Expose the amount of funds available for claim in ChannelMonitor

In general, we should always allow users to query for how much is
currently in-flight being claimed on-chain at any time.

This does so by examining the confirmed claims on-chain and
breaking down what is left to be claimed into a new
`ClaimableBalance` enum.

Fixes #995.

Author: TheBlueMatt

lightning/src/chain/channelmonitor.rs

@@ -504,6 +504,56 @@ impl_writeable_tlv_based_enum_upgradable!(ChannelMonitorUpdateStep,
 	},
 );
 
+/// Details about the balance available for claim once the channel appears on chain.
+#[derive(Clone, Debug, PartialEq, Eq)]
+#[cfg_attr(test, derive(PartialOrd, Ord))]
+pub enum ClaimableBalance {
+	/// The channel is not yet closed (or the initial commitment or closing transaction has not yet
+	/// been confirmed). The given balance is claimable (less on-chain fees) if the channel is
+	/// force-closed now.
+	ClaimableOnChannelClose {
+		/// The amount available to claim, in satoshis, ignoring the on-chain fees which will be
+		/// required to do so.
+		claimable_amount_satoshis: u64,
+	},
+	/// The channel has been closed, and the given balance is ours but awaiting confirmations until
+	/// we consider it spendable.
+	ClaimableAwaitingConfirmations {
+		/// The amount available to claim, in satoshis, possibly ignoring the on-chain fees which
+		/// were spent in broadcasting the transaction.
+		claimable_amount_satoshis: u64,
+		/// The height at which an [`Event::SpendableOutputs`] event will be generated for this
+		/// amount.
+		confirmation_height: u32,
+	},
+	/// The channel has been closed, and the given balance should be ours but awaiting spending
+	/// transaction confirmation. If the spending transaction does not confirm in time, it is
+	/// possible our counterparty can take the funds by broadcasting an HTLC timeout on-chain.
+	///
+	/// Once the spending transaction confirms, before it has reached enough confirmations to be
+	/// considered safe from chain reorganizations, the balance will instead be provided via
+	/// [`ClaimableBalance::ClaimableAwaitingConfirmations`].
+	ContentiousClaimable {
+		/// The amount available to claim, in satoshis, ignoring the on-chain fees which will be
+		/// required to do so.
+		claimable_amount_satoshis: u64,
+		/// The height at which the counterparty may be able to claim the balance if we have not
+		/// done so.
+		timeout_height: u32,
+	},
+	/// HTLCs which we sent to our counterparty which are claimable after a timeout (less on-chain
+	/// fees) if the counterparty does not know the preimage for the HTLCs. These are somewhat
+	/// likely to be claimed by our counterparty before we do.
+	PossiblyClaimableHTLCAwaitingTimeout {
+		/// The amount available to claim, in satoshis, ignoring the on-chain fees which will be
+		/// required to do so.
+		claimable_amount_satoshis: u64,
+		/// The height at which we will be able to claim the balance if our counterparty has not
+		/// done so.
+		claimable_height: u32,
+	},
+}
+
 /// An HTLC which has been irrevocably resolved on-chain, and has reached ANTI_REORG_DELAY.
 #[derive(PartialEq)]
 struct HTLCIrrevocablyResolved {
@@ -1266,6 +1316,107 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
 	pub fn current_best_block(&self) -> BestBlock {
 		self.inner.lock().unwrap().best_block.clone()
 	}
+
+	/// Gets the balances in this channel which are either claimable by us if we were to
+	/// force-close the channel now or which are claimable on-chain or claims which are awaiting
+	/// confirmation.
+	///
+	/// Any balances in the channel which are available on-chain (ignoring on-chain fees) are
+	/// included here until an [`Event::SpendableOutputs`] event has been generated for the
+	/// balance, or until our counterparty has claimed the balance and accrued several
+	/// confirmations on the claim transaction.
+	///
+	/// See [`ClaimableBalance`] for additional details on the types of claimable balances which
+	/// may be returned here and their meanings.
+	pub fn get_claimable_balances(&self) -> Vec<ClaimableBalance> {
