fix refleaks

Author: iritkatriel

Objects/typeobject.c

@@ -7767,10 +7767,14 @@ _PyType_SharedKeysMaxSize(PyTypeObject *type)
         PyObject *attrs = PyObject_GetAttr((PyObject*)type, &_Py_ID(__expected_attributes__));
         if (attrs != NULL && PyTuple_Check(attrs)) {
             Py_ssize_t num_keys = PyTuple_GET_SIZE(attrs);
+            Py_DECREF(attrs);
             if (num_keys > SHARED_KEYS_MAX_SIZE) {
                 return 1 + num_keys;
             }
         }
+        else {
+            Py_XDECREF(attrs);
+        }
     }
     return SHARED_KEYS_MAX_SIZE;
 }

Python/compile.c

@@ -2552,6 +2552,7 @@ compiler_class_body(struct compiler *c, stmt_ty s, int firstlineno)
         return ERROR;
     }
     ADDOP_LOAD_CONST(c, NO_LOCATION, expected_attributes);
+    Py_CLEAR(expected_attributes);
     if (compiler_nameop(c, NO_LOCATION, &_Py_ID(__expected_attributes__), Store) < 0) {
         compiler_exit_scope(c);
         return ERROR;