Fix a bug which could lead to incorrect state (#13278)

There are two fixes here:
1. A long-standing bug where we incorrectly calculated `delta_ids`; and
2. A bug introduced in #13267 where we got current state incorrect.

1 files changed, 2 insertions, 1 deletions

diff --git a/synapse/storage/controllers/persist_events.py b/synapse/storage/controllers/persist_events.py

index af65e5913b..cf98b0ab48 100644
--- a/synapse/storage/controllers/persist_events.py
+++ b/synapse/storage/controllers/persist_events.py
@@ -948,7 +948,8 @@ class EventsPersistenceStorageController:
                 events_context,
             )
 
-        return res.state, None, new_latest_event_ids
+        full_state = await res.get_state(self._state_controller)
+        return full_state, None, new_latest_event_ids
 
     async def _prune_extremities(
         self,