gossipd: apply private updates to announce channel.

We trade channel_update before channel_announce makes the channel
public, and currently forget them when we finally get the
channel_announce.  We should instead apply them, and not rely on
retransmission (which we remove in the next patch!).

This earlier channel_update means test_gossip_jsonrpc triggers too
early, so have that wait for node_announcement.

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

gossipd/routing.c

@@ -753,11 +753,16 @@ bool routing_add_channel_announcement(struct routing_state *rstate,
 	/* Channel is now public. */
 	chan->channel_announce = tal_dup_arr(chan, u8, msg, tal_count(msg), 0);
 
-	/* Clear any private updates: new updates will trigger broadcast of
-	 * this channel_announce. */
-	for (size_t i = 0; i < ARRAY_SIZE(chan->half); i++)
-		chan->half[i].channel_update
-			= tal_free(chan->half[i].channel_update);
+	/* Apply any private updates. */
+	for (size_t i = 0; i < ARRAY_SIZE(chan->half); i++) {
+		const u8 *update = chan->half[i].channel_update;
+		if (!update)
+			continue;
+
+		/* Remove from channel, otherwise it will be freed! */
+		chan->half[i].channel_update = NULL;
+		routing_add_channel_update(rstate, take(update));
+	}
 
 	return true;
 }

tests/test_gossip.py

@@ -282,7 +282,7 @@ def test_gossip_jsonrpc(node_factory):
                              'peer_in WIRE_ANNOUNCEMENT_SIGNATURES'])
 
     # Just wait for the update to kick off and then check the effect
-    needle = "Received channel_update for channel"
+    needle = "Received node_announcement for node"
     l1.daemon.wait_for_log(needle)
     l2.daemon.wait_for_log(needle)
     # Need to increase timeout, intervals cannot be shortened with DEVELOPER=0