htlc: keep rval (if known).

This makes struct htlc a complete object, containing its own information.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

daemon/htlc.h

@@ -19,6 +19,8 @@ struct htlc {
 	struct abs_locktime expiry;
 	/* The hash of the preimage which can redeem this HTLC */
 	struct sha256 rhash;
+	/* The preimage which hashes to rhash (if known) */
+	struct rval *r;
 
 	/* FIXME: We could union these together: */
 	/* Routing information sent with this HTLC. */

daemon/pay.c

@@ -16,21 +16,19 @@ struct pay_command {
 	struct command *cmd;
 };
 
-void complete_pay_command(struct peer *peer,
+void complete_pay_command(struct peer *peer, struct htlc *htlc)
-			  struct htlc *htlc,
-			  const struct rval *rval)
 {
 	struct pay_command *i;
 
 	list_for_each(&peer->pay_commands, i, list) {
 		if (i->htlc == htlc) {
-			if (rval) {
+			if (htlc->r) {
 				struct json_result *response;
 
 				response = new_json_result(i->cmd);	
 				json_object_start(response, NULL);
 				json_add_hex(response, "preimage",
-					     rval->r, sizeof(rval->r));
+					     htlc->r, sizeof(*htlc->r));
 				json_object_end(response);
 				command_success(i->cmd, response);
 			} else {
@@ -39,9 +37,10 @@ void complete_pay_command(struct peer *peer,
 			return;
 		}
 	}
+
 	/* Can happen if RPC connection goes away. */
 	log_unusual(peer->log, "No command for HTLC %"PRIu64" %s",
-		    htlc->id, rval ? "fulfill" : "fail");
+		    htlc->id, htlc->r ? "fulfill" : "fail");
 }
 
 static void remove_from_list(struct pay_command *pc)

daemon/pay.h

@@ -6,8 +6,6 @@ struct peer;
 struct htlc;
 struct rval;
 
-void complete_pay_command(struct peer *peer,
+void complete_pay_command(struct peer *peer, struct htlc *htlc);
-			  struct htlc *htlc,
-			  const struct rval *rval);
 
 #endif /* LIGHTNING_DAEMON_PAY_H */

daemon/peer.c

@@ -561,6 +561,9 @@ static bool command_htlc_fulfill(struct peer *peer,
 				 struct htlc *htlc,
 				 const struct rval *r)
 {
+	assert(!htlc->r);
+	htlc->r = tal_dup(htlc, struct rval, r);
+
 	if (!state_can_remove_htlc(peer->state))
 		return false;
 
@@ -904,6 +907,7 @@ struct htlc *peer_new_htlc(struct peer *peer,
 	h->id = id;
 	h->msatoshis = msatoshis;
 	h->rhash = *rhash;
+	h->r = NULL;
 	if (!blocks_to_abs_locktime(expiry, &h->expiry))
 		fatal("Invalid HTLC expiry %u", expiry);
 	h->routing = tal_dup_arr(h, u8, route, routelen, 0);
@@ -1633,8 +1637,11 @@ void our_htlc_fulfilled(struct peer *peer, struct htlc *htlc,
 {
 	if (htlc->src)
 		command_htlc_fulfill(htlc->src->peer, htlc->src, preimage);
-	else
+	else {
-		complete_pay_command(peer, htlc, preimage);
+		assert(!htlc->r);
+		htlc->r = tal_dup(htlc, struct rval, preimage);
+		complete_pay_command(peer, htlc);
+	}
 }
 
 static void their_htlc_depth(struct peer *peer,
@@ -2449,7 +2456,7 @@ static void our_htlc_failed(struct peer *peer, struct htlc *htlc)
 	if (htlc->src)
 		command_htlc_fail(htlc->src->peer, htlc->src);
 	else
-		complete_pay_command(peer, htlc, NULL);
+		complete_pay_command(peer, htlc);
 }
 
 /* When changes are committed to. */