bug#31193: 26.1; error in `term-down' after window configuration change

[Eli Zaretskii]

> From: Noam Postavsky <npostavs@gmail.com>
> Date: Tue, 17 Apr 2018 20:07:41 -0400
> Cc: 31193@debbugs.gnu.org
> 
> Okay, here's the patch with message.  Eli, should I apply this to
> emacs-26?

Yes, please.

> I believe it's safe because the term-current-row function
> simply returns the value of the term-current-row variable if that is
> non-nil.  Hence it should only affect cases where we were going to
> signal an error due to type-mismatch anyway.

Agreed.

Thanks.