bug#51930: 27.2; Buffer-local functions? Buffers specified buffer-locally?

[Eli Zaretskii <eliz@gnu.org>]

> From: Drew Adams <drew.adams@oracle.com>
> Date: Wed, 17 Nov 2021 21:51:29 +0000
> 
> I'm trying to read (elisp) `Window Hooks', and I can't make heads or
> tails of it.  Throughout this node there's mention of buffer-local
> functions: "functions specified buffer-locally".
> 
> I have no idea what is meant by this.  I search the Elisp manual for
> buffer-local, and I find zillions of matches that are about
> buffer-local variables, of course.  And I find a couple of mentions
> of buffer-local faces.  No mention, that I can find, of buffer-local
> functions or "functions specified buffer-locally".  How to specify a
> function buffer-locally?
> 
> A wild guess is that what you're trying to say has something to do
> with using the LOCAL argument to `add-hook' or `remove-hook`.  But
> if so, it's not clear what.
> 
> Please clean up this text so it's comprehensible by an average reader.
> If buffer-local functions are indeed a thing now, please document what
> they are, somewhere.

This is a very dramatic description of a problem ("can't make heads or
tails", "I have no idea what is meant", etc.), so I'm not sure whether
a simple cross-reference to the documentation of add-hook, which
explains what is meant by "buffer-local" in this case, will solve the
problem.  If it will, doing that is very easy.  In fact, I just did.