multi: add p2tr keyspend wallet support

sweep/sweeper_test.go

@@ -355,7 +355,7 @@ func assertTxFeeRate(t *testing.T, tx *wire.MsgTx,
 	outputAmt := tx.TxOut[0].Value
 
 	fee := btcutil.Amount(inputAmt - outputAmt)
-	_, estimator := getWeightEstimate(inputs, nil, 0)
+	_, estimator := getWeightEstimate(inputs, nil, 0, nil)
 	txWeight := estimator.weight()
 
 	expectedFee := expectedFeeRate.FeeForWeight(int64(txWeight))

sweep/txgenerator.go

@@ -139,7 +139,9 @@ func createSweepTx(inputs []input.Input, outputs []*wire.TxOut,
 	feePerKw chainfee.SatPerKWeight, signer input.Signer) (*wire.MsgTx,
 	error) {
 
-	inputs, estimator := getWeightEstimate(inputs, outputs, feePerKw)
+	inputs, estimator := getWeightEstimate(
+		inputs, outputs, feePerKw, changePkScript,
+	)
 	txFee := estimator.fee()
 
 	var (
@@ -312,7 +314,8 @@ func createSweepTx(inputs []input.Input, outputs []*wire.TxOut,
 // getWeightEstimate returns a weight estimate for the given inputs.
 // Additionally, it returns counts for the number of csv and cltv inputs.
 func getWeightEstimate(inputs []input.Input, outputs []*wire.TxOut,
-	feeRate chainfee.SatPerKWeight) ([]input.Input, *weightEstimator) {
+	feeRate chainfee.SatPerKWeight, outputPkScript []byte) ([]input.Input,
+	*weightEstimator) {
 
 	// We initialize a weight estimator so we can accurately asses the
 	// amount of fees we need to pay for this sweep transaction.
@@ -327,14 +330,18 @@ func getWeightEstimate(inputs []input.Input, outputs []*wire.TxOut,
 	}
 
 	// If there is any leftover change after paying to the given outputs
-	// and required outputs, it will go to a single segwit p2wkh address.
-	// This will be our change address, so ensure it contributes to our
-	// weight estimate. Note that if we have other outputs, we might end up
-	// creating a sweep tx without a change output. It is okay to add the
+	// and required outputs, it will go to a single segwit p2wkh or p2tr
+	// address. This will be our change address, so ensure it contributes to
+	// our weight estimate. Note that if we have other outputs, we might end
+	// up creating a sweep tx without a change output. It is okay to add the
 	// change output to the weight estimate regardless, since the estimated
 	// fee will just be subtracted from this already dust output, and
 	// trimmed.
-	weightEstimate.addP2WKHOutput()
+	if txscript.IsPayToTaproot(outputPkScript) {
+		weightEstimate.addP2TROutput()
+	} else {
+		weightEstimate.addP2WKHOutput()
+	}
 
 	// For each output, use its witness type to determine the estimate
 	// weight of its witness, and add it to the proper set of spendable

sweep/txgenerator_test.go

@@ -39,7 +39,7 @@ func TestWeightEstimate(t *testing.T) {
 		))
 	}
 
-	_, estimator := getWeightEstimate(inputs, nil, 0)
+	_, estimator := getWeightEstimate(inputs, nil, 0, nil)
 	weight := int64(estimator.weight())
 	if weight != expectedWeight {
 		t.Fatalf("unexpected weight. expected %d but got %d.",

sweep/walletsweep.go

@@ -255,6 +255,10 @@ func CraftSweepAllTx(feeRate chainfee.SatPerKWeight, blockHeight uint32,
 		case lnwallet.NestedWitnessPubKey:
 			witnessType = input.NestedWitnessKeyHash
 
+		case lnwallet.TaprootPubkey:
+			witnessType = input.TaprootPubKeySpend
+			signDesc.HashType = txscript.SigHashDefault
+
 		// All other output types we count as unknown and will fail to
 		// sweep.
 		default:

sweep/weight_estimator.go

@@ -77,6 +77,12 @@ func (w *weightEstimator) addP2WKHOutput() {
 	w.estimator.AddP2WKHOutput()
 }
 
+// addP2TROutput updates the weight estimate to account for an additional native
+// SegWit v1 P2TR output.
+func (w *weightEstimator) addP2TROutput() {
+	w.estimator.AddP2TROutput()
+}
+
 // addOutput updates the weight estimate to account for the known
 // output given.
 func (w *weightEstimator) addOutput(txOut *wire.TxOut) {