Send an empty headers response and wait for a replacement request

empty-headers.py

#!/usr/bin/env python3
"""Send an empty headers response and wait for a replacement request."""

import sys

sys.path.insert(0, "test/functional")

from test_framework.messages import msg_headers
from test_framework.p2p import NetworkThread, P2PInterface
from test_framework.util import wait_until_helper_internal


P2P_PORT = 18455
network_thread = NetworkThread()
network_thread.start()
wait_until_helper_internal(lambda: network_thread.network_event_loop is not None and network_thread.network_event_loop.is_running())


def connect():
    peer = P2PInterface()
    peer.peer_connect(dstaddr="127.0.0.1", dstport=P2P_PORT, net="regtest", timeout_factor=1, supports_v2_p2p=False, send_version=True)()
    peer.wait_for_connect()
    peer.wait_for_verack()
    # Ensure the node has processed the handshake before sending headers.
    peer.sync_with_ping()
    return peer


peers = []
try:
    initial = connect()
    peers.append(initial)
    initial.wait_for_getheaders(timeout=10)
    # The empty response clears the peer's local headers state.
    initial.send_and_ping(msg_headers())

    replacement = connect()
    peers.append(replacement)
    # This wait returns on the fix and times out when the slot remains stuck.
    replacement.wait_for_getheaders(timeout=10)
finally:
    for peer in peers:
        peer.peer_disconnect()
    network_thread.close(timeout=10)