errno = save_errno;
                        return -1;
                } else {
-                       hashclr(lock->old_oid.hash);
+                       oidclr(&lock->old_oid);
                        return 0;
                }
        }
        if (old_sha1 && hashcmp(lock->old_oid.hash, old_sha1)) {
                strbuf_addf(err, "ref %s is at %s but expected %s",
                            lock->ref_name,
-                           sha1_to_hex(lock->old_oid.hash),
+                           oid_to_hex(&lock->old_oid),
                            sha1_to_hex(old_sha1));
                errno = EBUSY;
                return -1;