diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 87f671708c..5e3d3886eb 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -21,7 +21,6 @@ from typing import TYPE_CHECKING, Any, Dict, List, Mapping, Optional, Tuple
from canonicaljson import encode_canonical_json
-from twisted.internet import defer
from twisted.internet.interfaces import IDelayedCall
from synapse import event_auth
@@ -57,7 +56,7 @@ from synapse.storage.databases.main.events_worker import EventRedactBehaviour
from synapse.storage.state import StateFilter
from synapse.types import Requester, RoomAlias, StreamToken, UserID, create_requester
from synapse.util import json_decoder, json_encoder, log_failure
-from synapse.util.async_helpers import Linearizer, unwrapFirstError
+from synapse.util.async_helpers import Linearizer, gather_results, unwrapFirstError
from synapse.util.caches.expiringcache import ExpiringCache
from synapse.util.metrics import measure_func
from synapse.visibility import filter_events_for_client
@@ -496,6 +495,7 @@ class EventCreationHandler:
require_consent: bool = True,
outlier: bool = False,
historical: bool = False,
+ allow_no_prev_events: bool = False,
depth: Optional[int] = None,
) -> Tuple[EventBase, EventContext]:
"""
@@ -607,6 +607,7 @@ class EventCreationHandler:
prev_event_ids=prev_event_ids,
auth_event_ids=auth_event_ids,
depth=depth,
+ allow_no_prev_events=allow_no_prev_events,
)
# In an ideal world we wouldn't need the second part of this condition. However,
@@ -882,6 +883,7 @@ class EventCreationHandler:
prev_event_ids: Optional[List[str]] = None,
auth_event_ids: Optional[List[str]] = None,
depth: Optional[int] = None,
+ allow_no_prev_events: bool = False,
) -> Tuple[EventBase, EventContext]:
"""Create a new event for a local client
@@ -912,6 +914,7 @@ class EventCreationHandler:
full_state_ids_at_event = None
if auth_event_ids is not None:
# If auth events are provided, prev events must be also.
+ # prev_event_ids could be an empty array though.
assert prev_event_ids is not None
# Copy the full auth state before it stripped down
@@ -943,14 +946,22 @@ class EventCreationHandler:
else:
prev_event_ids = await self.store.get_prev_events_for_room(builder.room_id)
- # we now ought to have some prev_events (unless it's a create event).
- #
- # do a quick sanity check here, rather than waiting until we've created the
+ # Do a quick sanity check here, rather than waiting until we've created the
# event and then try to auth it (which fails with a somewhat confusing "No
# create event in auth events")
- assert (
- builder.type == EventTypes.Create or len(prev_event_ids) > 0
- ), "Attempting to create an event with no prev_events"
+ if allow_no_prev_events:
+ # We allow events with no `prev_events` but it better have some `auth_events`
+ assert (
+ builder.type == EventTypes.Create
+ # Allow an event to have empty list of prev_event_ids
+ # only if it has auth_event_ids.
+ or auth_event_ids
+ ), "Attempting to create a non-m.room.create event with no prev_events or auth_event_ids"
+ else:
+ # we now ought to have some prev_events (unless it's a create event).
+ assert (
+ builder.type == EventTypes.Create or prev_event_ids
+ ), "Attempting to create a non-m.room.create event with no prev_events"
event = await builder.build(
prev_event_ids=prev_event_ids,
@@ -1156,9 +1167,9 @@ class EventCreationHandler:
# We now persist the event (and update the cache in parallel, since we
# don't want to block on it).
- result = await make_deferred_yieldable(
- defer.gatherResults(
- [
+ result, _ = await make_deferred_yieldable(
+ gather_results(
+ (
run_in_background(
self._persist_event,
requester=requester,
@@ -1170,12 +1181,12 @@ class EventCreationHandler:
run_in_background(
self.cache_joined_hosts_for_event, event, context
).addErrback(log_failure, "cache_joined_hosts_for_event failed"),
- ],
+ ),
consumeErrors=True,
)
).addErrback(unwrapFirstError)
- return result[0]
+ return result
async def _persist_event(
self,
|
