[xwiki-devs] Issue with copy of XWikiPreferences and custom mapped classes

Hi devs, Following upon an issue with migration encountered by Jeremie Bousquet, I felt on an unexpected issue that I do not really know how to fix. When you made a copy of a document containing a custom mapped class, a new custom mapped class is created by the exact copy of the original document class definition, but the custom mapping for this copied class is probably incorrect or not available. For exemple, if you made a copy of XWiki.XWikiPreferences, you get a new class that has an internal mapping, but since the .xbm is unchanged, there is probably no chance that the newly defined class has a mapped entity in the hibernate mapping. This is precisely the cause of the issue I have encounter with Jeremie, since the migration tried to migrate IDs of that new class, which was unusable. Initially, I had an NPE that I have transformed into an exception now, since I see this as a corruption somewhere in the store. The issue with a dynamically custom mapped class could even be worse, since both class will have the same mapping. So my question is more generally about how we handle copy of custom mapped classes ? now and in the future ? -- Denis Gervalle SOFTEC sa - CEO eGuilde sarl - CTO