switch (tolower (*s))
switch (tolower ((unsigned char) *s))
static int address_header_decode (char **h){  char *s = *h;  int l;  ADDRESS *a = NULL;  switch (tolower (*s))  {    case 'r':     {      if (ascii_strncasecmp (s, "return-path:", 12) == 0)      {	l = 12;	break;      }      else if (ascii_strncasecmp (s, "reply-to:", 9) == 0)      {	l = 9;	break;      }      return 0;    }    case 'f':     {      if (ascii_strncasecmp (s, "from:", 5)) 	return 0;       l = 5;      break;    }    case 'c':    {      if (ascii_strncasecmp (s, "cc:", 3))	return 0;      l = 3;      break;          }    case 'b':    {      if (ascii_strncasecmp (s, "bcc:", 4))	return 0;      l = 4;      break;    }    case 's':    {      if (ascii_strncasecmp (s, "sender:", 7))	return 0;      l = 7;      break;    }    case 't':    {      if (ascii_strncasecmp (s, "to:", 3))	return 0;      l = 3;      break;    }    case 'm':    {      if (ascii_strncasecmp (s, "mail-followup-to:", 17))	return 0;      l = 17;      break;    }    default: return 0;      }  if ((a = rfc822_parse_adrlist (a, s + l + 1)) == NULL)    return 0;    mutt_addrlist_to_local (a);  rfc2047_decode_adrlist (a);    *h = safe_calloc (1, l + 2);    strfcpy (*h, s, l + 1);    format_address_header (h, a);  rfc822_free_address (&a);    FREE (&s);  return 1;}