[issue23571] Raise SystemError if a function returns a result with an exception set

[Serhiy Storchaka]

Serhiy Storchaka added the comment:

We can ignore such little slow down (if this is not just compiler artifact).

The patch LGTM. I afraid there will be issues with third-party code that will need an adaptation to 3.5, but on other hand, this patch could help with catching some hidden bugs.

----------

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue23571>
_______________________________________