Factor out a separate `EventContext.for_outlier` (#10883)

Constructing an EventContext for an outlier is actually really simple, and
there's no sense in going via an `async` method in the `StateHandler`.

This also means that we can resolve a bunch of FIXMEs.

1 files changed, 2 insertions, 5 deletions

diff --git a/synapse/handlers/federation_event.py b/synapse/handlers/federation_event.py

index 3b95beeb08..10b3fdc222 100644
--- a/synapse/handlers/federation_event.py
+++ b/synapse/handlers/federation_event.py
@@ -1221,7 +1221,7 @@ class FederationEventHandler:
         async def prep(ev_info: _NewEventInfo) -> EventContext:
             event = ev_info.event
             with nested_logging_context(suffix=event.event_id):
-                res = await self._state_handler.compute_event_context(event)
+                res = EventContext.for_outlier()
                 res = await self._check_event_auth(
                     origin,
                     event,
@@ -1540,10 +1540,7 @@ class FederationEventHandler:
                             event.event_id,
                             auth_event.event_id,
                         )
-                        missing_auth_event_context = (
-                            await self._state_handler.compute_event_context(auth_event)
-                        )
-
+                        missing_auth_event_context = EventContext.for_outlier()
                         missing_auth_event_context = await self._check_event_auth(
                             origin,
                             auth_event,