diff options
Diffstat (limited to 'Lib/dataclasses.py')
| -rw-r--r-- | Lib/dataclasses.py | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/Lib/dataclasses.py b/Lib/dataclasses.py index 4645ebf..18ab690 100644 --- a/Lib/dataclasses.py +++ b/Lib/dataclasses.py @@ -1156,11 +1156,16 @@ def _add_slots(cls, is_frozen, weakref_slot): itertools.chain.from_iterable(map(_get_slots, cls.__mro__[1:-1])) ) # The slots for our class. Remove slots from our base classes. Add - # '__weakref__' if weakref_slot was given. + # '__weakref__' if weakref_slot was given, unless it is already present. cls_dict["__slots__"] = tuple( - itertools.chain( - itertools.filterfalse(inherited_slots.__contains__, field_names), - ("__weakref__",) if weakref_slot else ()) + itertools.filterfalse( + inherited_slots.__contains__, + itertools.chain( + # gh-93521: '__weakref__' also needs to be filtered out if + # already present in inherited_slots + field_names, ('__weakref__',) if weakref_slot else () + ) + ), ) for field_name in field_names: |