[rust-lightning] / lightning / src / ln / reorg_tests.rs

// This file is Copyright its original authors, visible in version control
// history.
//
// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
// You may not use this file except in accordance with one or both of these
// licenses.

//! Further functional tests which test blockchain reorganizations.

use chain::channelmonitor::{ANTI_REORG_DELAY, ChannelMonitor};
use chain::transaction::OutPoint;
use chain::{Confirm, Watch};
use ln::channelmanager::{ChannelManager, ChannelManagerReadArgs};
use ln::features::InitFeatures;
use ln::msgs::ChannelMessageHandler;
use util::enforcing_trait_impls::EnforcingSigner;
use util::events::{Event, MessageSendEvent, MessageSendEventsProvider, ClosureReason};
use util::test_utils;
use util::ser::{ReadableArgs, Writeable};

use bitcoin::blockdata::block::{Block, BlockHeader};
use bitcoin::blockdata::script::Builder;
use bitcoin::blockdata::opcodes;
use bitcoin::hash_types::BlockHash;
use bitcoin::secp256k1::Secp256k1;

use prelude::*;
use core::mem;

use ln::functional_test_utils::*;

fn do_test_onchain_htlc_reorg(local_commitment: bool, claim: bool) {
        // Our on-chain HTLC-claim learning has a few properties worth testing:
        //  * If an upstream HTLC is claimed with a preimage (both against our own commitment
        //    transaction our counterparty's), we claim it backwards immediately.
        //  * If an upstream HTLC is claimed with a timeout, we delay ANTI_REORG_DELAY before failing
        //    it backwards to ensure our counterparty can't claim with a preimage in a reorg.
        //
        // Here we test both properties in any combination based on the two bools passed in as
        // arguments.
        //
        // If local_commitment is set, we first broadcast a local commitment containing an offered HTLC
        // and an HTLC-Timeout tx, otherwise we broadcast a remote commitment containing a received
        // HTLC and a local HTLC-Timeout tx spending it.
        //
        // We then either allow these transactions to confirm (if !claim) or we wait until one block
        // before they otherwise would and reorg them out, confirming an HTLC-Success tx instead.
        let chanmon_cfgs = create_chanmon_cfgs(3);
        let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
        let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
        let nodes = create_network(3, &node_cfgs, &node_chanmgrs);

        create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
        let chan_2 = create_announced_chan_between_nodes(&nodes, 1, 2, InitFeatures::known(), InitFeatures::known());

        // Make sure all nodes are at the same starting height
        connect_blocks(&nodes[0], 2*CHAN_CONFIRM_DEPTH + 1 - nodes[0].best_block_info().1);
        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 (our_payment_preimage, our_payment_hash, _) = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1000000);

        // Provide preimage to node 2 by claiming payment
        nodes[2].node.claim_funds(our_payment_preimage);
        check_added_monitors!(nodes[2], 1);
        get_htlc_update_msgs!(nodes[2], nodes[1].node.get_our_node_id());

        let mut header = BlockHeader { version: 0x2000_0000, prev_blockhash: nodes[2].best_block_hash(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 };
        let claim_txn = if local_commitment {
                // Broadcast node 1 commitment txn to broadcast the HTLC-Timeout
                let node_1_commitment_txn = get_local_commitment_txn!(nodes[1], chan_2.2);
                assert_eq!(node_1_commitment_txn.len(), 2); // 1 local commitment tx, 1 Outbound HTLC-Timeout
                assert_eq!(node_1_commitment_txn[0].output.len(), 2); // to-self and Offered HTLC (to-remote/to-node-3 is dust)
                check_spends!(node_1_commitment_txn[0], chan_2.3);
                check_spends!(node_1_commitment_txn[1], node_1_commitment_txn[0]);

