User tests: Successful: Unsuccessful:
Really only a warning suppression in debug mode only.
Some extension do their own mysqli handling and free the result without using the Joomla function (as it is protected it can't be used).
Thus this fix is really needed.
Related tracker:
http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=31683
Closing as implemented into master with 6e8a34d