[Mondrian] Problems with functions throwing exceptions like CastFunDef

[julianhyde at speakeasy.net]

When values are not in the cache, the value returned by expressions should be a special value, not null. So, I'm surprised that NullPointerException is being thrown.

Can you try making CastFunDef return null if its input is null? Maybe that will workaround the problem and allow you to make progress.

Julian