+		let mut res = Vec::new();
+		let us = self.inner.lock().unwrap();
+
+		let mut confirmed_txid = us.funding_spend_confirmed;
+		if let Some((txid, conf_thresh)) = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
+			if let OnchainEvent::FundingSpendConfirmation { txid, .. } = event.event {
+				Some((txid, event.confirmation_threshold()))
+			} else { None }
+		}) {
+			debug_assert!(us.funding_spend_confirmed.is_none(), "We have a pending funding spend awaiting confirmation, we can't have confirmed it already!");
+			confirmed_txid = Some(txid);
+			res.push(ClaimableBalance::ClaimableAwaitingConfirmations {
+				claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat,
+				confirmation_height: conf_thresh,
+			});
+		}
+
+		macro_rules! walk_htlcs {
+			($holder_commitment: expr, $htlc_iter: expr) => {
+				for htlc in $htlc_iter {
+					if let Some(htlc_input_idx) = htlc.transaction_output_index {
+						if us.htlcs_resolved_on_chain.iter().any(|v| v.input_idx == htlc_input_idx) {
+								assert!(us.funding_spend_confirmed.is_some());
+						} else if htlc.offered == $holder_commitment {
+							res.push(ClaimableBalance::PossiblyClaimableHTLCAwaitingTimeout {
+								claimable_amount_satoshis: htlc.amount_msat / 1000,
+								claimable_height: htlc.cltv_expiry,
+							});
+						} else {
+							if us.payment_preimages.get(&htlc.payment_hash).is_some() {
+								if let Some(conf_thresh) = us.onchain_events_awaiting_threshold_conf.iter().find_map(|event| {
+									if let OnchainEvent::HTLCSpendConfirmation { input_idx, .. } = event.event {
+										if input_idx == htlc_input_idx { Some(event.confirmation_threshold()) } else { None }
+									} else { None }
+								}) {
+									res.push(ClaimableBalance::ClaimableAwaitingConfirmations {
+										claimable_amount_satoshis: htlc.amount_msat / 1000,
+										confirmation_height: conf_thresh,
+									});
+								} else {
+									res.push(ClaimableBalance::ContentiousClaimable {
+										claimable_amount_satoshis: htlc.amount_msat / 1000,
+										timeout_height: htlc.cltv_expiry,
+									});
+								}
+							}
+						}
+					}
+				}
+			}
+		}
+
+		if let Some(txid) = confirmed_txid {
+			if Some(txid) == us.current_counterparty_commitment_txid || Some(txid) == us.prev_counterparty_commitment_txid {
+				walk_htlcs!(false, us.counterparty_claimable_outpoints.get(&txid).unwrap().iter().map(|(a, _)| a));
+			} else if txid == us.current_holder_commitment_tx.txid {
+				walk_htlcs!(true, us.current_holder_commitment_tx.htlc_outputs.iter().map(|(a, _, _)| a));
+			} else if let Some(prev_commitment) = &us.prev_holder_signed_commitment_tx {
+				if txid == prev_commitment.txid {
+					walk_htlcs!(true, prev_commitment.htlc_outputs.iter().map(|(a, _, _)| a));
+				}
+			}
+			// TODO: Add logic to provide claimable balances for counterparty broadcasting revoked
+			// outputs.
+			// Otherwise assume we closed with a cooperative close which only needs the
+			// `ClaimableAwaitingConfirmations` balance pushed first.
+		} else {
+			let mut claimable_inbound_htlc_value_sat = 0;
+			for (htlc, _, _) in us.current_holder_commitment_tx.htlc_outputs.iter() {
+				if htlc.transaction_output_index.is_none() { continue; }
+				if htlc.offered {
+					res.push(ClaimableBalance::PossiblyClaimableHTLCAwaitingTimeout {
+						claimable_amount_satoshis: htlc.amount_msat / 1000,
+						claimable_height: htlc.cltv_expiry,
+					});
+				} else {
+					if us.payment_preimages.get(&htlc.payment_hash).is_some() {
+						claimable_inbound_htlc_value_sat += htlc.amount_msat / 1000;
+					}
+				}
+			}
+			res.push(ClaimableBalance::ClaimableOnChannelClose {
+				claimable_amount_satoshis: us.current_holder_commitment_tx.to_self_value_sat + claimable_inbound_htlc_value_sat,
+			});
+		}
+
+		res
+	}
 }
 
 /// Compares a broadcasted commitment transaction's HTLCs with those in the latest state,

lightning/src/ln/monitor_tests.rs

@@ -9,8 +9,10 @@
 
 //! Further functional tests which test blockchain reorganizations.
 
