f - extend test to cover forward channel confirmation

Author: alecchendev

lightning/src/ln/functional_tests.rs

@@ -2213,6 +2213,11 @@ fn channel_reserve_in_flight_removes() {
 
 #[test]
 fn test_fail_back_before_backwards_timeout() {
+	do_test_fail_back_before_backwards_timeout(false);
+	do_test_fail_back_before_backwards_timeout(true);
+}
+
+fn do_test_fail_back_before_backwards_timeout(forward_claims: bool) {
 	// Test that we fail an HTLC upstream if we are still waiting for confirmation downstream
 	// just before the upstream timeout expires
 	let chanmon_cfgs = create_chanmon_cfgs(3);
@@ -2227,21 +2232,21 @@ fn test_fail_back_before_backwards_timeout() {
 	connect_blocks(&nodes[1], 2*CHAN_CONFIRM_DEPTH + 1 - nodes[1].best_block_info().1);
 	connect_blocks(&nodes[2], 2*CHAN_CONFIRM_DEPTH + 1 - nodes[2].best_block_info().1);
 
-	let (_, payment_hash_1, _) = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 3_000_000);
+	let (payment_preimage, payment_hash, _) = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 3_000_000);
 
 	// Force close downstream with timeout
 	nodes[1].node.force_close_broadcasting_latest_txn(&chan_2.2, &nodes[2].node.get_our_node_id()).unwrap();
 	check_added_monitors!(nodes[1], 1);
 	check_closed_broadcast!(nodes[1], true);
 
 	connect_blocks(&nodes[1], TEST_FINAL_CLTV + LATENCY_GRACE_PERIOD_BLOCKS + 1);
-	test_txn_broadcast(&nodes[1], &chan_2, None, HTLCType::TIMEOUT);
-	check_closed_event!(nodes[1], 1, ClosureReason::HolderForceClosed);
+	let node_1_txn = test_txn_broadcast(&nodes[1], &chan_2, None, HTLCType::TIMEOUT);
+	check_closed_event(&nodes[1], 1, ClosureReason::HolderForceClosed, false);
 
 	// Nothing is confirmed for a while
 	connect_blocks(&nodes[1], MIN_CLTV_EXPIRY_DELTA as u32 - LATENCY_GRACE_PERIOD_BLOCKS - TIMEOUT_FAIL_BACK_BUFFER);
 
-	// Check that node 2 fails the HTLC upstream
+	// Check that nodes[1] fails the HTLC upstream
 	expect_pending_htlcs_forwardable_and_htlc_handling_failed!(nodes[1], vec![HTLCDestination::NextHopChannel { node_id: Some(nodes[2].node.get_our_node_id()), channel_id: chan_2.2 }]);
 	check_added_monitors!(nodes[1], 1);
 	let events = nodes[1].node.get_and_clear_pending_msg_events();
@@ -2260,7 +2265,30 @@ fn test_fail_back_before_backwards_timeout() {
 
 	nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &update_fail);
 	commitment_signed_dance!(nodes[0], nodes[1], commitment_signed, false);
-	expect_payment_failed_conditions(&nodes[0], payment_hash_1, false, PaymentFailedConditions::new().blamed_chan_closed(true));
+	expect_payment_failed_conditions(&nodes[0], payment_hash, false, PaymentFailedConditions::new().blamed_chan_closed(true));
+
+	// Make sure we don't generate duplicate fails from monitor events
+	if forward_claims {
+		// Claim and force close as nodes[2]
+		nodes[2].node.claim_funds(payment_preimage);
+		expect_payment_claimed!(nodes[2], payment_hash, 3_000_000);
+		check_added_monitors!(nodes[2], 1);
+		get_htlc_update_msgs(&nodes[2], &nodes[1].node.get_our_node_id());
+
+		connect_blocks(&nodes[2], TEST_FINAL_CLTV - CLTV_CLAIM_BUFFER + 2);
+		let node_2_txn = test_txn_broadcast(&nodes[2], &chan_2, None, HTLCType::SUCCESS);
+		check_closed_broadcast!(nodes[2], true);
+		check_closed_event(&nodes[2], 1, ClosureReason::CommitmentTxConfirmed, false);
+		check_added_monitors!(nodes[2], 1);
+
+		// Confirm nodes[2]'s claim with preimage
+		mine_transaction(&nodes[1], &node_2_txn[0]); // Commitment
+		mine_transaction(&nodes[1], &node_2_txn[1]); // HTLC success
+	} else {
+		// Confirm nodes[1]'s claim with timeout, make sure we don't fail upstream again
+		mine_transaction(&nodes[1], &node_1_txn[0]); // Commitment
+		mine_transaction(&nodes[1], &node_1_txn[1]); // HTLC timeout
+	}
 }
 
 #[test]