Fix cell rewriting some more.

src/attr/_make.py

@@ -386,7 +386,13 @@ def slots_setstate(self, state):
  # as `method.__closure__`. Since we replace the class with a
  # clone, we rewrite these references so it keeps working.
  for item in cls.__dict__.values():
- closure_cells = getattr(item, "__closure__", None)
+ if isinstance(item, (classmethod, staticmethod)):
+ # Class- and staticmethods hide their functions inside.
+ # These might need to be rewritten as well.
+ closure_cells = getattr(item.__func__, "__closure__", None)
+ else:
+ closure_cells = getattr(item, "__closure__", None)
+
  if not closure_cells: # Catch None or the empty list.
  continue
  for cell in closure_cells:

tests/test_slots.py

@@ -371,3 +371,30 @@ def my_subclass(self):
 
  assert non_slot_instance.my_subclass() is C2
  assert slot_instance.my_subclass() is C2Slots
+
+
+@pytest.mark.skipif(PY2, reason="closure cell rewriting is PY3-only.")
+@pytest.mark.parametrize("slots", [True, False])
+def test_closure_cell_rewriting_cls_static(slots):
+ """
+ Slot classes support proper closure cell rewriting for class- and static
+ methods.
+ """
+ # Python can reuse closure cells, so we create new classes just for
+ # this test.
+
+ @attr.s(slots=slots)
+ class C:
+ @classmethod
+ def clsmethod(cls):
+ return __class__ # noqa: F821
+
+ assert C.clsmethod() is C
+
+ @attr.s(slots=slots)
+ class D:
+ @staticmethod
+ def statmethod():
+ return __class__ # noqa: F821
+
+ assert D.statmethod() is D