When <paths> are given, this command does *not* switch
branches. It updates the named paths in the working tree from
-the index file, or from a named commit. In
+the index file, or from a named <tree-ish> (most often a commit). In
this case, the `-b` options is meaningless and giving
either of them results in an error. <tree-ish> argument can be
used to specify a specific tree-ish (i.e. commit, tag or tree)
<new_branch>::
Name for the new branch.
+<tree-ish>::
+ Tree to checkout from (when paths are given). If not specified,
+ the index will be used.
+
<branch>::
- Branch to checkout; may be any object ID that resolves to a
- commit. Defaults to HEAD.
+ Branch to checkout (when no paths are given); may be any object
+ ID that resolves to a commit. Defaults to HEAD.
+
When this parameter names a non-branch (but still a valid commit object),
your HEAD becomes 'detached'.
------------
+
<1> switch branch
-<2> take out a file out of other commit
-<3> restore hello.c from HEAD of current branch
+<2> take a file out of another commit
+<3> restore hello.c from the index
+
If you have an unfortunate branch that is named `hello.c`, this
step would be confused as an instruction to switch to that branch.
------------
$ git checkout -m mytopic
Auto-merging frotz
-merge: warning: conflicts during merge
ERROR: Merge conflict in frotz
fatal: merge program failed
------------