Bug 53201 NPE when re-running newly generated javadoc.xml
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javadocexport/JavadocWriter.java
Transformer transformer=TransformerFactory.newInstance().newTransformer();
		transformer.setOutputProperty(OutputKeys.METHOD, "xml"); 
		transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8"); 
		transformer.setOutputProperty(OutputKeys.INDENT, "yes"); 
		transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount","4"); 
		DOMSource source = new DOMSource(document);
		StreamResult result = new StreamResult(fOutputStream);
		transformer.transform(source, result);
	}
	
	private void xmlWriteJavadocStandardParams(JavadocOptionsManager store, Document document, Element xmlJavadocDesc) throws DOMException {
		String destination= getPathString(new Path(store.getDestination()));
		xmlJavadocDesc.setAttribute(store.DESTINATION, destination);
		xmlJavadocDesc.setAttribute(store.VISIBILITY, store.getAccess());
		if (store.isJDK14Mode()) {
			xmlJavadocDesc.setAttribute(store.SOURCE, "1.4"); 
		}
		xmlJavadocDesc.setAttribute(store.USE, booleanToString(store.getBoolean("use"))); 
		xmlJavadocDesc.setAttribute(store.NOTREE, booleanToString(store.getBoolean("notree"))); 
		xmlJavadocDesc.setAttribute(store.NONAVBAR, booleanToString(store.getBoolean("nonavbar"))); 
		xmlJavadocDesc.setAttribute(store.NOINDEX, booleanToString(store.getBoolean("noindex"))); 
		xmlJavadocDesc.setAttribute(store.SPLITINDEX, booleanToString(store.getBoolean("splitindex"))); 
		xmlJavadocDesc.setAttribute(store.AUTHOR, booleanToString(store.getBoolean("author"))); 
		xmlJavadocDesc.setAttribute(store.VERSION, booleanToString(store.getBoolean("version"))); 
		xmlJavadocDesc.setAttribute(store.NODEPRECATEDLIST, booleanToString(store.getBoolean("nodeprecatedlist"))); 
		xmlJavadocDesc.setAttribute(store.NODEPRECATED, booleanToString(store.getBoolean("nodeprecated"))); 
		
		List packages= new ArrayList();
		List sourcefiles= new ArrayList();