Re: bug in btowc(0)

[Corinna Vinschen <vinschen at redhat dot com>]

On Apr  6 07:09, Eric Blake wrote:
> On 04/06/2010 02:04 AM, Corinna Vinschen wrote:
> > On Apr  5 16:49, Eric Blake wrote:
> >> On the gnulib list, it was pointed out that cygwin btowc has a bug:
> >>
> >> +#include <stdio.h>
> >> +#include <string.h>
> >> +#include <wchar.h>
> >> +int main ()
> >> +{
> >> +  if (btowc ('\0') != 0)
> >> +    return 1;
> >> +  return 0;
> >> +}
> >>
> >> should have status 0, because NUL is an ASCII byte.  Right now, btowc is
> >> mistakenly returning WEOF and this program has status 1.
> > 
> > That's a newlib problem.  Please send the bug report to the newlib
> > list, for the records.  This patch should help:
> > 
> > Index: libc/stdlib/btowc.c
> > ===================================================================
> > RCS file: /cvs/src/src/newlib/libc/stdlib/btowc.c,v
> > retrieving revision 1.3
> > diff -u -p -r1.3 btowc.c
> > --- libc/stdlib/btowc.c	18 Nov 2009 09:49:57 -0000	1.3
> > +++ libc/stdlib/btowc.c	6 Apr 2010 08:02:37 -0000
> > @@ -13,6 +13,9 @@ btowc (int c)
> >    wchar_t pwc;
> >    unsigned char b;
> >  
> > +  if (c == EOF)
> > +    return WEOF;
> > +
> >    b = (unsigned char)c;
> >  
> >    /* Put mbs in initial state. */
> > @@ -22,8 +25,8 @@ btowc (int c)
> >  
> >    retval = __mbtowc (_REENT, &pwc, &b, 1, __locale_charset (), &mbs);
> >  
> > -  if (c == EOF || retval != 1)
> > +  if (retval != 0 && retval != 1)
> >      return WEOF;
> > -  else
> > -    return (wint_t)pwc;
> > +
> > +  return (wint_t)pwc;
> >  }
> > 
> > 
> > Corinna
> > 
> 
> For what it's worth, Corinna's patch looks good to me.

I've applied this patch.


Corinna

-- 
Corinna Vinschen
Cygwin Project Co-Leader
Red Hat