When running on some Linux kernels, the heap is mapped into memory low in the address space. Dereferencing a null pointer for class with a lot of fields an erroneously access the heap instead of throwing a NullPointerException.
-- Summary: NullPointerException not generated for large classes... Product: gcc Version: 4.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: libgcj AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: daney at gcc dot gnu dot org GCC build triplet: i686-pc-linux-gnu GCC host triplet: i686-pc-linux-gnu GCC target triplet: i686-pc-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26858