Re: Another "Rmail" problem I ran into

[Eli Zaretskii <eliz@gnu.org>]

> From: Dr Rainer Woitok <rainer.woitok@gmail.com>
> Date: Sun, 09 Jun 2024 18:19:13 +0200
> 
> Greetings,
> 
> because sometimes  Google sends  some reply mail  to my inbox  before it
> sends the corresponding original mail, I added the following lines to my
> "Rmail" configuration file:
> 
>    (defun Sort-Date ()
>     "Sort incoming mail by date."
>     (rmail-summary-sort-by-date nil))
> 
>    (add-hook 'rmail-get-new-mail-hook 'Sort-Date)

You cannot call rmail-summary functions from rmail-get-new-mail-hook,
not without switching to the right buffer and doing other bookkeeping.
rmail-get-new-mail-hook is a hook intended to act on the new messages
in the Rmail buffer, it is not intended to make summaries.

> But this leads  to either  the summary  or the message buffer  not being
> displayed, and in buffer "*Messages*" I find
> 
>    Getting mail from /home/rainer/mail/.HAM...
>    Counting new messages...done (1)
>    Finding sort keys...30
>    Reordering messages...30
>    Counting messages...done
>    Computing summary lines...done
>    rmail-show-message: Wrong type argument: stringp, nil
> 
> Just in case it matters: including the one new message there are 39 mes-
> sages in the summary buffer,  so why does "Rmail" only process 30 messa-
> ges?

Because when the hook is called, the Rmail buffer is narrowed to
include only the newly arrived email messages.