*
* http://xapian.org/docs/queryparser.html
*
- * As a special case, passing a length-zero string, (that is ""), will
+ * As a special case, passing either a length-zero string, (that is ""),
+ * or a string consisting of a single asterisk (that is "*"), will
* result in a query that returns all messages in the database.
*
* See notmuch_query_set_sort for controlling the order of results.