[test] feefilter during and after IBD

Co-authored-by: Jon Atack <jon@atack.com>

test/functional/p2p_ibd_txrelay.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python3
+# Copyright (c) 2020 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Test fee filters during and after IBD."""
+
+from decimal import Decimal
+
+from test_framework.messages import COIN
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import assert_equal
+
+MAX_FEE_FILTER = Decimal(9170997) / COIN
+NORMAL_FEE_FILTER = Decimal(100) / COIN
+
+
+class P2PIBDTxRelayTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.setup_clean_chain = True
+        self.num_nodes = 2
+        self.extra_args = [
+            ["-minrelaytxfee={}".format(NORMAL_FEE_FILTER)],
+            ["-minrelaytxfee={}".format(NORMAL_FEE_FILTER)],
+        ]
+    def run_test(self):
+        self.log.info("Check that nodes set minfilter to MAX_MONEY while still in IBD")
+        for node in self.nodes:
+            assert node.getblockchaininfo()['initialblockdownload']
+            for conn_info in node.getpeerinfo():
+                assert_equal(conn_info['minfeefilter'], MAX_FEE_FILTER)
+
+        # Come out of IBD by generating a block
+        self.nodes[0].generate(1)
+        self.sync_all()
+
+        self.log.info("Check that nodes reset minfilter after coming out of IBD")
+        for node in self.nodes:
+            assert not node.getblockchaininfo()['initialblockdownload']
+            for conn_info in node.getpeerinfo():
+                assert_equal(conn_info['minfeefilter'], NORMAL_FEE_FILTER)
+
+
+if __name__ == '__main__':
+    P2PIBDTxRelayTest().main()

test/functional/test_runner.py

@@ -246,6 +246,7 @@ BASE_SCRIPTS = [
     'rpc_help.py',
     'feature_help.py',
     'feature_shutdown.py',
+    'p2p_ibd_txrelay.py',
     # Don't append tests at the end to avoid merge conflicts
     # Put them in a random line within the section that fits their approximate run-time
 ]