BUG: fixed hang when ParallelRendering was enabled only on the root
BUG: fixed hang when ParallelRendering was enabled only on the root

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