notmuch.el question: reading all messages in thread

[Matt Armstrong <matt@rfc20.org>]

Sometimes a notmuch query matches only a subset of messages in a thread.
When this happens only that subset of messages will be "open".  Many
notmuch commands operate on the "open" messages only.  For example: SPC,
'n', 'p'.

Often this is what I want.  It works well when I'm looking for a
specific piece of information, or when I am interested in reading only
the unread messages in a long thread that I have seen previously.

Often this is not what I want.  I'm interested in seeing all messages
when I am looking for entire conversations where a topic is being
discussed.  E.g. when I want to re-read a long forgotten thread, or one
that surfaced through specific search terms that appear only in a few of
the messages in the thread.

For example, I subscribe to some lists but don't read all messages in a
timely manner, if I ever read them at all.  A search might surface
threads from those lists before I read them with my usual "tag:inbox
tag:somelist" query.  I typically find these threads with a query
"tag:inbox some other search term".

In the second case I can achieve what I want with queries like:

  thread:"{tag:inbox some other search term}"

But this is a burden to type and I often realize I want this after the
usual query has produced the search results, and then pressed 'Z' to get
a tree view, and realized that most of the messages are "closed."

I looked for a way to easily re-query a tree view buffer such that all
messages in all threads shown are "open" but did not find it.  Does this
exist?

I suppose I'm looking for the opposite of `notmuch-tree-filter'.  Maybe
`notmuch-tree-widen-to-thread' that produces a new notmuch tree widened
to the entire thread of the current message.