n1 = iconv (cd, &ib, &ibl, &ob, &obl);
n2 = iconv (cd, 0, 0, &ob, &obl);
assert (n1 != (size_t) (-1) && n2 != (size_t) (-1));
n1 = iconv (cd, &ib, &ibl, &ob, &obl);
n2 = iconv (cd, 0, 0, &ob, &obl);
assert (n1 != (size_t) (-1) && n2 != (size_t) (-1));