- T((T_CALLED("subwin(%p, %d, %d, %d, %d)"), w, l, c, y, x));
- T(("parent has begy = %ld, begx = %ld", (long) w->_begy, (long) w->_begx));
+ WINDOW *result = 0;
+
+ T((T_CALLED("subwin(%p, %d, %d, %d, %d)"), (void *) w, l, c, y, x));
+ if (w != 0) {
+ T(("parent has begy = %ld, begx = %ld", (long) w->_begy, (long) w->_begx));