[vtk-developers] Possible bug in StreamingDemandDriver

[Nathan Fabian]

Hi,

I think I've stumbled on a bug in vtkStreamingDemandDrivenPipeline.  On line
137 (and below) it looks like this:

if (!N2E && outputPort>-1 && this->GetNumberOfInputPorts())

  {
      
  vtkInformation* outInfo = outInfoVec->GetInformationObject(outputPort);
  vtkInformation* inInfo = inInfoVec[0]->GetInformationObject(0);
  int outNumberOfPieces = outInfo->Get(UPDATE_NUMBER_OF_PIECES());
  int inNumberOfPieces = inInfo->Get(UPDATE_NUMBER_OF_PIECES());

However, if the input port is optional then this will fail because there is
not necessarily an Information object for the line:

vtkInformation* inInfo = inInfoVec[0]->GetInformationObject(0);

I think the fix is to change line 137 to read:

if (!N2E && outputPort>-1 && this->GetNumberOfInputPorts() &&
    inInfoVec[0]->GetNumberOfInformationObjects () > 0)

Is this correct (it does resolve the problem I'm seeing)?  If so, I am happy
to commit the change.

Thanks,
Nathan.