public class Utl {

  // --- simple
  public static interface F1Itf<T>
    extends Comparable<T> {
    int getSize();

    T getField();
  }

  // --- nested typed-generic
  public static interface F2Itf<T>
    extends Comparable<F2Itf<T>> {
    int getSize();

    T getField();
  }

  // --- Comparable

  // Sun: ERROR
  // Eclipse: ERROR
  public static <T extends Comparable<?>> int cmp1(final T t1, final T t2) {
    return t1.compareTo(t2);
  }

  // Sun: OK
  // Eclipse: OK
  public static <T extends Comparable<T>> int cmp2(final T t1, final T t2) {
    return t1.compareTo(t2);
  }

  // --- F1Itf

  // Sun: ERROR
  // Eclipse: ERROR
  public static <T extends F1Itf<?>> int cmp3(final T t1, final T t2) {
    return t1.compareTo(t2);
  }

  // Sun: OK
  // Eclipse: OK
  public static <T extends F1Itf<T>> int cmp4(final T t1, final T t2) {
    return t1.compareTo(t2);
  }

  // --- F2Itf

  // Sun: ERROR
  // Eclipse: OK -> wildcard in F2Itf
  public static <T extends F2Itf<?>> int cmp5(final T t1, final T t2) {
    return t1.compareTo(t2);
  }

  // Sun: OK
  // Eclipse: OK
  public static <T extends F2Itf<T>> int cmp6(final T t1, final T t2) {
    return t1.compareTo(t2);
  }
}

/*
 * javac -version: javac 1.6.0_11
 * java -version:
 *   java version "1.6.0_11"
 *   Java(TM) SE Runtime Environment (build 1.6.0_11-b03)
 *   Java HotSpot(TM) Client VM (build 11.0-b16, mixed mode, sharing)
 *
 * Utl.java:24: compareTo(capture#407 of ?) in java.lang.Comparable<capture#407 of ?> cannot be applied to (T)
 *   return t1.compareTo(t2);
 *            ^
 * Utl.java:38: compareTo(capture#825 of ?) in java.lang.Comparable<capture#825 of ?> cannot be applied to (T)
 *   return t1.compareTo(t2);
 *            ^
 * Utl.java:52: compareTo(Utl.F2Itf<capture#105 of ?>) in java.lang.Comparable<Utl.F2Itf<capture#105 of ?>> cannot be applied to (T)
 *   return t1.compareTo(t2);
 *            ^
 * 3 errors
 */