message: Add functional test test_txid_inv_delay
  Add a simple functional test to cover TXID_RELAY_DELAY as applied
  as a TxRequestTracker parameter in AddTxAnnoucement.
diff: @@ -216,6 +216,25 @@ class TxDownloadTest(BitcoinTestFramework):
  with p2p_lock:
  assert_equal(peer.tx_getdata_count, 1)
  + def test_txid_inv_delay(self, glob_wtxid=False):
  + self.log.info('Check that inv from a txid-relay peers are delayed by {} s, with a wtxid peer {}'.format(TXID_RELAY_DELAY, glob_wtxid))
  + self.restart_node(0, extra_args=['-whitelist=noban@127.0.0.1'])
  + mock_time = int(time.time() + 1)
  + self.nodes[0].setmocktime(mock_time)
  + peer = self.nodes[0].add_p2p_connection(TestP2PConn(wtxidrelay=False))
  + if glob_wtxid:
  + # Add a second wtxid-relay connection otherwise TXID_RELAY_DELAY is waived in
  + # lack of wtxid-relay peers
  + self.nodes[0].add_p2p_connection(TestP2PConn(wtxidrelay=True))
  + peer.send_message(msg_inv([CInv(t=MSG_TX, h=0xff11ff11)]))
  + peer.sync_with_ping()
  + with p2p_lock:
  + assert_equal(peer.tx_getdata_count, 0 if glob_wtxid else 1)
  + self.nodes[0].setmocktime(mock_time + TXID_RELAY_DELAY)
  + peer.wait_until(lambda: peer.tx_getdata_count >= 1, timeout=1)
  + with p2p_lock:
  + assert_equal(peer.tx_getdata_count, 1)
  +
  def test_large_inv_batch(self):
  self.log.info('Test how large inv batches are handled with relay permission')
  self.restart_node(0, extra_args=['-whitelist=relay@127.0.0.1'])
  @@ -242,6 +261,8 @@ class TxDownloadTest(BitcoinTestFramework):
  self.test_disconnect_fallback()
  self.test_notfound_fallback()
  self.test_preferred_inv()
  + self.test_txid_inv_delay()
  + self.test_txid_inv_delay(True)
  self.test_large_inv_batch()
  self.test_spurious_notfound()
  