Always return max stream ID from remove account data repl cmds

...instead of returning None when there was not actually any account
data to delete.

This means that in the case of a replication call to remove account data
that didn't exist, the replication response body is now {max_stream_id:
current_stream_id} instead of {max_stream_id: None}.

synapse/handlers/account_data.py

@@ -155,9 +155,6 @@ async def remove_account_data_for_room(
             max_stream_id = await self._store.remove_account_data_for_room(
                 user_id, room_id, account_data_type
             )
-            if max_stream_id is None:
-                # The referenced account data did not exist, so no delete occurred.
-                return None
 
             self._notifier.on_new_event(
                 StreamKeyType.ACCOUNT_DATA, max_stream_id, users=[user_id]
@@ -230,9 +227,6 @@ async def remove_account_data_for_user(
             max_stream_id = await self._store.remove_account_data_for_user(
                 user_id, account_data_type
             )
-            if max_stream_id is None:
-                # The referenced account data did not exist, so no delete occurred.
-                return None
 
             self._notifier.on_new_event(
                 StreamKeyType.ACCOUNT_DATA, max_stream_id, users=[user_id]

synapse/storage/databases/main/account_data.py

@@ -585,7 +585,7 @@ async def add_account_data_to_room(
 
     async def remove_account_data_for_room(
         self, user_id: str, room_id: str, account_data_type: str
-    ) -> Optional[int]:
+    ) -> int:
         """Delete the room account data for the user of a given type.
 
         Args:
@@ -637,15 +637,13 @@ def _remove_account_data_for_room_txn(
                 next_id,
             )
 
-            if not row_updated:
-                return None
-
-            self._account_data_stream_cache.entity_has_changed(user_id, next_id)
-            self.get_room_account_data_for_user.invalidate((user_id,))
-            self.get_account_data_for_room.invalidate((user_id, room_id))
-            self.get_account_data_for_room_and_type.prefill(
-                (user_id, room_id, account_data_type), {}
-            )
+            if row_updated:
+                self._account_data_stream_cache.entity_has_changed(user_id, next_id)
+                self.get_room_account_data_for_user.invalidate((user_id,))
+                self.get_account_data_for_room.invalidate((user_id, room_id))
+                self.get_account_data_for_room_and_type.prefill(
+                    (user_id, room_id, account_data_type), {}
+                )
 
         return self._account_data_id_gen.get_current_token()
 
@@ -753,7 +751,7 @@ async def remove_account_data_for_user(
         self,
         user_id: str,
         account_data_type: str,
-    ) -> Optional[int]:
+    ) -> int:
         """
         Delete a single piece of user account data by type.
 
@@ -840,14 +838,12 @@ def _remove_account_data_for_user_txn(
                 next_id,
             )
 
-            if not row_updated:
-                return None
-
-            self._account_data_stream_cache.entity_has_changed(user_id, next_id)
-            self.get_global_account_data_for_user.invalidate((user_id,))
-            self.get_global_account_data_by_type_for_user.prefill(
-                (user_id, account_data_type), {}
-            )
+            if row_updated:
+                self._account_data_stream_cache.entity_has_changed(user_id, next_id)
+                self.get_global_account_data_for_user.invalidate((user_id,))
+                self.get_global_account_data_by_type_for_user.prefill(
+                    (user_id, account_data_type), {}
+                )
 
         return self._account_data_id_gen.get_current_token()