zilencer: Truncate "remove" notifications from remote servers.

This is 4d055a6695, but for notifications which are received from
remote hosts.

zerver/tests/test_push_notifications.py

@@ -279,28 +279,36 @@ class PushBouncerNotificationTest(BouncerTestCase):
         hamlet = self.example_user("hamlet")
         server = RemoteZulipServer.objects.get(uuid=self.server_uuid)
         token = "aaaa"
+        android_tokens = []
         for i in ["aa", "bb"]:
+            android_tokens.append(
                 RemotePushDeviceToken.objects.create(
                     kind=RemotePushDeviceToken.GCM,
                     token=hex_to_b64(token + i),
                     user_id=hamlet.id,
                     server=server,
                 )
-        RemotePushDeviceToken.objects.create(
+            )
+        apple_token = RemotePushDeviceToken.objects.create(
             kind=RemotePushDeviceToken.APNS,
             token=hex_to_b64(token),
             user_id=hamlet.id,
             server=server,
         )
+        many_ids = ",".join(str(i) for i in range(1, 250))
         payload = {
             "user_id": hamlet.id,
-            "gcm_payload": "test",
+            "gcm_payload": {"event": "remove", "zulip_message_ids": many_ids},
-            "apns_payload": "test",
+            "apns_payload": {"event": "remove", "zulip_message_ids": many_ids},
             "gcm_options": {},
         }
-        with mock.patch("zilencer.views.send_android_push_notification"), mock.patch(
+        with mock.patch(
+            "zilencer.views.send_android_push_notification"
+        ) as android_push, mock.patch(
             "zilencer.views.send_apple_push_notification"
-        ), self.assertLogs("zilencer.views", level="INFO") as logger:
+        ) as apple_push, self.assertLogs(
+            "zilencer.views", level="INFO"
+        ) as logger:
             result = self.uuid_post(
                 self.server_uuid,
                 "/api/v1/remotes/push/notify",
@@ -321,6 +329,19 @@ class PushBouncerNotificationTest(BouncerTestCase):
                 "2 via FCM devices, 1 via APNs devices"
             ],
         )
+        apple_push.assert_called_once_with(
+            hamlet.id,
+            [apple_token],
+            {"event": "remove", "zulip_message_ids": ",".join(str(i) for i in range(50, 250))},
+            remote=server,
+        )
+        android_push.assert_called_once_with(
+            hamlet.id,
+            list(reversed(android_tokens)),
+            {"event": "remove", "zulip_message_ids": ",".join(str(i) for i in range(50, 250))},
+            {},
+            remote=server,
+        )
 
     def test_remote_push_unregister_all(self) -> None:
         payload = self.get_generic_payload("register")

zilencer/views.py

@@ -202,10 +202,25 @@ def remote_server_notify_push(
         len(apple_devices),
     )
 
+    # Truncate incoming pushes to 200, due to APNs maximum message
+    # sizes; see handle_remove_push_notification for the version of
+    # this for notifications generated natively on the server.  We
+    # apply this to remote-server pushes in case they predate that
+    # commit.
+    def truncate_payload(payload: Dict[str, Any]) -> Dict[str, Any]:
+        MAX_MESSAGE_IDS = 200
+        if payload and payload.get("event") == "remove" and payload.get("zulip_message_ids"):
+            ids = [int(id) for id in payload["zulip_message_ids"].split(",")]
+            truncated_ids = list(sorted(ids))[-MAX_MESSAGE_IDS:]
+            payload["zulip_message_ids"] = ",".join(str(id) for id in truncated_ids)
+        return payload
+
+    gcm_payload = truncate_payload(gcm_payload)
     send_android_push_notification(
         user_id, android_devices, gcm_payload, gcm_options, remote=server
     )
 
+    apns_payload = truncate_payload(apns_payload)
     send_apple_push_notification(user_id, apple_devices, apns_payload, remote=server)
 
     return json_success(