Encryption vs. Gcc

[ludo@gnu.org (Ludovic Courtès)]

To keep a clear-text copy of encrypted messages that I send, I tried
this, as evasively suggested by the manual:

--8<---------------cut here---------------start------------->8---
;; Keep a clear-text copy of sent messages.
(setq gnus-gcc-post-body-encode-hook
      'mml-unsecure-message)
--8<---------------cut here---------------end--------------->8---

However, that doesn’t work, apparently because when the hook is called
the buffer that is current is not the message (see ‘gnus-inews-do-gcc’.)

Anyway, a more ideal solution for Gcc: would be this: if the message is
encrypted, then keep a copy encrypted with the sender’s public key
(rather than clear-text); otherwise keep a copy as is.

Does anyone have something like this?

TIA,  :-)
Ludo’.