BUG: Avoid segfault when filename is missing in the DOM.
BUG: Avoid segfault when filename is missing in the DOM.

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