[FFmpeg-cvslog] lzo: fix memcpy_backptr() with 0 offset

[Reimar Döffinger]

On Sun, Dec 25, 2011 at 03:43:19AM +0100, Michael Niedermayer wrote:
> On Sat, Dec 24, 2011 at 09:36:23PM +0100, Reimar Döffinger wrote:
> > On Sat, Dec 24, 2011 at 09:27:28PM +0100, Reimar Döffinger wrote:
> > > On Sat, Dec 24, 2011 at 06:53:09PM +0100, Michael Niedermayer wrote:
> > > > ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Sat Dec 24 03:55:58 2011 +0100| [58c41799ab6b52df86b6afe23304f34b62741326] | committer: Michael Niedermayer
> > > > 
> > > > lzo: fix memcpy_backptr() with 0 offset
> > > 
> > > Uh, could you explain why you believe something is broken with 0 offset?
> > > Except for a few useless read/writes the result is that nothing changes
> > > both before your commit and after your commit, so it seems to me it adds
> > > a completely pointless branch.
> > 
> > Ah, I see it would hang. However a value of 0 makes no sense anyway,
> > what code uses this?
> 
> lcldec.c IIRC, feel free to change it to anything you prefer

Hm. Do you know if that was a fuzzed file or something regular?
Because LZO always uses + 1 since 0 makes no sense, unless they use 0
as an escape they waste compression efficiency in MSZH design.