[issue39725] unrelated `from None` exceptions lose prior exception information

[Serhiy Storchaka]

Change by Serhiy Storchaka <storchaka+cpython at gmail.com>:


----------
keywords: +patch
pull_requests: +17996
stage:  -> patch review
pull_request: https://github.com/python/cpython/pull/18629

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue39725>
_______________________________________