Fixing inverted tets when subdividing a quadratic pyramid.

A quadratic pyramid is subdivided when contouring and clipping but the
4 tets produced were inverted (the 6 pyramids produced were fine).
Also initializing two pointers in vtkContourHelper to nullptr
for safety.

Addresses paraview/paraview#17574.
Status Job ID Name Coverage
  External
passed cdash

passed ghostflow-branch-check-master

passed ghostflow-commit-check

passed vtk-bigmac-osx-shared-debug+clang+opengl1+python

passed vtk-bigmac-osx-shared-debug+clang+python

passed vtk-dashlin1-linux-shared-release+mpi+opengl1+python+qt

passed vtk-dejagore-linux-shared-release+gcc+mpi+openmp+python+qt

passed vtk-eeloo-linux-shared-release+extdeps+java+mpi+python+python3+qt+qt5+tbb+tcl

passed vtk-eeloo-linux-shared-release+mpi+nogl

passed vtk-luigi-linux-shared-release+mpi+python+tbb

passed vtk-mun-windows-shared-release+kits+mpi+python+python3+qt+qt5+tbb

passed vtk-mun-windows-shared-release+mpi+python+python3+tbb

passed vtk-taanab-linux-shared-release+mpi+python

passed vtk-trey-osx-shared-release+python+python3+qt

passed vtk-bigmac-osx-shared-debug+clang+opengl1+python

passed vtk-bigmac-osx-shared-debug+clang+opengl1+python

passed vtk-bigmac-osx-shared-debug+clang+opengl1+python

00:28:45

passed vtk-bigmac-osx-shared-debug+clang+opengl1+python

passed vtk-bigmac-osx-shared-debug+clang+python

00:24:05

passed vtk-bigmac-osx-shared-debug+clang+python

passed vtk-bigmac-osx-shared-debug+clang+python

passed vtk-bigmac-osx-shared-debug+clang+python

passed vtk-dashlin1-linux-shared-release+mpi+opengl1+python+qt

00:48:13

passed vtk-dashlin1-linux-shared-release+mpi+opengl1+python+qt

passed vtk-dashlin1-linux-shared-release+mpi+opengl1+python+qt

passed vtk-dashlin1-linux-shared-release+mpi+opengl1+python+qt

passed vtk-dejagore-linux-shared-release+gcc+mpi+openmp+python+qt

passed vtk-dejagore-linux-shared-release+gcc+mpi+openmp+python+qt

passed vtk-dejagore-linux-shared-release+gcc+mpi+openmp+python+qt

passed vtk-dejagore-linux-shared-release+gcc+mpi+openmp+python+qt

00:56:41

passed vtk-eeloo-linux-shared-release+extdeps+java+mpi+python+python3+qt+qt5+tbb+tcl

00:33:29

passed vtk-eeloo-linux-shared-release+extdeps+java+mpi+python+python3+qt+qt5+tbb+tcl

passed vtk-eeloo-linux-shared-release+extdeps+java+mpi+python+python3+qt+qt5+tbb+tcl

passed vtk-eeloo-linux-shared-release+extdeps+java+mpi+python+python3+qt+qt5+tbb+tcl

passed vtk-eeloo-linux-shared-release+mpi+nogl

passed vtk-eeloo-linux-shared-release+mpi+nogl

passed vtk-eeloo-linux-shared-release+mpi+nogl

passed vtk-eeloo-linux-shared-release+mpi+nogl

00:12:04

passed vtk-luigi-linux-shared-release+mpi+python+tbb

passed vtk-luigi-linux-shared-release+mpi+python+tbb

passed vtk-luigi-linux-shared-release+mpi+python+tbb

passed vtk-luigi-linux-shared-release+mpi+python+tbb

00:06:03

failed vtk-luigi-linux-shared-release+mpi+python+tbb

00:02:45

failed vtk-luigi-linux-shared-release+mpi+python+tbb

failed vtk-luigi-linux-shared-release+mpi+python+tbb

failed vtk-luigi-linux-shared-release+mpi+python+tbb

failed vtk-luigi-linux-shared-release+mpi+python+tbb

failed vtk-luigi-linux-shared-release+mpi+python+tbb

00:24:52

failed vtk-luigi-linux-shared-release+mpi+python+tbb

failed vtk-luigi-linux-shared-release+mpi+python+tbb

failed vtk-luigi-linux-shared-release+mpi+python+tbb

failed vtk-luigi-linux-shared-release+mpi+python+tbb

failed vtk-luigi-linux-shared-release+mpi+python+tbb

00:01:01

failed vtk-luigi-linux-shared-release+mpi+python+tbb

failed vtk-luigi-linux-shared-release+mpi+python+tbb

failed vtk-luigi-linux-shared-release+mpi+python+tbb

failed vtk-luigi-linux-shared-release+mpi+python+tbb

passed vtk-mun-windows-shared-release+kits+mpi+python+python3+qt+qt5+tbb

passed vtk-mun-windows-shared-release+kits+mpi+python+python3+qt+qt5+tbb

passed vtk-mun-windows-shared-release+kits+mpi+python+python3+qt+qt5+tbb

00:17:31

passed vtk-mun-windows-shared-release+kits+mpi+python+python3+qt+qt5+tbb

passed vtk-mun-windows-shared-release+mpi+python+python3+tbb

00:17:06

passed vtk-mun-windows-shared-release+mpi+python+python3+tbb

passed vtk-mun-windows-shared-release+mpi+python+python3+tbb

passed vtk-mun-windows-shared-release+mpi+python+python3+tbb

passed vtk-taanab-linux-shared-release+mpi+python

passed vtk-taanab-linux-shared-release+mpi+python

00:16:04

passed vtk-taanab-linux-shared-release+mpi+python

passed vtk-taanab-linux-shared-release+mpi+python

passed vtk-trey-osx-shared-release+python+python3+qt

00:36:02

passed vtk-trey-osx-shared-release+python+python3+qt

passed vtk-trey-osx-shared-release+python+python3+qt

passed vtk-trey-osx-shared-release+python+python3+qt