-use chain::channelmonitor::ANTI_REORG_DELAY;
-use ln::{PaymentPreimage, PaymentHash};
+use chain::channelmonitor::{ANTI_REORG_DELAY, ClaimableBalance};
+use chain::transaction::OutPoint;
+use ln::{channel, PaymentPreimage, PaymentHash};
+use ln::channelmanager::BREAKDOWN_TIMEOUT;
 use ln::features::InitFeatures;
 use ln::msgs::{ChannelMessageHandler, HTLCFailChannelUpdate, ErrorAction};
 use util::events::{Event, MessageSendEvent, MessageSendEventsProvider};
@@ -19,6 +21,10 @@ use routing::router::get_route;
 use bitcoin::hashes::sha256::Hash as Sha256;
 use bitcoin::hashes::Hash;
 
+use bitcoin::blockdata::script::Builder;
+use bitcoin::blockdata::opcodes;
+use bitcoin::secp256k1::Secp256k1;
+
 use prelude::*;
 
 use ln::functional_test_utils::*;
@@ -79,3 +85,292 @@ fn chanmon_fail_from_stale_commitment() {
 	expect_payment_failed!(nodes[0], payment_hash, false);
 	expect_payment_failure_chan_update!(nodes[0], update_a.contents.short_channel_id, true);
 }
+
+#[test]
+fn chanmon_claim_value_coop_close() {
+	// Tests `get_claimable_balances` returns the correct values across a simple cooperative claim.
+	// Specifically, this tests that the channel non-HTLC balances show up in
+	// `get_claimable_balances` until the cooperative claims have confirmed and generated a
+	// `SpendableOutputs` event, and no longer.
+	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_id, funding_tx) =
+		create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 1_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 chan_feerate = get_feerate!(nodes[0], chan_id) as u64;
+
+	assert_eq!(vec![ClaimableBalance::ClaimableOnChannelClose {
+			claimable_amount_satoshis: 1_000_000 - 1_000 - chan_feerate * channel::COMMITMENT_TX_BASE_WEIGHT / 1000
+		}],
+		nodes[0].chain_monitor.chain_monitor.monitors.read().unwrap().get(&funding_outpoint).unwrap().get_claimable_balances());
+	assert_eq!(vec![ClaimableBalance::ClaimableOnChannelClose { claimable_amount_satoshis: 1_000, }],
+		nodes[1].chain_monitor.chain_monitor.monitors.read().unwrap().get(&funding_outpoint).unwrap().get_claimable_balances());
+
+	nodes[0].node.close_channel(&chan_id).unwrap();
+	let node_0_shutdown = get_event_msg!(nodes[0], MessageSendEvent::SendShutdown, nodes[1].node.get_our_node_id());
+	nodes[1].node.handle_shutdown(&nodes[0].node.get_our_node_id(), &InitFeatures::known(), &node_0_shutdown);
+	let node_1_shutdown = get_event_msg!(nodes[1], MessageSendEvent::SendShutdown, nodes[0].node.get_our_node_id());
+	nodes[0].node.handle_shutdown(&nodes[1].node.get_our_node_id(), &InitFeatures::known(), &node_1_shutdown);
+
+	let node_0_closing_signed = get_event_msg!(nodes[0], MessageSendEvent::SendClosingSigned, nodes[1].node.get_our_node_id());
+	nodes[1].node.handle_closing_signed(&nodes[0].node.get_our_node_id(), &node_0_closing_signed);
+	let (_, node_1_closing_signed) = get_closing_signed_broadcast!(nodes[1].node, nodes[0].node.get_our_node_id());
+	nodes[0].node.handle_closing_signed(&nodes[1].node.get_our_node_id(), &node_1_closing_signed.unwrap());
+	let (_, node_0_none) = get_closing_signed_broadcast!(nodes[0].node, nodes[1].node.get_our_node_id());
+	assert!(node_0_none.is_none());
+
+	let shutdown_tx = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
+	assert_eq!(shutdown_tx, nodes[1].tx_broadcaster.txn_broadcasted.lock().unwrap().split_off(0));
+	assert_eq!(shutdown_tx.len(), 1);
+
+	mine_transaction(&nodes[0], &shutdown_tx[0]);
+	mine_transaction(&nodes[1], &shutdown_tx[0]);
+
+	assert!(nodes[0].node.list_channels().is_empty());
+	assert!(nodes[1].node.list_channels().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());
+
+	assert_eq!(vec![ClaimableBalance::ClaimableAwaitingConfirmations {
