Re: [patch] *scanf: Allow language-dependent radix character

[Craig Howland <howland at LGSInnovations dot com>]

On 12/17/2013 05:49 PM, Corinna Vinschen wrote:
> On Dec 17 17:32, Craig Howland wrote:
> > On 12/17/2013 04:54 PM, Corinna Vinschen wrote:
> > > If you wonder about the (unsigned char) casts, these are necessary
> > > because the variable 'c' is of type signed int, which breaks the
> > > comparison for non-ASCII char values without the cast.
> > >
> > > The code creating the decpt value at the start of vfwscanf is the same
> > > code as in vfwprintf.
> > >
> > >
> > > Thanks for any review,
> > > Corinna
> > >
> > >
> > > 	* vfscanf.c (__SVFSCANF_R): Handle radix char language-dependent
> > > 	per POSIX.
> > > 	(__SVFWSCANF_R): Ditto.
> > >
> > >
> > > Index: libc/stdio/vfscanf.c
> > > ===================================================================
> > > RCS file: /cvs/src/src/newlib/libc/stdio/vfscanf.c,v
> > > retrieving revision 1.54
> > > diff -u -p -r1.54 vfscanf.c
> > > --- libc/stdio/vfscanf.c	29 Apr 2013 21:06:23 -0000	1.54
> > > +++ libc/stdio/vfscanf.c	17 Dec 2013 21:51:21 -0000
> > > @@ -162,6 +162,7 @@ Supporting OS subroutines required:
> > >   #ifdef FLOATING_POINT
> > > ...
> > > +		      if (decptpos > 0)
> > > +			{
> > > +			  /* We read part of a multibyte decimal point,
> > > +			     but the rest is invalid or we're at EOF,
> > > +			     so back off. */
> > > +			  while (decptpos-- > 0)
> > > +			    {
> > > +			      _ungetc_r (rptr, decpt[decptpos], fp);
> > Shouldn't it be (unsigned char) decpt[decptpos] here, too?  (The
> > same probably goes for the other unget.  Our ungetc directly warns
> > against giving back a signed char.)
> Per POSIX, ungetc is supposed to do the cast to unsigned char by itself,
> and newlib's _ungetc_r does that, so it's safe in this scenario.
Well, it does later on, but not before a comparison against EOF at the start.  
Is 0xFF a permitted byte value in multibyte?  (That would cause a problem.)