if (count <= 1) count = 45; /* default line length for UU-encoding */

str_len_ensure(mrb, dst, didx + ((slen * 4 + 2) / 3) + (slen / count + 1) * 2);

/* Calculate buffer size by accounting for per-line encoding

* Each line encodes separately, so padding happens per line, not globally

*/

mrb_int num_lines = (slen + count - 1) / count; /* Number of lines */

mrb_int total_encoded = 0;

mrb_int temp_slen = slen;

/* Calculate actual encoded size line by line */

while (temp_slen > 0) {

mrb_int line_len = (temp_slen > count) ? count : temp_slen;

total_encoded += ((line_len + 2) / 3) * 4; /* Each line's encoded size */

temp_slen -= line_len;

}

/* Total buffer = encoded data + (length char + newline) per line + terminating line */

mrb_int buffer_size = total_encoded + num_lines * 2 + 2;

str_len_ensure(mrb, dst, didx + buffer_size);

char *dptr = RSTRING_PTR(dst) + didx;

while (slen > 0) {