BUG: iloc.__setitem__ with DataFrame value, multiple blocks, non-unique columns
- [ ] closes #xxxx
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

does this directly close an issue? > does this directly close an issue?

No, stumbled on this bug yesterday