                // Give node 2 node 1's transactions and get its response (claiming the HTLC instead).
                connect_block(&nodes[2], &Block { header, txdata: node_1_commitment_txn.clone() });
                check_added_monitors!(nodes[2], 1);
                check_closed_broadcast!(nodes[2], true); // We should get a BroadcastChannelUpdate (and *only* a BroadcstChannelUpdate)
                check_closed_event!(nodes[2], 1, ClosureReason::CommitmentTxConfirmed);
                let node_2_commitment_txn = nodes[2].tx_broadcaster.txn_broadcasted.lock().unwrap();
                assert_eq!(node_2_commitment_txn.len(), 3); // ChannelMonitor: 1 offered HTLC-Claim, ChannelManger: 1 local commitment tx, 1 Received HTLC-Claim
                assert_eq!(node_2_commitment_txn[1].output.len(), 2); // to-remote and Received HTLC (to-self is dust)
                check_spends!(node_2_commitment_txn[1], chan_2.3);
                check_spends!(node_2_commitment_txn[2], node_2_commitment_txn[1]);
                check_spends!(node_2_commitment_txn[0], node_1_commitment_txn[0]);

                // Make sure node 1's height is the same as the !local_commitment case
                connect_blocks(&nodes[1], 1);
                // Confirm node 1's commitment txn (and HTLC-Timeout) on node 1
                header.prev_blockhash = nodes[1].best_block_hash();
                connect_block(&nodes[1], &Block { header, txdata: node_1_commitment_txn.clone() });

                // ...but return node 1's commitment tx in case claim is set and we're preparing to reorg
                vec![node_1_commitment_txn[0].clone(), node_2_commitment_txn[0].clone()]
        } else {
                // Broadcast node 2 commitment txn
                let mut node_2_commitment_txn = get_local_commitment_txn!(nodes[2], chan_2.2);
                assert_eq!(node_2_commitment_txn.len(), 2); // 1 local commitment tx, 1 Received HTLC-Claim
                assert_eq!(node_2_commitment_txn[0].output.len(), 2); // to-remote and Received HTLC (to-self is dust)
                check_spends!(node_2_commitment_txn[0], chan_2.3);
                check_spends!(node_2_commitment_txn[1], node_2_commitment_txn[0]);

                // Give node 1 node 2's commitment transaction and get its response (timing the HTLC out)
                mine_transaction(&nodes[1], &node_2_commitment_txn[0]);
                connect_blocks(&nodes[1], TEST_FINAL_CLTV - 1); // Confirm blocks until the HTLC expires
                let node_1_commitment_txn = nodes[1].tx_broadcaster.txn_broadcasted.lock().unwrap().clone();
                assert_eq!(node_1_commitment_txn.len(), 2); // ChannelMonitor: 1 offered HTLC-Timeout, ChannelManger: 1 local commitment tx
                assert_eq!(node_1_commitment_txn[0].output.len(), 2); // to-local and Offered HTLC (to-remote is dust)
                check_spends!(node_1_commitment_txn[0], chan_2.3);
                check_spends!(node_1_commitment_txn[1], node_2_commitment_txn[0]);

                // Confirm node 1's HTLC-Timeout on node 1
                mine_transaction(&nodes[1], &node_1_commitment_txn[1]);
                // ...but return node 2's commitment tx (and claim) in case claim is set and we're preparing to reorg
                vec![node_2_commitment_txn.pop().unwrap()]
        };
        check_added_monitors!(nodes[1], 1);
        check_closed_broadcast!(nodes[1], true); // We should get a BroadcastChannelUpdate (and *only* a BroadcstChannelUpdate)
        check_closed_event!(nodes[1], 1, ClosureReason::CommitmentTxConfirmed);
        // Connect ANTI_REORG_DELAY - 2 blocks, giving us a confirmation count of ANTI_REORG_DELAY - 1.
        connect_blocks(&nodes[1], ANTI_REORG_DELAY - 2);
        check_added_monitors!(nodes[1], 0);
        assert_eq!(nodes[1].node.get_and_clear_pending_events().len(), 0);

        if claim {
                disconnect_blocks(&nodes[1], ANTI_REORG_DELAY - 2);

                let block = Block {
                        header: BlockHeader { version: 0x20000000, prev_blockhash: nodes[1].best_block_hash(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 },
                        txdata: claim_txn,
                };
                connect_block(&nodes[1], &block);

