More EIP 96 stuff

Author: vub

ethereum/processblock.py

@@ -224,6 +224,7 @@ def __init__(self, block, tx):
         self.msg = lambda msg: _apply_msg(self, msg, self.get_code(msg.code_address))
         self.account_exists = block.account_exists
         self.post_homestead_hardfork = lambda: block.number >= block.config['HOMESTEAD_FORK_BLKNUM']
+        self.post_metropolis_hardfork = lambda: block.number >= block.config['METROPOLIS_FORK_BLKNUM']
 
 
 def apply_msg(ext, msg):

ethereum/vm.py

@@ -384,7 +384,11 @@ def vm_execute(ext, msg, code):
                         mem[start + i] = 0
         elif opcode < 0x50:
             if op == 'BLOCKHASH':
-                stk.append(utils.big_endian_to_int(ext.block_hash(stk.pop())))
+                if ext.post_metropolis_hardfork():
+                    bh_addr = ext._block.config["METROPOLIS_BLOCKHASH_STORE"]
+                    stk.append(ext.get_storage_data(bh_addr, stk.pop()))
+                else:
+                    stk.append(utils.big_endian_to_int(ext.block_hash(stk.pop())))
             elif op == 'COINBASE':
                 stk.append(utils.big_endian_to_int(ext.block_coinbase))
             elif op == 'TIMESTAMP':