void
chart_unref (struct chart *chart)
{
- assert (chart->ref_cnt > 0);
- if (--chart->ref_cnt == 0)
- chart->class->destroy (chart);
+ if (chart != NULL)
+ {
+ assert (chart->ref_cnt > 0);
+ if (--chart->ref_cnt == 0)
+ chart->class->destroy (chart);
+ }
}
void