new_contents: #!/usr/bin/env python3
  # Copyright (c) 2014-2018 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 mandatory coinbase feature"""
  
  from binascii import b2a_hex
  
  from test_framework.blocktools import create_coinbase
  from test_framework.messages import CBlock
  from test_framework.test_framework import BitcoinTestFramework
  from test_framework.util import assert_equal, assert_raises_rpc_error
  
  mandatory_privkey = "cNaQCDwmmh4dS9LzCgVtyy1e1xjCJ21GUDHe9K98nzb689JvinGV"
  mandatory_address = "n3NkSZqoPMCQN5FENxUBw4qVATbytH6FDK"
  mandatory_pubkey = "02fcba7ecf41bc7e1be4ee122d9d22e3333671eb0a3a87b5cdf099d59874e1940f"
  mandatory_script = "76a914efc58b838b3153174bf3d1677b7213353a4dccfd88ac"
  
  def b2x(b):
      return b2a_hex(b).decode('ascii')
  
  def assert_template(node, block, expect, rehash=True):
      if rehash:
          block.hashMerkleRoot = block.calc_merkle_root()
      rsp = node.getblocktemplate({'data': b2x(block.serialize()), 'mode': 'proposal'})
      assert_equal(rsp, expect)
  
  class MandatoryCoinbaseTest(BitcoinTestFramework):
      def set_test_params(self):
          self.num_nodes = 2
          self.setup_clean_chain = True
          # Non-zero coinbase outputs *must* match this. Not setting it means anything is allowed
          self.extra_args = [["-con_mandatorycoinbase="+mandatory_script], []]
  
      def run_test(self):
          node0 = self.nodes[0]
          node1 = self.nodes[1]
  
          node0.importprivkey(mandatory_privkey)
  
          self.log.info("generatetoaddress: Making blocks of various kinds, checking for rejection")
  
          # Create valid blocks to get out of IBD and get some funds (subsidy goes to permitted addr)
          node0.generatetoaddress(101, mandatory_address)
  
          # Generating for another address will not work
          assert_raises_rpc_error(-1, "CreateNewBlock: TestBlockValidity failed: bad-coinbase-txos", node0.generatetoaddress, 1, node0.getnewaddress())
  
          # Have non-mandatory node make a template
          self.sync_all()
          tmpl = node1.getblocktemplate()
  
          # We make a block with OP_TRUE coinbase output that will fail on node0
          coinbase_tx = create_coinbase(height=int(tmpl["height"]) + 1)
          # sequence numbers must not be max for nLockTime to have effect
          coinbase_tx.vin[0].nSequence = 2 ** 32 - 2
          coinbase_tx.rehash()
  
          block = CBlock()
          block.nVersion = tmpl["version"]
          block.hashPrevBlock = int(tmpl["previousblockhash"], 16)
          block.nTime = tmpl["curtime"]
          block.nBits = int(tmpl["bits"], 16)
          block.nNonce = 0
          block.vtx = [coinbase_tx]
  
          self.log.info("getblocktemplate: Test block on both nodes")
          assert_equal(node0.submitblock(b2x(block.serialize())), 'invalid')
          assert_template(node1, block, None)
  
          self.log.info("getblocktemplate: Test non-subsidy block on both nodes")
          # Without block reward anything goes, this allows commitment outputs like segwit
          coinbase_tx.vout[0].nValue = 0
          coinbase_tx.rehash()
          block.vtx = [coinbase_tx]
          assert_template(node0, block, None)
          assert_template(node1, block, None)
  
  if __name__ == '__main__':
      MandatoryCoinbaseTest().main()
  
subject: add mandatory coinbase functional test