Add a further debug_assert that disconnecting peers are connected

Author: TheBlueMatt

lightning/src/ln/channelmanager.rs

@@ -6318,7 +6318,7 @@ where
 				debug_assert!(peer_state.is_connected, "A disconnected peer cannot disconnect");
 				peer_state.is_connected = false;
 				peer_state.ok_to_remove(true)
-			} else { true }
+			} else { debug_assert!(false, "Unconnected peer disconnected"); true }
 		};
 		if remove_peer {
 			per_peer_state.remove(counterparty_node_id);

lightning/src/ln/payment_tests.rs

@@ -351,7 +351,7 @@ fn no_pending_leak_on_initial_send_failure() {
 	let (route, payment_hash, _, payment_secret) = get_route_and_payment_hash!(nodes[0], nodes[1], 100_000);
 
 	nodes[0].node.peer_disconnected(&nodes[1].node.get_our_node_id(), false);
-	nodes[1].node.peer_disconnected(&nodes[1].node.get_our_node_id(), false);
+	nodes[1].node.peer_disconnected(&nodes[0].node.get_our_node_id(), false);
 
 	unwrap_send_err!(nodes[0].node.send_payment(&route, payment_hash, &Some(payment_secret), PaymentId(payment_hash.0)),
 		true, APIError::ChannelUnavailable { ref err },