message: localmeshingheap: ensure we don't deref a null miniheap
diff: @@ -97,7 +97,7 @@ public:
  inline void free(void *ptr) {
  auto mh = _global->UNSAFEMiniheapFor(ptr);
  - if (likely(mh->isOwnedBy(pthread_self()))) {
  + if (likely(mh != nullptr && mh->isOwnedBy(pthread_self()))) {
  mh->localFree(ptr, _prng, _mwc);
  } else {
  _global->free(ptr);
  