BUG: Missing vtkScalarsToColors guard check before do/while loop.
BUG: Missing vtkScalarsToColors guard check before do/while loop.

The do/while loop is tempting for very fast code because it has
a few less opcodes than a for loop.  But if you forget to pre-check
for a zero counter... boom.

candy7393/VTK,daviddoria/PointGraphsPhase1,gram526/VTK,jmerkow/VTK,mspark93/VTK,sumedhasingla/VTK,sankhesh/VTK,biddisco/VTK,johnkit/vtk-dev,candy7393/VTK,sankhesh/VTK,spthaolt/VTK,ashray/VTK-EVM,SimVascular/VTK,sumedhasingla/VTK,jmerkow/VTK,msmolens/VTK,collects/VTK,mspark93/VTK,cjh1/VTK,sankhesh/VTK,ashray/VTK-EVM,SimVascular/VTK,keithroe/vtkoptix,spthaolt/VTK,aashish24/VTK-old,ashray/VTK-EVM,candy7393/VTK,johnkit/vtk-dev,sumedhasingla/VTK,demarle/VTK,demarle/VTK,SimVascular/VTK,collects/VTK,berendkleinhaneveld/VTK,collects/VTK,aashish24/VTK-old,aashish24/VTK-old,cjh1/VTK,aashish24/VTK-old,gram526/VTK,keithroe/vtkoptix,SimVascular/VTK,spthaolt/VTK,hendradarwin/VTK,jmerkow/VTK,hendradarwin/VTK,jmerkow/VTK,johnkit/vtk-dev,daviddoria/PointGraphsPhase1,berendkleinhaneveld/VTK,spthaolt/VTK,sumedhasingla/VTK,gram526/VTK,biddisco/VTK,ashray/VTK-EVM,cjh1/VTK,mspark93/VTK,biddisco/VTK,berendkleinhaneveld/VTK,candy7393/VTK,gram526/VTK,candy7393/VTK,candy7393/VTK,biddisco/VTK,keithroe/vtkoptix,mspark93/VTK,mspark93/VTK,jmerkow/VTK,candy7393/VTK,demarle/VTK,johnkit/vtk-dev,jmerkow/VTK,biddisco/VTK,hendradarwin/VTK,hendradarwin/VTK,collects/VTK,hendradarwin/VTK,berendkleinhaneveld/VTK,aashish24/VTK-old,daviddoria/PointGraphsPhase1,gram526/VTK,msmolens/VTK,daviddoria/PointGraphsPhase1,sankhesh/VTK,msmolens/VTK,candy7393/VTK,sankhesh/VTK,msmolens/VTK,collects/VTK,daviddoria/PointGraphsPhase1,demarle/VTK,spthaolt/VTK,mspark93/VTK,mspark93/VTK,johnkit/vtk-dev,spthaolt/VTK,demarle/VTK,jmerkow/VTK,msmolens/VTK,hendradarwin/VTK,msmolens/VTK,sumedhasingla/VTK,gram526/VTK,aashish24/VTK-old,msmolens/VTK,cjh1/VTK,sankhesh/VTK,keithroe/vtkoptix,sumedhasingla/VTK,ashray/VTK-EVM,berendkleinhaneveld/VTK,berendkleinhaneveld/VTK,daviddoria/PointGraphsPhase1,johnkit/vtk-dev,keithroe/vtkoptix,sumedhasingla/VTK,cjh1/VTK,SimVascular/VTK,keithroe/vtkoptix,gram526/VTK,collects/VTK,berendkleinhaneveld/VTK,biddisco/VTK,johnkit/vtk-dev,spthaolt/VTK,cjh1/VTK,mspark93/VTK,sankhesh/VTK,jmerkow/VTK,SimVascular/VTK,msmolens/VTK,biddisco/VTK,ashray/VTK-EVM,keithroe/vtkoptix,SimVascular/VTK,sumedhasingla/VTK,demarle/VTK,hendradarwin/VTK,ashray/VTK-EVM,SimVascular/VTK,demarle/VTK,ashray/VTK-EVM,sankhesh/VTK,demarle/VTK,gram526/VTK,keithroe/vtkoptix