Recent versions of notmuch support more config file locations as
described in the man page:
https://notmuchmail.org/manpages/notmuch-config-1/

The notmuch2 bindings change now means the retrieval of the oldest
subject from a thread needs to be reworked.

When the config option is chosen to use the oldest subject:
  # Set thread subjects to the first (oldest) message
  thread_subject = oldest

The following error is generated:

    File "/home/kbingham/iob/alot/alot/db/thread.py", line 50, in _refresh
      first_msg = list(thread.get_toplevel_messages())[0]
  AttributeError: 'Thread' object has no attribute 'get_toplevel_messages'

Update the code to use the correct interface on both the Thread and
Message objects.

Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

Thanks to Jonas Smedegaard dr@jones.dk
---
This is an updated patch which (slows down but) avoids crashing when deleting
an item 3 times in a list longer than 1 screen

as they are all broken as of today

try github Actions

0cd98062 ("db/manager: Handle tag toggling messages", 2020-05-18) moved
the handling of `toggletags` (i.e. the determination of tags to
removeand add) from the search buffer command to the db manager. It did
not move the corresponding code from the thread buffer command, though.

Refactor the thread buffer command so that it calls the db manager
methods as the search buffer command does. Besides reducing reduncancy,
this also fixes an old issue with `toggletags --all` in a thread buffer:
If this is supposed to do something useful and unsursprising then it
should act the same way as `toggletags` in a search buffer for
`thread:tid`, i.e. toggle a tag based on the presence in the thread (not
individually). The refactoring achieves this as an intended side-effect.

`toggletags` is supposed to toggle tags based on the presence of a tag
in a thread or search result.

0cd98062 ("db/manager: Handle tag toggling messages", 2020-05-18) moved
the handling of `toggletags` (i.e. the determination of tags to remove
and add) from the search buffer command to the db manager. Alas, it also
turned the handling to be per message: If you toggle the `unread` tag on
a thread with unread messages then the unread ones get untagged but the
read messages get tagged `unread`.

This might have gone unnoticed so far because - as long as the search
buffer does not get requeried by thread IDs - a search buffer for
`tag:unread` would not match other messages and would not act on them at
all. But this is different when you toggle a tag that you have not
searched for, of course.

(Re-)Teach the db manager to toggle tags based on the presence of a tag
in the results of a query.

This used to be available in the old notmuch bindings. Use direct access
with the new cffi bindings.

The request to upstream for exposing this library function is pending.

Explicitly expand or collapse every message, like we do in
ThreadBuffer.unfold_matching instead of only expanding or collapsing the
matching messages.

Closes #1496

Limiting the number of results for an exact move last doesn't make sense
if we will try to restore the focus first on the reversed threadlist,
potentially loading all threads with the default configuration.

The default limit is `200`, but `search_threads_rebuild_limit` is `0`
by default, however there is no heuristic approach on restoring focus.

After rebuilding the threadlist, we still need to actually update the
focused thread.

fix #1548

It seems the alot DBManager object is meant to only open the
database shortly and then cache the needed data out of it in
its own Message and Thread objects.  Implement this using
notmuch2's context manager support which ensure the database
is completely closed.

Configuration options to save named queries don't seem to be
implemented in the bindings at the moment, so the `setconfig` message
will simply raise an error for now.