Track the txid that resolves HTLCs even after resolution completes

We need this information when we look up if we still need to spend
a revoked output from an HTLC-Success/HTLC-Timeout transaction for
balance calculation.

diff --git a/lightning/src/chain/channelmonitor.rs b/lightning/src/chain/channelmonitor.rs
index 0d1c458bc2d9d2ae6c91497587d35ac26a27aff4..377657d6bca0ad974c87ee7d939710ea94a00a1d 100644 (file)
--- a/lightning/src/chain/channelmonitor.rs
+++ b/lightning/src/chain/channelmonitor.rs
@@ -588,12 +588,17 @@ pub enum Balance {
 #[derive(PartialEq)]
 struct IrrevocablyResolvedHTLC {
        commitment_tx_output_idx: u32,
+       /// The txid of the transaction which resolved the HTLC, this may be a commitment (if the HTLC
+       /// was not present in the confirmed commitment transaction), HTLC-Success, or HTLC-Timeout
+       /// transaction.
+       resolving_txid: Option<Txid>, // Added as optional, but always filled in, in 0.0.110
        /// Only set if the HTLC claim was ours using a payment preimage
        payment_preimage: Option<PaymentPreimage>,
 }
 
 impl_writeable_tlv_based!(IrrevocablyResolvedHTLC, {
        (0, commitment_tx_output_idx, required),
+       (1, resolving_txid, option),
        (2, payment_preimage, option),
 });
 
@@ -2727,7 +2732,10 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                                htlc_value_satoshis,
                                        }));
                                        if let Some(idx) = commitment_tx_output_idx {
-                                               self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC { commitment_tx_output_idx: idx, payment_preimage: None });
+                                               self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC {
+                                                       commitment_tx_output_idx: idx, resolving_txid: Some(entry.txid),
+                                                       payment_preimage: None,
+                                               });
                                        }
                                },
                                OnchainEvent::MaturingOutput { descriptor } => {
@@ -2737,7 +2745,10 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                        });
                                },
                                OnchainEvent::HTLCSpendConfirmation { commitment_tx_output_idx, preimage, .. } => {
-                                       self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC { commitment_tx_output_idx, payment_preimage: preimage });
+                                       self.htlcs_resolved_on_chain.push(IrrevocablyResolvedHTLC {
+                                               commitment_tx_output_idx, resolving_txid: Some(entry.txid),
+                                               payment_preimage: preimage,
+                                       });
                                },
                                OnchainEvent::FundingSpendConfirmation { commitment_tx_to_counterparty_output, .. } => {
                                        self.funding_spend_confirmed = Some(entry.txid);