f - account for outputs

Author: jkczyz

lightning/src/ln/interactivetxs.rs

@@ -1700,6 +1700,9 @@ pub(super) fn calculate_change_output_value(
 		}
 	}
 
+	let total_output_satoshis = funding_outputs.iter().fold(0u64, |total, out| {
+		total.saturating_add(out.value.to_sat())
+	});
 	let our_funding_outputs_weight = funding_outputs.iter().fold(0u64, |weight, out| {
 		weight.saturating_add(get_output_weight(&out.script_pubkey).to_wu())
 	});
@@ -1715,12 +1718,14 @@ pub(super) fn calculate_change_output_value(
 	let fees_sats = fee_for_weight(funding_feerate_sat_per_1000_weight, weight);
 	// Note: in case of additional outputs, they will have to be subtracted here
 
-	let total_inputs_less_fees = total_input_satoshis.saturating_sub(fees_sats);
-	if total_inputs_less_fees < our_contribution {
+	let net_total_less_fees = total_input_satoshis
+		.saturating_sub(total_output_satoshis)
+		.saturating_sub(fees_sats);
+	if net_total_less_fees < our_contribution {
 		// Not enough to cover contribution plus fees
 		return Err(AbortReason::InsufficientFees);
 	}
-	let remaining_value = total_inputs_less_fees.saturating_sub(our_contribution);
+	let remaining_value = net_total_less_fees.saturating_sub(our_contribution);
 	if remaining_value < change_output_dust_limit {
 		// Enough to cover contribution plus fees, but leftover is below dust limit; no change
 		Ok(None)
@@ -2596,16 +2601,15 @@ mod tests {
 			})
 			.collect::<Vec<(TxIn, TransactionU16LenLimited)>>();
 		let our_contributed = 110_000;
-		let txout = TxOut { value: Amount::from_sat(128_000), script_pubkey: ScriptBuf::new() };
-		let _value = txout.value.to_sat();
-		// let outputs = OutputOwned::Shared(SharedOwnedOutput::new(txout, value))];
-		let outputs = vec![];
+		let txout = TxOut { value: Amount::from_sat(10_000), script_pubkey: ScriptBuf::new() };
+		let outputs = vec![txout];
 		let funding_feerate_sat_per_1000_weight = 3000;
 
 		let total_inputs: u64 = input_prevouts.iter().map(|o| o.value.to_sat()).sum();
-		let gross_change = total_inputs - our_contributed;
-		let fees = 1638; // 1746 - 108;
-		let common_fees = 234; // 126 + 108;
+		let total_outputs: u64 = outputs.iter().map(|o| o.value.to_sat()).sum();
+		let gross_change = total_inputs - total_outputs - our_contributed;
+		let fees = 1746;
+		let common_fees = 234;
 		{
 			// There is leftover for change
 			let res = calculate_change_output_value(
@@ -2617,7 +2621,7 @@ mod tests {
 				funding_feerate_sat_per_1000_weight,
 				300,
 			);
-			assert_eq!(res.unwrap().unwrap(), gross_change - fees - common_fees);
+			assert_eq!(res, Ok(Some(gross_change - fees - common_fees)));
 		}
 		{
 			// There is leftover for change, without common fees
@@ -2630,7 +2634,7 @@ mod tests {
 				funding_feerate_sat_per_1000_weight,
 				300,
 			);
-			assert_eq!(res.unwrap().unwrap(), gross_change - fees);
+			assert_eq!(res, Ok(Some(gross_change - fees)));
 		}
 		{
 			// Larger fee, smaller change
@@ -2640,10 +2644,10 @@ mod tests {
 				&ScriptBuf::new(),
 				&inputs,
 				&outputs,
-				9000,
+				funding_feerate_sat_per_1000_weight * 3,
 				300,
 			);
-			assert_eq!(res.unwrap().unwrap(), 14384);
+			assert_eq!(res, Ok(Some(4060)));
 		}
 		{
 			// Insufficient inputs, no leftover
@@ -2656,33 +2660,33 @@ mod tests {
 				funding_feerate_sat_per_1000_weight,
 				300,
 			);
-			assert_eq!(res.err().unwrap(), AbortReason::InsufficientFees);
+			assert_eq!(res, Err(AbortReason::InsufficientFees));
 		}
 		{
 			// Very small leftover
 			let res = calculate_change_output_value(
 				false,
-				128_100,
+				118_000,
 				&ScriptBuf::new(),
 				&inputs,
 				&outputs,
 				funding_feerate_sat_per_1000_weight,
 				300,
 			);
-			assert!(res.unwrap().is_none());
+			assert_eq!(res, Ok(None));
 		}
 		{
 			// Small leftover, but not dust
 			let res = calculate_change_output_value(
 				false,
-				128_100,
+				117_992,
 				&ScriptBuf::new(),
 				&inputs,
 				&outputs,
 				funding_feerate_sat_per_1000_weight,
 				100,
 			);
-			assert_eq!(res.unwrap().unwrap(), 262);
+			assert_eq!(res, Ok(Some(262)));
 		}
 	}
 }