merge: use skip_prefix()

Get rid of a magic string length constant by using skip_prefix() instead
of starts_with().

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/merge.c b/builtin/merge.c
index 703827f..d9db0ba 100644 (file)
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -1118,8 +1118,8 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
         * current branch.
         */
        branch = branch_to_free = resolve_refdup("HEAD", 0, head_oid.hash, NULL);
-       if (branch && starts_with(branch, "refs/heads/"))
-               branch += 11;
+       if (branch)
+               skip_prefix(branch, "refs/heads/", &branch);
        if (!branch || is_null_oid(&head_oid))
                head_commit = NULL;
        else