A DESCRIPTION OF THE PROBLEM :
Type variable information is not always maintained for anonymous classes 

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run the source code

ACTUAL -
T
null

---------- BEGIN SOURCE ----------
public class Xx<S> {

    public static <T> void main(String[] args) {
        printIt(new Xx<T>() {}.getClass());

        Runnable r = () -> printIt(new Xx<T>() {}.getClass());
        r.run();
    }

    static void printIt(Class<?> cl) {
        ParameterizedType pt = (ParameterizedType) cl.getGenericSuperclass();
        System.out.println(pt.getActualTypeArguments()[0]);
    }
}

---------- END SOURCE ----------

FREQUENCY : always