bug#53885: 28.0.51 [PATCH] Autoload package-installed-p

[Eli Zaretskii]

> From: Corwin Brust <corwin@bru.st>
> Date: Thu, 10 Feb 2022 01:21:59 -0600
> Cc: Eli Zaretskii <eliz@gnu.org>, 53885@debbugs.gnu.org
> 
> On Thu, Feb 10, 2022 at 12:45 AM Lars Ingebrigtsen <larsi@gnus.org> wrote:
> >
> > Eli Zaretskii <eliz@gnu.org> writes:
> >
> > > Thanks, but I don't think I understand the relevance, probably because
> > > I don't use use-package.  Why do you need package-installed-p to be
> > > autoloaded in this scenario, and why cannot use-package do that by
> > > itself?
> >
> > Yes, that's the puzzling thing.  But I've never used use-package
> > myself -- I assumed that it was a framework built around package.el, but
> > perhaps it's not related to package.el at all?
> >
> 
> I'm sure I follow the logic here.  If use-package isn't installed, how
> does it matter what relationship it may have to package.el?
> 
> That said, one can replace `use-package' with any feature not present
> in Emacs as shipped.
> 
> Perhaps the use-case is more generally expressed as such:
> 
> I would like to have my init scripts automatically install a package
> that isn't available "out of the box", but only if that feature hasn't
> already been installed.
> 
> As things presently stand, `package-installed-p' is nearly perfect for
> this, however one must take care to ensure package.el has been
> manually loaded before calling it, in order to avoid Emacs raising the
> error shown in the original report.

Now I'm confused: which code calls package-installed-p in the
scenarios you have in mind?  I thought it was use-package, but you
seem to say that's not the case?