const char *
notmuch_thread_get_thread_id (notmuch_thread_t *thread);
+/* Get the authors of 'thread'
+ *
+ * The returned string is a comma-separated list of the names of the
+ * authors of mail messages in the query results that belong to this
+ * thread.
+ *
+ * The returned string belongs to 'thread' and as such, should not be
+ * modified by the caller and will only be valid for as long as the
+ * thread is valid, (which is until notmuch_thread_destroy or until
+ * the query from which it derived is destroyed).
+ */
+const char *
+notmuch_thread_get_authors (notmuch_thread_t *thread);
+
/* Get the subject of 'thread'
*
* The subject is taken from the first message (according to the query
* modified or freed by the caller (nor should it be referenced after
* the message is destroyed).
*
- * Returns NULL if the message does not contain a header line matching
- * 'header' of if any error occurs.
+ * Returns an empty string ("") if the message does not contain a
+ * header line matching 'header'. Returns NULL if any error occurs.
*/
const char *
notmuch_message_get_header (notmuch_message_t *message, const char *header);