On Mon, Jul 11, 2016 at 8:07 AM, Daniel Kinzler <daniel.kinzler@wikimedia.de
wrote:
There's another fix: never write null into rev_content_model. Always put the actual model ID there. That's pretty wasteful, but it's robust and reliable.
This. We probably would have done this a long time ago except it's blocked on T105652 so it won't significantly expand the size of the revision table, and that you blocked by T107595.
Both your (a) and (b) are wrong in some cases. Until we really fix it, we should probably just stick with the current (b) instead of dealing with the hassle of switching between one bad option and another.