Revert "WIP: Don't include the event we branch from"

This reverts commit 9a6d8fa.

synapse/storage/databases/main/event_federation.py

@@ -1094,7 +1094,8 @@ def _get_backfill_events(self, txn, room_id, event_list, limit):
             if event_id in event_results:
                 continue
 
-            found_connected_historical_messages = False
+            event_results.add(event_id)
+
             if self.hs.config.experimental.msc2716_enabled:
                 # Try and find any potential historical batches of message history.
                 #
@@ -1116,9 +1117,7 @@ def _get_backfill_events(self, txn, room_id, event_list, limit):
                     connected_insertion_event_stream_ordering = row[1]
                     connected_insertion_event_id = row[2]
                     connected_insertion_event_type = row[3]
-
                     if connected_insertion_event_id not in event_results:
-                        found_connected_historical_messages = True
                         queue.put(
                             (
                                 -connected_insertion_event_depth,
@@ -1147,26 +1146,18 @@ def _get_backfill_events(self, txn, room_id, event_list, limit):
                         if row[2] not in event_results:
                             queue.put((-row[0], -row[1], row[2], row[3]))
 
-            # Only add the event_result itself if we didn't branch off on the history first
-            # TODO: How can we not branch off to the historical batch if
-            # the federated homeserver already has it backfilled? We
-            # can't make any requests here (no async stuff and should
-            # really only be database calls)
-            if not found_connected_historical_messages:
-                event_results.add(event_id)
-
-                txn.execute(
-                    connected_prev_event_query,
-                    (event_id, False, limit - len(event_results)),
-                )
-                prev_event_id_results = txn.fetchall()
-                logger.debug(
-                    "_get_backfill_events: prev_event_ids %s", prev_event_id_results
-                )
+            txn.execute(
+                connected_prev_event_query,
+                (event_id, False, limit - len(event_results)),
+            )
+            prev_event_id_results = txn.fetchall()
+            logger.debug(
+                "_get_backfill_events: prev_event_ids %s", prev_event_id_results
+            )
 
-                for row in prev_event_id_results:
-                    if row[2] not in event_results:
-                        queue.put((-row[0], -row[1], row[2], row[3]))
+            for row in prev_event_id_results:
+                if row[2] not in event_results:
+                    queue.put((-row[0], -row[1], row[2], row[3]))
 
         return event_results