* Peter Levart: > But I see that the new IMM_LIST_NULLS type is needed for one other > thing - the immutable list implementation of that type has different > behavior of indexOf and lastIndexOf methods (it doesn't throw NPE when > null is passed to those methods) so this behavior has to be preserved in > the deserialized instance and there is not way to achieve that on old > JDK with existing serialization format, so there has to be an > incompatible change in the serialization format for that matter.
I think it's also needed for an efficient null element check in List::copyOf. I have a hunch that with the posted implementation, it would incorrectly produce an immutable list that contains null elements.
