splice: Add call to hsmd_sync_outpoint when mutual splice_locked

Author: ksedgwic

channeld/channeld.c

@@ -751,6 +751,16 @@ static void check_mutual_splice_locked(struct peer *peer)
 	status_debug("mutual splice_locked, channel updated to: %s",
 		     type_to_string(tmpctx, struct channel, peer->channel));
 
+	/* Make sure the hsmd agrees that this outpoint is
+	 * sufficiently buried. */
+	const u8 *msg2;
+	msg2 = towire_hsmd_sync_outpoint(NULL, &inflight->outpoint);
+	msg2 = hsm_req(tmpctx, take(msg2));
+	if (!fromwire_hsmd_sync_outpoint_reply(msg2))
+		status_failed(STATUS_FAIL_HSM_IO,
+			      "Bad hsmd_sync_outpoint_reply: %s",
+			      tal_hex(tmpctx, msg2));
+
 	msg = towire_channeld_got_splice_locked(NULL, inflight->amnt,
 						inflight->splice_amnt,
 						&inflight->outpoint.txid);