                // ChannelManager only polls chain::Watch::release_pending_monitor_events when we
                // probe it for events, so we probe non-message events here (which should just be the
                // PaymentForwarded event).
                expect_payment_forwarded!(nodes[1], nodes[0], Some(1000), true);
        } else {
                // Confirm the timeout tx and check that we fail the HTLC backwards
                let block = Block {
                        header: BlockHeader { version: 0x20000000, prev_blockhash: nodes[1].best_block_hash(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 },
                        txdata: vec![],
                };
                connect_block(&nodes[1], &block);
                expect_pending_htlcs_forwardable!(nodes[1]);
        }

        check_added_monitors!(nodes[1], 1);
        // Which should result in an immediate claim/fail of the HTLC:
        let htlc_updates = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
        if claim {
                assert_eq!(htlc_updates.update_fulfill_htlcs.len(), 1);
                nodes[0].node.handle_update_fulfill_htlc(&nodes[1].node.get_our_node_id(), &htlc_updates.update_fulfill_htlcs[0]);
        } else {
                assert_eq!(htlc_updates.update_fail_htlcs.len(), 1);
                nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &htlc_updates.update_fail_htlcs[0]);
        }
        commitment_signed_dance!(nodes[0], nodes[1], htlc_updates.commitment_signed, false, true);
        if claim {
                expect_payment_sent!(nodes[0], our_payment_preimage);
        } else {
                expect_payment_failed_with_update!(nodes[0], our_payment_hash, false, chan_2.0.contents.short_channel_id, true);
        }
}

#[test]
fn test_onchain_htlc_claim_reorg_local_commitment() {
        do_test_onchain_htlc_reorg(true, true);
}
#[test]
fn test_onchain_htlc_timeout_delay_local_commitment() {
        do_test_onchain_htlc_reorg(true, false);
}
#[test]
fn test_onchain_htlc_claim_reorg_remote_commitment() {
        do_test_onchain_htlc_reorg(false, true);
}
#[test]
fn test_onchain_htlc_timeout_delay_remote_commitment() {
        do_test_onchain_htlc_reorg(false, false);
}

fn do_test_unconf_chan(reload_node: bool, reorg_after_reload: bool, use_funding_unconfirmed: bool, connect_style: ConnectStyle) {
        // After creating a chan between nodes, we disconnect all blocks previously seen to force a
        // channel close on nodes[0] side. We also use this to provide very basic testing of logic
        // around freeing background events which store monitor updates during block_[dis]connected.
        let chanmon_cfgs = create_chanmon_cfgs(2);
        let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
        let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
        let persister: test_utils::TestPersister;
        let new_chain_monitor: test_utils::TestChainMonitor;
        let nodes_0_deserialized: ChannelManager<EnforcingSigner, &test_utils::TestChainMonitor, &test_utils::TestBroadcaster, &test_utils::TestKeysInterface, &test_utils::TestFeeEstimator, &test_utils::TestLogger>;
        let mut nodes = create_network(2, &node_cfgs, &node_chanmgrs);
        *nodes[0].connect_style.borrow_mut() = connect_style;

        let chan = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());

        let channel_state = nodes[0].node.channel_state.lock().unwrap();
        assert_eq!(channel_state.by_id.len(), 1);
        assert_eq!(channel_state.short_to_id.len(), 2);
        mem::drop(channel_state);

        if !reorg_after_reload {
                if use_funding_unconfirmed {
                        let relevant_txids = nodes[0].node.get_relevant_txids();
                        assert_eq!(&relevant_txids[..], &[chan.3.txid()]);
                        nodes[0].node.transaction_unconfirmed(&relevant_txids[0]);
                } else {
                        disconnect_all_blocks(&nodes[0]);
                }
                handle_announce_close_broadcast_events(&nodes, 0, 1, true, "Channel closed because of an exception: Funding transaction was un-confirmed. Locked at 6 confs, now have 0 confs.");
                check_added_monitors!(nodes[1], 1);
                {
                        let channel_state = nodes[0].node.channel_state.lock().unwrap();
                        assert_eq!(channel_state.by_id.len(), 0);
                        assert_eq!(channel_state.short_to_id.len(), 0);
                }
        }

        if reload_node {
                // Since we currently have a background event pending, it's good to test that we survive a
                // serialization roundtrip. Further, this tests the somewhat awkward edge-case of dropping
                // the Channel object from the ChannelManager, but still having a monitor event pending for
                // it when we go to deserialize, and then use the ChannelManager.
                let nodes_0_serialized = nodes[0].node.encode();
                let mut chan_0_monitor_serialized = test_utils::TestVecWriter(Vec::new());
                get_monitor!(nodes[0], chan.2).write(&mut chan_0_monitor_serialized).unwrap();

