cmd: new input selection changes are adopted.

The new NewUnsignedTransaction function requires different input
values. Now a constant input slice and the input selection
strategy is needed.

cmd/sweepaccount/main.go

@@ -22,6 +22,7 @@ import (
 	"github.com/btcsuite/btcwallet/wallet/txauthor"
 	"github.com/btcsuite/btcwallet/wallet/txrules"
 	"github.com/btcsuite/btcwallet/wallet/txsizes"
+	"github.com/btcsuite/btcwallet/wtxmgr"
 	"github.com/jessevdk/go-flags"
 )
 
@@ -187,6 +188,56 @@ func makeInputSource(outputs []btcjson.ListUnspentResult) txauthor.InputSource {
 	}
 }
 
+// fetchInputs fetches every unspent output with non-zero output values.
+func fetchInputs(outputs []btcjson.ListUnspentResult) ([]wtxmgr.Credit, error) {
+	var (
+		totalInputValue btcutil.Amount
+		inputs          = make([]wtxmgr.Credit, 0, len(outputs))
+		sourceErr       error
+	)
+	for _, output := range outputs {
+		output := output
+
+		outputAmount, err := btcutil.NewAmount(output.Amount)
+		if err != nil {
+			sourceErr = fmt.Errorf(
+				"invalid amount `%v` in listunspent result",
+				output.Amount)
+			break
+		}
+		if outputAmount == 0 {
+			continue
+		}
+		if !saneOutputValue(outputAmount) {
+			sourceErr = fmt.Errorf(
+				"impossible output amount `%v` in listunspent result",
+				outputAmount)
+			break
+		}
+		totalInputValue += outputAmount
+
+		previousOutPoint, err := parseOutPoint(&output)
+		if err != nil {
+			sourceErr = fmt.Errorf(
+				"invalid data in listunspent result: %v",
+				err)
+			break
+		}
+
+		inputs = append(inputs, wtxmgr.Credit{
+			OutPoint: previousOutPoint,
+			Amount:   outputAmount,
+		})
+	}
+
+	if sourceErr == nil && totalInputValue == 0 {
+		sourceErr = noInputValue{}
+	}
+
+	return inputs, sourceErr
+
+}
+
 // makeDestinationScriptSource creates a ChangeSource which is used to receive
 // all correlated previous input value.  A non-change address is created by this
 // function.
@@ -277,10 +328,15 @@ func sweep() error {
 		numErrors++
 	}
 	for _, previousOutputs := range sourceOutputs {
-		inputSource := makeInputSource(previousOutputs)
+		// inputSource := makeInputSource(previousOutputs)
+		inputs, err := fetchInputs(previousOutputs)
+		if err != nil {
+			return err
+		}
 		destinationSource := makeDestinationScriptSource(rpcClient, opts.DestinationAccount)
+		// We are only selecting postive yieling outputs.
 		tx, err := txauthor.NewUnsignedTransaction(nil, opts.FeeRate.Amount,
-			inputSource, destinationSource)
+			inputs, txauthor.PositiveYieldingSelection, destinationSource)
 		if err != nil {
 			if err != (noInputValue{}) {
 				reportError("Failed to create unsigned transaction: %v", err)