diff -r b1fb4185e47c -r 037890ecaff5 mercurial/bundle2.py
--- a/mercurial/bundle2.py	Thu Feb 02 17:18:37 2023 +0100
+++ b/mercurial/bundle2.py	Thu Feb 02 17:19:26 2023 +0100
@@ -1234,7 +1234,7 @@
         # we only support fixed size data now.
         # This will be improved in the future.
         if util.safehasattr(self.data, 'next') or util.safehasattr(
-            self.data, b'__next__'
+            self.data, '__next__'
         ):
             buff = util.chunkbuffer(self.data)
             chunk = buff.read(preferedchunksize)