bug#67521: 29.1; Describe with-current-buffer in more details

[Eli Zaretskii <eliz@gnu.org>]

> From: Xiyue Deng <manphiz@gmail.com>
> Date: Tue, 28 Nov 2023 23:01:58 -0800
> 
> In section 5.1, "The Definition of `copy-to-buffer'" of "Introduction to
> Emacs Lisp", when describing the implementation, the description of
> function `with-current-buffer' is a little too succinct with a sentence
> "Then, the `with-current-buffer 'function evaluates its body with that
> buffer temporarily current." and another one in the parentheses
> "`with-current-buffer' is a newer, and arguably easier, mechanism."
> 
> AIUI the intro book is intended for people without programming
> experience.  While arguably these two sentences do describe the
> `with-current-buffer' function, it would be better to expand a little
> more on what it does after "with that buffer temporarily current", such
> as it will switch back to the current buffer upon finishing the inner
> operations, etc.
> 
> Below is a proposed patch to expand the description a little.  Thanks in
> advance for considering!

Thanks, installed on the emacs-29 branch, and closing the issue.