hi all--

TIL about tree-view -- pressing 'Z' from a "notmuch-show" buffer is very
nice, thanks to all who worked on this feature.

I have a small usability improvement to ask for, sorry that my elisp is
too weak to propose a patch.

when i've hit Z, i get a split emacs view with two buffers -- one is the
"notmuch-tree" buffer, and the other is a "notmuch-show" buffer.

when i hit enter on a point inside the notmuch-tree buffer, the
notmuch-show buffer's contents change.

It would be great if the notmuch-tree buffer would maintain a specific
marker indicating which message is being shown.  As it stands, the
highlighted row in notmuch-tree can change if i move where the point is,
but don't hit enter -- so one message in notmuch-tree is highlighted,
but a different message in displayed in notmuch-show.

There are hints that they don't match already, of course -- the metadata
about each message is likely to be different, and an astute reader can
catch it.

Avoiding the confusion entirely by having a distinct indicator of the
shown message (e.g. maybe a "─►" to the left of the line corresponding
to the message in notmuch-tree) would be pretty nice.

    --dkg