NAME
----
-git-checkout - Checkout and switch to a branch.
+git-checkout - Checkout and switch to a branch
SYNOPSIS
--------
-'git-checkout' [-f] [-b <new_branch>] [<branch>] [<paths>...]
+[verse]
+'git-checkout' [-f] [-b <new_branch>] [-m] [<branch>]
+'git-checkout' [-m] [<branch>] <paths>...
DESCRIPTION
-----------
-When <paths> are not given, this command switches branches, by
+When <paths> are not given, this command switches branches by
updating the index and working tree to reflect the specified
branch, <branch>, and updating HEAD to be <branch> or, if
-specified, <new_branch>.
+specified, <new_branch>. Using -b will cause <new_branch> to
+be created.
When <paths> are given, this command does *not* switch
branches. It updates the named paths in the working tree from
OPTIONS
-------
-f::
- Force an re-read of everything.
+ Force a re-read of everything.
-b::
- Create a new branch and start it at <branch>.
+ Create a new branch named <new_branch> and start it at
+ <branch>. The new branch name must pass all checks defined
+ by gitlink:git-check-ref-format[1]. Some of these checks
+ may restrict the characters allowed in a branch name.
+
+-m::
+ If you have local modifications to one or more files that
+ are different between the current branch and the branch to
+ which you are switching, the command refuses to switch
+ branches in order to preserve your modifications in context.
+ However, with this option, a three-way merge between the current
+ branch, your working tree contents, and the new branch
+ is done, and you will be on the new branch.
++
+When a merge conflict happens, the index entries for conflicting
+paths are left unmerged, and you need to resolve the conflicts
+and mark the resolved paths with `git update-index`.
<new_branch>::
Name for the new branch.
commit. Defaults to HEAD.
-EXAMPLE
--------
+EXAMPLES
+--------
-The following sequence checks out the `master` branch, reverts
+. The following sequence checks out the `master` branch, reverts
the `Makefile` to two revisions back, deletes hello.c by
mistake, and gets it back from the index.
-
++
------------
-$ git checkout master <1>
-$ git checkout master~2 Makefile <2>
+$ git checkout master <1>
+$ git checkout master~2 Makefile <2>
$ rm -f hello.c
-$ git checkout hello.c <3>
-
+$ git checkout hello.c <3>
+------------
++
<1> switch branch
<2> take out a file out of other commit
-<3> or "git checkout -- hello.c", as in the next example.
+<3> restore hello.c from HEAD of current branch
++
+If you have an unfortunate branch that is named `hello.c`, this
+step would be confused as an instruction to switch to that branch.
+You should instead write:
++
+------------
+$ git checkout -- hello.c
------------
-If you have an unfortunate branch that is named `hello.c`, the
-last step above would be confused as an instruction to switch to
-that branch. You should instead write:
-
+. After working in a wrong branch, switching to the correct
+branch would be done using:
++
------------
-$ git checkout -- hello.c
+$ git checkout mytopic
+------------
++
+However, your "wrong" branch and correct "mytopic" branch may
+differ in files that you have locally modified, in which case,
+the above checkout would fail like this:
++
+------------
+$ git checkout mytopic
+fatal: Entry 'frotz' not uptodate. Cannot merge.
+------------
++
+You can give the `-m` flag to the command, which would try a
+three-way merge:
++
+------------
+$ git checkout -m mytopic
+Auto-merging frotz
+------------
++
+After this three-way merge, the local modifications are _not_
+registered in your index file, so `git diff` would show you what
+changes you made since the tip of the new branch.
+
+. When a merge conflict happens during switching branches with
+the `-m` option, you would see something like this:
++
+------------
+$ git checkout -m mytopic
+Auto-merging frotz
+merge: warning: conflicts during merge
+ERROR: Merge conflict in frotz
+fatal: merge program failed
+------------
++
+At this point, `git diff` shows the changes cleanly merged as in
+the previous example, as well as the changes in the conflicted
+files. Edit and resolve the conflict and mark it resolved with
+`git update-index` as usual:
++
+------------
+$ edit frotz
+$ git update-index frotz
------------