The first two patches in this series should be uncontroversial (they're
just establishing a baseline), and i'd appreciate it if they could be
considered for merging regardless of whether anyone raises an objection
to this last patch of the series.

On Mon 2019-04-22 13:18:14 -0400, Daniel Kahn Gillmor wrote:
> When we have not been able to evaluate the signature status of a given
> MIME part, showing a content-free (and interaction-free) "[ Unknown
> signature status ]" button doesn't really help the user at all, and
> takes up valuable screen real-estate.
>
> A visual reminder that a given message is *not* signed isn't helpful
> unless it is always present, in which case we'd want to see "[ Unknown
> signature status ]" buttons on all messages, even ones that don't have
> a signing structure, but i don't think we want that.

This is a small step down the path of making notmuch-emacs friendlier
with regards to encrypted messages, but it's one that will have an
effect on future patch series that work with encrypted messages.  I'd be
happy to hear any concerns people have about this change, but i find
notmuch-emacs is more pleasant to use this way.

     --dkg