while (notmuch_messages_valid (messages)) {
unsigned int doc_id = _notmuch_mset_messages_get_doc_id (messages);
g_array_append_val (threads->doc_ids, doc_id);
while (notmuch_messages_valid (messages)) {
unsigned int doc_id = _notmuch_mset_messages_get_doc_id (messages);
g_array_append_val (threads->doc_ids, doc_id);