[FFmpeg-devel] [PATCH 3/8] Prevent svq3_get_ue_golomb() from returning a negative value.

[Laurent Aimar]

On Sat, Sep 17, 2011 at 05:49:32PM +0200, Michael Niedermayer wrote:
> On Sat, Sep 17, 2011 at 04:56:31PM +0200, fenrir at elivagar.org wrote:
> > From: Laurent Aimar <fenrir at videolan.org>
> > 
> > ---
> >  libavcodec/golomb.h |    2 +-
> >  1 files changed, 1 insertions(+), 1 deletions(-)
> > 
> > diff --git a/libavcodec/golomb.h b/libavcodec/golomb.h
> > index 83d277f..58707ed 100644
> > --- a/libavcodec/golomb.h
> > +++ b/libavcodec/golomb.h
> > @@ -124,7 +124,7 @@ static inline int svq3_get_ue_golomb(GetBitContext *gb){
> >          }
> >  
> >          CLOSE_READER(re, gb);
> > -        return ret - 1;
> > +        return (ret - 1) & INT_MAX;
> 
> the individual uses of this function should check if the data is within
> the supported range.
> simply forcing it to be positiv is unlikely to be enough for all
> cases. Also it causes a tiny speedloss where such checks exists
> already
 Well, en general users of this function check for upper bound not lower bound
(which seems logical given the function names).
 Another way would be to make it return unsigned and check for every usage but
it's more work and I think more prone to breakage in the future.

-- 
fenrir