ENH: check whether GetHandle() returns zero, and don't do a Render until      it returns nonzero (this is cleaner than the previous fix)
ENH: check whether GetHandle() returns zero, and don't do a Render until
     it returns nonzero (this is cleaner than the previous fix)

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