Update dependencies

- uses newer version of go-ethereum required for go1.11

vendor/github.com/btcsuite/btcd/blockchain/weight.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2013-2016 The btcsuite developers
+// Copyright (c) 2013-2017 The btcsuite developers
 // Use of this source code is governed by an ISC
 // license that can be found in the LICENSE file.
 
@@ -8,6 +8,7 @@ import (
 	"fmt"
 
 	"github.com/btcsuite/btcd/txscript"
+	"github.com/btcsuite/btcd/wire"
 	"github.com/btcsuite/btcutil"
 )
 
@@ -27,13 +28,21 @@ const (
 
 	// MaxBlockSigOpsCost is the maximum number of signature operations
 	// allowed for a block. It is calculated via a weighted algorithm which
-	// weights segragated witness sig ops lower than regular sig ops.
+	// weights segregated witness sig ops lower than regular sig ops.
 	MaxBlockSigOpsCost = 80000
 
 	// WitnessScaleFactor determines the level of "discount" witness data
 	// receives compared to "base" data. A scale factor of 4, denotes that
 	// witness data is 1/4 as cheap as regular non-witness data.
 	WitnessScaleFactor = 4
+
+	// MinTxOutputWeight is the minimum possible weight for a transaction
+	// output.
+	MinTxOutputWeight = WitnessScaleFactor * wire.MinTxOutPayload
+
+	// MaxOutputsPerBlock is the maximum number of transaction outputs there
+	// can be in a block of max weight size.
+	MaxOutputsPerBlock = MaxBlockWeight / MinTxOutputWeight
 )
 
 // GetBlockWeight computes the value of the weight metric for a given block.
@@ -71,9 +80,7 @@ func GetTransactionWeight(tx *btcutil.Tx) int64 {
 // legacy sig op count scaled according to the WitnessScaleFactor, the sig op
 // count for all p2sh inputs scaled by the WitnessScaleFactor, and finally the
 // unscaled sig op count for any inputs spending witness programs.
-func GetSigOpCost(tx *btcutil.Tx, isCoinBaseTx bool, utxoView *UtxoViewpoint,
-	bip16, segWit bool) (int, error) {
-
+func GetSigOpCost(tx *btcutil.Tx, isCoinBaseTx bool, utxoView *UtxoViewpoint, bip16, segWit bool) (int, error) {
 	numSigOps := CountSigOps(tx) * WitnessScaleFactor
 	if bip16 {
 		numP2SHSigOps, err := CountP2SHSigOps(tx, isCoinBaseTx, utxoView)
@@ -86,11 +93,10 @@ func GetSigOpCost(tx *btcutil.Tx, isCoinBaseTx bool, utxoView *UtxoViewpoint,
 	if segWit && !isCoinBaseTx {
 		msgTx := tx.MsgTx()
 		for txInIndex, txIn := range msgTx.TxIn {
-			// Ensure the referenced input transaction is available.
-			originTxHash := &txIn.PreviousOutPoint.Hash
-			originTxIndex := txIn.PreviousOutPoint.Index
-			txEntry := utxoView.LookupEntry(originTxHash)
-			if txEntry == nil || txEntry.IsOutputSpent(originTxIndex) {
+			// Ensure the referenced output is available and hasn't
+			// already been spent.
+			utxo := utxoView.LookupEntry(txIn.PreviousOutPoint)
+			if utxo == nil || utxo.IsSpent() {
 				str := fmt.Sprintf("output %v referenced from "+
 					"transaction %s:%d either does not "+
 					"exist or has already been spent",
@@ -101,7 +107,7 @@ func GetSigOpCost(tx *btcutil.Tx, isCoinBaseTx bool, utxoView *UtxoViewpoint,
 
 			witness := txIn.Witness
 			sigScript := txIn.SignatureScript
-			pkScript := txEntry.PkScriptByIndex(originTxIndex)
+			pkScript := utxo.PkScript()
 			numSigOps += txscript.GetWitnessSigOpCount(sigScript, pkScript, witness)
 		}