                persister = test_utils::TestPersister::new();
                let keys_manager = &chanmon_cfgs[0].keys_manager;
                new_chain_monitor = test_utils::TestChainMonitor::new(Some(nodes[0].chain_source), nodes[0].tx_broadcaster.clone(), nodes[0].logger, node_cfgs[0].fee_estimator, &persister, keys_manager);
                nodes[0].chain_monitor = &new_chain_monitor;
                let mut chan_0_monitor_read = &chan_0_monitor_serialized.0[..];
                let (_, mut chan_0_monitor) = <(BlockHash, ChannelMonitor<EnforcingSigner>)>::read(
                        &mut chan_0_monitor_read, keys_manager).unwrap();
                assert!(chan_0_monitor_read.is_empty());

                let mut nodes_0_read = &nodes_0_serialized[..];
                nodes_0_deserialized = {
                        let mut channel_monitors = HashMap::new();
                        channel_monitors.insert(chan_0_monitor.get_funding_txo().0, &mut chan_0_monitor);
                        <(BlockHash, ChannelManager<EnforcingSigner, &test_utils::TestChainMonitor, &test_utils::TestBroadcaster,
                          &test_utils::TestKeysInterface, &test_utils::TestFeeEstimator, &test_utils::TestLogger>)>::read(
                                &mut nodes_0_read, ChannelManagerReadArgs {
                                        default_config: *nodes[0].node.get_current_default_configuration(),
                                        keys_manager,
                                        fee_estimator: node_cfgs[0].fee_estimator,
                                        chain_monitor: nodes[0].chain_monitor,
                                        tx_broadcaster: nodes[0].tx_broadcaster.clone(),
                                        logger: nodes[0].logger,
                                        channel_monitors,
                        }).unwrap().1
                };
                nodes[0].node = &nodes_0_deserialized;
                assert!(nodes_0_read.is_empty());
                if !reorg_after_reload {
                        // If the channel is already closed when we reload the node, we'll broadcast a closing
                        // transaction via the ChannelMonitor which is missing a corresponding channel.
                        assert_eq!(nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().len(), 1);
                        nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().clear();
                }

                nodes[0].chain_monitor.watch_channel(chan_0_monitor.get_funding_txo().0.clone(), chan_0_monitor).unwrap();
                check_added_monitors!(nodes[0], 1);
        }

        if reorg_after_reload {
                if use_funding_unconfirmed {
                        let relevant_txids = nodes[0].node.get_relevant_txids();
                        assert_eq!(&relevant_txids[..], &[chan.3.txid()]);
                        nodes[0].node.transaction_unconfirmed(&relevant_txids[0]);
                } else {
                        disconnect_all_blocks(&nodes[0]);
                }
                handle_announce_close_broadcast_events(&nodes, 0, 1, true, "Channel closed because of an exception: Funding transaction was un-confirmed. Locked at 6 confs, now have 0 confs.");
                check_added_monitors!(nodes[1], 1);
                {
                        let channel_state = nodes[0].node.channel_state.lock().unwrap();
                        assert_eq!(channel_state.by_id.len(), 0);
                        assert_eq!(channel_state.short_to_id.len(), 0);
                }
        }
        // With expect_channel_force_closed set the TestChainMonitor will enforce that the next update
        // is a ChannelForcClosed on the right channel with should_broadcast set.
        *nodes[0].chain_monitor.expect_channel_force_closed.lock().unwrap() = Some((chan.2, true));
        nodes[0].node.test_process_background_events(); // Required to free the pending background monitor update
        check_added_monitors!(nodes[0], 1);
        let expected_err = "Funding transaction was un-confirmed. Locked at 6 confs, now have 0 confs.";
        check_closed_event!(nodes[1], 1, ClosureReason::CounterpartyForceClosed { peer_msg: "Channel closed because of an exception: ".to_owned() + expected_err });
        check_closed_event!(nodes[0], 1, ClosureReason::ProcessingError { err: expected_err.to_owned() });
        assert_eq!(nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().len(), 1);
        nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().clear();

        // Now check that we can create a new channel
        create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
        send_payment(&nodes[0], &[&nodes[1]], 8000000);
}

