[vtkusers] update extent error

[Dominik Szczerba]

I get this error after updating the extents of the source to my filter
only iff the new extents are smaller:

ERROR:
In /home/domel/pack/vtk-5.4.0/Filtering/vtkStreamingDemandDrivenPipeline.cxx, line 818
vtkStreamingDemandDrivenPipeline (0x8fd69b8): The update extent
specified in the information for output port 0 on algorithm
vtkImageGaussianSmooth(0x8fd5b70) is 70 317 112 264 96 159, which is
outside the whole extent 72 315 114 262 98 157.

I see issue this raised several times on both vtkusers and vtkdevelopers
but never resolved.

It "normally" does not break the pipeline execution, but my critical
problem is I have an observer following vtkCommand::ErrorEvent that has
to quit the application.

How do I clean this error?

-- Dominik