f clean up forwarding handling in test_check_htlc_underpaying

Author: TheBlueMatt

lightning/src/ln/functional_tests.rs

@@ -7500,6 +7500,10 @@ fn test_check_htlc_underpaying() {
 	let mut payment_event = SendEvent::from_event(events.pop().unwrap());
 	nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &payment_event.msgs[0]);
 	commitment_signed_dance!(nodes[1], nodes[0], payment_event.commitment_msg, false);
+
+	// Note that we first have to wait a random delay before processing the receipt of the HTLC,
+	// and then will wait a second random delay before failing the HTLC back:
+	expect_pending_htlcs_forwardable!(nodes[1]);
 	expect_pending_htlcs_forwardable!(nodes[1]);
 
 	// Node 3 is expecting payment of 100_000 but received 10_000,
@@ -7528,7 +7532,6 @@ fn test_check_htlc_underpaying() {
 	let mut expected_failure_data = byte_utils::be64_to_array(10_000).to_vec();
 	expected_failure_data.extend_from_slice(&byte_utils::be32_to_array(CHAN_CONFIRM_DEPTH));
 	expect_payment_failed!(nodes[0], our_payment_hash, true, 0x4000|15, &expected_failure_data[..]);
-	nodes[1].node.get_and_clear_pending_events();
 }
 
 #[test]