#[test]
fn test_unconf_chan() {
        do_test_unconf_chan(true, true, false, ConnectStyle::BestBlockFirstSkippingBlocks);
        do_test_unconf_chan(false, true, false, ConnectStyle::BestBlockFirstSkippingBlocks);
        do_test_unconf_chan(true, false, false, ConnectStyle::BestBlockFirstSkippingBlocks);
        do_test_unconf_chan(false, false, false, ConnectStyle::BestBlockFirstSkippingBlocks);
}

#[test]
fn test_unconf_chan_via_listen() {
        do_test_unconf_chan(true, true, false, ConnectStyle::FullBlockViaListen);
        do_test_unconf_chan(false, true, false, ConnectStyle::FullBlockViaListen);
        do_test_unconf_chan(true, false, false, ConnectStyle::FullBlockViaListen);
        do_test_unconf_chan(false, false, false, ConnectStyle::FullBlockViaListen);
}

#[test]
fn test_unconf_chan_via_funding_unconfirmed() {
        do_test_unconf_chan(true, true, true, ConnectStyle::BestBlockFirstSkippingBlocks);
        do_test_unconf_chan(false, true, true, ConnectStyle::BestBlockFirstSkippingBlocks);
        do_test_unconf_chan(true, false, true, ConnectStyle::BestBlockFirstSkippingBlocks);
        do_test_unconf_chan(false, false, true, ConnectStyle::BestBlockFirstSkippingBlocks);

        do_test_unconf_chan(true, true, true, ConnectStyle::FullBlockViaListen);
        do_test_unconf_chan(false, true, true, ConnectStyle::FullBlockViaListen);
        do_test_unconf_chan(true, false, true, ConnectStyle::FullBlockViaListen);
        do_test_unconf_chan(false, false, true, ConnectStyle::FullBlockViaListen);
}

#[test]
fn test_set_outpoints_partial_claiming() {
        // - remote party claim tx, new bump tx
        // - disconnect remote claiming tx, new bump
        // - disconnect tx, see no tx anymore
        let chanmon_cfgs = create_chanmon_cfgs(2);
        let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
        let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
        let nodes = create_network(2, &node_cfgs, &node_chanmgrs);

        let chan = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1000000, 59000000, InitFeatures::known(), InitFeatures::known());
        let payment_preimage_1 = route_payment(&nodes[1], &vec!(&nodes[0])[..], 3_000_000).0;
        let payment_preimage_2 = route_payment(&nodes[1], &vec!(&nodes[0])[..], 3_000_000).0;

        // Remote commitment txn with 4 outputs: to_local, to_remote, 2 outgoing HTLC
        let remote_txn = get_local_commitment_txn!(nodes[1], chan.2);
        assert_eq!(remote_txn.len(), 3);
        assert_eq!(remote_txn[0].output.len(), 4);
        assert_eq!(remote_txn[0].input.len(), 1);
        assert_eq!(remote_txn[0].input[0].previous_output.txid, chan.3.txid());
        check_spends!(remote_txn[1], remote_txn[0]);
        check_spends!(remote_txn[2], remote_txn[0]);

        // Connect blocks on node A to advance height towards TEST_FINAL_CLTV
        // Provide node A with both preimage
        nodes[0].node.claim_funds(payment_preimage_1);
        nodes[0].node.claim_funds(payment_preimage_2);
        check_added_monitors!(nodes[0], 2);
        nodes[0].node.get_and_clear_pending_events();
        nodes[0].node.get_and_clear_pending_msg_events();

        // Connect blocks on node A commitment transaction
        mine_transaction(&nodes[0], &remote_txn[0]);
        check_closed_broadcast!(nodes[0], true);
        check_closed_event!(nodes[0], 1, ClosureReason::CommitmentTxConfirmed);
        check_added_monitors!(nodes[0], 1);
        // Verify node A broadcast tx claiming both HTLCs
        {
                let mut node_txn = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap();
                // ChannelMonitor: claim tx, ChannelManager: local commitment tx + HTLC-Success*2
                assert_eq!(node_txn.len(), 4);
                check_spends!(node_txn[0], remote_txn[0]);
                check_spends!(node_txn[1], chan.3);
                check_spends!(node_txn[2], node_txn[1]);
                check_spends!(node_txn[3], node_txn[1]);
                assert_eq!(node_txn[0].input.len(), 2);
                node_txn.clear();
        }

