This method regenerates the left/right ids for the nested set based on the parent/child relations. This function executes three queries per item, so it should only be called, when the set has one of the following problems: - The set has a duplicated value inside the left/right id chain - The set has a missing value inside the left/right id chain - The set has items that do not have a left/right is set When regenerating the items, the items are sorted by parent id and their current left id, so the current child/parent relationships are kept and running the function on a working set will not change any orders. PHPBB3-11495