(tests) Upstream large responses not break later queries

test.py

@@ -10,6 +10,7 @@ from aiodnsresolver import (
     TYPES,
     DnsRecordDoesNotExist,
     DnsResponseCode,
+    DnsTimeout,
     IPv4AddressExpiresAt,
     Message,
     ResourceRecord,
@@ -271,6 +272,56 @@ class TestProxy(unittest.TestCase):
         for response in responses:
             self.assertEqual(type(response[0]), IPv4AddressExpiresAt)
 
+    @async_test
+    async def test_too_large_response_from_upstream_not_affect_later(self):
+        num_records = 200
+
+        async def get_response(query_data):
+            query = parse(query_data)
+            response_records = tuple(
+                ResourceRecord(
+                    name=query.qd[0].name,
+                    qtype=TYPES.A,
+                    qclass=1,
+                    ttl=0,
+                    rdata=ipaddress.IPv4Address('123.100.123.' + str(i)).packed,
+                ) for i in range(0, num_records)
+            )
+
+            response = Message(
+                qid=query.qid, qr=RESPONSE, opcode=0, aa=0, tc=0, rd=0, ra=1, z=0, rcode=0,
+                qd=query.qd, an=response_records, ns=(), ar=(),
+            )
+            return pack(response)
+
+        stop_nameserver = await start_nameserver(54, get_response)
+        self.add_async_cleanup(stop_nameserver)
+
+        resolve, clear_cache = get_resolver(53)
+        self.add_async_cleanup(clear_cache)
+
+        start = DnsProxy(rules=((r'(^.*$)', r'\1'),), get_resolver=lambda: get_resolver(54))
+        stop = await start()
+        self.add_async_cleanup(stop)
+
+        tasks = [
+            asyncio.create_task(resolve('www.google.com', TYPES.A))
+            for _ in range(0, 100000)
+        ]
+
+        for task in tasks:
+            with self.assertRaises(DnsTimeout):
+                await task
+
+        num_records = 1
+        tasks = [
+            asyncio.create_task(resolve('www.google.com', TYPES.A))
+            for _ in range(0, 100000)
+        ]
+        responses = await asyncio.gather(*tasks)
+        for response in responses:
+            self.assertEqual(str(response[0]), '123.100.123.0')
+
 
 def get_socket(port):
     def _get_socket():