Add back full-text indexing, (see last version of notmuch-index-message.c in the archives). Investigate using just a simple hash while constructing threads during "notmuch setup", then just writing out to Xapian in one shot at the end without haivng to rewrite documents nor look anything up. 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.