[vtkusers] vtkAppendPolyData bug

[Jeff Baumes]

On Tue, Dec 15, 2009 at 8:39 PM, David Doria <daviddoria+vtk at gmail.com> wrote:
> At line 239 in vtkAppendPolyData.cxx, there is:
>
>  if ( numPts < 1 || numCells < 1 )
>    {
>    vtkDebugMacro(<<"No data to append!");
>    return 1;
>    }
>
> this prevents the polydata's from being appended if there are no
> cells, even if there are points. I think it should be changed to
>  if ( numPts < 1 && numCells < 1 )
>
> so that only if there are no points and no cells it should fail.
>
> Anyone agree/disagree?

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