Null geodesic incompleteness means that some maximal geodesic with a null tangent has a finite endpoint of its affine parameter. This can indicate a removable missing region or a genuine obstruction; it does not alone assert curvature divergence.
The globally hyperbolic maximal Cauchy development of appropriate Reissner-Nordstrom spacetime data obeys the Penrose singularity theorem when it contains a closed trapped surface. Its resulting null geodesic incompleteness can include generators reaching a smoothly extendible inner Cauchy horizon in finite affine parameter. The full analytic extension is not globally hyperbolic and cannot be substituted into that version of the theorem. Incompleteness alone does not establish curvature blowup at every endpoint.