Cannot return a null object back to QML from a Q_INVOKABLE method

Consider a Q_INVOKABLE method in an item defined in a plugin that returns a QObject pointer:

Q_INVOKABLE QObject *fetchObject(int arg);

If the function returns a non-null object then everything is happy and the QObject can be used in the normal JavaScript/QML way. However, if the function returns null (e.g. because the argument refers to a non-existent entity), then a crash will occur every time deep inside JSC. The attached example shows the problem.

This particular pattern is needed in several places in Qt/3D:

• Fetching a named material from a mesh.
• Asking for the object that is under a specific mouse position using 3D object picking.
• etc

My expectation was that returning a null from C++ should result in the JavaScript "null" or "undefined" value, not a segfault.