"Herbert J. Skuhra" <herbert@gojira.at> writes:

> On Wed, Jan 18, 2023 at 09:17:59PM +0200, Eli Zaretskii wrote:
>> > this is strange because I can reproduce it easily on different systems:
>> > 
>> > - master on FreeBSD 13.1-STABLE 
>> > - emacs-29 and master on macOS 12.6.2
>> > - master on WLS2/Windows11 (Ubuntu)

I can now reproduce the error, too. The problem was that at the time Lars
closed the bug report by applying the attached patch (after quite a long
time of it sitting dormant), I had some additional local changes for
sieve.el and sieve-manage.el on a branch which I didn't get to submit.
And when I tried to reproduce the error, I've still been using this
branch without realizing it. Sorry for that.

>> ...
>> Thanks.  The error is here:
>> 
>> (defun sieve-manage--append-to-log (&rest args)
>>   "Append ARGS to sieve-manage log buffer.
>> 
>> ARGS can be a string or a list of strings.
>> The buffer to use for logging is specifified via
>> `sieve-manage-log'. If it is nil, logging is disabled."
>>   (when sieve-manage-log
>>     (with-current-buffer (or (get-buffer sieve-manage-log)
>>                              (with-current-buffer  <<<<<<<<<<<<<<<<<<<<<<
>>                                  (get-buffer-create sieve-manage-log)
>>                                (set-buffer-multibyte nil)
>>                                (buffer-disable-undo)))
>> 
>> And I admit that I don't understand this code.  What is it trying to
>> do?  Shouldn't it be just
>> 
>>   (when sieve-manage-log
>>     (with-current-buffer (get-buffer-create sieve-manage-log)
>>       (set-buffer-multibyte nil)
>>       (buffer-disable-undo)))
>> 
>> Kai, am I missing something?

The additional '(or ...' was meant to only run

  (set-buffer-multibyte nil)
  (buffer-disable-undo)

once, when creating the log buffer (not everytime something gets
appended to the log). What is missing in my code is an additional
`current-buffer'. Here's the complete fixed function:

(defun sieve-manage--append-to-log (&rest args)
  "Append ARGS to sieve-manage log buffer.

ARGS can be a string or a list of strings.
The buffer to use for logging is specifified via
`sieve-manage-log'. If it is nil, logging is disabled."
  (when sieve-manage-log
    (with-current-buffer (or (get-buffer sieve-manage-log)
                             (with-current-buffer
                                 (get-buffer-create sieve-manage-log)
                               (set-buffer-multibyte nil)
                               (buffer-disable-undo)
                               (current-buffer)))
      (goto-char (point-max))
      (apply #'insert args))))

>> Herbert, if you make the change above, does the problem go away?
>
> Yes, this change resolves the issue:
>
> diff --git a/lisp/net/sieve-manage.el b/lisp/net/sieve-manage.el
> index 5bee4f4c4a..636c7cbc5b 100644
> --- a/lisp/net/sieve-manage.el
> +++ b/lisp/net/sieve-manage.el
> @@ -174,11 +174,9 @@ sieve-manage--append-to-log
>  The buffer to use for logging is specifified via
>  `sieve-manage-log'. If it is nil, logging is disabled."
>    (when sieve-manage-log
> -    (with-current-buffer (or (get-buffer sieve-manage-log)
> -                             (with-current-buffer
> -                                 (get-buffer-create sieve-manage-log)
> +    (with-current-buffer (get-buffer-create sieve-manage-log)
>                                 (set-buffer-multibyte nil)
> -                               (buffer-disable-undo)))
> +                               (buffer-disable-undo)
>        (goto-char (point-max))
>        (apply #'insert args))))
>

Here's a patch which preserves the logic of the original code: