On ocm.update transaction, the Current implementation of DefaultCollectionConverterImpl recreates the colleciton-element nodes if there is no id field specificaiton. This is completely valid for majority of the cases. But I came across a case where the colleciton element has a uuid field. In this case also what is happening with the current implementation is that it drops all the elements from the old collection-elements and recreates the new ones. The major flip side is that now I am left with brand new UUIDs. I think we should address the uniqueness characteristics specified through UUID also while mapping colleciton elements.
I have a patch and a TestCase to verify the same. I have implemented it only for the digester. If people feel the approach is right I will work out an annotation based testcase as well. I do not think it is going to fail even with annotations.