bug#36828: 27.0.50; Uninstalled emacs shows installed documentation

[Eli Zaretskii]

> From: Štěpán Němec <stepnem@gmail.com>
> Cc: 36828@debbugs.gnu.org, ofv@wanadoo.es
> Date: Mon, 29 Jul 2019 16:47:49 +0200
> 
> Indeed I do consider this a bug, and quite explicitely so. That emacs
> should always default to using the data most relevant for the running
> executable seems obvious to me. What am I missing?

I think you are missing the perspective of someone who considers the
current behavior to be TRT.

IOW, why should we assume that the version of NEWS in the source tree
is necessarily more up-to-date/useful than the one in the installation
directory.  It could be, but then it could not be.

And please also read the code, where you will see that this is a
kind-of bootstrap problem, whereby we only figure out where some
directory is based on some other directory.  At some point near the
beginning of this bootstrap we need to make some assumption more or
less out of thin air, so we make it based on the most frequent use
case.