Merge bitcoin/bitcoin#34429: test: Check that redundant verack message is ignored

fafdae4 test: Check that redundant verack message is ignored (MarcoFalke)

Pull request description:

  The code exists and is uncovered (ref https://maflcko.github.io/b-c-cov/total.coverage/src/net_processing.cpp.gcov.html#L3795), so add a trivial test to cover it.

ACKs for top commit:
  brunoerg:
    ACK fafdae4
  sedited:
    ACK fafdae4

Tree-SHA512: 157f434c2faa16243890b2344c4ee36bc359e56c80ba8a04f0bba71e9760cf9106c38ed755ff57eff8d1957f35516d20b3d010e0ecb8633b845f5314cc0d050a

Author: sedited

test/functional/p2p_handshake.py

@@ -16,6 +16,7 @@
     NODE_NONE,
     NODE_P2P_V2,
     NODE_WITNESS,
+    msg_verack,
 )
 from test_framework.p2p import P2PInterface
 from test_framework.util import p2p_port
@@ -72,6 +73,13 @@ def generate_at_mocktime(self, time):
 
     def run_test(self):
         node = self.nodes[0]
+
+        self.log.info("Check that redundant verack message is ignored")
+        verack_conn = node.add_p2p_connection(P2PInterface())
+        with node.assert_debug_log(["ignoring redundant verack message"]):
+            verack_conn.send_and_ping(msg_verack())
+        node.disconnect_p2ps()
+
         self.log.info("Check that lacking desired service flags leads to disconnect (non-pruned peers)")
         self.test_desirable_service_flags(node, [NODE_NONE, NODE_NETWORK, NODE_WITNESS],
                                           DESIRABLE_SERVICE_FLAGS_FULL, expect_disconnect=True)