This program doesn't compile and causes a stack overflow:

import java.util.*;

class Test<T extends Comparable<? super T>> {

    abstract class Group<E extends Comparable<? super E>>
extends ArrayList<E>
implements Comparable<Group<? extends E>> {}

    abstract class Sequence<E extends Comparable<? super E>>
extends TreeSet<E>
implements Comparable<Sequence<? extends E>> {}

    public void containsCombination(SortedSet<Group<T>> groups,
SortedSet<Sequence<T>> sequences) {
foo(groups, sequences);
    }

    <C extends Collection<T>> void foo(SortedSet<? extends C> setToCheck,
SortedSet<? extends C> validSet) {}

}

###@###.### 2005-05-20 01:26:32 GMT
Stack overflow in 5.0u6:

The system is out of resources.
Consult the following stack trace for details.
java.lang.StackOverflowError
        at com.sun.tools.javac.code.Type.accept(Type.java:80)
        at com.sun.tools.javac.code.Types.lowerBound(Types.java:112)
        at com.sun.tools.javac.code.Types$IsSubTypeFcn.visitClassType(Types.java:410)
        at com.sun.tools.javac.code.Type$ClassType.accept(Type.java:482)
        at com.sun.tools.javac.code.Types$IsSubTypeFcn.isSubType(Types.java:347)