[fuzz] Do not fail in FST if a channel is closed before we fund it

Author: TheBlueMatt

fuzz/src/full_stack.rs

@@ -38,6 +38,7 @@ use lightning::ln::msgs::DecodeError;
 use lightning::routing::router::get_route;
 use lightning::routing::network_graph::NetGraphMsgHandler;
 use lightning::util::config::UserConfig;
+use lightning::util::errors::APIError;
 use lightning::util::events::{EventsProvider,Event};
 use lightning::util::enforcing_trait_impls::EnforcingSigner;
 use lightning::util::logger::Logger;
@@ -526,7 +527,13 @@ pub fn do_test(data: &[u8], logger: &Arc<dyn Logger>) {
 							continue 'outer_loop;
 						}
 					};
-					channelmanager.funding_transaction_generated(&funding_generation.0, tx.clone()).unwrap();
+					if let Err(e) = channelmanager.funding_transaction_generated(&funding_generation.0, tx.clone()) {
+						// Its possible the channel has been closed in the mean time, but any other
+						// failure may be a bug.
+						if let APIError::ChannelUnavailable { err } = e {
+							assert_eq!(err, "No such channel");
+						} else { panic!(); }
+					}
 					pending_funding_signatures.insert(funding_output, tx);
 				}
 			},