diff --git a/tests/handlers/test_sync.py b/tests/handlers/test_sync.py
index 897c52c785..5d8e886541 100644
--- a/tests/handlers/test_sync.py
+++ b/tests/handlers/test_sync.py
@@ -355,6 +355,86 @@ class SyncTestCase(tests.unittest.HomeserverTestCase):
[s2_event],
)
+ def test_state_includes_changes_on_forks_when_events_excluded(self) -> None:
+ """A variation on the previous test, but where one event is filtered
+
+ The DAG is the same as the previous test, but E4 is excluded by the filter.
+
+ E1
+ ↗ ↖
+ | S2
+ | ↑
+ --|------|----
+ | |
+ E3 |
+ ↖ /
+ (E4)
+
+ """
+
+ alice = self.register_user("alice", "password")
+ alice_tok = self.login(alice, "password")
+ alice_requester = create_requester(alice)
+ room_id = self.helper.create_room_as(alice, is_public=True, tok=alice_tok)
+
+ # Do an initial sync as Alice to get a known starting point.
+ initial_sync_result = self.get_success(
+ self.sync_handler.wait_for_sync_for_user(
+ alice_requester, generate_sync_config(alice)
+ )
+ )
+ last_room_creation_event_id = (
+ initial_sync_result.joined[0].timeline.events[-1].event_id
+ )
+
+ # Send a state event, and a regular event, both using the same prev ID
+ with self._patch_get_latest_events([last_room_creation_event_id]):
+ s2_event = self.helper.send_state(room_id, "s2", {}, tok=alice_tok)[
+ "event_id"
+ ]
+ e3_event = self.helper.send(room_id, "e3", tok=alice_tok)["event_id"]
+
+ # Send a final event, joining the two branches of the dag
+ self.helper.send(room_id, "e4", type="not_a_normal_message", tok=alice_tok)[
+ "event_id"
+ ]
+
+ # do an incremental sync, with a filter that will only return E3, excluding S2
+ # and E4.
+ incremental_sync = self.get_success(
+ self.sync_handler.wait_for_sync_for_user(
+ alice_requester,
+ generate_sync_config(
+ alice,
+ filter_collection=FilterCollection(
+ self.hs,
+ {
+ "room": {
+ "timeline": {
+ "limit": 1,
+ "not_types": ["not_a_normal_message"],
+ }
+ }
+ },
+ ),
+ ),
+ since_token=initial_sync_result.next_batch,
+ )
+ )
+
+ # The state event should appear in the 'state' section of the response.
+ room_sync = incremental_sync.joined[0]
+ self.assertEqual(room_sync.room_id, room_id)
+ self.assertTrue(room_sync.timeline.limited)
+ self.assertEqual(
+ [e.event_id for e in room_sync.timeline.events],
+ [e3_event],
+ )
+ self.assertEqual(
+ [e.event_id for e in room_sync.state.values()],
+ [s2_event],
+ )
+
@parameterized.expand(
[
(False, False),
|
