Developer credits
Git commits in Moodle 3.6.x by Cameron Ball
commit 3282dda765c972d69d2a5d2d431b6c844ccc8a0c Author: Cameron Ball <cameron@moodle.com> Date: Thu, 21 Mar 2019 16:04:37 +0800 Tag: v3.6.4 MDL-65104 registration: Ensure $registration is always null when no record exists