message: qa: Relax so that the subscriber is ready before publishing zmq messages
diff: @@ -10,6 +10,7 @@ from test_framework.test_framework import BitcoinTestFramework
  from test_framework.messages import CTransaction, hash256
  from test_framework.util import assert_equal, connect_nodes
  from io import BytesIO
  +from time import sleep
  def hash256_reversed(byte_str):
  return hash256(byte_str)[::-1]
  @@ -61,7 +62,6 @@ class ZMQTest (BitcoinTestFramework):
  address = 'tcp://127.0.0.1:28332'
  socket = self.ctx.socket(zmq.SUB)
  socket.set(zmq.RCVTIMEO, 60000)
  - socket.connect(address)
  # Subscribe to all available topics.
  hashblock = ZMQSubscriber(socket, b"hashblock")
  @@ -71,6 +71,9 @@ class ZMQTest (BitcoinTestFramework):
  self.restart_node(0, ["-zmqpub%s=%s" % (sub.topic.decode(), address) for sub in [hashblock, hashtx, rawblock, rawtx]])
  connect_nodes(self.nodes[0], 1)
  + socket.connect(address)
  + # Relax so that the subscriber is ready before publishing zmq messages
  + sleep(0.2)
  num_blocks = 5
  self.log.info("Generate %(n)d blocks (and %(n)d coinbase txes)" % {"n": num_blocks})
  @@ -128,11 +131,13 @@ class ZMQTest (BitcoinTestFramework):
  address = 'tcp://127.0.0.1:28333'
  socket = self.ctx.socket(zmq.SUB)
  socket.set(zmq.RCVTIMEO, 60000)
  - socket.connect(address)
  hashblock = ZMQSubscriber(socket, b'hashblock')
  # Should only notify the tip if a reorg occurs
  self.restart_node(0, ['-zmqpub%s=%s' % (hashblock.topic.decode(), address)])
  + socket.connect(address)
  + # Relax so that the subscriber is ready before publishing zmq messages
  + sleep(0.2)
  # Generate 1 block in nodes[0] and receive all notifications
  self.nodes[0].generatetoaddress(1, ADDRESS_BCRT1_UNSPENDABLE)
  