Fix crash when selecting a shiva filter or generator

[Boudewijn Rempt]

On Wednesday 11 November 2009, Cyrille Berger wrote:
> On Tuesday 10 November 2009, Boudewijn Rempt wrote:
> > On Tuesday 10 November 2009, Cyrille Berger wrote:
> > > hi,
> > >
> > > Those two patches fixes crashes when selecting some of the shiva
> > > filters that have already been used, and also when reconfiguring some
> > > of the generators.
> > >
> > > I would like to backport them to branch/2.1.
> >
> > I trust your expertise here, so it's okay as far as I'm concerned.
> 
> well, while it is nice to have such confidence, the review is intented to
>  be sure the "expert" has not overlook something ;p
> 

I see you check your variables now before setting them, so it _must_ be an 
improvement :-)

-- 
Boudewijn Rempt | http://www.valdyas.org