rem: int ch = *((*format_ptr)++);
add: unsigned char ch = *(*format_ptr)++;
context: get_format_conv_type (char **format_ptr){  int ch = *((*format_ptr)++);  switch (ch)    {    case 'd':    case 'i':    case 'o':    case 'u':    case 'x':    case 'X':      break;    case 0:      error (EXIT_FAILURE, 0, _("missing conversion specifier in suffix"));      break;    default:      if (ISPRINT (ch))        error (EXIT_FAILURE, 0,	       _("invalid conversion specifier in suffix: %c"), ch);      else	error (EXIT_FAILURE, 0,	       _("invalid conversion specifier in suffix: \\%.3o"), ch);    }}