bug#66554: [PATCH] Add the public API of Compat to the core

[Eli Zaretskii]

> From: Daniel Mendler <mail@daniel-mendler.de>
> Cc: philipk@posteo.net,  66554@debbugs.gnu.org,  stefankangas@gmail.com,
>   monnier@iro.umontreal.ca
> Date: Sat, 10 Feb 2024 19:14:38 +0100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> From: Daniel Mendler <mail@daniel-mendler.de>
> >> Cc: Philip Kaludercic <philipk@posteo.net>,  66554@debbugs.gnu.org,
> >>   stefankangas@gmail.com,  monnier@iro.umontreal.ca
> >> Date: Sat, 10 Feb 2024 18:40:21 +0100
> >> 
> >> Eli Zaretskii <eliz@gnu.org> writes:
> >> 
> >> >> From: Philip Kaludercic <philipk@posteo.net>
> >> >> Cc: mail@daniel-mendler.de,  66554@debbugs.gnu.org,  
> >> >> stefankangas@gmail.com,
> >> >>   monnier@iro.umontreal.ca
> >> >> Date: Sat, 10 Feb 2024 16:46:30 +0000
> >> >> 
> >> >> I might be mistaken, but from a cursory peak at package.el, specifically
> >> >> `package-activate-1', the Info search path is only updated if the
> >> >> package is activated.  If the core-package takes priority over an
> >> >> external package, the external package shouldn't get activated.
> >> >> 
> >> >> This hasn't been a problem in the past, because core packages don't come
> >> >> with their own manuals, but this is an exception since core-Compat is
> >> >> not really the same code as ELPA-Compat.
> >> >> 
> >> >> One way to fix this, would be to explain how to disable a package via
> >> >> `package-load-list' in the Compat manual.  I'll have to try it out, but
> >> >> if it works, I think that solution should be acceptable.
> >> >
> >> > Another way to fix this is simply to include the Compat manual in
> >> > emacs.git.
> >> 
> >> No, this won't be useful. The Compat manual available at a given time is
> >> not relevant for the Emacs version developed at that time. If we would
> >> include the manual Compat 30 in Emacs 30, the manual will document
> >> functionality already present and documented in the Emacs 30 manual
> >> itself. The Compat 30 manual is only relevant for Emacs versions 29 and
> >> older.
> >
> > People who actually install and activate Compat from ELPA will have
> > the manual which comes with it first on the Info search path, no?  So
> > where's the problem, and what does "won't be useful" mean in this
> > context?  To recap, we are discussing ways to make the cross-reference
> > to the Compat manual work in as many use cases as possible, in
> > particular when Compat is either not installed or "not activated".
> 
> I assume it will lead to less confusion if we focus on documenting the
> compat.el functionality in the Elisp manual and refer to the Compat
> manual on ELPA via an http link, instead of copying the Compat manual.
> There should not be a cross-reference problem then?

But we will be back to the issue of having too much to say in the
ELisp manual about a relatively minor, perhaps even obscure, aspects.
Which is why I'd prefer not to have all the information in the ELisp
reference.