fix: add_transaction

Author: heikoheiko

ethereum/chain.py

@@ -270,8 +270,6 @@ def add_transaction(self, transaction):
                   if the transaction was invalid
         """
         assert self.head_candidate is not None
-        _log = log.bind(tx_hash=transaction)
-        _log.debug("add transaction")
         old_state_root = self.head_candidate.state_root
         # revert finalization
         self.head_candidate.state_root = self.pre_finalize_state_root
@@ -283,20 +281,18 @@ def add_transaction(self, transaction):
             log.debug('invalid tx', tx_hash=transaction, errors=e)
             success = False
 
-        # finalize
-        self.pre_finalize_state_root = self.head_candidate.state_root
-        self.head_candidate.finalize()
-
-        if not success:
-            log.debug('tx not applied', tx_hash=transaction)
-            assert old_state_root == self.head_candidate.state_root
-            return False
-        else:
+        if success:
             assert transaction in self.get_transactions()
-            log.debug('transaction applied', tx_hash=transaction,
+            self.pre_finalize_state_root = self.head_candidate.state_root
+            self.head_candidate.finalize()
+            log.debug('tx applied', tx_hash=transaction,
                       block_hash=self.head_candidate, result=output)
             assert old_state_root != self.head_candidate.state_root
             return True
+        else:
+            log.debug('tx not applied', tx_hash=transaction)
+            self.head_candidate.state_root = old_state_root  # reset
+            return False
 
     def get_transactions(self):
         """Get a list of new transactions not yet included in a mined block