We will certainly hear from Stuart on this very soon. Meanwhile, I have to say that the situation you've described is not that clear-cut in my opinion.
I understand there might be a discrepancy between how the `modCount` field is described and how it is actually used. Incrementing `modCount` unconditionally makes more sense to me. The whole purpose of this mechanism is to fail fast, exposing possible bugs in the client code. I believe it should be incremented on an attempt to modify the collection, rather than on the effective result of that attempt. It's somewhat similar to the following question: should Collections.emptyList (or Collections.emptySet) throw an exception on an attempt to call `clear` (or `remove(e)` where `e` is not a member of the said collection)? -Pavel
