Bug 19014 Empty CU after reorg
F2 - enable single click and show in members in packages view - open TestCase.java in editor - give focus to packages view - change it on disk - copy a method in TestCase using DnD - activate the TestCase.java editor - answer question with no - activate revert from context menu observe: CU is empty
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitDocumentProvider.java
private boolean fIsAboutToSave= false;
	
	private ISavePolicy fSavePolicy;
	
	private IPropertyChangeListener fPropertyListener;
	
	
	private GlobalAnnotationModelListener fGlobalAnnotationModelListener;	
	
	/**
	 * Constructor
	 */
	public CompilationUnitDocumentProvider() {
		fPropertyListener= new IPropertyChangeListener() {
			public void propertyChange(PropertyChangeEvent event) {
				if (HANDLE_TEMPORARY_PROBLEMS.equals(event.getProperty()))
					enableHandlingTemporaryProblems();
			}
		};
		
		fGlobalAnnotationModelListener= new GlobalAnnotationModelListener();
		
		JavaPlugin.getDefault().getPreferenceStore().addPropertyChangeListener(fPropertyListener);
	}
	
	/**
	 * Sets the document provider's save policy.
	 */
	public void setSavePolicy(ISavePolicy savePolicy) {