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
/*
	 * @see AbstractDocumentProvider#createDocument(Object)
	 */
	protected IDocument createDocument(Object element) throws CoreException {
		
		if (element instanceof IEditorInput) {
			Document document= new PartiallySynchronizedDocument();
			if (setDocumentContent(document, (IEditorInput) element, getEncoding(element))) {
		initializeDocument(document);
		return document;
	}
		}
	
		return null;
	}
	
	/*
	 * @see AbstractDocumentProvider#resetDocument(Object)
	 */
	public void resetDocument(Object element) throws CoreException {
		if (element == null)
			return;
			
		ElementInfo elementInfo= getElementInfo(element);		
		if (elementInfo instanceof CompilationUnitInfo) {
			CompilationUnitInfo info= (CompilationUnitInfo) elementInfo;
			
			IDocument document;
			IStatus status= null;