+# With paths, we are _never_ switching branch, but checking out
+# the named paths from either index (when no rev is given),
+# or the named tree-ish (when rev is given).
+
+if test "$#" -ge 1
+then
+ hint=
+ if test "$#" -eq 1
+ then
+ hint="
+Did you intend to checkout '$@' which can not be resolved as commit?"
+ fi
+ if test '' != "$newbranch$force$merge"
+ then
+ die "git checkout: updating paths is incompatible with switching branches/forcing$hint"
+ fi
+ if test '' != "$new"
+ then
+ # from a specific tree-ish; note that this is for
+ # rescuing paths and is never meant to remove what
+ # is not in the named tree-ish.
+ git-ls-tree --full-name -r "$new" "$@" |
+ git-update-index --index-info || exit $?
+ fi
+ git-checkout-index -f -u -- "$@"
+ exit $?
+else
+ # Make sure we did not fall back on $arg^{tree} codepath
+ # since we are not checking out from an arbitrary tree-ish,
+ # but switching branches.
+ if test '' != "$new"
+ then
+ git-rev-parse --verify "$new^{commit}" >/dev/null 2>&1 ||
+ die "Cannot switch branch to a non-commit."
+ fi
+fi
+
+# We are switching branches and checking out trees, so
+# we *NEED* to be at the toplevel.
+cdup=$(git-rev-parse --show-cdup)
+if test ! -z "$cdup"
+then
+ cd "$cdup"
+fi
+
+[ -z "$new" ] && new=$old && new_name="$old_name"
+