gossipd: don't broadcast node_announcement if we have no public channels.

This could always happen if we armed the timer when we did have public
channels, and by the time we did our node_announcement we no longer
did, but it gets triggered in our tests when we remove (our own!)
zombied node_announcement in the next patch.

gossipd/gossip_generation.c

@@ -263,6 +263,10 @@ static bool update_own_node_announcement(struct daemon *daemon,
 	/* Discard existing timer. */
 	daemon->node_announce_timer = tal_free(daemon->node_announce_timer);
 
+	/* If we don't have any channels now, don't send node_announcement */
+	if (!self || !node_has_broadcastable_channels(self))
+		goto reset_timer;
+
 	/* If we ever use set-based propagation, ensuring the toggle the lower
 	 * bit in consecutive timestamps makes it more robust. */
 	if (self && self->bcast.index
@@ -327,6 +331,7 @@ static bool update_own_node_announcement(struct daemon *daemon,
 send:
 	sign_and_send_nannounce(daemon, nannounce, timestamp);
 
+reset_timer:
 	/* Generate another one in 24 hours. */
 	setup_force_nannounce_regen_timer(daemon);
 
@@ -341,13 +346,6 @@ static void update_own_node_announcement_after_startup(struct daemon *daemon)
 /* This creates and transmits a *new* node announcement */
 static void force_self_nannounce_regen(struct daemon *daemon)
 {
-	struct node *self = get_node(daemon->rstate, &daemon->id);
-	/* Clear timer pointer now. */
-	daemon->node_announce_regen_timer = NULL;
-	/* No channels left?  We'll restart timer once we have one. */
-	if (!self || !self->bcast.index)
-		return;
-
 	update_own_node_announcement(daemon, false, true);
 }
 

gossipd/routing.c

@@ -416,7 +416,7 @@ static bool is_node_zombie(struct node* node)
 
 /* We can *send* a channel_announce for a channel attached to this node:
  * we only send once we have a channel_update. */
-static bool node_has_broadcastable_channels(struct node *node)
+bool node_has_broadcastable_channels(const struct node *node)
 {
 	struct chan_map_iter i;
 	struct chan *c;

gossipd/routing.h

@@ -434,6 +434,9 @@ bool would_ratelimit_cupdate(struct routing_state *rstate,
 			     const struct half_chan *hc,
 			     u32 timestamp);
 
+/* Does this node have public, non-zombie channels? */
+bool node_has_broadcastable_channels(const struct node *node);
+
 /* Returns an error string if there are unfinalized entries after load */
 const char *unfinalized_entries(const tal_t *ctx, struct routing_state *rstate);
 

gossipd/test/run-check_node_announcement.c

@@ -68,6 +68,9 @@ struct oneshot *new_reltimer_(struct timers *timers UNNEEDED,
 			      struct timerel expire UNNEEDED,
 			      void (*cb)(void *) UNNEEDED, void *arg UNNEEDED)
 { fprintf(stderr, "new_reltimer_ called!\n"); abort(); }
+/* Generated stub for node_has_broadcastable_channels */
+bool node_has_broadcastable_channels(const struct node *node UNNEEDED)
+{ fprintf(stderr, "node_has_broadcastable_channels called!\n"); abort(); }
 /* Generated stub for queue_peer_msg */
 void queue_peer_msg(struct peer *peer UNNEEDED, const u8 *msg TAKES UNNEEDED)
 { fprintf(stderr, "queue_peer_msg called!\n"); abort(); }

gossipd/test/run-crc32_of_update.c

@@ -94,6 +94,9 @@ struct oneshot *new_reltimer_(struct timers *timers UNNEEDED,
 			      struct timerel expire UNNEEDED,
 			      void (*cb)(void *) UNNEEDED, void *arg UNNEEDED)
 { fprintf(stderr, "new_reltimer_ called!\n"); abort(); }
+/* Generated stub for node_has_broadcastable_channels */
+bool node_has_broadcastable_channels(const struct node *node UNNEEDED)
+{ fprintf(stderr, "node_has_broadcastable_channels called!\n"); abort(); }
 /* Generated stub for peer_supplied_good_gossip */
 void peer_supplied_good_gossip(struct peer *peer UNNEEDED, size_t amount UNNEEDED)
 { fprintf(stderr, "peer_supplied_good_gossip called!\n"); abort(); }