fix create contract address collision, GST +1

GeneralStateTests.md

@@ -186,14 +186,14 @@ OK: 50/79 Fail: 0/79 Skip: 29/79
   createInitFailUndefinedInstruction.json                         Skip
 + createInitFail_OOGduringInit.json                               OK
 + createInitOOGforCREATE.json                                     OK
-  createJS_ExampleContract.json                                   Skip
++ createJS_ExampleContract.json                                   OK
 + createJS_NoCollision.json                                       OK
 + createNameRegistratorPerTxs.json                                OK
 + createNameRegistratorPerTxsNotEnoughGas.json                    OK
 + createNameRegistratorPreStore1NotEnoughGas.json                 OK
 + createNameRegistratorendowmentTooHigh.json                      OK
 ```
-OK: 18/39 Fail: 0/39 Skip: 21/39
+OK: 19/39 Fail: 0/39 Skip: 20/39
 ## stCallDelegateCodesCallCodeHomestead
 ```diff
   callcallcallcode_001.json                                       Skip
@@ -2520,4 +2520,4 @@ OK: 0/133 Fail: 0/133 Skip: 133/133
 OK: 0/130 Fail: 0/130 Skip: 130/130
 
 ---TOTAL---
-OK: 1309/2334 Fail: 0/2334 Skip: 1025/2334
+OK: 1310/2334 Fail: 0/2334 Skip: 1024/2334

nimbus/p2p/executor.nim

@@ -29,17 +29,23 @@ proc processTransaction*(tx: Transaction, sender: EthAddress, vmState: BaseVMSta
   if balance < upfrontGasCost:
     return tx.gasLimit
 
-  var computation = setupComputation(vmState, tx, sender, forkOverride)
+  let recipient = tx.getRecipient()
+  let isCollision = vmState.readOnlyStateDb().hasCodeOrNonce(recipient)
+
+  var computation = setupComputation(vmState, tx, sender, recipient, forkOverride)
   if computation.isNil:
     return 0
-    
+
   vmState.mutateStateDB:
     db.incNonce(sender)
     db.subBalance(sender, upfrontGasCost)
 
+  if tx.isContractCreation and isCollision:
+    return tx.gasLimit
+
   var snapshot = vmState.snapshot()
   defer: snapshot.dispose()
- 
+
   var contractOK = true
   result = tx.gasLimit
 

nimbus/rpc/p2p.nim

@@ -35,11 +35,13 @@ template balance(addressDb: ReadOnlyStateDb, address: EthAddress): GasInt =
 
 proc binarySearchGas(vmState: var BaseVMState, transaction: Transaction, sender: EthAddress, gasPrice: GasInt, tolerance = 1): GasInt =
   proc dummyComputation(vmState: var BaseVMState, transaction: Transaction, sender: EthAddress): BaseComputation =
+    let recipient = transaction.getRecipient()
     # Note that vmState may be altered
     setupComputation(
         vmState,
         transaction,
-        sender)
+        sender, 
+        recipient)
 
   proc dummyTransaction(gasLimit, gasPrice: GasInt, destination: EthAddress, value: UInt256): Transaction =
     Transaction(

nimbus/vm_state_transactions.nim

@@ -24,14 +24,13 @@ proc validateTransaction*(vmState: BaseVMState, transaction: Transaction, sender
     transaction.accountNonce == readOnlyDB.getNonce(sender) and
     readOnlyDB.getBalance(sender) >= gasCost
 
-proc setupComputation*(vmState: BaseVMState, tx: Transaction, sender: EthAddress, forkOverride=none(Fork)) : BaseComputation =
+proc setupComputation*(vmState: BaseVMState, tx: Transaction, sender, recipient: EthAddress, forkOverride=none(Fork)) : BaseComputation =
   let fork =
     if forkOverride.isSome:
       forkOverride.get
     else:
       vmState.blockNumber.toFork
 
-  var recipient: EthAddress
   var gas = tx.gasLimit - tx.intrinsicGas
 
   # TODO: refactor message to use byterange
@@ -39,12 +38,10 @@ proc setupComputation*(vmState: BaseVMState, tx: Transaction, sender: EthAddress
   var data, code: seq[byte]
 
   if tx.isContractCreation:
-    recipient = generateAddress(sender, tx.accountNonce)
     gas = gas - gasFees[fork][GasTXCreate]
     data = @[]
     code = tx.payload
   else:
-    recipient = tx.to
     data = tx.payload
     code = vmState.readOnlyStateDB.getCode(tx.to).toSeq
 

tests/test_generalstate_failing.nim

@@ -78,8 +78,7 @@ func allowedFailingGeneralStateTest*(folder, name: string): bool =
     "callcodecallcallcode_ABCB_RECURSIVE.json",
     "callcodecallcodecall_ABCB_RECURSIVE.json",
     "callcodecallcodecallcode_ABCB_RECURSIVE.json",
-    # Frontier failed test cases
+    # Frontier failed test cases    
-    "createJS_ExampleContract.json",
     "callcallcallcode_001_OOGMAfter_1.json",
     "callcallcallcode_001_OOGMAfter_2.json",
     "createInitFailUndefinedInstruction.json",