        // Connect blocks on node B
        connect_blocks(&nodes[1], 135);
        check_closed_broadcast!(nodes[1], true);
        check_closed_event!(nodes[1], 1, ClosureReason::CommitmentTxConfirmed);
        check_added_monitors!(nodes[1], 1);
        // Verify node B broadcast 2 HTLC-timeout txn
        let partial_claim_tx = {
                let node_txn = nodes[1].tx_broadcaster.txn_broadcasted.lock().unwrap();
                assert_eq!(node_txn.len(), 3);
                check_spends!(node_txn[1], node_txn[0]);
                check_spends!(node_txn[2], node_txn[0]);
                assert_eq!(node_txn[1].input.len(), 1);
                assert_eq!(node_txn[2].input.len(), 1);
                node_txn[1].clone()
        };

        // Broadcast partial claim on node A, should regenerate a claiming tx with HTLC dropped
        mine_transaction(&nodes[0], &partial_claim_tx);
        {
                let mut node_txn = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap();
                assert_eq!(node_txn.len(), 1);
                check_spends!(node_txn[0], remote_txn[0]);
                assert_eq!(node_txn[0].input.len(), 1); //dropped HTLC
                node_txn.clear();
        }
        nodes[0].node.get_and_clear_pending_msg_events();

        // Disconnect last block on node A, should regenerate a claiming tx with HTLC dropped
        disconnect_blocks(&nodes[0], 1);
        {
                let mut node_txn = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap();
                assert_eq!(node_txn.len(), 1);
                check_spends!(node_txn[0], remote_txn[0]);
                assert_eq!(node_txn[0].input.len(), 2); //resurrected HTLC
                node_txn.clear();
        }

        //// Disconnect one more block and then reconnect multiple no transaction should be generated
        disconnect_blocks(&nodes[0], 1);
        connect_blocks(&nodes[0], 15);
        {
                let mut node_txn = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap();
                assert_eq!(node_txn.len(), 0);
                node_txn.clear();
        }
}

fn do_test_to_remote_after_local_detection(style: ConnectStyle) {
        // In previous code, detection of to_remote outputs in a counterparty commitment transaction
        // was dependent on whether a local commitment transaction had been seen on-chain previously.
        // This resulted in some edge cases around not being able to generate a SpendableOutput event
        // after a reorg.
        //
        // Here, we test this by first confirming one set of commitment transactions, then
        // disconnecting them and reconnecting another. We then confirm them and check that the correct
        // SpendableOutput event is generated.
        let chanmon_cfgs = create_chanmon_cfgs(2);
        let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
        let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
        let mut nodes = create_network(2, &node_cfgs, &node_chanmgrs);

        *nodes[0].connect_style.borrow_mut() = style;
        *nodes[1].connect_style.borrow_mut() = style;

        let (_, _, chan_id, funding_tx) =
                create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 100_000_000, InitFeatures::known(), InitFeatures::known());
        let funding_outpoint = OutPoint { txid: funding_tx.txid(), index: 0 };
        assert_eq!(funding_outpoint.to_channel_id(), chan_id);

        let remote_txn_a = get_local_commitment_txn!(nodes[0], chan_id);
        let remote_txn_b = get_local_commitment_txn!(nodes[1], chan_id);

        mine_transaction(&nodes[0], &remote_txn_a[0]);
        mine_transaction(&nodes[1], &remote_txn_a[0]);

        assert!(nodes[0].node.list_channels().is_empty());
        check_closed_broadcast!(nodes[0], true);
        check_added_monitors!(nodes[0], 1);
        check_closed_event!(nodes[0], 1, ClosureReason::CommitmentTxConfirmed);
        assert!(nodes[1].node.list_channels().is_empty());
        check_closed_broadcast!(nodes[1], true);
        check_added_monitors!(nodes[1], 1);
        check_closed_event!(nodes[1], 1, ClosureReason::CommitmentTxConfirmed);

