lnwallet/chanfunding: assumes all change outputs are P2TR

lnwallet/chanfunding/coin_select.go

@@ -98,8 +98,8 @@ func calculateFees(utxos []Coin, feeRate chainfee.SatPerKWeight) (btcutil.Amount
 	requiredFeeNoChange := feeRate.FeeForWeight(totalWeight)
 
 	// Estimate the fee required for a transaction with a change output.
-	// Assume that change output is a P2WKH output.
+	// Assume that change output is a P2TR output.
-	weightEstimate.AddP2WKHOutput()
+	weightEstimate.AddP2TROutput()
 
 	// Now that we have added the change output, redo the fee
 	// estimate.
@@ -209,7 +209,8 @@ func CoinSelectSubtractFees(feeRate chainfee.SatPerKWeight, amt,
 	// Obtain fee estimates both with and without using a change
 	// output.
 	requiredFeeNoChange, requiredFeeWithChange, err := calculateFees(
-		selectedUtxos, feeRate)
+		selectedUtxos, feeRate,
+	)
 	if err != nil {
 		return nil, 0, 0, err
 	}

lnwallet/chanfunding/coin_select_test.go

@@ -44,7 +44,7 @@ func fundingFee(feeRate chainfee.SatPerKWeight, numInput int, // nolint:unparam
 
 	// Optionally count a change output.
 	if change {
-		weightEstimate.AddP2WKHOutput()
+		weightEstimate.AddP2TROutput()
 	}
 
 	totalWeight := int64(weightEstimate.Weight())
@@ -81,7 +81,7 @@ func TestCalculateFees(t *testing.T) {
 			},
 
 			expectedFeeNoChange:   487,
-			expectedFeeWithChange: 611,
+			expectedFeeWithChange: 659,
 			expectedErr:           nil,
 		},
 
@@ -97,7 +97,7 @@ func TestCalculateFees(t *testing.T) {
 			},
 
 			expectedFeeNoChange:   579,
-			expectedFeeWithChange: 703,
+			expectedFeeWithChange: 751,
 			expectedErr:           nil,
 		},