+ if (old_rev) {
+ if (get_sha1(old_rev, old_sha1)) {
+ cgit_print_error("Bad object id: %s", old_rev);
+ return;
+ }
+ if (!lookup_commit_reference(old_sha1)) {
+ cgit_print_error("Bad commit reference: %s", old_rev);
+ return;
+ }
+ } else if (commit->parents && commit->parents->item) {