Re: notmuch.el question: reading all messages in thread

[Kyle Meyer <kyle@kyleam.com>]

Matt Armstrong writes:

[...]
> I looked for a way to easily re-query a tree view buffer such that all
> messages in all threads shown are "open" but did not find it.  Does this
> exist?

I've wanted something like this too and will be happy if someone points
out an existing way to do it.  I'm not aware of one.

> I suppose I'm looking for the opposite of `notmuch-tree-filter'.  Maybe
> `notmuch-tree-widen-to-thread' that produces a new notmuch tree widened
> to the entire thread of the current message.

In show buffers, I remap notmuch-tree-from-show-current-query to a
custom function.  Like the original variant, it displays the tree for a
message's thread, but giving a prefix argument says to display all the
messages as "open".

I don't think that's exactly what you're asking for, but it still might
be useful (at least for adapting to something that behaves as you want).

--8<---------------cut here---------------start------------->8---
(defun km/notmuch-thread-id-from-message-id (message-id)
  (let ((threads (with-temp-buffer
                   (call-process "notmuch" nil t nil
                                 "search" "--format=sexp" "--output=threads"
                                 message-id)
                   (goto-char (point-min))
                   (read (current-buffer)))))
    (cl-case (length threads)
      (0
       (user-error "No thread found for %S" message-id))
      (1
       (concat "thread:" (car threads)))
      (t
       (error "Got multiple threads for %S" message-id)))))

;;;###autoload
(defun km/notmuch-tree-from-show-current-query (&optional ignore-context)
  (interactive "P")
  (let* ((mid (or (notmuch-show-get-message-id)
                  (error "No message ID found")))
         (tid (if (and notmuch-show-thread-id
                       ;; notmuch's variant works with
                       ;; notmuch-show-thread-id ...
                       (string-prefix-p "thread:" notmuch-show-thread-id))
                  notmuch-show-thread-id
                ;; ... but there are cases where this is set to the
                ;; message ID, leading to the tree result that is
                ;; always narrowed to the message.  Try harder to get
                ;; the actual thread ID.
                (km/notmuch-thread-id-from-message-id mid)))
         (notmuch-show-query-context (and (not ignore-context)
                                          notmuch-show-query-context)))
    (notmuch-tree tid notmuch-show-query-context mid)))
--8<---------------cut here---------------end--------------->8---