+			claimable_amount_satoshis: 1_000_000 - 1_000 - chan_feerate * channel::COMMITMENT_TX_BASE_WEIGHT / 1000,
+			confirmation_height: nodes[0].best_block_info().1 + ANTI_REORG_DELAY - 1,
+		}],
+		nodes[0].chain_monitor.chain_monitor.monitors.read().unwrap().get(&funding_outpoint).unwrap().get_claimable_balances());
+	assert_eq!(vec![ClaimableBalance::ClaimableAwaitingConfirmations {
+			claimable_amount_satoshis: 1000,
+			confirmation_height: nodes[1].best_block_info().1 + ANTI_REORG_DELAY - 1,
+		}],
+		nodes[1].chain_monitor.chain_monitor.monitors.read().unwrap().get(&funding_outpoint).unwrap().get_claimable_balances());
+
+	connect_blocks(&nodes[0], ANTI_REORG_DELAY - 1);
+	connect_blocks(&nodes[1], ANTI_REORG_DELAY - 1);
+
+	assert_eq!(Vec::<ClaimableBalance>::new(),
+		nodes[0].chain_monitor.chain_monitor.monitors.read().unwrap().get(&funding_outpoint).unwrap().get_claimable_balances());
+	assert_eq!(Vec::<ClaimableBalance>::new(),
+		nodes[1].chain_monitor.chain_monitor.monitors.read().unwrap().get(&funding_outpoint).unwrap().get_claimable_balances());
+
+	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, shutdown_tx[0]);
+	}
+
+	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, shutdown_tx[0]);
+	}
+}
+
+fn sorted_vec<T: Ord>(mut v: Vec<T>) -> Vec<T> {
+	v.sort_unstable();
+	v
+}
+
+#[test]
+fn test_claim_value_force_close() {
+	// Tests `get_claimable_balances` with an HTLC across a force-close.
+	// We build a channel with an HTLC pending, then force close the channel and check that the
+	// `get_claimable_balances` return value is correct as transactions confirm on-chain.
+	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_id, funding_tx) =
+		create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 1_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 payment_preimage = route_payment(&nodes[0], &[&nodes[1]], 3_000_000).0;
+	// This HTLC will be dust, and not be claimable at all:
+	let (dust_payment_preimage, dust_payment_hash, _) = route_payment(&nodes[0], &[&nodes[1]], 3_000);
+
+	let htlc_cltv_timeout = nodes[0].best_block_info().1 + TEST_FINAL_CLTV + 1; // Note ChannelManager adds one to CLTV timeouts for safety
+
+	let chan_feerate = get_feerate!(nodes[0], chan_id) as u64;
+
+	let remote_txn = get_local_commitment_txn!(nodes[1], chan_id);
+	// Before B receives the payment preimage, it only suggests the push_msat value of 1_000 sats
+	// as claimable. A lists both its to-self balance and the (possibly-claimable) HTLC.
+	assert_eq!(sorted_vec(vec![ClaimableBalance::ClaimableOnChannelClose {
+			claimable_amount_satoshis: 1_000_000 - 3_000 - 1_000 - 3 - chan_feerate *
+				(channel::COMMITMENT_TX_BASE_WEIGHT + channel::COMMITMENT_TX_WEIGHT_PER_HTLC) / 1000,
+		}, ClaimableBalance::PossiblyClaimableHTLCAwaitingTimeout {
+			claimable_amount_satoshis: 3_000,
+			claimable_height: htlc_cltv_timeout,
+		}]),
+		sorted_vec(nodes[0].chain_monitor.chain_monitor.monitors.read().unwrap().get(&funding_outpoint).unwrap().get_claimable_balances()));
+	assert_eq!(vec![ClaimableBalance::ClaimableOnChannelClose {
+			claimable_amount_satoshis: 1_000,
+		}],
+		nodes[1].chain_monitor.chain_monitor.monitors.read().unwrap().get(&funding_outpoint).unwrap().get_claimable_balances());
+
+	nodes[1].node.claim_funds(payment_preimage);
+	check_added_monitors!(nodes[1], 1);
+	get_htlc_update_msgs!(&nodes[1], nodes[0].node.get_our_node_id());
+	// We claim the dust payment here as well, but it won't impact our claimable balances as its
+	// dust and thus doesn't appear on chain at all.
+	nodes[1].node.claim_funds(dust_payment_preimage);
+	check_added_monitors!(nodes[1], 1);
+
