Minor changes post review

Author: optout21

lightning/src/ln/channel.rs

@@ -1702,20 +1702,20 @@ pub(super) trait InteractivelyFunded<SP: Deref> where SP::Target: SignerProvider
 			funding_inputs.push(prev_funding_input);
 		}
 
-		let mut funding_inputs_prev_outputs: Vec<TxOut> = Vec::with_capacity(funding_inputs.len());
+		let mut funding_inputs_prev_outputs: Vec<&TxOut> = Vec::with_capacity(funding_inputs.len());
 		// Check that vouts exist for each TxIn in provided transactions.
-		for (idx, input) in funding_inputs.iter().enumerate() {
-			if let Some(output) = input.1.as_transaction().output.get(input.0.previous_output.vout as usize) {
-				funding_inputs_prev_outputs.push(output.clone());
+		for (idx, (txin, tx)) in funding_inputs.iter().enumerate() {
+			if let Some(output) = tx.as_transaction().output.get(txin.previous_output.vout as usize) {
+				funding_inputs_prev_outputs.push(output);
 			} else {
 				return Err(APIError::APIMisuseError {
 					err: format!("Transaction with txid {} does not have an output with vout of {} corresponding to TxIn at funding_inputs[{}]",
-						input.1.as_transaction().compute_txid(), input.0.previous_output.vout, idx) });
+						tx.as_transaction().compute_txid(), txin.previous_output.vout, idx) });
 			}
 		}
 
 		let total_input_satoshis: u64 = funding_inputs.iter().map(
-			|input| input.1.as_transaction().output.get(input.0.previous_output.vout as usize).map(|out| out.value.to_sat()).unwrap_or(0)
+			|(txin, tx)| tx.as_transaction().output.get(txin.previous_output.vout as usize).map(|out| out.value.to_sat()).unwrap_or(0)
 		).sum();
 		if total_input_satoshis < self.dual_funding_context().our_funding_satoshis {
 			return Err(APIError::APIMisuseError {
@@ -1757,18 +1757,24 @@ pub(super) trait InteractivelyFunded<SP: Deref> where SP::Target: SignerProvider
 				|err| APIError::APIMisuseError {
 					err: format!("Failed to get change script as new destination script, {:?}", err),
 				})?;
-			add_funding_change_output(change_value, change_script,
-				&mut funding_outputs, self.dual_funding_context().funding_feerate_sat_per_1000_weight);
+			let mut change_output = TxOut {
+				value: Amount::from_sat(change_value),
+				script_pubkey: change_script,
+			};
+			let change_output_weight = get_output_weight(&change_output.script_pubkey).to_wu();
+			let change_output_fee = fee_for_weight(self.dual_funding_context().funding_feerate_sat_per_1000_weight, change_output_weight);
+			change_output.value = Amount::from_sat(change_value.saturating_sub(change_output_fee));
+			funding_outputs.push(OutputOwned::Single(change_output));
 		}
 
 		let constructor_args = InteractiveTxConstructorArgs {
 			entropy_source,
 			holder_node_id,
 			counterparty_node_id: self.context().counterparty_node_id,
 			channel_id: self.context().channel_id(),
-			feerate_sat_per_kw: self.dual_funding_context_mut().funding_feerate_sat_per_1000_weight,
+			feerate_sat_per_kw: self.dual_funding_context().funding_feerate_sat_per_1000_weight,
 			is_initiator: self.is_initiator(),
-			funding_tx_locktime: self.dual_funding_context_mut().funding_tx_locktime,
+			funding_tx_locktime: self.dual_funding_context().funding_tx_locktime,
 			inputs_to_contribute: funding_inputs,
 			outputs_to_contribute: funding_outputs,
 			expected_remote_shared_funding_output,
@@ -1777,7 +1783,7 @@ pub(super) trait InteractivelyFunded<SP: Deref> where SP::Target: SignerProvider
 			.map_err(|_| APIError::APIMisuseError { err: "Incorrect shared output provided".into() })?;
 		let msg = tx_constructor.take_initiator_first_message();
 
