TableCell selected property changes value even if the selection doesn't change

Run the app from RT-14613 with the following lines uncommented:

        tableView.getSelectionModel().setCellSelectionEnabled(true);
        tableView.getSelectionModel().setSelectionMode(SelectionMode.MULTIPLE_INTERVAL_SELECTION);

Select several cells. Clear output. Add one more cell to selection using shift-click. You'll get all previously selected cells to change their selected value to false and then back to true.