Method implementation:

    private static boolean emptyOrWhite(String s){
        if(s==null){
            return true;
        }
        if(s.trim().length()<0){
            return true;
        }
        return false;
    }

Note that the (trimmed) length is checked to see if it is less than zero. This will always be false.

./form.refactoring/src/org/netbeans/modules/form/refactoring/RADComponentRenameRefactoringSupport.java:129