QSharedDataPointer detaches on ptrInst == nullptr

friend bool operator==(T *a, QSharedDataPointer<T> const &b) const

friend bool operator==(QSharedDataPointer<T> const &a, T *b) const

ptrInst == nullptr

QSharedDataPointer<int> ptrInst(new int(-1));
QSharedDataPointer<int> secondInst = ptrInst; // ref()
bool isNull;
isNull = !ptrInst; // ok, no detach()
isNull = ptrInst == nullptr; // NOT OK, detaches!