Any test with call to setComponentZOrder throws NPE, the stack is

java.lang.NullPointerException
        at sun.awt.X11.XWindow.initGraphicsConfiguration(XWindow.java:169)
        at sun.awt.X11.XComponentPeer.updateGraphicsData(XComponentPeer.java:1566)
        at java.awt.Component.setGraphicsConfiguration(Component.java:1035)
        at java.awt.Container.removeDelicately(Container.java:509)
        at java.awt.Container.setComponentZOrder(Container.java:711)
        at Test$4.mousePressed(Test.java:593)
        at java.awt.Component.processMouseEvent(Component.java:6247)
        at java.awt.Component.processEvent(Component.java:6015)
        at java.awt.Button.processEvent(Button.java:380)
        at java.awt.Component.dispatchEventImpl(Component.java:4610)
        at java.awt.Component.dispatchEvent(Component.java:4436)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:605)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:286)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:201)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:191)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:186)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:178)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:139)

Introduced by the changes in Container.removeDelicately() for 6804747.

              comp.parent = null;
+ comp.setGraphicsConfiguration(null);
              component.remove(index);
The regression test java/awt/Container/ZOrder can be used to reproduce the failure.