Index: memberlist.php
===================================================================
--- memberlist.php	(revision 10196)
+++ memberlist.php	(working copy)
@@ -430,11 +430,25 @@
 
 		$user_id = (int) $member['user_id'];
 
+		//Check currently logged-in user's group memberships
+		include($phpbb_root_path . 'includes/functions_user.' . $phpEx);
+		$memberships = $group_membership_ids = array();
+		$memberships = group_memberships(false, $user->data['user_id']);
+
+		if ($memberships)
+		{
+			foreach ($memberships as $row)
+			{
+				$group_membership_ids[] = $row['group_id'];
+			}
+		}
+		unset($memberships);
+
 		// Do the SQL thang
 		$sql = 'SELECT g.group_id, g.group_name, g.group_type
 			FROM ' . GROUPS_TABLE . ' g, ' . USER_GROUP_TABLE . " ug
 			WHERE ug.user_id = $user_id
-				AND g.group_id = ug.group_id" . ((!$auth->acl_gets('a_group', 'a_groupadd', 'a_groupdel')) ? ' AND g.group_type <> ' . GROUP_HIDDEN : '') . '
+				AND g.group_id = ug.group_id" . ((!$auth->acl_gets('a_group', 'a_groupadd', 'a_groupdel')) ? ' AND (g.group_type <> ' . GROUP_HIDDEN . ((sizeof($group_membership_ids)) ? ' OR ' . $db->sql_in_set('ug.group_id', $group_membership_ids) : '') . ')' : '') . '
 				AND ug.user_pending = 0
 			ORDER BY g.group_type, g.group_name';
 		$result = $db->sql_query($sql);