"C" character set (again)

[Andy Koppe]

2010/1/8 Corinna Vinschen:
>> But I think it would actually be quite easy to wave invalid bytes
>> through anyway: print the byte, reset the multibyte conversion state,
>> and continue processing the string. Still valid according to POSIX,
>> but also Linux-compatible. I'll propose a patch.
>
> I hacked a patch already yesterday:

Cool. Got round to trying it now.

> Index: libc/stdio/vfprintf.c
> ===================================================================
> RCS file: /cvs/src/src/newlib/libc/stdio/vfprintf.c,v
> retrieving revision 1.76
> diff -u -p -r1.76 vfprintf.c
> --- libc/stdio/vfprintf.c       18 Nov 2009 09:49:56 -0000      1.76
> +++ libc/stdio/vfprintf.c       8 Jan 2010 12:47:31 -0000
> @@ -724,8 +724,12 @@ _DEFUN(_VFPRINTF_R, (data, fp, fmt0, ap)
>                cp = fmt;
>  #ifdef _MB_CAPABLE
>                while ((n = __mbtowc (data, &wc, fmt, MB_CUR_MAX,
> -                                     __locale_charset (), &state)) > 0) {
> -                    if (wc == '%')
> +                                     __locale_charset (), &state)) != 0) {
> +                   if (n < 0) {
> +                       memset (&state, 0, sizeof state);
> +                       n = 1;
> +                   }
> +                    else if (wc == '%')
>                         break;
>                     fmt += n;
>                }
>
> It works, but I'm feeling uneasy about this.

Looks good to me, and works here too. As far as I can see, there's
nothing down the line (i.e. in  __(s)sprint_r)  that would choke on
invalid bytes.

(Btw, I was surprised to discover the integer-only variants of the
printf functions. Those seem rather unnecessary for Cygwin, but I
guess once they're in it's impossible to throw them out ...)

Andy