From 89d86d07ac89d60b84b28482c1181ac871ee7b6a Mon Sep 17 00:00:00 2001
From: Dave Collins <davec@conformal.com>
Date: Fri, 25 Oct 2013 10:33:37 -0500
Subject: [PATCH] ValidateTransactionScripts now accepts script flags.

This commit modifies the ValidateTransactionScripts API to accept the
recently added ScriptFlags from btcscript.  This provides flexibility to
the caller to choose validation behavior based on those new flags.
---
 scriptval.go | 23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/scriptval.go b/scriptval.go
index 72a67cf7..8426e14f 100644
--- a/scriptval.go
+++ b/scriptval.go
@@ -10,7 +10,6 @@ import (
 	"github.com/conformal/btcutil"
 	"github.com/conformal/btcwire"
 	"math"
-	"time"
 )
 
 // txValidate is used to track results of validating scripts for each
@@ -29,7 +28,7 @@ type txProcessList struct {
 // validateTxIn validates a the script pair for the passed spending transaction
 // (along with the specific input index) and origin transaction (with the
 // specific output index).
-func validateTxIn(txInIdx int, txin *btcwire.TxIn, txSha *btcwire.ShaHash, tx *btcwire.MsgTx, timestamp time.Time, originTx *btcwire.MsgTx) error {
+func validateTxIn(txInIdx int, txin *btcwire.TxIn, txSha *btcwire.ShaHash, tx *btcwire.MsgTx, originTx *btcwire.MsgTx, flags btcscript.ScriptFlags) error {
 	// If the input transaction has no previous input, there is nothing
 	// to check.
 	originTxIdx := txin.PreviousOutpoint.Index
@@ -39,14 +38,15 @@ func validateTxIn(txInIdx int, txin *btcwire.TxIn, txSha *btcwire.ShaHash, tx *b
 
 	if originTxIdx >= uint32(len(originTx.TxOut)) {
 		originTxSha := &txin.PreviousOutpoint.Hash
-		log.Warnf("unable to locate source tx %v spending tx %v", originTxSha, &txSha)
+		log.Warnf("unable to locate source tx %v spending tx %v",
+			originTxSha, &txSha)
 		return fmt.Errorf("invalid index %x", originTxIdx)
 	}
 
 	sigScript := txin.SignatureScript
 	pkScript := originTx.TxOut[originTxIdx].PkScript
 	engine, err := btcscript.NewScript(sigScript, pkScript, txInIdx, tx,
-		timestamp.After(btcscript.Bip16Activation))
+		flags)
 	if err != nil {
 		return err
 	}
@@ -62,7 +62,7 @@ func validateTxIn(txInIdx int, txin *btcwire.TxIn, txSha *btcwire.ShaHash, tx *b
 
 // ValidateTransactionScripts validates the scripts for the passed transaction
 // using multiple goroutines.
-func ValidateTransactionScripts(tx *btcwire.MsgTx, txHash *btcwire.ShaHash, timestamp time.Time, txStore TxStore) (err error) {
+func ValidateTransactionScripts(tx *btcwire.MsgTx, txHash *btcwire.ShaHash, txStore TxStore, flags btcscript.ScriptFlags) (err error) {
 	c := make(chan txValidate)
 	job := tx.TxIn
 	resultErrors := make([]error, len(job))
@@ -87,8 +87,8 @@ func ValidateTransactionScripts(tx *btcwire.MsgTx, txHash *btcwire.ShaHash, time
 			}
 			originTx = txInfo.Tx
 		}
-		err := validateTxIn(txInIdx, job[txInIdx], txHash, tx, timestamp,
-			originTx)
+		err := validateTxIn(txInIdx, job[txInIdx], txHash, tx, originTx,
+			flags)
 		r := txValidate{txInIdx, err}
 		c <- r
 	}
@@ -123,7 +123,12 @@ func ValidateTransactionScripts(tx *btcwire.MsgTx, txHash *btcwire.ShaHash, time
 // checkBlockScripts executes and validates the scripts for all transactions in
 // the passed block.
 func checkBlockScripts(block *btcutil.Block, txStore TxStore) error {
-	timestamp := block.MsgBlock().Header.Timestamp
+	// Setup the script validation flags.  Blocks created after the BIP0016
+	// activation time need to have the pay-to-script-hash checks enabled.
+	var flags btcscript.ScriptFlags
+	if block.MsgBlock().Header.Timestamp.After(btcscript.Bip16Activation) {
+		flags |= btcscript.ScriptBip16
+	}
 
 	txList := block.MsgBlock().Transactions
 	c := make(chan txValidate)
@@ -135,7 +140,7 @@ func checkBlockScripts(block *btcutil.Block, txStore TxStore) error {
 		tx := txList[txIdx]
 		txHash, _ := block.TxSha(txIdx)
 
-		err := ValidateTransactionScripts(tx, txHash, timestamp, txStore)
+		err := ValidateTransactionScripts(tx, txHash, txStore, flags)
 		r := txValidate{txIdx, err}
 		c <- r
 	}