[test] Test that -blocksonly nodes still serve compact blocks.

test/functional/p2p_compactblocks_blocksonly.py

@@ -13,6 +13,7 @@ from test_framework.messages import (
     CInv,
     from_hex,
     msg_block,
+    msg_getdata,
     msg_headers,
     msg_sendcmpct,
 )
@@ -107,5 +108,23 @@ class P2PCompactBlocksBlocksOnly(BitcoinTestFramework):
         p2p_conn_low_bw.sync_with_ping()
         assert_equal(p2p_conn_low_bw.last_message['getdata'].inv, [CInv(MSG_CMPCT_BLOCK, block1.sha256)])
 
+        self.log.info("Test that -blocksonly nodes still serve compact blocks")
+
+        def test_for_cmpctblock(block):
+            if 'cmpctblock' not in p2p_conn_blocksonly.last_message:
+                return False
+            return p2p_conn_blocksonly.last_message['cmpctblock'].header_and_shortids.header.rehash() == block.sha256
+
+        p2p_conn_blocksonly.send_message(msg_getdata([CInv(MSG_CMPCT_BLOCK, block0.sha256)]))
+        p2p_conn_blocksonly.wait_until(lambda: test_for_cmpctblock(block0))
+
+        # Request BIP152 high bandwidth mode from the -blocksonly node.
+        p2p_conn_blocksonly.send_and_ping(msg_sendcmpct(announce=True, version=2))
+
+        block2 = self.build_block_on_tip()
+        self.nodes[0].submitblock(block1.serialize().hex())
+        self.nodes[0].submitblock(block2.serialize().hex())
+        p2p_conn_blocksonly.wait_until(lambda: test_for_cmpctblock(block2))
+
 if __name__ == '__main__':
     P2PCompactBlocksBlocksOnly().main()