complain when a class variable shadows a name in __slots__ (closes #12766)
diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
index 1f2039e..3f68ee9 100644
--- a/Lib/test/test_descr.py
+++ b/Lib/test/test_descr.py
@@ -4253,6 +4253,14 @@
foo = Foo()
str(foo)
+ def test_slot_shadows_class(self):
+ with self.assertRaises(ValueError) as cm:
+ class X:
+ __slots__ = ["foo"]
+ foo = None
+ m = str(cm.exception)
+ self.assertEqual("'foo' in __slots__ conflicts with class variable", m)
+
class DictProxyTests(unittest.TestCase):
def setUp(self):
class C(object):
diff --git a/Misc/NEWS b/Misc/NEWS
index 038dc90..4cf9dda 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,9 @@
Core and Builtins
-----------------
+- Issue #12766: Raise an ValueError when creating a class with a class variable
+ that conflicts with a name in __slots__.
+
- Issue #12266: Fix str.capitalize() to correctly uppercase/lowercase
titlecased and cased non-letter characters.
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index bb4622f..3c1d3a1 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -2094,6 +2094,12 @@
if (!tmp)
goto bad_slots;
PyList_SET_ITEM(newslots, j, tmp);
+ if (PyDict_GetItem(dict, tmp)) {
+ PyErr_Format(PyExc_ValueError,
+ "%R in __slots__ conflicts with class variable",
+ tmp);
+ goto bad_slots;
+ }
j++;
}
assert(j == nslots - add_dict - add_weak);