Bug 9066 ClassCastException opening a editor.
Got the following error opening a editor. Not sure how to reproduce it. 4 org.eclipse.ui 0 org.eclipse.ui.texteditor.AbstractDocumentProvider$ElementInfo java.lang.ClassCastException: org.eclipse.ui.texteditor.AbstractDocumentProvider$ElementInfo at org.eclipse.ui.editors.text.StorageDocumentProvider.isReadOnly (StorageDocumentProvider.java:185) at org.eclipse.ui.texteditor.AbstractTextEditor.isEditorInputReadOnly (AbstractTextEditor.java:2259) at org.eclipse.ui.texteditor.AbstractTextEditor.updateStatusField (AbstractTextEditor.java:2210) at org.eclipse.ui.texteditor.AbstractTextEditor.doSetInput (AbstractTextEditor.java:1164) at org.eclipse.jdt.internal.ui.javaeditor.JavaEditor.doSetInput (JavaEditor.java:338) at org.eclipse.jdt.internal.ui.javaeditor.ClassFileEditor.doSetInput (ClassFileEditor.java:181) at org.eclipse.ui.texteditor.AbstractTextEditor.setInput (AbstractTextEditor.java:1175) at org.eclipse.ui.internal.EditorManager.openEditor (EditorManager.java:363) at org.eclipse.ui.internal.EditorManager.openEditor (EditorManager.java:269) at org.eclipse.ui.internal.WorkbenchPage.openEditor (WorkbenchPage.java:1206) at org.eclipse.ui.internal.WorkbenchPage.openEditor (WorkbenchPage.java:1102) at org.eclipse.ui.actions.OpenFileAction.openFile (OpenFileAction.java:89) at org.eclipse.ui.actions.OpenSystemEditorAction.run (OpenSystemEditorAction.java:91) at org.eclipse.ui.actions.OpenFileAction.handleDoubleClick (OpenFileAction.java:111) at org.eclipse.ui.views.navigator.OpenActionFactory.handleDoubleClick (OpenActionFactory.java:124) at org.eclipse.ui.views.navigator.ResourceNavigatorActionFactory.handleDoubleClick (ResourceNavigatorActionFactory.java:118) at org.eclipse.ui.views.navigator.ResourceNavigator.handleDoubleClick (ResourceNavigator.java:389) at org.eclipse.ui.views.navigator.ResourceNavigator$4.doubleClick (ResourceNavigator.java:186) at org.eclipse.jface.viewers.StructuredViewer.fireDoubleClick (StructuredViewer.java:272) at org.eclipse.jface.viewers.StructuredViewer.handleDoubleSelect (StructuredViewer.java:416) at org.eclipse.jface.viewers.AbstractTreeViewer$1.widgetDefaultSelected (AbstractTreeViewer.java:627) at org.eclipse.swt.widgets.TypedListener.handleEvent (TypedListener.java:92) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:74) at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:637) at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:1413) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:1205) at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:827) at org.eclipse.ui.internal.Workbench.run(Workbench.java:810) at org.eclipse.core.internal.boot.InternalBootLoader.run (InternalBootLoader.java:895) at org.eclipse.core.boot.BootLoader.run(BootLoader.java:321) at SlimLauncher.main(SlimLauncher.java:14)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/ClassFileEditor.java
*	setAction(ITextEditorActionConstants.RULER_MANAGE_BOOKMARKS, new ClassFileMarkerRulerAction("ManageBookmarks.", getVerticalRuler(), this, IMarker.BOOKMARK, true)); 
		 *	setAction(ITextEditorActionConstants.RULER_MANAGE_TASKS, new ClassFileMarkerRulerAction("ManageTasks.", getVerticalRuler(), this, IMarker.TASK, true)); 
		 */
		setAction(ITextEditorActionConstants.BOOKMARK, null);
		setAction(ITextEditorActionConstants.ADD_TASK, null);
		setAction(ITextEditorActionConstants.RULER_MANAGE_BOOKMARKS, null);
		setAction(ITextEditorActionConstants.RULER_MANAGE_TASKS, null);
		
		setAction(ITextEditorActionConstants.RULER_DOUBLE_CLICK, getAction("ManageBreakpoints"));		 
	}
	
	/**
	 * @see JavaEditor#getElementAt(int)
	 */
	protected IJavaElement getElementAt(int offset) {
		if (getEditorInput() instanceof IClassFileEditorInput) {
			try {
				IClassFileEditorInput input= (IClassFileEditorInput) getEditorInput();
				return input.getClassFile().getElementAt(offset);
			} catch (JavaModelException x) {
			}
		}
		return null;
	}
	
	/**
	 * @see JavaEditor#getCorrespondingElement(IJavaElement)
	 */
	protected IJavaElement getCorrespondingElement(IJavaElement element) {
		if (getEditorInput() instanceof IClassFileEditorInput) {