already_checked
const STACK_OF(X509) *already_checked)
for (i = sk_X509_num(already_checked /* may be NULL */); i > 0; i--)
if (X509_cmp(sk_X509_value(already_checked, i - 1), cert) == 0)
if (already_checked(cert, already_checked1)
|| already_checked(cert, already_checked2)) {