Created attachment 143576 [details]
Stack traces from VisualVM

I encountered a deadlock in the IDE when switching between project groups.

These are the relevant stack traces for the blocked threads:

"org.openide.text Document Processing" daemon prio=2 tid=0x0c6c5800 nid=0xbac waiting for monitor entry [0x0690f000]
   java.lang.Thread.State: BLOCKED (on object monitor)
	at org.netbeans.modules.debugger.jpda.projects.LineTranslations$BreakpointLineUpdater.propertyChange(LineTranslations.java:514)
	- waiting to lock <0x1b10b110> (a org.netbeans.modules.debugger.jpda.projects.LineTranslations$BreakpointLineUpdater)
	at java.beans.PropertyChangeSupport.fire(PropertyChangeSupport.java:335)
	at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:327)
	at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:263)
	at org.openide.text.CloneableEditorSupport.firePropertyChange(CloneableEditorSupport.java:483)
	at org.openide.text.CloneableEditorSupport.fireDocumentChange(CloneableEditorSupport.java:1730)
	at org.openide.text.DocumentOpenClose$DocumentClose.run(DocumentOpenClose.java:1007)
	at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1432)
	at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2042)

   Locked ownable synchronizers:
	- None

"AWT-EventQueue-0" prio=6 tid=0x082fb000 nid=0x1cbc waiting for monitor entry [0x08ecf000]
   java.lang.Thread.State: BLOCKED (on object monitor)
	at org.netbeans.modules.debugger.jpda.projects.LineTranslations$BreakpointLineUpdater.propertyChange(LineTranslations.java:495)
	- waiting to lock <0x1b10b110> (a org.netbeans.modules.debugger.jpda.projects.LineTranslations$BreakpointLineUpdater)
	at java.beans.PropertyChangeSupport.fire(PropertyChangeSupport.java:335)
	at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:327)
	at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:263)
	at org.openide.text.CloneableEditorSupport.firePropertyChange(CloneableEditorSupport.java:483)
	at org.openide.text.CloneableEditor.componentClosed(CloneableEditor.java:340)
	at org.netbeans.core.spi.multiview.text.MultiViewCloneableEditor.componentClosed(MultiViewCloneableEditor.java:119)
	at org.netbeans.core.spi.multiview.text.MultiViewEditorElement.componentClosed(MultiViewEditorElement.java:129)
	at org.netbeans.core.multiview.MultiViewPeer.peerComponentClosed(MultiViewPeer.java:328)
	at org.netbeans.core.multiview.MultiViewCloneableTopComponent.componentClosed(MultiViewCloneableTopComponent.java:124)
	at org.openide.windows.WindowManager.componentCloseNotify(WindowManager.java:322)
	at org.netbeans.core.windows.WindowManagerImpl.notifyTopComponentClosed(WindowManagerImpl.java:1156)
	at org.netbeans.core.windows.Central.removeModeTopComponent(Central.java:1025)
	at org.netbeans.core.windows.ModeImpl.removeTopComponent(ModeImpl.java:478)
	at org.netbeans.core.windows.ModeImpl.close(ModeImpl.java:286)
	at org.netbeans.core.windows.WindowManagerImpl.topComponentClose(WindowManagerImpl.java:1321)
	at org.openide.windows.TopComponent.close(TopComponent.java:561)
	at org.openide.windows.TopComponent.close(TopComponent.java:548)
	at org.netbeans.modules.project.ui.ProjectUtilities$1.doClose(ProjectUtilities.java:211)
	at org.netbeans.modules.project.ui.ProjectUtilities$1.access$200(ProjectUtilities.java:111)
	at org.netbeans.modules.project.ui.ProjectUtilities$1$1.run(ProjectUtilities.java:147)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:241)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:733)
	at java.awt.EventQueue.access$200(EventQueue.java:103)
	at java.awt.EventQueue$3.run(EventQueue.java:694)
	at java.awt.EventQueue$3.run(EventQueue.java:692)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:703)
	at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

   Locked ownable synchronizers:
	- None