[TabPane] Tab.setContextMenu(null) throws NPE when the tab is not assigned to a TabPane (regression from 8)

I am debugging some application code where a Tab is set up with a context menu. At a certain point, the Tab is removed from its TabPane and afterwards the context menu is reset to null. This throws a NullPointerException, which is a bit fragile. I have created a small test application which triggers the same exception:

Caused by: java.lang.NullPointerException
at com.sun.javafx.scene.control.ControlAcceleratorSupport.removeAcceleratorsFromScene(ControlAcceleratorSupport.java:191)
at javafx.scene.control.Tab$3.invalidated(Tab.java:396)
at javafx.beans.property.ObjectPropertyBase.markInvalid(ObjectPropertyBase.java:111)
at javafx.beans.property.ObjectPropertyBase.set(ObjectPropertyBase.java:146)
at javafx.scene.control.Tab.setContextMenu(Tab.java:374)
at ContextMenuTest.start(ContextMenuTest.java:27)

Here is the test app:

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.ContextMenu;
import javafx.scene.control.MenuItem;
import javafx.scene.control.Tab;
import javafx.stage.Stage;

public class ContextMenuTest extends Application {

  public static void main(String[] args) {
      launch(args);
  }

  @Override
  public void start(Stage stage) {
// for a button it is OK to set the context menu then nullify it
    Button b1 = new Button("B1");
    b1.setContextMenu(createContextMenu("B1"));
    b1.setContextMenu(null);
    
// but for a tab it throws an exception
    Tab t1 = new Tab("T1");
    t1.setContextMenu(createContextMenu("T1"));
    t1.setContextMenu(null);
    
    stage.setScene(new Scene(b1));
    stage.show();
  }
  
  private static ContextMenu createContextMenu(String prefix) {
final ContextMenu contextMenu = new ContextMenu();
MenuItem item1 = new MenuItem(prefix + ": About");
item1.setOnAction(new EventHandler<ActionEvent>() {
public void handle(ActionEvent e) {
System.out.println("About");
}
});
MenuItem item2 = new MenuItem(prefix + ": Preferences");
item2.setOnAction(new EventHandler<ActionEvent>() {
public void handle(ActionEvent e) {
System.out.println("Preferences");
}
});
contextMenu.getItems().addAll(item1, item2);
return contextMenu;
  }
}