Merge branch 'master' into 'stable-3.1'

Till Brehm

2016-05-19 dc7aa0813f52eed4eb039a21ee13d6a5cb7f104c

 interface/lib/classes/listform.inc.php

@@ -563,7 +563,7 @@
               break;

            case 'DATE':
               if($record[$key] != '' && $record[$key] != '0000-00-00') {
               if($record[$key] != '' && !is_null($record[$key]) && $record[$key] != '0000-00-00') {
                  $record[$key] = $record[$key];
               }
               break;