Bug 66923 [typing]Can delete word (Ctrl-Backspace) on read only file
When you open read-only java file, all editing functions are disabled except deleting with Ctrl-Backspace and Ctrl-Del, then it is imposible to save this file. On simple text file it works ok - it blocks all edditing functions (including Ctrl-Backspace). I am using build 200406111814
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
* 
	 * @param annotationModel the annotation model
	 * @return the annotation model's lock object
	 * @since 3.0
	 */
	private Object getLockObject(IAnnotationModel annotationModel) { 
		if (annotationModel instanceof ISynchronizable)
			return ((ISynchronizable)annotationModel).getLockObject();
		else
			return annotationModel;
	}
	
	/**
	 * Updates the annotation views that show the given annotation.
	 * 
	 * @param annotation the annotation
	 */
	private void updateAnnotationViews(Annotation annotation) {
		IMarker marker= null;
		if (annotation instanceof MarkerAnnotation)
			marker= ((MarkerAnnotation) annotation).getMarker();
		else if (annotation instanceof IJavaAnnotation) {
			Iterator e= ((IJavaAnnotation) annotation).getOverlaidIterator();
			if (e != null) {
				while (e.hasNext()) {
					Object o= e.next();
					if (o instanceof MarkerAnnotation) {
						marker= ((MarkerAnnotation) o).getMarker();
						break;
					}