Index: includes/bootstrap.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/bootstrap.inc,v
retrieving revision 1.206.2.13
diff -u -p -r1.206.2.13 bootstrap.inc
--- includes/bootstrap.inc	14 Sep 2009 13:33:39 -0000	1.206.2.13
+++ includes/bootstrap.inc	15 Nov 2009 04:11:12 -0000
@@ -1198,7 +1198,8 @@ function ip_address() {
       if (!empty($reverse_proxy_addresses) && in_array($ip_address, $reverse_proxy_addresses, TRUE)) {
         // If there are several arguments, we need to check the most
         // recently added one, i.e. the last one.
-        $ip_address = array_pop(explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']));
+        $ip_address_parts = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);
+        $ip_address = array_pop($ip_address_parts);
       }
     }
   }