Refresh the instance from the database before doing any file handling with it

src/documents/signals/handlers.py

@@ -400,6 +400,13 @@ def update_filename_and_move_files(sender, instance, **kwargs):
 
     with FileLock(settings.MEDIA_LOCK):
         try:
+
+            # If this was waiting for the lock, the filename or archive_filename
+            # of this document may have been updated.  This happens if multiple updates
+            # get queued from the UI for the same document
+            # So freshen up the data before doing anything
+            instance.refresh_from_db()
+
             old_filename = instance.filename
             old_source_path = instance.source_path