vtkImplicitPlaneWidget2: tubing error

This issue was created automatically from an original Mantis Issue. Further discussion may take place here.

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When the plane is incident to one of the vertices of the box, the cutter produces two points for this vertex, leading to an error during the tubing:

Generic Warning: In F:\lhabert\dev\VTK-6.3.0\Common\DataModel\vtkPolyLine.cxx, line 106 Coincident points in polyline...can't compute normals

Warning: In F:\lhabert\dev\VTK-6.3.0\Filters\Core\vtkTubeFilter.cxx, line 243 vtkTubeFilter (0000000020976ED0): Could not generate normals for line. Skipping to next.