Activity Stream doesn't report correctly the dates when a document is copied

Imagine the following scenario:

• You have a document created one year ago
• You use $xwiki.copyDocument or the UI to copy it to a new document (without using the reset date parameter)
• You check the AS

Result: you won't see the action performed because the AS will report the new document creation using the creation date of the original document (i.e. one year ago). This is because copy will do a saveDocument which sends the events and since the new document has a creation date of the original document, the event is sent with that date.

For the record this is what happened on extensions.xwiki.org. Several hundreds doc were copied from the old code wiki to the extensions wiki at some point (someone run our copy script that wasn't protected...) and there's no way to see when this happened...

I think we need more specific events like Copy events, Rename events and possibly deduplication (for ex all events sent in a "transaction" use the same id).

Any idea?