[vtkusers] Update extent outside whole extent

[ns451 at srcf.net]

Hello,

I recently came across the above error, so wrote a toy script to narrow it
down: https://gist.github.com/55e045ab8fea8960749a.git

The error message when I run that script (with the 'bad' input) is:
"ERROR: In ...\Common\ExecutionModel\vtkStreamingDemandDrivenPipeline.cxx,
line 857 vtkCompositeDataPipeline (...): The update extent specified in
the information for output port 0 on algorithm vtkStructuredGrid(...) is 0
69 0 4 0 2, which is outside the whole extent 0 27 0 23 0 16."

I think that vtkProbeFilter::RequestUpdateExtent should set the update
extent of the source to the source's whole extent, because it has nothing
to do with the update extent of the input or output. The following patch
to vtkProbeFilter.cxx fixes the error from the toy script, but I'm not
sure whether it should go elsewhere in the function.

700,702d699
<     sourceInfo->Set(
<       vtkStreamingDemandDrivenPipeline::UPDATE_EXTENT(),
<      
sourceInfo->Get(vtkStreamingDemandDrivenPipeline::UPDATE_EXTENT()), 6);

Cheers,
Nishad.