nrv2b cleanup patch (again)

[Myles Watson]

This very short patch fixes nrv2b compression in lar.

It also fixes lzma compression in lar to fix the silent memory
corruption that was possible when files didn't compress well.

It adds some comments to both files and the file that calls them.

Myles

Signed-off-by: Myles Watson

[Stefan Reinauer]

Myles Watson wrote:
> This very short patch fixes nrv2b compression in lar.
>
> It also fixes lzma compression in lar to fix the silent memory
> corruption that was possible when files didn't compress well.
>
> It adds some comments to both files and the file that calls them.
>
> Myles
>
> Signed-off-by: Myles Watson

Acked-by: Stefan Reinauer
> std::memcpy(out, &result[0], *out_len);
> if (*out_len < in_len)
> std::memcpy(out, &result[0], *out_len);

I think this one should even be memcpy instead of std:memcpy.. I had 
some versions of gcc complain that memcpy is not in the std scope.

Not really part of this patch, but I saw later down you use memcpy 
without std:: anyways.

Stefan

[Myles Watson]

> Myles Watson wrote:
> > This very short patch fixes nrv2b compression in lar.
> >
> > It also fixes lzma compression in lar to fix the silent memory
> > corruption that was possible when files didn't compress well.
> >
> > It adds some comments to both files and the file that calls them.
> >
> > Myles
> >
> > Signed-off-by: Myles Watson
>
> Acked-by: Stefan Reinauer

Rev 658.

Thanks,

Myles
> > std::memcpy(out, &result[0], *out_len);
> > if (*out_len < in_len)
> > std::memcpy(out, &result[0], *out_len);
>
> I think this one should even be memcpy instead of std:memcpy.. I had
> some versions of gcc complain that memcpy is not in the std scope.

Either one works for me.  There are four of them in this file, and we could
change it.  A Google search suggested that some versions of gcc have
problems when std is not there, but they seemed to be fairly old.
> Not really part of this patch, but I saw later down you use memcpy
> without std:: anyways.

The difference is that one file was a C++ file and the other was C.  I just
used the same memcpy that was already in each file.

It's a trivial patch.  I'll generate it if you'd like.

Myles