f send when we should

Author: TheBlueMatt

lightning/src/ln/channelmanager.rs

@@ -613,8 +613,14 @@ impl MsgHandleErrInternal {
 		Self {
 			err: match err {
 				ChannelError::Warn(msg) =>  LightningError {
-					err: msg,
-					action: msgs::ErrorAction::IgnoreError,
+					err: msg.clone(),
+					action: msgs::ErrorAction::SendWarningMessage {
+						msg: msgs::WarningMessage {
+							channel_id,
+							data: msg
+						},
+						log_level: Level::Warn,
+					},
 				},
 				ChannelError::Ignore(msg) => LightningError {
 					err: msg,
@@ -1373,9 +1379,7 @@ macro_rules! convert_chan_err {
 	($self: ident, $err: expr, $short_to_id: expr, $channel: expr, $channel_id: expr) => {
 		match $err {
 			ChannelError::Warn(msg) => {
-				//TODO: Once warning messages are merged, we should send a `warning` message to our
-				//peer here.
-				(false, MsgHandleErrInternal::from_chan_no_close(ChannelError::Ignore(msg), $channel_id.clone()))
+				(false, MsgHandleErrInternal::from_chan_no_close(ChannelError::Warn(msg), $channel_id.clone()))
 			},
 			ChannelError::Ignore(msg) => {
 				(false, MsgHandleErrInternal::from_chan_no_close(ChannelError::Ignore(msg), $channel_id.clone()))

lightning/src/ln/functional_test_utils.rs

@@ -780,6 +780,22 @@ macro_rules! get_closing_signed_broadcast {
 	}
 }
 
+#[cfg(test)]
+macro_rules! check_warn_msg {
+	($node: expr, $recipient_node_id: expr, $chan_id: expr) => {{
+		let msg_events = $node.node.get_and_clear_pending_msg_events();
+		assert_eq!(msg_events.len(), 1);
+		match msg_events[0] {
+			MessageSendEvent::HandleError { action: ErrorAction::SendWarningMessage { ref msg, log_level: _ }, node_id } => {
+				assert_eq!(node_id, $recipient_node_id);
+				assert_eq!(msg.channel_id, $chan_id);
+				msg.data.clone()
+			},
+			_ => panic!("Unexpected event"),
+		}
+	}}
+}
+
 /// Check that a channel's closing channel update has been broadcasted, and optionally
 /// check whether an error message event has occurred.
 #[macro_export]

lightning/src/ln/shutdown_tests.rs

@@ -762,10 +762,8 @@ fn do_test_closing_signed_reinit_timeout(timeout_step: TimeoutStep) {
 
 	if timeout_step != TimeoutStep::AfterShutdown {
 		nodes[1].node.handle_closing_signed(&nodes[0].node.get_our_node_id(), &node_0_closing_signed);
-		// At this point nodes[1] should send back a warning message indicating it disagrees with the
-		// given channel-closing fee. Currently we do not implement warning messages so instead we
-		// remain silent here.
-		assert!(nodes[1].node.get_and_clear_pending_msg_events().is_empty());
+		assert!(check_warn_msg!(nodes[1], nodes[0].node.get_our_node_id(), chan_id)
+			.starts_with("Unable to come to consensus about closing feerate"));
 
 		// Now deliver a mutated closing_signed indicating a higher acceptable fee range, which
 		// nodes[1] should happily accept and respond to.