It it turns out that the current proposed fix, will at least bring back the old behaviour, I think we should go for it and address potential improvements in a follow up issue. WDYT?

I totally agree with you. I don't think it's a good idea to change the logic in a bugfix release so applying Yoann's fix for now is what I would have suggested.

We compared the logic of AbstractDocumentBuilder with the new one the other day and it's the only issue we found.

That said, I think we should wait for Marc's feedback before thinking about releasing a fixed version. Thanks for having pushed a snapshot.