Add test for peer disconnect and async signing

This adds a test that disconnects and reconnects the peers with a commitment
signature pending.

lightning/src/ln/async_signer_tests.rs

@@ -189,3 +189,70 @@ fn test_async_commitment_signature_for_commitment_signed() {
 	};
 }
 
+#[test]
+fn test_async_commitment_signature_for_peer_disconnect() {
+	let chanmon_cfgs = create_chanmon_cfgs(2);
+	let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+	let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+	let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+	create_announced_chan_between_nodes(&nodes, 0, 1);
+
+	let chan_id = {
+		let per_peer_state = nodes[0].node.per_peer_state.read().unwrap();
+		let chan_lock = per_peer_state.get(&nodes[1].node.get_our_node_id()).unwrap().lock().unwrap();
+		let chan_ids = chan_lock.channel_by_id.keys().collect::<Vec<_>>();
+		let n = chan_ids.len();
+		assert_eq!(n, 1, "expected one channel, not {}", n);
+		*chan_ids[0]
+	};
+
+	// Send a payment.
+	let src = &nodes[0];
+	let dst = &nodes[1];
+	let (route, our_payment_hash, _our_payment_preimage, our_payment_secret) = get_route_and_payment_hash!(src, dst, 8000000);
+	src.node.send_payment_with_route(&route, our_payment_hash,
+		RecipientOnionFields::secret_only(our_payment_secret), PaymentId(our_payment_hash.0)).unwrap();
+	check_added_monitors!(src, 1);
+
+	// Pass the payment along the route.
+	let payment_event = {
+		let mut events = src.node.get_and_clear_pending_msg_events();
+		assert_eq!(events.len(), 1);
+		SendEvent::from_event(events.remove(0))
+	};
+	assert_eq!(payment_event.node_id, dst.node.get_our_node_id());
+	assert_eq!(payment_event.msgs.len(), 1);
+
+	dst.node.handle_update_add_htlc(&src.node.get_our_node_id(), &payment_event.msgs[0]);
+
+	// Mark dst's signer as unavailable and handle src's commitment_signed: while dst won't yet have a
+	// `commitment_signed` of its own to offer, it should publish a `revoke_and_ack`.
+	dst.set_channel_signer_available(&src.node.get_our_node_id(), &chan_id, false);
+	dst.node.handle_commitment_signed(&src.node.get_our_node_id(), &payment_event.commitment_msg);
+	check_added_monitors(dst, 1);
+
+	get_event_msg!(dst, MessageSendEvent::SendRevokeAndACK, src.node.get_our_node_id());
+
+	// Now disconnect and reconnect the peers.
+	src.node.peer_disconnected(&dst.node.get_our_node_id());
+	dst.node.peer_disconnected(&src.node.get_our_node_id());
+	let mut reconnect_args = ReconnectArgs::new(&nodes[0], &nodes[1]);
+	reconnect_args.send_channel_ready = (false, false);
+	reconnect_args.pending_raa = (true, false);
+	reconnect_nodes(reconnect_args);
+
+	// Mark dst's signer as available and retry: we now expect to see dst's `commitment_signed`.
+	dst.set_channel_signer_available(&src.node.get_our_node_id(), &chan_id, true);
+	dst.node.signer_unblocked(Some((src.node.get_our_node_id(), chan_id)));
+
+	{
+		let events = dst.node.get_and_clear_pending_msg_events();
+		let n = events.len();
+		assert_eq!(n, 1, "expected one message, got {}", n);
+		if let MessageSendEvent::UpdateHTLCs { ref node_id, ref updates } = events[0] {
+			assert_eq!(node_id, &src.node.get_our_node_id());
+		} else {
+			panic!("expected UpdateHTLCs message, not {:?}", events[0]);
+		};
+	}
+}

lightning/src/ln/functional_test_utils.rs

@@ -3118,24 +3118,28 @@ pub fn reconnect_nodes<'a, 'b, 'c, 'd>(args: ReconnectArgs<'a, 'b, 'c, 'd>) {
 		// If a expects a channel_ready, it better not think it has received a revoke_and_ack
 		// from b
 		for reestablish in reestablish_1.iter() {
-			assert_eq!(reestablish.next_remote_commitment_number, 0);
+			let n = reestablish.next_remote_commitment_number;
+			assert_eq!(n, 0, "expected a->b next_remote_commitment_number to be 0, got {}", n);
 		}
 	}
 	if send_channel_ready.1 {
 		// If b expects a channel_ready, it better not think it has received a revoke_and_ack
 		// from a
 		for reestablish in reestablish_2.iter() {
-			assert_eq!(reestablish.next_remote_commitment_number, 0);
+			let n = reestablish.next_remote_commitment_number;
+			assert_eq!(n, 0, "expected b->a next_remote_commitment_number to be 0, got {}", n);
 		}
 	}
 	if send_channel_ready.0 || send_channel_ready.1 {
 		// If we expect any channel_ready's, both sides better have set
 		// next_holder_commitment_number to 1
 		for reestablish in reestablish_1.iter() {
-			assert_eq!(reestablish.next_local_commitment_number, 1);
+			let n = reestablish.next_local_commitment_number;
+			assert_eq!(n, 1, "expected a->b next_local_commitment_number to be 1, got {}", n);
 		}
 		for reestablish in reestablish_2.iter() {
-			assert_eq!(reestablish.next_local_commitment_number, 1);
+			let n = reestablish.next_local_commitment_number;
+			assert_eq!(n, 1, "expected b->a next_local_commitment_number to be 1, got {}", n);
 		}
 	}