Consider pending funding when handling commitment_signed

A FundedChannel may have more than one pending FundingScope during
splicing, one for the splice attempt and one or more for any RBF
attempts. When handling a commitment_signed, each FundingScope needs to
be considered during validation. If validation fails for any scope, then
the commitment_signed must be failed.

Author: jkczyz

lightning/src/ln/channel.rs

@@ -5651,7 +5651,17 @@ impl<SP: Deref> FundedChannel<SP> where
 			return Err(ChannelError::close("Peer sent commitment_signed after we'd started exchanging closing_signeds".to_owned()));
 		}
 
-		let commitment_tx_info = self.context.validate_commitment_signed(&self.funding, &self.holder_commitment_point, msg, logger)?;
+		let mut updates: Vec<ChannelMonitorUpdateStep> = core::iter::once(&self.funding)
+			.chain(self.pending_funding.iter())
+			.map(|funding| self.context
+				.validate_commitment_signed(funding, &self.holder_commitment_point, msg, logger)
+				.map(|LatestHolderCommitmentTXInfo { commitment_tx, htlc_outputs, nondust_htlc_sources }|
+					ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo {
+						commitment_tx, htlc_outputs, claimed_htlcs: vec![], nondust_htlc_sources,
+					}
+				)
+			)
+			.collect::<Result<Vec<_>, ChannelError>>()?;
 
 		if self.holder_commitment_point.advance(&self.context.holder_signer, &self.context.secp_ctx, logger).is_err() {
 			// We only fail to advance our commitment point/number if we're currently
@@ -5706,19 +5716,22 @@ impl<SP: Deref> FundedChannel<SP> where
 			}
 		}
 
-		let LatestHolderCommitmentTXInfo {
-			commitment_tx, htlc_outputs, nondust_htlc_sources,
-		} = commitment_tx_info;
+		for mut update in updates.iter_mut() {
+			if let ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo {
+				claimed_htlcs: ref mut update_claimed_htlcs, ..
+			} = &mut update {
+				debug_assert!(update_claimed_htlcs.is_empty());
+				*update_claimed_htlcs = claimed_htlcs.clone();
+			} else {
+				debug_assert!(false);
+			}
+		}
+
 		self.context.latest_monitor_update_id += 1;
 		let mut monitor_update = ChannelMonitorUpdate {
 			update_id: self.context.latest_monitor_update_id,
 			counterparty_node_id: Some(self.context.counterparty_node_id),
-			updates: vec![ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo {
-				commitment_tx,
-				htlc_outputs,
-				claimed_htlcs,
-				nondust_htlc_sources,
-			}],
+			updates,
 			channel_id: Some(self.context.channel_id()),
 		};