+	// Once B has received the payment preimage, it includes the value of the HTLC in its
+	// "claimable if you were to close the channel" balance.
+	assert_eq!(sorted_vec(vec![ClaimableBalance::ClaimableOnChannelClose {
+			claimable_amount_satoshis: 1_000_000 - // Channel funding value in satoshis
+				3_000 - // The larger HTLC value in satoshis
+				1_000 - // The push_msat value in satoshis
+				3 - // The dust HTLC value in satoshis
+				// The commitment transaction fee with one HTLC output:
+				chan_feerate * (channel::COMMITMENT_TX_BASE_WEIGHT + channel::COMMITMENT_TX_WEIGHT_PER_HTLC) / 1000,
+		}, ClaimableBalance::PossiblyClaimableHTLCAwaitingTimeout {
+			claimable_amount_satoshis: 3_000,
+			claimable_height: htlc_cltv_timeout,
+		}]),
+		sorted_vec(nodes[0].chain_monitor.chain_monitor.monitors.read().unwrap().get(&funding_outpoint).unwrap().get_claimable_balances()));
+	assert_eq!(vec![ClaimableBalance::ClaimableOnChannelClose {
+			claimable_amount_satoshis: 1_000 + 3_000,
+		}],
+		nodes[1].chain_monitor.chain_monitor.monitors.read().unwrap().get(&funding_outpoint).unwrap().get_claimable_balances());
+
+	// Broadcast the closing transaction (which has the pending HTLC in it) and get B's broadcasted
+	// HTLC claim transaction with preimage.
+	let node_b_commitment_claimable = nodes[1].best_block_info().1 + BREAKDOWN_TIMEOUT as u32;
+	mine_transaction(&nodes[0], &remote_txn[0]);
+	mine_transaction(&nodes[1], &remote_txn[0]);
+
+	let b_broadcast_txn = nodes[1].tx_broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
+	assert_eq!(b_broadcast_txn.len(), 3);
+	assert_eq!(b_broadcast_txn[0], b_broadcast_txn[2]);
+	// b_broadcast_txn[0] should spend the HTLC output of the commitment tx for 3_000 sats
+	check_spends!(b_broadcast_txn[0], remote_txn[0]);
+	assert_eq!(b_broadcast_txn[0].input.len(), 1);
+	assert_eq!(remote_txn[0].output[b_broadcast_txn[0].input[0].previous_output.vout as usize].value, 3_000);
+	check_spends!(b_broadcast_txn[1], funding_tx);
+
+	assert!(nodes[0].node.list_channels().is_empty());
+	check_closed_broadcast!(nodes[0], true);
+	check_added_monitors!(nodes[0], 1);
+	assert!(nodes[1].node.list_channels().is_empty());
+	check_closed_broadcast!(nodes[1], true);
+	check_added_monitors!(nodes[1], 1);
+	assert!(nodes[0].node.get_and_clear_pending_events().is_empty());
+	assert!(nodes[1].node.get_and_clear_pending_events().is_empty());
+
+	// Once the commitment transaction confirms, we will wait until ANTI_REORG_DELAY until we
+	// generate any `SpendableOutputs` events. Thus, the same balances will still be listed
+	// available in `get_claimable_balances`. However, both will swap from `ClaimableOnClose` to
+	// other ClaimableBalance variants, as close has already happened.
+	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());
+
+	assert_eq!(sorted_vec(vec![ClaimableBalance::ClaimableAwaitingConfirmations {
+			claimable_amount_satoshis: 1_000_000 - 3_000 - 1_000 - 3 - chan_feerate *
+				(channel::COMMITMENT_TX_BASE_WEIGHT + channel::COMMITMENT_TX_WEIGHT_PER_HTLC) / 1000,
+			confirmation_height: nodes[0].best_block_info().1 + ANTI_REORG_DELAY - 1,
+		}, ClaimableBalance::PossiblyClaimableHTLCAwaitingTimeout {
+			claimable_amount_satoshis: 3_000,
+			claimable_height: htlc_cltv_timeout,
+		}]),
+		sorted_vec(nodes[0].chain_monitor.chain_monitor.monitors.read().unwrap().get(&funding_outpoint).unwrap().get_claimable_balances()));
+	// The main non-HTLC balance is just awaiting confirmations, but the claimable height is the
+	// CSV delay, not ANTI_REORG_DELAY.
+	assert_eq!(sorted_vec(vec![ClaimableBalance::ClaimableAwaitingConfirmations {
+			claimable_amount_satoshis: 1_000,
+			confirmation_height: node_b_commitment_claimable,
