This patch is the fix for and OF-17.
Patch looks good to me. Patch is not doing an actual update but a remove and create so we are not keeping a creation and updated date which would be a nice thing to have.
FYI, more than a Bug this issue is an enhancement. The version of pubsub that was implemented didn't support updates of items but just add and remove.
I only had version 1.12 of the spec to go by, so it is quite possible that this should go as a subtask of OF-25, which is what I did with other tasks that I knew were related to version updates.
According to 1.12, if a new item is published with the same id as an existing one, it must overwrite the existing one. I checked the diffs for changes between versions and I did not see this listed as a change between 1.8 (which I believe is the currently supported version) and 1.12
New ID is only created when it is not supplied by the publisher. A duplicate id will overwrite the old item.