Merge pull request #754 from matrix-org/markjh/check_for_nop

Check that something has happend before running the selects

1 files changed, 3 insertions, 0 deletions

diff --git a/synapse/storage/receipts.py b/synapse/storage/receipts.py

index 3b8805593e..935fc503d9 100644
--- a/synapse/storage/receipts.py
+++ b/synapse/storage/receipts.py
@@ -391,6 +391,9 @@ class ReceiptsStore(SQLBaseStore):
         )
 
     def get_all_updated_receipts(self, last_id, current_id, limit=None):
+        if last_id == current_id:
+            return defer.succeed([])
+
         def get_all_updated_receipts_txn(txn):
             sql = (
                 "SELECT stream_id, room_id, receipt_type, user_id, event_id, data"