- if (get_sha1("HEAD", head))
- return error(_("You do not have a valid HEAD"));
- if (index_differs_from("HEAD", 0))
+ unborn = get_sha1("HEAD", head);
+ if (unborn)
+ hashcpy(head, EMPTY_TREE_SHA1_BIN);
+ if (index_differs_from(unborn ? EMPTY_TREE_SHA1_HEX : "HEAD", 0))