f Add TransactionType::Splice variant for splice transactions

Add a new `Splice` variant to `TransactionType` to distinguish splice
transactions from regular funding transactions when broadcasting.

Update `FundingTxSigned` to include the transaction type alongside the
funding transaction, allowing the channel manager to broadcast with the
correct type information for both initial funding and splice operations.

Co-Authored-By: HAL 9000

Author: tnull

lightning/src/chain/chaininterface.rs

@@ -63,6 +63,11 @@ pub enum TransactionType {
 		/// A single sweep transaction may aggregate outputs from multiple channels.
 		channel_ids: Vec<ChannelId>,
 	},
+	/// A splice transaction modifying an existing channel's funding.
+	Splice {
+		/// The ID of the channel being spliced.
+		channel_id: ChannelId,
+	},
 }
 
 // TODO: Define typed abstraction over feerates to handle their conversions.

lightning/src/ln/channel.rs

@@ -28,7 +28,7 @@ use bitcoin::{secp256k1, sighash, FeeRate, Sequence, TxIn};
 
 use crate::blinded_path::message::BlindedMessagePath;
 use crate::chain::chaininterface::{
-	fee_for_weight, ConfirmationTarget, FeeEstimator, LowerBoundedFeeEstimator,
+	fee_for_weight, ConfirmationTarget, FeeEstimator, LowerBoundedFeeEstimator, TransactionType,
 };
 use crate::chain::channelmonitor::{
 	ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateStep, CommitmentHTLCData,
@@ -6865,8 +6865,8 @@ pub struct FundingTxSigned {
 	/// Signatures that should be sent to the counterparty, if necessary.
 	pub tx_signatures: Option<msgs::TxSignatures>,
 
-	/// The fully-signed funding transaction to be broadcast.
-	pub funding_tx: Option<Transaction>,
+	/// The fully-signed funding transaction to be broadcast, along with the transaction type.
+	pub funding_tx: Option<(Transaction, TransactionType)>,
 
 	/// Information about the completed funding negotiation.
 	pub splice_negotiated: Option<SpliceFundingNegotiated>,
@@ -9178,6 +9178,15 @@ where
 			(None, None)
 		};
 
+		let funding_tx = funding_tx.map(|tx| {
+			let tx_type = if splice_negotiated.is_some() {
+				TransactionType::Splice { channel_id: self.context.channel_id }
+			} else {
+				TransactionType::Funding { channel_ids: vec![self.context.channel_id] }
+			};
+			(tx, tx_type)
+		});
+
 		Ok(FundingTxSigned { tx_signatures, funding_tx, splice_negotiated, splice_locked })
 	}
 
@@ -9245,6 +9254,15 @@ where
 			(None, None)
 		};
 
+		let funding_tx = funding_tx.map(|tx| {
+			let tx_type = if splice_negotiated.is_some() {
+				TransactionType::Splice { channel_id: self.context.channel_id }
+			} else {
+				TransactionType::Funding { channel_ids: vec![self.context.channel_id] }
+			};
+			(tx, tx_type)
+		});
+
 		Ok(FundingTxSigned {
 			tx_signatures: holder_tx_signatures,
 			funding_tx,

lightning/src/ln/channelmanager.rs

@@ -6459,10 +6459,11 @@ where
 								splice_negotiated,
 								splice_locked,
 							}) => {
-								if let Some(funding_tx) = funding_tx {
+								if let Some((funding_tx, tx_type)) = funding_tx {
 									self.broadcast_interactive_funding(
 										chan,
 										&funding_tx,
+										Some(tx_type),
 										&self.logger,
 									);
 								}
@@ -6539,18 +6540,19 @@ where
 	}
 
 	fn broadcast_interactive_funding(
-		&self, channel: &mut FundedChannel<SP>, funding_tx: &Transaction, logger: &L,
+		&self, channel: &mut FundedChannel<SP>, funding_tx: &Transaction,
+		transaction_type: Option<TransactionType>, logger: &L,
 	) {
 		let logger = WithChannelContext::from(logger, channel.context(), None);
 		log_info!(
 			logger,
 			"Broadcasting signed interactive funding transaction {}",
 			funding_tx.compute_txid()
 		);
-		self.tx_broadcaster.broadcast_transactions(&[(
-			funding_tx,
-			TransactionType::Funding { channel_ids: vec![channel.context().channel_id()] },
-		)]);
+		let tx_type = transaction_type.unwrap_or_else(|| TransactionType::Funding {
+			channel_ids: vec![channel.context().channel_id()],
+		});
+		self.tx_broadcaster.broadcast_transactions(&[(funding_tx, tx_type)]);
 		{
 			let mut pending_events = self.pending_events.lock().unwrap();
 			emit_channel_pending_event!(pending_events, channel);
@@ -10287,8 +10289,8 @@ This indicates a bug inside LDK. Please report this error at https://github.com/
 						splice_negotiated,
 						splice_locked,
 					}) => {
-						if let Some(funding_tx) = funding_tx {
-							self.broadcast_interactive_funding(channel, &funding_tx, &self.logger);
+						if let Some((funding_tx, tx_type)) = funding_tx {
+							self.broadcast_interactive_funding(channel, &funding_tx, Some(tx_type), &self.logger);
 						}
 
 						if let Some(splice_negotiated) = splice_negotiated {
@@ -11400,8 +11402,8 @@ This indicates a bug inside LDK. Please report this error at https://github.com/
 								msg: splice_locked,
 							});
 						}
-						if let Some(ref funding_tx) = funding_tx {
-							self.broadcast_interactive_funding(chan, funding_tx, &self.logger);
+						if let Some((ref funding_tx, ref tx_type)) = funding_tx {
+							self.broadcast_interactive_funding(chan, funding_tx, Some(tx_type.clone()), &self.logger);
 						}
 						if let Some(splice_negotiated) = splice_negotiated {
 							self.pending_events.lock().unwrap().push_back((