/sync: fix bug in calculating state response (#16930)

Fix a long-standing issue which could cause state to be omitted from the
sync response if the last event was filtered out.

Fixes: https://github.com/element-hq/synapse/issues/16928
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Richard van der Hoff 2024-04-04 13:14:24 +01:00 committed by GitHub
parent 05957ac70f
commit 230b709d9d
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3 changed files with 94 additions and 41 deletions

1
changelog.d/16930.bugfix Normal file
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@ -0,0 +1 @@
Fix a long-standing bug which could cause state to be omitted from `/sync` responses when certain events are filtered out of the timeline.

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@ -1187,15 +1187,14 @@ class SyncHandler:
await_full_state = True
lazy_load_members = False
if batch:
state_at_timeline_end = (
await self._state_storage_controller.get_state_ids_for_event(
batch.events[-1].event_id,
state_at_timeline_end = await self.get_state_at(
room_id,
stream_position=end_token,
state_filter=state_filter,
await_full_state=await_full_state,
)
)
if batch:
state_at_timeline_start = (
await self._state_storage_controller.get_state_ids_for_event(
batch.events[0].event_id,
@ -1204,13 +1203,6 @@ class SyncHandler:
)
)
else:
state_at_timeline_end = await self.get_state_at(
room_id,
stream_position=end_token,
state_filter=state_filter,
await_full_state=await_full_state,
)
state_at_timeline_start = state_at_timeline_end
state_ids = _calculate_state(
@ -1305,17 +1297,6 @@ class SyncHandler:
await_full_state=await_full_state,
)
if batch:
state_at_timeline_end = (
await self._state_storage_controller.get_state_ids_for_event(
batch.events[-1].event_id,
state_filter=state_filter,
await_full_state=await_full_state,
)
)
else:
# We can get here if the user has ignored the senders of all
# the recent events.
state_at_timeline_end = await self.get_state_at(
room_id,
stream_position=end_token,
@ -2847,15 +2828,6 @@ def _calculate_state(
# timeline. We have no way to represent that in the /sync response, and we don't
# even try; it is ether omitted or plonked into `state` as if it were at the start
# of the timeline, depending on what else is in the timeline.)
#
# ----------
#
# Aside 2: it's worth noting that `timeline_end`, as provided to us, is actually
# the state *before* the final event in the timeline. In other words: if the final
# event in the timeline is a state event, it won't be included in `timeline_end`.
# However, that doesn't matter here, because the only difference can be in that
# one piece of state, and by definition that event is in the timeline, so we
# don't need to include it in the `state` section.
state_ids = (
(timeline_end_ids | timeline_start_ids)

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@ -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),