delete i64s

lightning/src/ln/channel.rs

@@ -3404,7 +3404,7 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider {
 			}
 		}
 
-		let value_to_self_msat: i64 = self.value_to_self_msat as i64 + value_to_self_msat_offset;
+		let value_to_self_msat: u64 = u64::try_from((self.value_to_self_msat as i64) + value_to_self_msat_offset).unwrap();
 
 		use crate::sign::tx_builder::SpecTxBuilder;
 		use crate::sign::tx_builder::TxBuilder;

lightning/src/sign/tx_builder.rs

@@ -22,7 +22,7 @@ pub(crate) trait TxBuilder {
 	fn build_commitment_transaction<'a>(
 		&self, local: bool, commitment_number: u64, per_commitment_point: &PublicKey,
 		channel_parameters: &ChannelTransactionParameters, secp_ctx: &Secp256k1<secp256k1::All>,
-		channel_value_satoshis: u64, value_to_self_msat: i64,
+		channel_value_satoshis: u64, value_to_self_msat: u64,
 		htlcs_in_tx: Vec<(HTLCOutputInCommitment, Option<&'a HTLCSource>)>, feerate_per_kw: u32,
 		broadcaster_dust_limit_satoshis: u64,
 	) -> CommitmentStats<'a>;
@@ -36,7 +36,7 @@ impl TxBuilder for SpecTxBuilder {
 	fn build_commitment_transaction<'a>(
 		&self, local: bool, commitment_number: u64, per_commitment_point: &PublicKey,
 		channel_parameters: &ChannelTransactionParameters, secp_ctx: &Secp256k1<secp256k1::All>,
-		channel_value_satoshis: u64, mut value_to_self_msat: i64,
+		channel_value_satoshis: u64, mut value_to_self_msat: u64,
 		htlcs_in_tx: Vec<(HTLCOutputInCommitment, Option<&'a HTLCSource>)>, feerate_per_kw: u32,
 		broadcaster_dust_limit_satoshis: u64,
 	) -> CommitmentStats<'a> {
@@ -94,10 +94,9 @@ impl TxBuilder for SpecTxBuilder {
 			}
 		}
 
-		let mut value_to_remote_msat: i64 =
-			(channel_value_satoshis * 1000) as i64 - value_to_self_msat;
-		value_to_self_msat -= local_htlc_total_msat as i64;
-		value_to_remote_msat -= remote_htlc_total_msat as i64;
+		let mut value_to_remote_msat = u64::checked_sub(channel_value_satoshis * 1000, value_to_self_msat).unwrap();
+		value_to_self_msat           = u64::checked_sub(value_to_self_msat, local_htlc_total_msat).unwrap();
+		value_to_remote_msat         = u64::checked_sub(value_to_remote_msat, remote_htlc_total_msat).unwrap();
 
 		let total_fee_sat = chan_utils::commit_tx_fee_sat(
 			feerate_per_kw,
@@ -108,16 +107,16 @@ impl TxBuilder for SpecTxBuilder {
 			crate::ln::channel::ANCHOR_OUTPUT_VALUE_SATOSHI * 2
 		} else {
 			0
-		} as i64;
+		};
 		let (value_to_self, value_to_remote) = if channel_parameters.is_outbound_from_holder {
 			(
-				value_to_self_msat / 1000 - anchors_val - total_fee_sat as i64,
+				(value_to_self_msat / 1000).saturating_sub(anchors_val).saturating_sub(total_fee_sat),
 				value_to_remote_msat / 1000,
 			)
 		} else {
 			(
 				value_to_self_msat / 1000,
-				value_to_remote_msat / 1000 - anchors_val - total_fee_sat as i64,
+				(value_to_remote_msat / 1000).saturating_sub(anchors_val).saturating_sub(total_fee_sat),
 			)
 		};
 
@@ -128,13 +127,13 @@ impl TxBuilder for SpecTxBuilder {
 			params.countersignatory_pubkeys().funding_pubkey,
 		);
 
-		if value_to_a >= (broadcaster_dust_limit_satoshis as i64) {
+		if value_to_a >= broadcaster_dust_limit_satoshis {
 			//log_trace!(logger, "   ...including {} output with value {}", if local { "to_local" } else { "to_remote" }, value_to_a);
 		} else {
 			value_to_a = 0;
 		}
 
-		if value_to_b >= (broadcaster_dust_limit_satoshis as i64) {
+		if value_to_b >= broadcaster_dust_limit_satoshis {
 			//log_trace!(logger, "   ...including {} output with value {}", if local { "to_remote" } else { "to_local" }, value_to_b);
 		} else {
 			value_to_b = 0;
@@ -158,9 +157,6 @@ impl TxBuilder for SpecTxBuilder {
 			&mut included_non_dust_htlcs,
 			&params,
 		);
-		// TODO: do checked subs
-		// checkout the debug assertions we deleted
-		// do we need to return the trimmed sum / value ?
 
 		included_non_dust_htlcs.sort_unstable_by_key(|h| h.0.transaction_output_index.unwrap());
 		let num_nondust_htlcs = included_non_dust_htlcs.len();