MDL-59173 tablelib.php: changed default of $params in set_sql to array()
MDL-59173 tablelib.php: changed default of $params in set_sql to array()

Default of $params = null leads to a problem in query_db().
There this value is used in array_merge, which can not handle null
values. If null is passed for one of the params the outcome will be null
independent of the value of the second param!

dilawar/moodle