OH man, that was a little harder than I thought it would be. Does `make test` randomly checkout a new branch or something? 

This patch adds a new long-winded variable `org-src-restore-window-config`, t by default, which if set to `nil` will inhibit restoration of previous window config in `org-edit-src-exit`.
I'm afraid I don't really understand the tests and I learn so slowly that I don't have time to keep trying today.  But hopefully this simple patch is adequate. I also wrote a changelog entry in my git commit msg, which is here:

Make restoration of window config optional on exit from src buffer

* org-srce.el (org-src-restore-window-config, org-exit-from-src): New
  variable org-src-restore-window-config allows user to opt out of
  restoring window config when exiting from source buffer with
  org-exit-from-src.




On Fri, Nov 23, 2018 at 1:31 AM Eric S Fraga <esflists@gmail.com> wrote:
On Thursday, 22 Nov 2018 at 14:09, Matt Price wrote:
> SO far this is working for me but I wondered whether other people would
> similarly want to change this behaviour and I should put together a proper
> proposal & patch?

Yes, please.  This is becoming more and more necessary as monitors get
larger.  I am using a very wide (and very nice) 38" monitor at work.  My
window configuration within a single frame can get quite
complex.  Having org (and other tools) change this configuration can be
quite annoying.

--
Eric S Fraga via Emacs 27.0.50, Org release_9.1.14-1035-gfeb442