- in_reply_to = _notmuch_message_get_in_reply_to (message);
- if (in_reply_to && strlen (in_reply_to) &&
- g_hash_table_lookup_extended (thread->message_hash,
- in_reply_to, NULL,
- (void **) &parent))
- _notmuch_message_add_reply (parent, message);
- else
+ if (! _parent_via_in_reply_to (thread, message))
+ _notmuch_message_list_add_message (thread->toplevel_list, message);
+ }
+
+ /*
+ * if we reach the end of the list without finding a top-level
+ * message, that means the thread is a cycle (or set of cycles)
+ * and any message can be considered top-level. Choose the oldest
+ * message, which happens to be first in our list.
+ */
+ if (first_node) {
+ message = first_node->message;
+ if (_notmuch_message_list_empty(thread->toplevel_list) ||
+ ! _parent_via_in_reply_to (thread, message)) {