[Ffmpeg-devel] [PATCH] MinGW and portability

[Måns Rullgård]

Rich Felker <dalias at aerifal.cx> writes:

> On Tue, Mar 28, 2006 at 09:43:54PM +0100, M?ns Rullg?rd wrote:
>> >  #define fseeko(x,y,z)  fseeko64(x,y,z)
>> >  #define ftello(x)      ftello64(x)
>> > +#else
>> > +#define fseeko(x,y,z)  fseek(x,y,z)
>> > +#define ftello(x)      ftell(x)
>> > +#endif
>
> This is EXTREMELY WRONG and will break large file support on every
> single platform except windows!!

Not quite that bad.  There was an #ifdef __MINGW32__ around that whole
lot.

>> > +#if defined(WIN32) || defined(__MINGW32__)
>> > +
>> > +#include <stdarg.h>
>> > +
>> > +int snprintf(char *buf, const char *fmt, size_t size, ...) {
>> > +  va_list ap;
>> > +  int ret;
>> > +
>> > +  va_start(ap, size);
>> > +  ret = vsprintf(buf, fmt, ap);
>> > +  va_end(ap);
>> > +  return ret;
>> > +}
>> > +
>> > +#endif
>> 
>> Potential security risk.  Rejected.
>
> More than just potential.

The potential is there only if it is ever called with a pattern that
can overflow the supplied buffer.  With only numerical arguments it is
easy to calculate the maximum size (although people tend to forget
little details like - signs).  String arguments can do anything, of
course.

-- 
M?ns Rullg?rd
mru at inprovide.com