Bug 32893 Workspace Compatibility Problems 2.0 -> 2.1
Build 2.1 RC1 This PR collects problems related to opening a 2.0 workspace with 2.1.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/java/hover/JavaProblemHover.java
if (model != null) {
			Iterator e= new JavaAnnotationIterator(model, true);
			while (e.hasNext()) {
				Annotation a= (Annotation) e.next();
				Position p= model.getPosition(a);
				if (p.overlapsWith(hoverRegion.getOffset(), hoverRegion.getLength())) {
					String msg= ((IJavaAnnotation) a).getMessage();
					if (msg != null && msg.trim().length() > 0)
						return formatMessage(msg);
				}
			}
		}
		
		return null;
	}
	
	/*
	 * @see IJavaEditorTextHover#setEditor(IEditorPart)
	 */
	public void setEditor(IEditorPart editor) {
		if (editor instanceof CompilationUnitEditor)
			super.setEditor(editor);
		else
			super.setEditor(null);
	}
	static boolean isJavaProblemHover(String id) {
		return JavaPlugin.ID_PROBLEM_HOVER.equals(id);
	}
}