Call to undefined function load_config() – squirrelmail-1.4.8-5.el4.centos.3

During one of my squirrelmail upgrades I have discovered strange behavior. Users were able to login, but only blank page had appeared. I have found this in log:

[Mon Feb 09 18:29:10 2009] [error] [client 89.103.46.115] PHP Fatal error:  Call to undefined function load_config() in /usr/share/squirrelmail/plugins/change_sqlpass/functions.php
on line 326, referer: http://blabla.blabla.tld/src/login.php

change_sqlpass pluging needs compatibility plugin to run. So here is the patch:

--- ../../functions/strings.php.orig    2006-08-11 04:15:43.000000000 -0700
+++ ../../functions/strings.php 2006-09-01 06:11:03.000000000 -0700
@@ -31,6 +31,7 @@
* For that reason, bring in global.php AFTER we define the version strings.
*/
require_once(SM_PATH . 'functions/global.php');
+include_once(SM_PATH . 'plugins/compatibility/functions.php');

/**
* Wraps text at $wrap characters