StackOverflowError in SetUniqueList.add() when it receives itself

Hi.

We found that the following test case fails with a StackOverFlowError exception:

test() {        
   SetUniqueList l = new SetUniqueList(new LinkedList<Object>()) ;        
   l.add((Object) l) ;    
}

The add() execution traps into an infinite recursion which crashes the program.

From the stack trace, we found that the infinite recursion occurs

at AbstractList.hashCode() since it invokes hashCode() of each of its elements.