Hi Marvin,
what do you think is faster ? Scanning the input or
allocing more memory ? For European languages
the length should be between 1 and 2 wcslen(src).
Also where does the +1 come from ?
Last but not least I just wanted to mention there is
a bug in the INPUT part as I use char instead of U8.
Here is the correct code:
INPUT
T_WCHAR
{
// Alloc memory for wide char string. This could be a bit more
// then necessary.
Newz(0, $var, SvLEN($arg), wchar_t);
U8* src = (U8*) SvPV_nolen($arg);
wchar_t* dst = (wchar_t*) $var;
if (SvUTF8($arg)) {
// UTF8 to wide char mapping
STRLEN len;
while (*src) {
*dst++ = utf8_to_uvuni(src, &len);
src += len;
}
} else {
// char to wide char mapping
while (*src) {
*dst++ = (wchar_t) *src++;
}
}
*dst = 0;
SAVEFREEPV($var);
}
Thomas.
Quoting Marvin Humphrey <[EMAIL PROTECTED]>:
>
> On Nov 29, 2006, at 10:55 AM, Thomas Busch wrote:
> > // Alloc memory for wide char string. This is clearly wider
> > // then necessary in most cases but no choice.
> > Newz(0, dst, 3 * wcslen(src), U8);
>
> I think you need to bump that allocation to 4 * wcslen(src) + 1,
> otherwise you run the risk of a buffer overflow in the event that
> your data has too many code points above the BMP. Alternately, you
> can scan the input first and determine how much space you need to
> allocate.
>
> > while (*src) {
> > d = uvuni_to_utf8(d, *src++);
> > }
> > *d = 0;
>
> I assume that uvuni_to_utf8 handles invalid input safely.
>
> The crucial thing here is not to open a security hole. If a user can
> supply input, assume that pathologically munged input is on its way.
> Since this is typemap code, many functions are potentially affected.
>
> Marvin Humphrey
> Rectangular Research
> http://www.rectangular.com/
>
>
