Changed vtkLine::Derivatives, if deltaX[i] is zero, set the corresponding derivative to zero.
Changed vtkLine::Derivatives, if deltaX[i] is zero, set the corresponding derivative to zero.

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