        // Drop transactions broadcasted in response to the first commitment transaction (we have good
        // test coverage of these things already elsewhere).
        assert_eq!(nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().split_off(0).len(), 1);
        assert_eq!(nodes[1].tx_broadcaster.txn_broadcasted.lock().unwrap().split_off(0).len(), 1);

        assert!(nodes[0].chain_monitor.chain_monitor.get_and_clear_pending_events().is_empty());
        assert!(nodes[1].chain_monitor.chain_monitor.get_and_clear_pending_events().is_empty());

        disconnect_blocks(&nodes[0], 1);
        disconnect_blocks(&nodes[1], 1);

        assert!(nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().is_empty());
        assert!(nodes[1].tx_broadcaster.txn_broadcasted.lock().unwrap().is_empty());
        assert!(nodes[0].chain_monitor.chain_monitor.get_and_clear_pending_events().is_empty());
        assert!(nodes[1].chain_monitor.chain_monitor.get_and_clear_pending_events().is_empty());

        connect_blocks(&nodes[0], ANTI_REORG_DELAY - 1);
        connect_blocks(&nodes[1], ANTI_REORG_DELAY - 1);

        assert!(nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().is_empty());
        assert!(nodes[1].tx_broadcaster.txn_broadcasted.lock().unwrap().is_empty());
        assert!(nodes[0].chain_monitor.chain_monitor.get_and_clear_pending_events().is_empty());
        assert!(nodes[1].chain_monitor.chain_monitor.get_and_clear_pending_events().is_empty());

        mine_transaction(&nodes[0], &remote_txn_b[0]);
        mine_transaction(&nodes[1], &remote_txn_b[0]);

        assert!(nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().is_empty());
        assert!(nodes[1].tx_broadcaster.txn_broadcasted.lock().unwrap().is_empty());
        assert!(nodes[0].chain_monitor.chain_monitor.get_and_clear_pending_events().is_empty());
        assert!(nodes[1].chain_monitor.chain_monitor.get_and_clear_pending_events().is_empty());

        connect_blocks(&nodes[0], ANTI_REORG_DELAY - 1);
        connect_blocks(&nodes[1], ANTI_REORG_DELAY - 1);

        let mut node_a_spendable = nodes[0].chain_monitor.chain_monitor.get_and_clear_pending_events();
        assert_eq!(node_a_spendable.len(), 1);
        if let Event::SpendableOutputs { outputs } = node_a_spendable.pop().unwrap() {
                assert_eq!(outputs.len(), 1);
                let spend_tx = nodes[0].keys_manager.backing.spend_spendable_outputs(&[&outputs[0]], Vec::new(),
                        Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script(), 253, &Secp256k1::new()).unwrap();
                check_spends!(spend_tx, remote_txn_b[0]);
        }

        // nodes[1] is waiting for the to_self_delay to expire, which is many more than
        // ANTI_REORG_DELAY. Instead, walk it back and confirm the original remote_txn_a commitment
        // again and check that nodes[1] generates a similar spendable output.
        // Technically a reorg of ANTI_REORG_DELAY violates our assumptions, so this is undefined by
        // our API spec, but we currently handle this correctly and there's little reason we shouldn't
        // in the future.
        assert!(nodes[1].chain_monitor.chain_monitor.get_and_clear_pending_events().is_empty());
        disconnect_blocks(&nodes[1], ANTI_REORG_DELAY);
        mine_transaction(&nodes[1], &remote_txn_a[0]);
        connect_blocks(&nodes[1], ANTI_REORG_DELAY - 1);

        let mut node_b_spendable = nodes[1].chain_monitor.chain_monitor.get_and_clear_pending_events();
        assert_eq!(node_b_spendable.len(), 1);
        if let Event::SpendableOutputs { outputs } = node_b_spendable.pop().unwrap() {
                assert_eq!(outputs.len(), 1);
                let spend_tx = nodes[1].keys_manager.backing.spend_spendable_outputs(&[&outputs[0]], Vec::new(),
                        Builder::new().push_opcode(opcodes::all::OP_RETURN).into_script(), 253, &Secp256k1::new()).unwrap();
                check_spends!(spend_tx, remote_txn_a[0]);
        }
}

#[test]
fn test_to_remote_after_local_detection() {
        do_test_to_remote_after_local_detection(ConnectStyle::BestBlockFirst);
        do_test_to_remote_after_local_detection(ConnectStyle::BestBlockFirstSkippingBlocks);
        do_test_to_remote_after_local_detection(ConnectStyle::TransactionsFirst);
        do_test_to_remote_after_local_detection(ConnectStyle::TransactionsFirstSkippingBlocks);
        do_test_to_remote_after_local_detection(ConnectStyle::FullBlockViaListen);
}