[mu4e bug] mu4e-compose-pre-hook is broken in v1.12+

[milouse]

Describe the bug

Due to an old known bug in date time formatting, my setup relies on preparatory work done for every draft. I expose it in this old issue: #2113 (comment)

To make it short, I temporarily store the mu4e-compose-parent-message in a variable, to be able to get it again to generate the citation line (historically the parent-message variable was lost while generating the citation line. Maybe this is not the case anymore, but this is another subject).

Please note the documentation for the mu4e-compose-pre-hook still say the following:

Hook run just before message composition starts.

If the compose-type is a symbol, either ‘reply’ or ‘forward’, the
variable ‘mu4e-compose-parent-message’ is the message replied to
/ being forwarded / edited, and ‘mu4e-compose-type’ contains the
type of message to be composed.

However, in version 1.12.0 through 1.12.5 the mu4e-compose-pre-hook call has disapeared and any functions added to the hook is never called. From 3ff2f9f the hook is called again… but too soon in the chain: mu4e-compose-parent-message and mu4e-compose-type are only set after the hook is run in the function mu4e--draft

How to Reproduce

• Add a function to mu4e-compose-pre-hook
• Start a draft

The function is never called, or after 3ff2f9f, they are called but mu4e-compose-parent-message and mu4e-compose-type are nil.

Possible solution

If I may, I’d have moved the following block:

(cl-assert (member compose-type '(reply forward edit new)))
  (cl-assert (eq (if parent t nil)
                 (if (member compose-type '(reply forward)) t nil)))
  ;; remember some variables, e.g for user hooks. These are permanent-local
  ;; hence survive the mode-switch below (we do this so these useful vars are
  ;; available in mode-hooks.
  (setq-local
   mu4e-compose-parent-message parent
   mu4e-compose-type compose-type)

from the function mu4e--prepare-draft-buffer to the function mu4e--prepare-draft, before calling the pre-hook.

However this implies to call mu4e--prepare-draft with the compose-type as parameter, what is not possible today, and I’m not sure about the implication of such a move.

Environment

Emacs 29.3 with mu 1.12.5

Checklist

• you are running either an 1.10.x/1.12.x release or master (otherwise please upgrade)
• you can reproduce the problem without 3rd party extensions (including Doom/Evil, various extensions etc.)
• you have read all of the above

[djcb]

That's indeed broken, I fixed it a some point.. but apparently it broke again :-|

Also thank you for the PR... I'm pushing a change that is slightly different, running the hook a bit earlier so that (as the docstring suggests) one could influence the later draft-creation steps.

[milouse]

Good to know. If you need I’m willing to test it :)

[milouse]

I just checked your implementation and it’s far more simple and better than mine.

It leverages just a little thing: maybe you should also run the cl-assert from the mu4e--prepare-draft-buffer before even running the hooks? The idea being to fail sooner if the message-type or parent variables are not valid?

I’m speaking about these lines:

  (cl-assert (member compose-type '(reply forward edit new)))
  (cl-assert (eq (if parent t nil)
                 (if (member compose-type '(reply forward)) t nil)))

[djcb]

Maybe we could copy them to the being of mu4e--draft, but tbh, these assert are more-or-less leftovers from development, so don't care too much about them.

Anyway, thanks for the heads up! Closing this ticket.