Add persistence test for htlc in the LocalRemoved state

Increase coverage and prepare for attributable failures which are going
to extend the update_fail_htlc message with an additional field that
needs to be persisted as well.

Author: joostjager

lightning/src/ln/channelmanager.rs

@@ -14834,7 +14834,7 @@ mod tests {
 	use crate::events::{Event, HTLCDestination, MessageSendEvent, MessageSendEventsProvider, ClosureReason};
 	use crate::ln::types::ChannelId;
 	use crate::types::payment::{PaymentPreimage, PaymentHash, PaymentSecret};
-	use crate::ln::channelmanager::{create_recv_pending_htlc_info, inbound_payment, ChannelConfigOverrides, HTLCForwardInfo, InterceptId, PaymentId, RecipientOnionFields};
+	use crate::ln::channelmanager::{RAACommitmentOrder, create_recv_pending_htlc_info, inbound_payment, ChannelConfigOverrides, HTLCForwardInfo, InterceptId, PaymentId, RecipientOnionFields};
 	use crate::ln::functional_test_utils::*;
 	use crate::ln::msgs::{self, AcceptChannel, ErrorAction};
 	use crate::ln::msgs::ChannelMessageHandler;
@@ -15306,6 +15306,80 @@ mod tests {
 		nodes[1].logger.assert_log_contains("lightning::ln::channelmanager", "Payment preimage didn't match payment hash", 1);
 	}
 
+	#[test]
+	fn test_htlc_localremoved_persistence() {
+		let chanmon_cfgs: Vec<TestChanMonCfg> = create_chanmon_cfgs(2);
+		let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+
+		let persister;
+		let chain_monitor;
+		let deserialized_chanmgr;
+
+		// Send a keysend payment that fails because of a preimage mismatch.
+		let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+		let mut nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+		let payer_pubkey = nodes[0].node.get_our_node_id();
+		let payee_pubkey = nodes[1].node.get_our_node_id();
+
+		let _chan = create_chan_between_nodes(&nodes[0], &nodes[1]);
+		let route_params = RouteParameters::from_payment_params_and_value(
+			PaymentParameters::for_keysend(payee_pubkey, 40, false), 10_000);
+		let network_graph = nodes[0].network_graph;
+		let first_hops = nodes[0].node.list_usable_channels();
+		let scorer = test_utils::TestScorer::new();
+		let random_seed_bytes = chanmon_cfgs[1].keys_manager.get_secure_random_bytes();
+		let route = find_route(
+			&payer_pubkey, &route_params, &network_graph, Some(&first_hops.iter().collect::<Vec<_>>()),
+			nodes[0].logger, &scorer, &Default::default(), &random_seed_bytes
+		).unwrap();
+
+		let test_preimage = PaymentPreimage([42; 32]);
+		let mismatch_payment_hash = PaymentHash([43; 32]);
+		let session_privs = nodes[0].node.test_add_new_pending_payment(mismatch_payment_hash,
+			RecipientOnionFields::spontaneous_empty(), PaymentId(mismatch_payment_hash.0), &route).unwrap();
+		nodes[0].node.test_send_payment_internal(&route, mismatch_payment_hash,
+			RecipientOnionFields::spontaneous_empty(), Some(test_preimage), PaymentId(mismatch_payment_hash.0), None, session_privs).unwrap();
+		check_added_monitors!(nodes[0], 1);
+
+		let updates = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+		nodes[1].node.handle_update_add_htlc(nodes[0].node.get_our_node_id(), &updates.update_add_htlcs[0]);
+		commitment_signed_dance!(nodes[1], nodes[0], &updates.commitment_signed, false);
+		expect_pending_htlcs_forwardable!(nodes[1]);
+		expect_htlc_handling_failed_destinations!(nodes[1].node.get_and_clear_pending_events(), &[HTLCDestination::FailedPayment { payment_hash: mismatch_payment_hash }]);
+		check_added_monitors(&nodes[1], 1);
+
+		// Save the update_fail_htlc message for later comparison.
+		let msgs = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+		let htlc_fail_msg = msgs.update_fail_htlcs[0].clone();
+
+		// Reload node.
+		nodes[0].node.peer_disconnected(nodes[1].node.get_our_node_id());
+		nodes[1].node.peer_disconnected(nodes[0].node.get_our_node_id());
+
+		let monitor_encoded = get_monitor!(nodes[1], _chan.3).encode();
+		reload_node!(nodes[1], nodes[1].node.encode(), &[&monitor_encoded], persister, chain_monitor, deserialized_chanmgr);
+
+		nodes[0].node.peer_connected(nodes[1].node.get_our_node_id(), &msgs::Init {
+			features: nodes[1].node.init_features(), networks: None, remote_network_address: None
+		}, true).unwrap();
+		let reestablish_1 = get_chan_reestablish_msgs!(nodes[0], nodes[1]);
+		assert_eq!(reestablish_1.len(), 1);
+		nodes[1].node.peer_connected(nodes[0].node.get_our_node_id(), &msgs::Init {
+			features: nodes[0].node.init_features(), networks: None, remote_network_address: None
+		}, false).unwrap();
+		let reestablish_2 = get_chan_reestablish_msgs!(nodes[1], nodes[0]);
+		assert_eq!(reestablish_2.len(), 1);
+		nodes[0].node.handle_channel_reestablish(nodes[1].node.get_our_node_id(), &reestablish_2[0]);
+		handle_chan_reestablish_msgs!(nodes[0], nodes[1]);
+		nodes[1].node.handle_channel_reestablish(nodes[0].node.get_our_node_id(), &reestablish_1[0]);
+
+		// Assert that same failure message is resent after reload.
+		let msgs = handle_chan_reestablish_msgs!(nodes[1], nodes[0]);
+		let htlc_fail_msg_after_reload = msgs.2.unwrap().update_fail_htlcs[0].clone();
+		assert_eq!(htlc_fail_msg, htlc_fail_msg_after_reload);
+	}
+
 	#[test]
 	fn test_multi_hop_missing_secret() {
 		let chanmon_cfgs = create_chanmon_cfgs(4);