RE: [css3-animations] What does animation-fill-mode do when animation-iteration-count is zero?

[Tab Atkins Jr.:] 
> On Thu, Feb 2, 2012 at 5:30 AM, Øyvind Stenhaug <oyvinds@opera.com> wrote:
> > On Thu, 02 Feb 2012 01:58:33 +0100, Sylvain Galineau
> > <sylvaing@microsoft.com> wrote:
> >> I assume animation-iteration-count:0 means no animation occurs and no
> >> animation events are thrown regardless of duration and delay.
> >>
> >> Does animation-fill-mode have any effect in this case?
> >
> > When I raised this back in
> > <http://lists.w3.org/Archives/Public/www-style/2011Oct/0107.html>,
> > David argued that it would make sense to avoid a discontinuity at 0.
> > With that reasoning,
> >
> > - start event and end event should dispatch at the end of the delay
> > - fill mode 'backwards'/'both' should have an effect during the delay
> > phase
> > - fill mode 'forwards'/'both' should have an effect after the delay
> > phase
> 
> I agree with dbaron that this is the ideal behavior.
> 
Why is it ideal?