Check for EIP155 condition in sign() and extract that check to reusab…

…le function.

index.js

@@ -6,6 +6,12 @@ const BN = ethUtil.BN
 // secp256k1n/2
 const N_DIV_2 = new BN('7fffffffffffffffffffffffffffffff5d576e7357a4501ddfe92f46681b20a0', 16)
 
+const vMeetsEIP155Conditions = (v, _this) => {
+  const vOptions = [_this._chainId * 2 + 35, _this._chainId * 2 + 35 + 1]
+  const hardforkGteSpuriousDragon = _this._common.gteHardfork('spuriousDragon')
+  return hardforkGteSpuriousDragon && vOptions.includes(v)
+}
+
 /**
  * Creates a new transaction object.
  *
@@ -181,10 +187,8 @@ class Transaction {
       // elements (i.e. nonce, gasprice, startgas, to, value, data), hash nine elements, with v replaced by
       // CHAIN_ID, r = 0 and s = 0.
 
-      const onSpuriousDragonOrLater = this._common.gteHardfork('spuriousDragon')
       const v = ethUtil.bufferToInt(this.v)
-      const vMeetsEIP155Conditions = v === this._chainId * 2 + 35 || v === this._chainId * 2 + 36
-      if (onSpuriousDragonOrLater && vMeetsEIP155Conditions) {
+      if (vMeetsEIP155Conditions(v, this)) {
         const raw = this.raw.slice()
         this.v = this._chainId
         this.r = 0
@@ -245,8 +249,7 @@ class Transaction {
 
     try {
       const v = ethUtil.bufferToInt(this.v)
-      const useChainIdWhileRecoveringPubKey = v >= this._chainId * 2 + 35 && this._common.gteHardfork('spuriousDragon')
-      this._senderPubKey = ethUtil.ecrecover(msgHash, v, this.r, this.s, useChainIdWhileRecoveringPubKey && this._chainId)
+      this._senderPubKey = ethUtil.ecrecover(msgHash, v, this.r, this.s, vMeetsEIP155Conditions(v, this) && this._chainId)
     } catch (e) {
       return false
     }
@@ -261,7 +264,7 @@ class Transaction {
   sign (privateKey) {
     const msgHash = this.hash(false)
     const sig = ethUtil.ecsign(msgHash, privateKey)
-    if (this._chainId > 0) {
+    if (vMeetsEIP155Conditions(sig.v, this)) {
       sig.v += this._chainId * 2 + 8
     }
     Object.assign(this, sig)