diff --git a/changelog.d/14592.bugfix b/changelog.d/14592.bugfix
new file mode 100644
index 0000000000..149ee99dd7
--- /dev/null
+++ b/changelog.d/14592.bugfix
@@ -0,0 +1 @@
+Fix a long-standing bug where a device list update might not be sent to clients in certain circumstances.
diff --git a/synapse/handlers/presence.py b/synapse/handlers/presence.py
index cf08737d11..1799174c2f 100644
--- a/synapse/handlers/presence.py
+++ b/synapse/handlers/presence.py
@@ -1764,14 +1764,14 @@ class PresenceEventSource(EventSource[int, UserPresenceState]):
Returns:
A list of presence states for the given user to receive.
"""
+ updated_users = None
if from_key:
# Only return updates since the last sync
updated_users = self.store.presence_stream_cache.get_all_entities_changed(
from_key
)
- if not updated_users:
- updated_users = []
+ if updated_users is not None:
# Get the actual presence update for each change
users_to_state = await self.get_presence_handler().current_state_for_users(
updated_users
diff --git a/synapse/storage/databases/main/devices.py b/synapse/storage/databases/main/devices.py
index 534f7fc04a..8ba995df3b 100644
--- a/synapse/storage/databases/main/devices.py
+++ b/synapse/storage/databases/main/devices.py
@@ -842,12 +842,11 @@ class DeviceWorkerStore(RoomMemberWorkerStore, EndToEndKeyWorkerStore):
user_ids, from_key
)
- if not user_ids_to_check:
+ # If an empty set was returned, there's nothing to do.
+ if user_ids_to_check is not None and not user_ids_to_check:
return set()
def _get_users_whose_devices_changed_txn(txn: LoggingTransaction) -> Set[str]:
- changes: Set[str] = set()
-
stream_id_where_clause = "stream_id > ?"
sql_args = [from_key]
@@ -858,19 +857,25 @@ class DeviceWorkerStore(RoomMemberWorkerStore, EndToEndKeyWorkerStore):
sql = f"""
SELECT DISTINCT user_id FROM device_lists_stream
WHERE {stream_id_where_clause}
- AND
"""
- # Query device changes with a batch of users at a time
- # Assertion for mypy's benefit; see also
- # https://mypy.readthedocs.io/en/stable/common_issues.html#narrowing-and-inner-functions
- assert user_ids_to_check is not None
- for chunk in batch_iter(user_ids_to_check, 100):
- clause, args = make_in_list_sql_clause(
- txn.database_engine, "user_id", chunk
- )
- txn.execute(sql + clause, sql_args + args)
- changes.update(user_id for user_id, in txn)
+ # If the stream change cache gave us no information, fetch *all*
+ # users between the stream IDs.
+ if user_ids_to_check is None:
+ txn.execute(sql, sql_args)
+ return {user_id for user_id, in txn}
+
+ # Otherwise, fetch changes for the given users.
+ else:
+ changes: Set[str] = set()
+
+ # Query device changes with a batch of users at a time
+ for chunk in batch_iter(user_ids_to_check, 100):
+ clause, args = make_in_list_sql_clause(
+ txn.database_engine, "user_id", chunk
+ )
+ txn.execute(sql + " AND " + clause, sql_args + args)
+ changes.update(user_id for user_id, in txn)
return changes
|
