[Vagrant Cascadian] Bug#759646: notmuch-emacs: switching mode= to invalid value sends unencrypted mail

[Jani Nikula]

On Thu, 28 Aug 2014, Vagrant Cascadian <vagrant at debian.org> wrote:
> When sending mail from notmuch-emacs interface, I usually use pgpmine
> signatures, but sometimes I want to send a signed encrypted message, so
> I manually edit the mode=sign to mode=signencrypt ... but if I make a
> typo, i.e. mode=signinvalidencrypt, notmuch happily and without warning
> sends the mail unencrypted.
> 
> i.e. #secure method=pgpmime mode=signinvalidencrypt will end up
> sending an encrypted message (with the <>, of course).
> 
> It seems like it should error out if the mode= is set to an invalid or
> unknown value, rather than sending mail in the clear.
> 
> I've got this set up in ~/.emacs, not sure what all else might be coming
> into play:
> 
>  '(message-setup-hook (quote (mml-secure-message-sign)))
>  '(notmuch-crypto-process-mime t)

I'm inclined to think this is a bug in message-mode. But we should
probably try to see what we could do to mitigate this.

As a workaround of sorts, I'd suggest not messing with the #secure tag
manually. Instead, you can use mml-secure-message-sign and
mml-secure-message-sign-encrypt to change the mode.

BR,
Jani.