Sometimes I get a concurrent modification exception:

java.util.ConcurrentModificationException
	at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:859)
	at java.util.ArrayList$Itr.next(ArrayList.java:831)
	at org.strategoxt.imp.runtime.editor.SpoofaxEditor$SelectionProvider.setSelection2(SpoofaxEditor.java:205)
	at org.strategoxt.imp.runtime.editor.SpoofaxEditor$1.selectionChanged(SpoofaxEditor.java:86)
	at org.eclipse.jface.viewers.Viewer$2.run(Viewer.java:164)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
	at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:49)
	at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
	at org.eclipse.jface.viewers.Viewer.fireSelectionChanged(Viewer.java:162)
	at org.eclipse.jface.text.TextViewer.fireSelectionChanged(TextViewer.java:2738)
	at org.eclipse.jface.text.TextViewer.selectionChanged(TextViewer.java:2717)
	at org.eclipse.jface.text.TextViewer$4.widgetSelected(TextViewer.java:1836)
	at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:248)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
	at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4166)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1466)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1489)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1474)
	at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:1279)
	at org.eclipse.swt.custom.StyledText.sendSelectionEvent(StyledText.java:8071)
	at org.eclipse.swt.custom.StyledText.doSelection(StyledText.java:3226)
	at org.eclipse.swt.custom.StyledText.doMouseSelection(StyledText.java:2841)
	at org.eclipse.swt.custom.StyledText.doMouseLocationChange(StyledText.java:2824)
	at org.eclipse.swt.custom.StyledText.handleMouseMove(StyledText.java:6071)
	at org.eclipse.swt.custom.StyledText$7.handleEvent(StyledText.java:5641)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
	at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4166)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1466)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1489)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1474)
	at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:1279)
	at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4012)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3651)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1113)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:997)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:140)
	at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:611)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:567)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:150)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:124)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:354)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:181)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:636)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:591)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1450)

Submitted by Gabriël Konat on 17 April 2014 at 16:58

fixed
https://github.com/metaborg/spoofax/commit/57cc402632e50b8749b84c1b6eba3487a9542d70