+ cgit_print_error(fmt("Bad object name: %s", new_rev));
+ return;
+ }
+ if (type != OBJ_COMMIT) {
+ cgit_print_error(fmt("Unhandled object type: %s",
+ typename(type)));
+ return;
+ }
+
+ commit = lookup_commit_reference(sha1);
+ if (!commit || parse_commit(commit))
+ cgit_print_error(fmt("Bad commit: %s", sha1_to_hex(sha1)));
+
+ if (old_rev)
+ get_sha1(old_rev, sha2);
+ else if (commit->parents && commit->parents->item)
+ hashcpy(sha2, commit->parents->item->object.sha1);
+ else
+ hashclr(sha2);
+
+ if (!is_null_sha1(sha2)) {