Developer credits
Git commits in Moodle 2.6.2 by Matt Petro
commit 82d0300757d1906584fe7fa2dec5a959429c24a2 Author: Matt Petro <petro@engr.wisc.edu> Date: Fri, 07 Feb 2014 02:32:04 +0800 Tag: v2.6.2 MDL-44029 mod_quiz: Fixing group deleted handler so it does not remove user overrides.