Fixes #3817 Added a warning when groups in ugly mode are about to lose data

plugins/admin/groups/class_group.inc

@@ -96,6 +96,11 @@ class group extends plugin
       }
       $this->memberUid= $tmp;
       ksort ($this->memberUid);
+      if (($config->get_cfg_value("rfc2307bis") == "TRUE") &&
+          isset($this->attrs['member']) &&
+          ($this->attrs['member']['count'] !== $this->attrs['memberUid']['count'])) {
+        msg_dialog::display(_('Inconsitent data'), _('The member and memberUid fields of this groups are incoherent. FusionDirectory will use members from memberUid values upon saving. Cancel if you do not want this.'), WARNING_DIALOG);
+      }
     }
 
     /* Save gidNumber for later use */