[Zope] _v_container KeyError in CoreSessionTracking 0.9

[Chris McDonough]

> Man, that was fast. Thanks, Chris.

No problem... ;-)

> Is this safe to do, or is it just a quick hack to get rid of the 
> exception? Do you know that it won't cause any harm?

This will fix that bug.  I think it's safe.

> I'd like to upgrade to Zope 2.5 for many reasons, but I'm not in the 
> mood for doing the compatibility dance right now :-(

Right.  Hopefully this will get you through.