txscript/script.go

@@ -864,44 +864,44 @@ func finalOpcodeData(scriptVersion uint16, script []byte) []byte {
 // Pay-To-Script-Hash script in order to find the precise number of signature
 // operations in the transaction.  If the script fails to parse, then the count
 // up to the point of failure is returned.
-func GetPreciseSigOpCount(scriptSig, scriptPubKey []byte, bip16 bool) int {
-	// Don't check error since parseScript returns the parsed-up-to-error
-	// list of pops.
-	pops, _ := parseScript(scriptPubKey)
+//
+// WARNING: This function always treats the passed script as version 0.  Great
+// care must be taken if introducing a new script version because it is used in
+// consensus which, unfortunately as of the time of this writing, does not check
+// script versions before counting their signature operations which means nodes
+// on existing rules will count new version scripts as if they were version 0.
+//
+// The third parameter is DEPRECATED and is unused.
+func GetPreciseSigOpCount(scriptSig, scriptPubKey []byte, _ bool) int {
+	const scriptVersion = 0
 
-	// Treat non P2SH transactions as normal.
-	if !(bip16 && isScriptHash(pops)) {
-		return getSigOpCount(pops, true)
-	}
-
-	// The public key script is a pay-to-script-hash, so parse the signature
-	// script to get the final item.  Scripts that fail to fully parse count
-	// as 0 signature operations.
-	sigPops, err := parseScript(scriptSig)
-	if err != nil {
-		return 0
+	// Treat non P2SH transactions as normal.  Note that signature operation
+	// counting includes all operations up to the first parse failure.
+	if !isScriptHashScript(scriptPubKey) {
+		return countSigOpsV0(scriptPubKey, true)
 	}
 
 	// The signature script must only push data to the stack for P2SH to be
 	// a valid pair, so the signature operation count is 0 when that is not
 	// the case.
-	if !isPushOnly(sigPops) || len(sigPops) == 0 {
+	if len(scriptSig) == 0 || !IsPushOnlyScript(scriptSig) {
 		return 0
 	}
 
 	// The P2SH script is the last item the signature script pushes to the
 	// stack.  When the script is empty, there are no signature operations.
-	shScript := sigPops[len(sigPops)-1].data
-	if len(shScript) == 0 {
+	//
+	// Notice that signature scripts that fail to fully parse count as 0
+	// signature operations unlike public key and redeem scripts.
+	redeemScript := finalOpcodeData(scriptVersion, scriptSig)
+	if len(redeemScript) == 0 {
 		return 0
 	}
 
-	// Parse the P2SH script and don't check the error since parseScript
-	// returns the parsed-up-to-error list of pops and the consensus rules
-	// dictate signature operations are counted up to the first parse
-	// failure.
-	shPops, _ := parseScript(shScript)
-	return getSigOpCount(shPops, true)
+	// Return the more precise sigops count for the redeem script.  Note that
+	// signature operation counting includes all operations up to the first
+	// parse failure.
+	return countSigOpsV0(redeemScript, true)
 }
 
 // GetWitnessSigOpCount returns the number of signature operations generated by