-		self.interactive_tx_constructor_mut().replace(tx_constructor);
+		*self.interactive_tx_constructor_mut() = Some(tx_constructor);
 
 		Ok(msg)
 	}
@@ -4264,21 +4270,6 @@ fn get_v2_channel_reserve_satoshis(channel_value_satoshis: u64, dust_limit_satos
 	cmp::min(channel_value_satoshis, cmp::max(q, dust_limit_satoshis))
 }
 
-#[allow(dead_code)] // TODO(dual_funding): Remove once begin_interactive_funding_tx_construction() is used
-fn add_funding_change_output(
-	change_value: u64, change_script: ScriptBuf,
-	funding_outputs: &mut Vec<OutputOwned>, funding_feerate_sat_per_1000_weight: u32,
-) {
-	let mut change_output = TxOut {
-		value: Amount::from_sat(change_value),
-		script_pubkey: change_script,
-	};
-	let change_output_weight = get_output_weight(&change_output.script_pubkey).to_wu();
-	let change_output_fee = fee_for_weight(funding_feerate_sat_per_1000_weight, change_output_weight);
-	change_output.value = Amount::from_sat(change_value.saturating_sub(change_output_fee));
-	funding_outputs.push(OutputOwned::Single(change_output.clone()));
-}
-
 pub(super) fn calculate_our_funding_satoshis(
 	is_initiator: bool, funding_inputs: &[(TxIn, TransactionU16LenLimited)],
 	total_witness_weight: Weight, funding_feerate_sat_per_1000_weight: u32,

lightning/src/ln/interactivetxs.rs

@@ -1669,7 +1669,7 @@ impl InteractiveTxConstructor {
 /// or None if a change is not needed/possible.
 #[allow(dead_code)] // TODO(dual_funding): Remove once begin_interactive_funding_tx_construction() is used
 pub(super) fn calculate_change_output_value(
-	is_initiator: bool, our_contribution: u64, funding_inputs_prev_outputs: &Vec<TxOut>,
+	is_initiator: bool, our_contribution: u64, funding_inputs_prev_outputs: &Vec<&TxOut>,
 	funding_outputs: &Vec<OutputOwned>, funding_feerate_sat_per_1000_weight: u32,
 	holder_dust_limit_satoshis: u64,
 ) -> Option<u64> {
@@ -2640,10 +2640,11 @@ mod tests {
 
 	#[test]
 	fn test_calculate_change_output_value_open() {
-		let input_prevouts = vec![
+		let input_prevouts_owned = vec![
 			TxOut { value: Amount::from_sat(70_000), script_pubkey: ScriptBuf::new() },
 			TxOut { value: Amount::from_sat(60_000), script_pubkey: ScriptBuf::new() },
 		];
+		let input_prevouts: Vec<&TxOut> = input_prevouts_owned.iter().collect();
 		let our_contributed = 110_000;
 		let txout = TxOut { value: Amount::from_sat(128_000), script_pubkey: ScriptBuf::new() };
 		let outputs = vec![OutputOwned::SharedControlFullyOwned(txout)];
@@ -2729,10 +2730,11 @@ mod tests {
 
 	#[test]
 	fn test_calculate_change_output_value_splice() {
-		let input_prevouts = vec![
+		let input_prevouts_owned = vec![
 			TxOut { value: Amount::from_sat(70_000), script_pubkey: ScriptBuf::new() },
 			TxOut { value: Amount::from_sat(60_000), script_pubkey: ScriptBuf::new() },
 		];
+		let input_prevouts: Vec<&TxOut> = input_prevouts_owned.iter().collect();
 		let our_contributed = 110_000;
 		let txout = TxOut { value: Amount::from_sat(148_000), script_pubkey: ScriptBuf::new() };
 		let outputs = vec![OutputOwned::Shared(SharedOwnedOutput::new(txout, our_contributed))];