sweep: pass dustLimit to CreateSweepTx

rpcserver.go

@@ -1254,7 +1254,8 @@ func (r *rpcServer) SendCoins(ctx context.Context,
 		// single transaction. This will be generated in a concurrent
 		// safe manner, so no need to worry about locking.
 		sweepTxPkg, err := sweep.CraftSweepAllTx(
-			feePerKw, uint32(bestHeight), targetAddr, wallet,
+			feePerKw, lnwallet.DefaultDustLimit(),
+			uint32(bestHeight), targetAddr, wallet,
 			wallet.WalletController, wallet.WalletController,
 			r.server.cc.FeeEstimator, r.server.cc.Signer,
 		)

sweep/sweeper.go

@@ -1165,7 +1165,7 @@ func (s *UtxoSweeper) sweep(inputs inputSet, feeRate chainfee.SatPerKWeight,
 	// Create sweep tx.
 	tx, err := createSweepTx(
 		inputs, s.currentOutputScript, uint32(currentHeight), feeRate,
-		s.cfg.Signer,
+		dustLimit(s.relayFeeRate), s.cfg.Signer,
 	)
 	if err != nil {
 		return fmt.Errorf("create sweep tx: %v", err)
@@ -1455,7 +1455,8 @@ func (s *UtxoSweeper) CreateSweepTx(inputs []input.Input, feePref FeePreference,
 	}
 
 	return createSweepTx(
-		inputs, pkScript, currentBlockHeight, feePerKw, s.cfg.Signer,
+		inputs, pkScript, currentBlockHeight, feePerKw,
+		dustLimit(s.relayFeeRate), s.cfg.Signer,
 	)
 }
 

sweep/tx_input_set.go

@@ -83,14 +83,18 @@ type txInputSet struct {
 	wallet Wallet
 }
 
+func dustLimit(relayFee chainfee.SatPerKWeight) btcutil.Amount {
+	return txrules.GetDustThreshold(
+		input.P2WPKHSize,
+		btcutil.Amount(relayFee.FeePerKVByte()),
+	)
+}
+
 // newTxInputSet constructs a new, empty input set.
 func newTxInputSet(wallet Wallet, feePerKW,
 	relayFee chainfee.SatPerKWeight, maxInputs int) *txInputSet {
 
-	dustLimit := txrules.GetDustThreshold(
-		input.P2WPKHSize,
-		btcutil.Amount(relayFee.FeePerKVByte()),
-	)
+	dustLimit := dustLimit(relayFee)
 
 	state := txInputSetState{
 		weightEstimate: newWeightEstimator(feePerKW),

sweep/txgenerator.go

@@ -132,7 +132,7 @@ func generateInputPartitionings(sweepableInputs []txInput,
 // createSweepTx builds a signed tx spending the inputs to a the output script.
 func createSweepTx(inputs []input.Input, outputPkScript []byte,
 	currentBlockHeight uint32, feePerKw chainfee.SatPerKWeight,
-	signer input.Signer) (*wire.MsgTx, error) {
+	dustLimit btcutil.Amount, signer input.Signer) (*wire.MsgTx, error) {
 
 	inputs, estimator := getWeightEstimate(inputs, feePerKw)
 
@@ -169,14 +169,16 @@ func createSweepTx(inputs []input.Input, outputPkScript []byte,
 	}
 
 	// Sweep as much possible, after subtracting txn fees.
-	sweepAmt := int64(totalSum - txFee)
+	sweepAmt := totalSum - txFee
 
 	// The txn will sweep the amount after fees to the pkscript generated
 	// above.
-	sweepTx.AddTxOut(&wire.TxOut{
-		PkScript: outputPkScript,
-		Value:    sweepAmt,
-	})
+	if sweepAmt >= dustLimit {
+		sweepTx.AddTxOut(&wire.TxOut{
+			PkScript: outputPkScript,
+			Value:    int64(sweepAmt),
+		})
+	}
 
 	// We'll default to using the current block height as locktime, if none
 	// of the inputs commits to a different locktime.

sweep/walletsweep.go

@@ -153,10 +153,10 @@ type WalletSweepPackage struct {
 // by the delivery address. The sweep transaction will be crafted with the
 // target fee rate, and will use the utxoSource and outpointLocker as sources
 // for wallet funds.
-func CraftSweepAllTx(feeRate chainfee.SatPerKWeight, blockHeight uint32,
-	deliveryAddr btcutil.Address, coinSelectLocker CoinSelectionLocker,
-	utxoSource UtxoSource, outpointLocker OutpointLocker,
-	feeEstimator chainfee.Estimator,
+func CraftSweepAllTx(feeRate chainfee.SatPerKWeight, dustLimit btcutil.Amount,
+	blockHeight uint32, deliveryAddr btcutil.Address,
+	coinSelectLocker CoinSelectionLocker, utxoSource UtxoSource,
+	outpointLocker OutpointLocker, feeEstimator chainfee.Estimator,
 	signer input.Signer) (*WalletSweepPackage, error) {
 
 	// TODO(roasbeef): turn off ATPL as well when available?
@@ -273,7 +273,8 @@ func CraftSweepAllTx(feeRate chainfee.SatPerKWeight, blockHeight uint32,
 	// Finally, we'll ask the sweeper to craft a sweep transaction which
 	// respects our fee preference and targets all the UTXOs of the wallet.
 	sweepTx, err := createSweepTx(
-		inputsToSweep, deliveryPkScript, blockHeight, feeRate, signer,
+		inputsToSweep, deliveryPkScript, blockHeight, feeRate,
+		dustLimit, signer,
 	)
 	if err != nil {
 		unlockOutputs()

sweep/walletsweep_test.go

@@ -288,7 +288,7 @@ func TestCraftSweepAllTxCoinSelectFail(t *testing.T) {
 	utxoLocker := newMockOutpointLocker()
 
 	_, err := CraftSweepAllTx(
-		0, 100, nil, coinSelectLocker, utxoSource, utxoLocker, nil, nil,
+		0, 100, 10, nil, coinSelectLocker, utxoSource, utxoLocker, nil, nil,
 	)
 
 	// Since we instructed the coin select locker to fail above, we should
@@ -313,7 +313,7 @@ func TestCraftSweepAllTxUnknownWitnessType(t *testing.T) {
 	utxoLocker := newMockOutpointLocker()
 
 	_, err := CraftSweepAllTx(
-		0, 100, nil, coinSelectLocker, utxoSource, utxoLocker, nil, nil,
+		0, 100, 10, nil, coinSelectLocker, utxoSource, utxoLocker, nil, nil,
 	)
 
 	// Since passed in a p2wsh output, which is unknown, we should fail to
@@ -347,7 +347,7 @@ func TestCraftSweepAllTx(t *testing.T) {
 	utxoLocker := newMockOutpointLocker()
 
 	sweepPkg, err := CraftSweepAllTx(
-		0, 100, deliveryAddr, coinSelectLocker, utxoSource, utxoLocker,
+		0, 100, 10, deliveryAddr, coinSelectLocker, utxoSource, utxoLocker,
 		feeEstimator, signer,
 	)
 	if err != nil {