--- a/mercurial/interfaces/repository.py	Thu Aug 01 05:35:06 2024 +0200
+++ b/mercurial/interfaces/repository.py	Thu Aug 01 13:40:46 2024 +0200
@@ -1187,7 +1187,7 @@
         The returned object conforms to the ``imanifestdict`` interface.
         """
 
-    def read_any_fast_delta(valid_bases, *, shallow=False):
+    def read_any_fast_delta(valid_bases=None, *, shallow=False):
         """read some manifest information as fast if possible
 
         This might return a "delta", a manifest object containing only file