bug#65209: 30.0.50; Unexpected behaviour of setq-local

[Eli Zaretskii <eliz@gnu.org>]

> From: Michael Heerdegen <michael_heerdegen@web.de>
> Cc: 65209@debbugs.gnu.org,  gerd.moellmann@gmail.com,  monnier@iro.umontreal.ca
> Date: Tue, 22 Aug 2023 05:09:44 +0200
> 
> But the manual leaves open some questions (after reading the manual I
> was not able to tell that the bug in this report was a bug):
> 
> How are bindings working when not changing the current buffer inside the
> let?  If I create a buffer-local binding and the `let' is left, what
> binding is left in the buffer - is the variable in that buffer still
> buffer local, or does leaving the let maybe also remove the local
> variable?

If someone knows how to describe what happens in this situation in a
way that won't confuse the reader, I'm okay with adding such a
description.

> Finally, should we also talk about lexical variables vs. buffer-local?
> They are different again:

Same thing here.

IOW, it is impossible for me to judge whether some text is good enough
for the manual without seeing the proposed text.  IME, some very
complicated issues are better left unsaid, especially if they
sufficiently rare and obscure, to avoid making the more common
scenarios potentially less clear.