Fix p2p-feefilter.py for changed tx relay behavior

qa/rpc-tests/p2p-feefilter.py

@@ -62,6 +62,7 @@ def setup_network(self):
 
     def run_test(self):
         node1 = self.nodes[1]
+        node0 = self.nodes[0]
         # Get out of IBD
         node1.generate(1)
         sync_blocks(self.nodes)
@@ -91,8 +92,17 @@ def run_test(self):
         node1.settxfee(Decimal("0.00010000"))
         [node1.sendtoaddress(node1.getnewaddress(), 1) for x in range(3)]
         sync_mempools(self.nodes) # must be sure node 0 has received all txs 
-        time.sleep(10) # wait 10 secs to be sure its doesn't relay any
-        assert(allInvsMatch([], test_node))
+
+        # Send one transaction from node0 that should be received, so that we
+        # we can sync the test on receipt (if node1's txs were relayed, they'd
+        # be received by the time this node0 tx is received). This is
+        # unfortunately reliant on the current relay behavior where we batch up
+        # to 35 entries in an inv, which means that when this next transaction
+        # is eligible for relay, the prior transactions from node1 are eligible
+        # as well.
+        node0.settxfee(Decimal("0.00020000"))
+        txids = [node0.sendtoaddress(node0.getnewaddress(), 1)]
+        assert(allInvsMatch(txids, test_node))
         test_node.clear_invs()
 
         # Remove fee filter and check that txs are received again