notmuch/TODO

Write a "notmuch tag" command to add/remove tags from messages
matching a search query.

Rename notmuch_thread_results_t and notmuch_message_results_t to
notmuch_threads_t and notmuch_messages_t respectively.

Add a talloc context as the first argument to each command in
notmuch.c.

Write a "notmuch show" that displays a single thread.

Fix to use the *last* Message-ID header if multiple such headers are
encountered, (I noticed this is one thing that kept me from seeing the
same message-ID values as sup).

Audit everything for dealing with out-of-memory (and drop xutil.c).

Write a test suite.

Achieve 100% test coverage with the test suite.

Think about this race condition:

	A client executes "notmuch search"
	Then executes "notmuch show" on a thread
	While user is reading, new mail is added to database for the thread
	Client asks for the thread to be archived.

   The bug here is that email that was never read will be
   archived. That's bad. The fix for the above is for the client to
   archive the individual messages already retrieved and shown, not
   the thread. (And in fact, we don't even have functions for removing
   tags on threads.)

   But this one is harder to fix:

	A client executes "notmuch search"
	While user is reading, new mail is added to database for the thread
	Client asks for a thread to be archived.

   To support this operation, (archiving a thread without even seeing
   the individual messages), we might need to provide a command to
   archive a thread as a whole. The problem is actually easy to fix
   for a persistent client. It can onto the originally retrieved
   thread objects which can hold onto the originally retrieved
   messages. So archiving those thread objects, (and not newly created
   thread objects), will be safe.

   It's harder to fix the non-persistent "notmuch" client. One
   approach is to simply tell the user to not run "notmuch new"
   between reading the results of "notmuch search" and executing
   "notmuch archive-thread" (or whatever we name it).