
|
|
are allowed have differences from your `HEAD` commit that match
|
|
|
|
|
the result of trivial merge (e.g. you received the same patch
|
|
|
|
|
from external source to produce the same result as what you are
|
|
|
|
|
merging). For example, if a path did not exist in the common
|
|
|
|
|
ancestor and your head commit but exists in the tree you are
|
|
|
|
|
merging into your repository, and if you already happen to have
|
|
|
|
|
that path exactly in your index, the merge does not have to
|
|
|
|
|
fail.
|
|
|
|
|
|
|
|
|
|
Otherwise, merge will refuse to do any harm to your repository
|
|
|
|
|
(that is, it may fetch the objects from remote, and it may even
|
|
|
|
|
update the local branch used to keep track of the remote branch
|
|
|
|
|
with `git pull remote rbranch:lbranch`, but your working tree,
|
|
|
|
|
`.git/HEAD` pointer and index file are left intact).
|
|
|
|
|
|
|
|
|
|
You may have local modifications in the working tree files. In
|
|
|
|
|
other words, `git-diff` is allowed to report changes.
|
|
|
|
|
However, the merge uses your working tree as the working area,
|
|
|
|
|
and in order to prevent the merge operation from losing such
|
|
|
|
|
changes, it makes sure that they do not interfere with the
|
|
|
|
|
merge. Those complex tables in read-tree documentation define
|
|
|
|
|
what it means for a path to "interfere with the merge". And if
|
|
|
|
|
your local modifications interfere with the merge, again, it
|
|
|
|
|
stops before touching anything.
|
|
|
|
|
|
|
|
|
|
So in the above two "failed merge" case, you do not have to
|
2006-07-09 09:44:30 +02:00
|
|
|
worry about loss of data --- you simply were not ready to do
|
2005-11-29 07:54:30 +01:00
|
|
|
a merge, so no merge happened at all. You may want to finish
|
|
|
|
|
whatever you were in the middle of doing, and retry the same
|
|
|
|
|
pull after you are done and ready.
|
|
|
|
|
|
|
|
|
|
When things cleanly merge, these things happen:
|
|
|
|
|
|
|
|
|
|
1. the results are updated both in the index file and in your
|
|
|
|
|
working tree,
|
|
|
|
|
2. index file is written out as a tree,
|
2007-06-07 09:04:01 +02:00
|
|
|
3. the tree gets committed, and
|
2005-11-29 07:54:30 +01:00
|
|
|
4. the `HEAD` pointer gets advanced.
|
|
|
|
|
|
|
|
|
|
Because of 2., we require that the original state of the index
|
|
|
|
|
file to match exactly the current `HEAD` commit; otherwise we
|
|
|
|
|
will write out your local changes already registered in your
|
|
|
|
|
index file along with the merge result, which is not good.
|
|
|
|
|
Because 1. involves only the paths different between your
|
|
|
|
|
branch and the remote branch you are pulling from during the
|
|
|
|
|
merge (which is typically a fraction of the whole tree), you can
|
|
|
|
|
have local modifications in your working tree as long as they do
|
|
|
|
|
not overlap with what the merge updates.
|
|
|
|
|
|
|
|
|
|
When there are conflicts, these things happen:
|
|
|
|
|
|
|
|
|
|
1. `HEAD` stays the same.
|
|
|
|
|
|
|
|
|
|
2. Cleanly merged paths are updated both in the index file and
|
|
|
|
|
in your working tree.
|
|
|
|
|
|
2005-12-02 10:05:35 +01:00
|
|
|
3. For conflicting paths, the index file records up to three
|
|
|
|
|
versions; stage1 stores the version from the common ancestor,
|
|
|
|
|
stage2 from `HEAD`, and stage3 from the remote branch (you
|
|
|
|
|
can inspect the stages with `git-ls-files -u`). The working
|
|
|
|
|
tree files have the result of "merge" program; i.e. 3-way
|
|
|
|
|
merge result with familiar conflict markers `<<< === >>>`.
|
2005-11-29 07:54:30 +01:00
|
|
|
|
|
|
|
|
4. No other changes are done. In particular, the local
|
|
|
|
|
modifications you had before you started merge will stay the
|
|
|
|
|
same and the index entries for them stay as they were,
|
|
|
|
|
i.e. matching `HEAD`.
|
|
|
|
|
|
|
|
|
|
After seeing a conflict, you can do two things:
|
|
|
|
|
|
|
|
|
|
* Decide not to merge. The only clean-up you need are to reset
|
|
|
|
|
the index file to the `HEAD` commit to reverse 2. and to clean
|
|
|
|
|
up working tree changes made by 2. and 3.; `git-reset` can
|
|
|
|
|
be used for this.
|
|
|
|
|
|
|
|
|
|
* Resolve the conflicts. `git-diff` would report only the
|
|
|
|
|
conflicting paths because of the above 2. and 3.. Edit the
|
2007-02-17 10:43:42 +01:00
|
|
|
working tree files into a desirable shape, `git-add` or `git-rm`
|
2005-11-29 07:54:30 +01:00
|
|
|
them, to make the index file contain what the merge result
|
|
|
|
|
should be, and run `git-commit` to commit the result.
|
|
|
|
|
|
|
|
|
|
|
2005-11-01 21:45:55 +01:00
|
|
|
SEE ALSO
|
|
|
|
|
--------
|
2005-11-05 10:37:00 +01:00
|
|
|
gitlink:git-fmt-merge-msg[1], gitlink:git-pull[1]
|
2005-11-01 21:45:55 +01:00
|
|
|
|
|
|
|
|
|
2005-09-09 10:15:47 +02:00
|
|
|
Author
|
|
|
|
|
------
|
|
|
|
|
Written by Junio C Hamano <junkio@cox.net>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Documentation
|
|
|
|
|
--------------
|
|
|
|
|
Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
|
|
|
|
|
|
|
|
|
|
GIT
|
|
|
|
|
---
|
2005-09-19 12:10:51 +02:00
|
|
|
Part of the gitlink:git[7] suite
|
