Don't bundle events in /sync or /events

As we'll send down the annotations too anyway, so this just ends up
confusing clients.

synapse/events/utils.py

@@ -330,12 +330,13 @@ class EventClientSerializer(object):
         )
 
     @defer.inlineCallbacks
-    def serialize_event(self, event, time_now, **kwargs):
+    def serialize_event(self, event, time_now, bundle_aggregations=True, **kwargs):
         """Serializes a single event.
 
         Args:
             event (EventBase)
             time_now (int): The current time in milliseconds
+            bundle_aggregations (bool): Whether to bundle in related events
             **kwargs: Arguments to pass to `serialize_event`
 
         Returns:
@@ -350,7 +351,7 @@ class EventClientSerializer(object):
 
         # If MSC1849 is enabled then we need to look if thre are any relations
         # we need to bundle in with the event
-        if self.experimental_msc1849_support_enabled:
+        if self.experimental_msc1849_support_enabled and bundle_aggregations:
             annotations = yield self.store.get_aggregation_groups_for_event(
                 event_id,
             )

synapse/handlers/events.py

@@ -122,6 +122,9 @@ class EventStreamHandler(BaseHandler):
 
             chunks = yield self._event_serializer.serialize_events(
                 events, time_now, as_client_event=as_client_event,
+                # We don't bundle "live" events, as otherwise clients
+                # will end up double counting annotations.
+                bundle_aggregations=False,
             )
 
             chunk = {

synapse/rest/client/v2_alpha/sync.py

@@ -358,6 +358,9 @@ class SyncRestServlet(RestServlet):
         def serialize(events):
             return self._event_serializer.serialize_events(
                 events, time_now=time_now,
+                # We don't bundle "live" events, as otherwise clients
+                # will end up double counting annotations.
+                bundle_aggregations=False,
                 token_id=token_id,
                 event_format=event_formatter,
                 only_event_fields=only_fields,