strbuf_addstr(&ref, oid_to_hex(&oid));
                full_hex = ref.buf + base_len;
 
-               if (read_ref(ref.buf, oid.hash)) {
+               if (read_ref(ref.buf, &oid)) {
                        error("replace ref '%s' not found.", full_hex);
                        had_error = 1;
                        continue;
 static int delete_replace_ref(const char *name, const char *ref,
                              const struct object_id *oid)
 {
-       if (delete_ref(NULL, ref, oid->hash, 0))
+       if (delete_ref(NULL, ref, oid, 0))
                return 1;
        printf("Deleted replace ref '%s'\n", name);
        return 0;
        if (check_refname_format(ref->buf, 0))
                die("'%s' is not a valid ref name.", ref->buf);
 
-       if (read_ref(ref->buf, prev->hash))
+       if (read_ref(ref->buf, prev))
                oidclr(prev);
        else if (!force)
                die("replace ref '%s' already exists", ref->buf);
 
        transaction = ref_transaction_begin(&err);
        if (!transaction ||
-           ref_transaction_update(transaction, ref.buf, repl->hash, prev.hash,
+           ref_transaction_update(transaction, ref.buf, repl, &prev,
                                   0, NULL, &err) ||
            ref_transaction_commit(transaction, &err))
                die("%s", err.buf);
 
                if (fstat(fd, &st) < 0)
                        die_errno("unable to fstat %s", filename);
-               if (index_fd(oid->hash, fd, &st, type, NULL, flags) < 0)
+               if (index_fd(oid, fd, &st, type, NULL, flags) < 0)
                        die("unable to write object to database");
                /* index_fd close()s fd for us */
        }