ns_name_skip (unsigned char **x, unsigned char *y) { *x = 0; return 0; } unsigned char a[2]; int dn_skipname(unsigned char *ptr, unsigned char *eom) { unsigned char *saveptr = ptr; if (ns_name_skip(&ptr, eom) == -1) return (-1); return (ptr - saveptr); } main() { if (dn_skipname (&a[0], &a[1]) == 0) abort (); exit (0); }