Ensure that we delete staging push actions on errors

synapse/handlers/message.py

@@ -683,9 +683,15 @@ class EventCreationHandler(object):
             event, context
         )
 
-        (event_stream_id, max_stream_id) = yield self.store.persist_event(
-            event, context=context
-        )
+        try:
+            (event_stream_id, max_stream_id) = yield self.store.persist_event(
+                event, context=context
+            )
+        except:  # noqa: E722, as we reraise the exception this is fine.
+            # Ensure that we actually remove the entries in the push actions
+            # staging area
+            preserve_fn(self.store.remove_push_actions_from_staging)(event.event_id)
+            raise
 
         # this intentionally does not yield: we don't care about the result
         # and don't need to wait for it.

synapse/storage/event_push_actions.py

@@ -782,6 +782,22 @@ class EventPushActionsStore(SQLBaseStore):
             desc="add_push_actions_to_staging",
         )
 
+    def remove_push_actions_from_staging(self, event_id):
+        """Called if we failed to persist the event to ensure that stale push
+        actions don't build up in the DB
+
+        Args:
+            event_id (str)
+        """
+
+        return self._simple_delete(
+            table="event_push_actions_staging",
+            keyvalues={
+                "event_id": event_id,
+            },
+            desc="remove_push_actions_from_staging",
+        )
+
 
 def _action_has_highlight(actions):
     for action in actions: