951 static PyObject *
952 bitarray_append(bitarrayobject *self, PyObject *v)
953 {
954     if (append_item(self, v) < 0)
when considering range: -0x80000000 <= value <= -1
taking True path
955         return NULL;
956 
957     Py_RETURN_NONE;
958 }
returning (PyObject*)NULL without setting an exception