joomla/joomla-framework — pull request #283 by elgenie (2013-11-22 14:47:37+00:00)
Title: Make ArrayHelperTest resilient against undefined sort order

The documentation of usort (http://us1.php.net/manual/en/function.usort.php)
makes it clear that "If two members compare as equal, their relative order in the sorted array is undefined."

The dependency on undefined behavior makes this test fail on the HHVM php runtime (http://www.hhvm.com/)