bug#63311: 30.0.50; [PATCH] smtpmail-send-it split

[Manuel Giraud via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Manuel Giraud <manuel@ledu-giraud.fr>
>> Cc: 63311@debbugs.gnu.org
>> Date: Wed, 10 May 2023 13:47:11 +0200
>> 
>> So I guess, my question is how does one mix Lisp thread with
>> unwind-protect?
>
> I'm not sure I understand why you need to.  The two unwind-protect
> handlers will run at different times and most probably will need to
> unwind different stuff, although there could be overlap.  So why is it
> a problem to have two separate unwind forms?

I was not talking about two separate unwind forms.  I was talking about
*thread* and unwind.  Here is a minimal example that exhibits my
problem:

--8<---------------cut here---------------start------------->8---
(setq-local lexical-binding t)

(defun my-problem ()
  (interactive)
  (let ((buf (generate-new-buffer "*foo*")))
    (with-current-buffer buf
      (insert "secret message"))
    (unwind-protect
	(make-thread #'(lambda ()
			 (with-current-buffer buf
			   (sit-for 10)
			   (message (buffer-string)))))
      (kill-buffer buf))))
--8<---------------cut here---------------end--------------->8---

The thread won't have a chance to do its job since the buffer will
already be dead.
-- 
Manuel Giraud