Make 'event.redacts' never raise. (#6771)

There are quite a few places that we assume that a redaction event has a
corresponding `redacts` key, which is not always the case. So lets
cheekily make it so that event.redacts just returns None instead.

2 files changed, 2 insertions, 2 deletions

diff --git a/synapse/storage/data_stores/main/events.py b/synapse/storage/data_stores/main/events.py
index 596daf8909..ce553566a5 100644
--- a/synapse/storage/data_stores/main/events.py
+++ b/synapse/storage/data_stores/main/events.py
@@ -951,7 +951,7 @@ class EventsStore(
             elif event.type == EventTypes.Message:
                 # Insert into the event_search table.
                 self._store_room_message_txn(txn, event)
-            elif event.type == EventTypes.Redaction:
+            elif event.type == EventTypes.Redaction and event.redacts is not None:
                 # Insert into the redactions table.
                 self._store_redaction(txn, event)
             elif event.type == EventTypes.Retention:
diff --git a/synapse/storage/data_stores/main/events_worker.py b/synapse/storage/data_stores/main/events_worker.py
index 3b93e0597a..7251e819f5 100644
--- a/synapse/storage/data_stores/main/events_worker.py
+++ b/synapse/storage/data_stores/main/events_worker.py
@@ -287,7 +287,7 @@ class EventsWorkerStore(SQLBaseStore):
             # we have to recheck auth now.
 
             if not allow_rejected and entry.event.type == EventTypes.Redaction:
-                if not hasattr(entry.event, "redacts"):
+                if entry.event.redacts is None:
                     # A redacted redaction doesn't have a `redacts` key, in
                     # which case lets just withhold the event.
                     #