bug#20834: 25.0.50; install-autoremove cycle with the tablist package

[Tassilo Horn <tsdh@gnu.org>]

Tassilo Horn <tsdh@gnu.org> writes:

> Ok, there's a new package version for `names'.  So here's what I get
> with your recipe.
>
>> Could you try the following?
>>
>> 1. Delete `tablist`.
>
> Done (or rather I've uninstalled it previously in another emacs
> instance).
>
>> 2. Hit `U` to mark packages for upgrade.
>
> I can upgrade names-20150611.636 to the recent version 20150617.359.
>
>> 3. Does `tablist` get marked for installation?
>
> No.
>
> Now I went through all installed packages and their dependencies, and
> none of them requires tablist.  So that suggests that when doing
> `package-autoremove' the removed packages might still be left over in
> some variable which forces a reinstall with the next upgrade.  This
> doesn't seem to happen when I explicitly remove a package using `U'

I've meant `d', not `U'.

> followed by `x'.

Anyway.  I've just restarted emacs and it errored during startup because
actually the pdf-tools package uses tablist although it doesn't
explicitly declare it as dependency.  In its git repository, it has
tablist.el bundled but that's not distributed via the package.  Reported
here:

  https://github.com/politza/pdf-tools/issues/103

Does that explain something?  E.g., package-autoremove only works with
the declared dependencies whereas a package upgrade will also recognize
that (featurep 'tablist) is true in the currently running emacs which
means it is actually used and thus it must be installed again?

Bye,
Tassilo