I was looking into RT-36686 and run into an interesting bug which appears to be occuring at the glass level, so I thought I better report it.

Steps to reproduce:
1) Open the HelloListView class file.
2) Search for the line: listTwo.setItems(listTwoItems);
3) Replace with: listTwo.setItems(null);
4) Run HelloListView
5) Go to the 'DnD' tab
6) Drag an item from the left ListView to the right ListView
7) On my Windows 8 machine, I got the exception in the attached screenshot (sorry about the screenshot, for whatever reason IntelliJ was not allowing for copy/paste).

The reason why this occurs is obvious - in HelloListView there is the following code (note the comment):

EventHandler<DragEvent> dragDropped = new EventHandler<DragEvent>() {
    public void handle(DragEvent event) {
        ListView<String> list = (ListView) event.getGestureTarget();

        Dragboard db = event.getDragboard();
        boolean success = false;
        if (db.hasString()) {
            list.getItems().add(db.getString()); // <------- list.getItems() is null, so we're getting a NPE here.
            success = true;
        }

        event.setDropCompleted(success);
        event.consume();
    }
};