+		},
+		// The HTLC balance is "contentious" as our counterparty could claim it if we wait too
+		// long.
+		ClaimableBalance::ContentiousClaimable {
+			claimable_amount_satoshis: 3_000,
+			timeout_height: htlc_cltv_timeout,
+		}]),
+		sorted_vec(nodes[1].chain_monitor.chain_monitor.monitors.read().unwrap().get(&funding_outpoint).unwrap().get_claimable_balances()));
+
+	connect_blocks(&nodes[0], ANTI_REORG_DELAY - 1);
+	expect_payment_failed!(nodes[0], dust_payment_hash, true);
+	connect_blocks(&nodes[1], ANTI_REORG_DELAY - 1);
+
+	// After ANTI_REORG_DELAY, A will consider its balance fully spendable and generate a
+	// `SpendableOutputs` event. However, B still has to wait for the CSV delay.
+	assert_eq!(vec![ClaimableBalance::PossiblyClaimableHTLCAwaitingTimeout {
+			claimable_amount_satoshis: 3_000,
+			claimable_height: htlc_cltv_timeout,
+		}],
+		nodes[0].chain_monitor.chain_monitor.monitors.read().unwrap().get(&funding_outpoint).unwrap().get_claimable_balances());
+	assert_eq!(sorted_vec(vec![ClaimableBalance::ClaimableAwaitingConfirmations {
+			claimable_amount_satoshis: 1_000,
+			confirmation_height: node_b_commitment_claimable,
+		}, ClaimableBalance::ContentiousClaimable {
+			claimable_amount_satoshis: 3_000,
+			timeout_height: htlc_cltv_timeout,
+		}]),
+		sorted_vec(nodes[1].chain_monitor.chain_monitor.monitors.read().unwrap().get(&funding_outpoint).unwrap().get_claimable_balances()));
+
+	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[0]);
+	}
+
+	assert!(nodes[1].chain_monitor.chain_monitor.get_and_clear_pending_events().is_empty());
+
+	// After broadcasting the HTLC claim transaction, node A will still consider the HTLC
+	// possibly-claimable up to ANTI_REORG_DELAY, at which point it will drop it.
+	mine_transaction(&nodes[0], &b_broadcast_txn[0]);
+	expect_payment_sent!(nodes[0], payment_preimage);
+	assert_eq!(vec![ClaimableBalance::PossiblyClaimableHTLCAwaitingTimeout {
+			claimable_amount_satoshis: 3_000,
+			claimable_height: htlc_cltv_timeout,
+		}],
+		nodes[0].chain_monitor.chain_monitor.monitors.read().unwrap().get(&funding_outpoint).unwrap().get_claimable_balances());
+	connect_blocks(&nodes[0], ANTI_REORG_DELAY - 1);
+	assert_eq!(Vec::<ClaimableBalance>::new(),
+		nodes[0].chain_monitor.chain_monitor.monitors.read().unwrap().get(&funding_outpoint).unwrap().get_claimable_balances());
+
+	// Node B will no longer consider the HTLC "contentious" after the HTLC claim transaction
+	// confirms, and consider it simply "awaiting confirmations".
+	mine_transaction(&nodes[1], &b_broadcast_txn[0]);
+	assert_eq!(sorted_vec(vec![ClaimableBalance::ClaimableAwaitingConfirmations {
+			claimable_amount_satoshis: 1_000,
+			confirmation_height: node_b_commitment_claimable,
+		}, ClaimableBalance::ClaimableAwaitingConfirmations {
+			claimable_amount_satoshis: 3_000,
+			confirmation_height: nodes[1].best_block_info().1 + ANTI_REORG_DELAY - 1,
+		}]),
+		sorted_vec(nodes[1].chain_monitor.chain_monitor.monitors.read().unwrap().get(&funding_outpoint).unwrap().get_claimable_balances()));
+
+	// Finally, after ANTI_REORG_DELAY confirmations on the HTLC transaction, plus reaching the
+	// commitment output CSV, we'll get a SpendableOutputs event for both and have no further
+	// claimable balance for node B.
+	connect_blocks(&nodes[1], BREAKDOWN_TIMEOUT as u32 - ANTI_REORG_DELAY - 1);
+	assert_eq!(nodes[1].best_block_info().1, node_b_commitment_claimable);
+
+	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[0]);
+	}
+
+	assert_eq!(Vec::<ClaimableBalance>::new(),
+		nodes[1].chain_monitor.chain_monitor.monitors.read().unwrap().get(&funding_outpoint).unwrap().get_claimable_balances());
+}