JavaHelp throws the following exception in Netbeans with latest Mustang:
> java.lang.ClassCastException: sun.awt.UngrabEvent cannot be cast to
> java.awt.event.WindowEvent
> at
> org.netbeans.modules.javahelp.JavaHelp.eventDispatched(JavaHelp.java:389)
> at
> java.awt.Toolkit$SelectiveAWTEventListener.eventDispatched(Toolkit.java:2339)
> at
> java.awt.Toolkit$ToolkitEventMulticaster.eventDispatched(Toolkit.java:2232)
> at
> java.awt.Toolkit$ToolkitEventMulticaster.eventDispatched(Toolkit.java:2231)
> at
> java.awt.Toolkit$ToolkitEventMulticaster.eventDispatched(Toolkit.java:2231)
> at
> java.awt.Toolkit$ToolkitEventMulticaster.eventDispatched(Toolkit.java:2231)
> at
> java.awt.Toolkit$ToolkitEventMulticaster.eventDispatched(Toolkit.java:2231)
> at
> java.awt.Toolkit$ToolkitEventMulticaster.eventDispatched(Toolkit.java:2231)
> at
> java.awt.Toolkit$ToolkitEventMulticaster.eventDispatched(Toolkit.java:2231)
> at java.awt.Toolkit.notifyAWTEventListeners(Toolkit.java:2190)
> at java.awt.Component.dispatchEventImpl(Component.java:4263)
> at java.awt.Container.dispatchEventImpl(Container.java:2018)
> at java.awt.Window.dispatchEventImpl(Window.java:2210)
> at java.awt.Component.dispatchEvent(Component.java:4195)
> [catch] at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
> at
> java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
> at
> java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
> at
> java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
> at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
> at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
> at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)

This happens because UngrabEvent is selected by WINDOW_EVENT_MASK in AWTEventListener, but it is not WindowEvent. This is a regression from 4311449.