Bug 17423 Revert apears twice in the popup menu.
Build F1. 1) Open a java editor. 2) Popup the menu. There is only one Revert option disable as it should be. 3) Make the editor dirty. 4) Popup the menu. There are two Revert option in the menu. One after UNDO and other before FORMAT.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitEditor.java
if (action instanceof IUpdate)
	 			((IUpdate) action).update();
	 		
	 		if (!action.isEnabled())	
	 			return;
	 		IMenuManager subMenu= menu.findMenuUsingPath(group);
	 		if (subMenu != null)
	 			subMenu.add(action);
	 		else
	 			menu.appendToGroup(group, action);
	 	}
	}
	 
	/*
	 * @see JavaEditor#setOutlinePageInput(JavaOutlinePage, IEditorInput)
	 */
	protected void setOutlinePageInput(JavaOutlinePage page, IEditorInput input) {
		if (page != null) {
			IWorkingCopyManager manager= JavaPlugin.getDefault().getWorkingCopyManager();
			page.setInput(manager.getWorkingCopy(input));
		}
	}
	
	/*
	 * @see AbstractTextEditor#performSaveOperation(WorkspaceModifyOperation, IProgressMonitor)
	 */
	protected void performSaveOperation(WorkspaceModifyOperation operation, IProgressMonitor progressMonitor) {
		IDocumentProvider p= getDocumentProvider();
		if (p instanceof CompilationUnitDocumentProvider) {
			CompilationUnitDocumentProvider cp= (CompilationUnitDocumentProvider) p;