initialize __dict__ if needed

Lib/test/test_descr.py

@@ -1444,6 +1444,7 @@ order (MRO) for bases """
             self.fail("classmethod shouldn't accept keyword args")
 
         cm = classmethod(f)
+        self.assertEqual(cm.__dict__, {})
         cm.x = 42
         self.assertEqual(cm.x, 42)
         self.assertEqual(cm.__dict__, {"x" : 42})
@@ -1482,6 +1483,7 @@ order (MRO) for bases """
         self.assertEqual(d.foo(1), (d, 1))
         self.assertEqual(D.foo(d, 1), (d, 1))
         sm = staticmethod(None)
+        self.assertEqual(sm.__dict__, {})
         sm.x = 42
         self.assertEqual(sm.x, 42)
         self.assertEqual(sm.__dict__, {"x" : 42})

Objects/funcobject.c

@@ -832,10 +832,13 @@ cm_get___isabstractmethod__(classmethod *cm, void *closure)
 }
 
 static PyObject *
-cm_get___dict__(classmethod *cm, void *closure)
+cm_get___dict__(PyObject *cm, void *closure)
 {
-    Py_INCREF(cm->cm_dict);
-    return cm->cm_dict;
+    PyObject **dictptr = _PyObject_GetDictPtr(cm);
+    if (*dictptr == NULL)
+        *dictptr = PyDict_New();
+    Py_XINCREF(*dictptr);
+    return *dictptr;
 }
 
 static PyGetSetDef cm_getsetlist[] = {
@@ -1018,10 +1021,13 @@ sm_get___isabstractmethod__(staticmethod *sm, void *closure)
 }
 
 static PyObject *
-sm_get___dict__(staticmethod *sm, void *closure)
+sm_get___dict__(PyObject *sm, void *closure)
 {
-    Py_INCREF(sm->sm_dict);
-    return sm->sm_dict;
+    PyObject **dictptr = _PyObject_GetDictPtr(sm);
+    if (*dictptr == NULL)
+        *dictptr = PyDict_New();
+    Py_XINCREF(*dictptr);
+    return *dictptr;
 }
 
 static PyGetSetDef sm_getsetlist[] = {