[vtkusers] vtkAppendPolyData bug

[David Doria]

> It seems if you are going to change it, it should be to
>
> if ( numPts < 1 )
>
> Having no points infers that there are no cells, correct? So &&-ing
> the second conditional is superfluous.
>
> I think it makes sense to change it, provided that you test it to make
> sure the filter code can handle cases where there are no cells.
>
> Jeff
>

Or even
if (numPts == 0)
?

By make sure the filter code can handle no cells, is that covered by
"just make sure all tests still pass"? Or did you have some certain
demo in mind that I'd need to perform?

Thanks,

David