From fa4d609e20318821e2ffbeb35bfddbc86be81be0 Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Thu, 23 Jan 2020 15:19:03 +0000 Subject: [PATCH] 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. --- changelog.d/6771.bugfix | 1 + synapse/events/__init__.py | 28 ++++++++++++--- synapse/storage/data_stores/main/events.py | 2 +- .../storage/data_stores/main/events_worker.py | 2 +- tests/storage/test_redaction.py | 35 +++++++++++++++++++ 5 files changed, 62 insertions(+), 6 deletions(-) create mode 100644 changelog.d/6771.bugfix diff --git a/changelog.d/6771.bugfix b/changelog.d/6771.bugfix new file mode 100644 index 000000000..623ba24ac --- /dev/null +++ b/changelog.d/6771.bugfix @@ -0,0 +1 @@ +Fix persisting redaction events that have been redacted (or otherwise don't have a redacts key). diff --git a/synapse/events/__init__.py b/synapse/events/__init__.py index 88ed6d764..72c09327f 100644 --- a/synapse/events/__init__.py +++ b/synapse/events/__init__.py @@ -116,16 +116,32 @@ class _EventInternalMetadata(object): return getattr(self, "redacted", False) -def _event_dict_property(key): +_SENTINEL = object() + + +def _event_dict_property(key, default=_SENTINEL): + """Creates a new property for the given key that delegates access to + `self._event_dict`. + + The default is used if the key is missing from the `_event_dict`, if given, + otherwise an AttributeError will be raised. + + Note: If a default is given then `hasattr` will always return true. + """ + # We want to be able to use hasattr with the event dict properties. # However, (on python3) hasattr expects AttributeError to be raised. Hence, # we need to transform the KeyError into an AttributeError - def getter(self): + + def getter_raises(self): try: return self._event_dict[key] except KeyError: raise AttributeError(key) + def getter_default(self): + return self._event_dict.get(key, default) + def setter(self, v): try: self._event_dict[key] = v @@ -138,7 +154,11 @@ def _event_dict_property(key): except KeyError: raise AttributeError(key) - return property(getter, setter, delete) + if default is _SENTINEL: + # No default given, so use the getter that raises + return property(getter_raises, setter, delete) + else: + return property(getter_default, setter, delete) class EventBase(object): @@ -165,7 +185,7 @@ class EventBase(object): origin = _event_dict_property("origin") origin_server_ts = _event_dict_property("origin_server_ts") prev_events = _event_dict_property("prev_events") - redacts = _event_dict_property("redacts") + redacts = _event_dict_property("redacts", None) room_id = _event_dict_property("room_id") sender = _event_dict_property("sender") user_id = _event_dict_property("sender") diff --git a/synapse/storage/data_stores/main/events.py b/synapse/storage/data_stores/main/events.py index 596daf890..ce553566a 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 3b93e0597..7251e819f 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. # diff --git a/tests/storage/test_redaction.py b/tests/storage/test_redaction.py index dc4517335..feb1c07cb 100644 --- a/tests/storage/test_redaction.py +++ b/tests/storage/test_redaction.py @@ -398,3 +398,38 @@ class RedactionTestCase(unittest.HomeserverTestCase): self.get_success( self.store.get_event(first_redact_event.event_id, allow_none=True) ) + + def test_store_redacted_redaction(self): + """Tests that we can store a redacted redaction. + """ + + self.get_success( + self.inject_room_member(self.room1, self.u_alice, Membership.JOIN) + ) + + builder = self.event_builder_factory.for_room_version( + RoomVersions.V1, + { + "type": EventTypes.Redaction, + "sender": self.u_alice.to_string(), + "room_id": self.room1.to_string(), + "content": {"reason": "foo"}, + }, + ) + + redaction_event, context = self.get_success( + self.event_creation_handler.create_new_client_event(builder) + ) + + self.get_success( + self.storage.persistence.persist_event(redaction_event, context) + ) + + # Now lets jump to the future where we have censored the redaction event + # in the DB. + self.reactor.advance(60 * 60 * 24 * 31) + + # We just want to check that fetching the event doesn't raise an exception. + self.get_success( + self.store.get_event(redaction_event.event_id, allow_none=True) + )