[net processing] Do not request transaction relay from feeler connections

Add a test to verify that feeler connections do not request transaction relay.

Author: jnewbery

src/net_processing.cpp

@@ -1096,7 +1096,7 @@ void PeerManagerImpl::PushNodeVersion(CNode& pnode, int64_t nTime)
     CService addr_you = addr.IsRoutable() && !IsProxy(addr) && addr.IsAddrV1Compatible() ? addr : CService();
     uint64_t your_services{addr.nServices};
 
-    const bool tx_relay = !m_ignore_incoming_txs && pnode.m_tx_relay != nullptr;
+    const bool tx_relay = !m_ignore_incoming_txs && pnode.m_tx_relay != nullptr && !pnode.IsFeelerConn();
     m_connman.PushMessage(&pnode, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::VERSION, PROTOCOL_VERSION, my_services, nTime,
             your_services, addr_you, // Together the pre-version-31402 serialization of CAddress "addrYou" (without nTime)
             my_services, CService(), // Together the pre-version-31402 serialization of CAddress "addrMe" (without nTime)

test/functional/p2p_add_connections.py

@@ -106,6 +106,8 @@ def run_test(self):
 
         # Verify version message received
         assert_equal(feeler_conn.message_count["version"], 1)
+        # Feeler connections do not request tx relay
+        assert_equal(feeler_conn.last_message["version"].relay, 0)
 
 if __name__ == '__main__':
     P2PAddConnections().main()