bug#27804: 26.0.50; Emacs backgrounds itself during package-list-packages on WSL

[Josh Howard <jraitch@outlook.com>]

> From: Eli Zaretskii <eliz@gnu.org>
> Sent: Tuesday, July 25, 2017 11:34 AM
 
>> Cc: jraitch@outlook.com, bug-gnu-emacs@gnu.org
>> From: Angelo Graziosi <angelo.graziosi@alice.it>
>> Date: Tue, 25 Jul 2017 20:06:08 +0200
>> 
>> >> How, then, do you explain that Emacs 24.3, both installed with WSL
>> >> package manager (apt) and rebuilding it from source (see also this
>> >> thread [1]), work just fine?
>> > 
>> > It doesn't seem to be the case, as at least one of the participants in
>> > the discussion of that issue said the problem happened in Emacs 24 as
>> > well.
>> 
>> No, almost surely they are using 24.5.1, what current WSL installs with 
>> "sudo apt install emacs[-nox]"...
>> 
>> The have to use 24.3! to verify their conclusions..

> OK, but meanwhile I understand that a later build of WSL fixed some
> terminal-related bugs, and the problem is now gone.

Both of these appear to be true. The WSL has a fix which seems to address the problem and 24.3 does not display the issue. Something happened between 24.3 and now which causes Emacs to tickle this bug, but it may not be relevant.