bug#36828: 27.0.50; Uninstalled emacs shows installed documentation

[Óscar Fuentes]

Eli Zaretskii <eliz@gnu.org> writes:

> I prefer not to consider such radical changes in this logic, because
> we've been using what's there now for ages.  Who knows how many
> legitimate use cases this could potentially break?  Your use case is
> quite specialized: having an older binary of the exact same version
> installed is unusual, IME.  So radical changes due to this use case
> are unjustified, IMO.
>
> Let's try to find a way of detecting your situation without making too
> many waves elsewhere, okay?

Once we know that we are running a non-installed emacs, detecting that
it is an out-of-source build seems quite easy, because the build
directory contains build artifacts without the sources. Checking for the
presence of Makefile and the absence of Makefile.in, for instance,
should be enough.

Said that, I'll like to clarify that this is nothing about me. This
issue caught me by surprise once and, now that I know about it, it is
not a problem anymore. In fact, because your past comments about its
small relevance I closed the bug and it was reopened by other
participant who thinks (as I do) that the use case is not as rare as you
think. The difference between that other participant and me seems to be
that I don't consider this issue worth of arguing about. If you close it
as wontfix, I'm fine. If you think it is worth fixing, I'll try to
provide an acceptable patch.