Cast with unbounded wildcards with fbounds causes infinite loop in javac

FULL PRODUCT VERSION :
javac 1.6.0_26

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.1.7601]

A DESCRIPTION OF THE PROBLEM :
The program copied below should compile, but causes an infinite recursion instead.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Compile the source code given below.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
It should compile withouth problem.
ACTUAL -
It produces a stack overflow shown below

ERROR MESSAGES/STACK TRACES THAT OCCUR :
The system is out of resources.
Consult the following stack trace for details.
java.lang.StackOverflowError
        at com.sun.tools.javac.code.Types$1.visitWildcardType(Types.java:98)
        at com.sun.tools.javac.code.Type$WildcardType.accept(Type.java:416)
        at com.sun.tools.javac.code.Types$MapVisitor.visit(Types.java:3270)
        at com.sun.tools.javac.code.Types.upperBound(Types.java:95)
        at com.sun.tools.javac.code.Types.adaptRecursive(Types.java:2990)
        at com.sun.tools.javac.code.Types.adapt(Types.java:3020)
        at com.sun.tools.javac.code.Types.adaptRecursive(Types.java:2981)
        at com.sun.tools.javac.code.Types.adaptRecursive(Types.java:2990)
        at com.sun.tools.javac.code.Types.adapt(Types.java:3020)
[...]


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
class StackOverflow implements AInterface<AClass<?>> {
@Override
public void doA(final AInterface<AClass<?>> vm) {
final StackOverflow cast = (StackOverflow) vm;
}
}

class AClass<T extends Comparable<T>> {}

interface AInterface<V> {
void doA(AInterface<V> vm);
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
It is working in Java7.

If possible, you can change the code to use a specific generic type, that way it will also compile with Java6:

class StackOverflow<S extends Comparable<S>> implements AInterface<AClass<S>> {
@Override
public void doA(final AInterface<AClass<S>> vm) {
final StackOverflow cast = (StackOverflow) vm;
}
}

class AClass<T extends Comparable<T>> {}

interface AInterface<V> {
void doA(AInterface<V> vm);
}