Watch all outputs irrespective of claimable outpoints.

This removes dependency of watched_outputs from
per_commitment_claimable_outpoints, it is required since we will
no longer have direct access to per_commitment_claimable_outpoints
once we start publishing PersistClaimInfo as part of #3049.

Author: G8XSU

lightning/src/chain/channelmonitor.rs

@@ -3232,16 +3232,14 @@ impl<Signer: EcdsaChannelSigner> ChannelMonitorImpl<Signer> {
 	/// height > height + CLTV_SHARED_CLAIM_BUFFER. In any case, will install monitoring for
 	/// HTLC-Success/HTLC-Timeout transactions.
 	///
-	/// Returns packages to claim the revoked output(s), as well as additional outputs to watch and
-	/// general information about the output that is to the counterparty in the commitment
-	/// transaction.
+	/// Returns packages to claim the revoked output(s) and general information about the output that
+	/// is to the counterparty in the commitment transaction.
 	fn check_spend_counterparty_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, block_hash: &BlockHash, logger: &L)
-		-> (Vec<PackageTemplate>, TransactionOutputs, CommitmentTxCounterpartyOutputInfo)
+		-> (Vec<PackageTemplate>, CommitmentTxCounterpartyOutputInfo)
 	where L::Target: Logger {
 		// Most secp and related errors trying to create keys means we have no hope of constructing
 		// a spend transaction...so we return no transactions to broadcast
 		let mut claimable_outpoints = Vec::new();
-		let mut watch_outputs = Vec::new();
 		let mut to_counterparty_output_info = None;
 
 		let commitment_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
@@ -3251,7 +3249,7 @@ impl<Signer: EcdsaChannelSigner> ChannelMonitorImpl<Signer> {
 			( $thing : expr ) => {
 				match $thing {
 					Ok(a) => a,
-					Err(_) => return (claimable_outpoints, (commitment_txid, watch_outputs), to_counterparty_output_info)
+					Err(_) => return (claimable_outpoints, to_counterparty_output_info)
 				}
 			};
 		}
@@ -3285,8 +3283,7 @@ impl<Signer: EcdsaChannelSigner> ChannelMonitorImpl<Signer> {
 						if transaction_output_index as usize >= tx.output.len() ||
 								tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
 							// per_commitment_data is corrupt or our commitment signing key leaked!
-							return (claimable_outpoints, (commitment_txid, watch_outputs),
-								to_counterparty_output_info);
+							return (claimable_outpoints, to_counterparty_output_info);
 						}
 						let revk_htlc_outp = RevokedHTLCOutput::build(per_commitment_point, self.counterparty_commitment_params.counterparty_delayed_payment_base_key, self.counterparty_commitment_params.counterparty_htlc_base_key, per_commitment_key, htlc.amount_msat / 1000, htlc.clone(), &self.onchain_tx_handler.channel_transaction_parameters.channel_type_features);
 						let justice_package = PackageTemplate::build_package(commitment_txid, transaction_output_index, PackageSolvingData::RevokedHTLCOutput(revk_htlc_outp), htlc.cltv_expiry, height);
@@ -3299,9 +3296,6 @@ impl<Signer: EcdsaChannelSigner> ChannelMonitorImpl<Signer> {
 			if !claimable_outpoints.is_empty() || per_commitment_option.is_some() { // ie we're confident this is actually ours
 				// We're definitely a counterparty commitment transaction!
 				log_error!(logger, "Got broadcast of revoked counterparty commitment transaction, going to generate general spend tx with {} inputs", claimable_outpoints.len());
-				for (idx, outp) in tx.output.iter().enumerate() {
-					watch_outputs.push((idx as u32, outp.clone()));
-				}
 				self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
 
 				if let Some(per_commitment_claimable_data) = per_commitment_option {
@@ -3327,9 +3321,6 @@ impl<Signer: EcdsaChannelSigner> ChannelMonitorImpl<Signer> {
 			// already processed the block, resulting in the counterparty_commitment_txn_on_chain entry
 			// not being generated by the above conditional. Thus, to be safe, we go ahead and
 			// insert it here.
-			for (idx, outp) in tx.output.iter().enumerate() {
-				watch_outputs.push((idx as u32, outp.clone()));
-			}
 			self.counterparty_commitment_txn_on_chain.insert(commitment_txid, commitment_number);
 
 			log_info!(logger, "Got broadcast of non-revoked counterparty commitment transaction {}", commitment_txid);
@@ -3345,7 +3336,7 @@ impl<Signer: EcdsaChannelSigner> ChannelMonitorImpl<Signer> {
 			}
 
 		}
-		(claimable_outpoints, (commitment_txid, watch_outputs), to_counterparty_output_info)
+		(claimable_outpoints, to_counterparty_output_info)
 	}
 
 	/// Returns the HTLC claim package templates and the counterparty output info
@@ -3777,24 +3768,25 @@ impl<Signer: EcdsaChannelSigner> ChannelMonitorImpl<Signer> {
 					self.funding_spend_seen = true;
 					let mut commitment_tx_to_counterparty_output = None;
 					if (tx.input[0].sequence.0 >> 8*3) as u8 == 0x80 && (tx.lock_time.to_consensus_u32() >> 8*3) as u8 == 0x20 {
-						let (mut new_outpoints, new_outputs, counterparty_output_idx_sats) =
-							self.check_spend_counterparty_transaction(&tx, height, &block_hash, &logger);
-						commitment_tx_to_counterparty_output = counterparty_output_idx_sats;
-						if !new_outputs.1.is_empty() {
-							watch_outputs.push(new_outputs);
-						}
-						claimable_outpoints.append(&mut new_outpoints);
-						if new_outpoints.is_empty() {
-							if let Some((mut new_outpoints, new_outputs)) = self.check_spend_holder_transaction(&tx, height, &block_hash, &logger) {
-								#[cfg(not(fuzzing))]
-								debug_assert!(commitment_tx_to_counterparty_output.is_none(),
-									"A commitment transaction matched as both a counterparty and local commitment tx?");
-								if !new_outputs.1.is_empty() {
-									watch_outputs.push(new_outputs);
-								}
-								claimable_outpoints.append(&mut new_outpoints);
-								balance_spendable_csv = Some(self.on_holder_tx_csv);
+						if let Some((mut new_outpoints, new_outputs)) = self.check_spend_holder_transaction(&tx, height, &block_hash, &logger) {
+							if !new_outputs.1.is_empty() {
+								watch_outputs.push(new_outputs);
+							}
+
+							claimable_outpoints.append(&mut new_outpoints);
+							balance_spendable_csv = Some(self.on_holder_tx_csv);
+						} else {
+							let mut new_watch_outputs = Vec::new();
+							for (idx, outp) in tx.output.iter().enumerate() {
+								new_watch_outputs.push((idx as u32, outp.clone()));
 							}
+							watch_outputs.push((txid, new_watch_outputs));
+
+							let (mut new_outpoints, counterparty_output_idx_sats) =
+								self.check_spend_counterparty_transaction(&tx, height, &block_hash, &logger);
+							commitment_tx_to_counterparty_output = counterparty_output_idx_sats;
+
+							claimable_outpoints.append(&mut new_outpoints);
 						}
 					}
 					self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {