1void abort (void);
2
3int j;
4
5void bla (int *r)
6{
7  int *p, *q;
8
9  p = q = r;
10  if (!p)
11    p = &j;
12
13  if (p != q)
14    j = 1;
15}
16
17int main (void)
18{
19  bla (0);
20  if (!j)
21    abort ();
22  return 0;
23}
24