text: #!/usr/bin/env python2
  # Copyright (c) 2014 The Bitcoin Core developers
  # Distributed under the MIT software license, see the accompanying
  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #
  # Test re-org scenarios with a mempool that contains transactions
  # that spend (directly or indirectly) coinbase transactions.
  #
  
  from test_framework.test_framework import BitcoinTestFramework
  from test_framework.util import *
  import os
  import shutil
  
  # Create one-input, one-output, no-fee transaction:
  class MempoolCoinbaseTest(BitcoinTestFramework):
  
      alert_filename = None  # Set by setup_network
  
      def setup_network(self):
          args = ["-checkmempool", "-debug=mempool"]
          self.nodes = []
          self.nodes.append(start_node(0, self.options.tmpdir, args))
          self.nodes.append(start_node(1, self.options.tmpdir, args))
          connect_nodes(self.nodes[1], 0)
          self.is_network_split = False
          self.sync_all
  
      def create_tx(self, from_txid, to_address, amount):
          inputs = [{ "txid" : from_txid, "vout" : 0}]
          outputs = { to_address : amount }
          rawtx = self.nodes[0].createrawtransaction(inputs, outputs)
          signresult = self.nodes[0].signrawtransaction(rawtx)
          assert_equal(signresult["complete"], True)
          return signresult["hex"]
  
      def run_test(self):
          start_count = self.nodes[0].getblockcount()
  
          # Mine three blocks. After this, nodes[0] blocks
          # 101, 102, and 103 are spend-able.
          new_blocks = self.nodes[1].generate(4)
          self.sync_all()
  
          node0_address = self.nodes[0].getnewaddress()
          node1_address = self.nodes[1].getnewaddress()
  
          # Three scenarios for re-orging coinbase spends in the memory pool:
          # 1. Direct coinbase spend  :  spend_101
          # 2. Indirect (coinbase spend in chain, child in mempool) : spend_102 and spend_102_1
          # 3. Indirect (coinbase and child both in chain) : spend_103 and spend_103_1
          # Use invalidatblock to make all of the above coinbase spends invalid (immature coinbase),
          # and make sure the mempool code behaves correctly.
          b = [ self.nodes[0].getblockhash(n) for n in range(102, 105) ]
          coinbase_txids = [ self.nodes[0].getblock(h)['tx'][0] for h in b ]
          spend_101_raw = self.create_tx(coinbase_txids[0], node1_address, 10)
          spend_102_raw = self.create_tx(coinbase_txids[1], node0_address, 10)
          spend_103_raw = self.create_tx(coinbase_txids[2], node0_address, 10)
  
          # Broadcast and mine spend_102 and 103:
          spend_102_id = self.nodes[0].sendrawtransaction(spend_102_raw)
          spend_103_id = self.nodes[0].sendrawtransaction(spend_103_raw)
          self.nodes[0].generate(1)
  
          # Create 102_1 and 103_1:
          spend_102_1_raw = self.create_tx(spend_102_id, node1_address, 10)
          spend_103_1_raw = self.create_tx(spend_103_id, node1_address, 10)
  
          # Broadcast and mine 103_1:
          spend_103_1_id = self.nodes[0].sendrawtransaction(spend_103_1_raw)
          self.nodes[0].generate(1)
  
          # ... now put spend_101 and spend_102_1 in memory pools:
          spend_101_id = self.nodes[0].sendrawtransaction(spend_101_raw)
          spend_102_1_id = self.nodes[0].sendrawtransaction(spend_102_1_raw)
  
          self.sync_all()
  
          assert_equal(set(self.nodes[0].getrawmempool()), set([ spend_101_id, spend_102_1_id ]))
  
          # Use invalidateblock to re-org back and make all those coinbase spends
          # immature/invalid:
          for node in self.nodes:
              node.invalidateblock(new_blocks[0])
  
          self.sync_all()
  
          # mempool should be empty.
          assert_equal(set(self.nodes[0].getrawmempool()), set())
  
  if __name__ == '__main__':
      MempoolCoinbaseTest().main()
  