Created attachment 102732 [details]
Ultimately, we'd have to fix the bug 34564 to fix the root cause of all these crazy markup but we can fix this particular case.
To reproduce this bug, select all, copy & paste in the attached demo
Created attachment 102733 [details]
work in progress
The idea here is to extend r81887 and r83322 to remove most of block nodes as well.
Duplicate of bug 26483?
(In reply to comment #2)
> Duplicate of bug 26483?
Yes! I was looking for that bug yesterday but couldn't find it.
*** This bug has been marked as a duplicate of bug 26483 ***