f log errors

Author: TheBlueMatt

lightning/src/ln/channelmanager.rs

@@ -3817,13 +3817,16 @@ where
 							}
 						} else { Ok(()) }
 					};
-					let _ = handle_error!(self, res, counterparty_node_id);
 					if !found_chan {
 						// TODO: If this channel has since closed, we're likely providing a payment
 						// preimage update, which we must ensure is durable! We currently don't,
-						// however, ensure that, and when we have a strategy therefor we should
-						// apply it here.
+						// however, ensure that.
+						if res.is_err() {
+							log_error!(self.logger,
+								"Failed to provide ChannelMonitorUpdate to closed channel! This likely lost us a payment preimage!");
+						}
 					}
+					let _ = handle_error!(self, res, counterparty_node_id);
 				},
 			}
 		}