if (chs && strcmp (chs, "us-ascii") && strcmp (chs, Charset)) mutt_convert_string (dest, 0, chs, Charset);
static void rfc2231_decode_one (char *dest, char *src, char *chs){  char *d;  for (d = dest; *src; src++)  {    if (*src == '%' && isxdigit (*(src + 1)) && isxdigit (*(src + 2)))    {      *d++ = (hexval (*(src + 1)) << 4) | (hexval (*(src + 2)));      src += 2;    }    else      *d++ = *src;  }    *d = '\0';    if (chs && strcmp (chs, "us-ascii") && strcmp (chs, Charset))    mutt_convert_string (dest, 0, chs, Charset);}