comment=

/*
 * ???
 */
static VALUE
rb_gzfile_set_comment(obj, str)
    VALUE obj, str;
{
    struct gzfile *gz = get_gzfile(obj);
    VALUE s;
    char *p;

    if (gz->z.flags & GZFILE_FLAG_HEADER_FINISHED) {
        rb_raise(cGzError, "header is already written");
    }
    s = rb_str_dup(rb_str_to_str(str));
    p = memchr(RSTRING(s)->ptr, '\0', RSTRING(s)->len);
    if (p) {
        rb_str_resize(s, p - RSTRING(s)->ptr);
    }
    gz->comment = s;
    return str;
}