Index: install.php
===================================================================
RCS file: /cvs/drupal/drupal/install.php,v
retrieving revision 1.181
diff -u -p -r1.181 install.php
--- install.php	30 Jun 2009 21:44:06 -0000	1.181
+++ install.php	2 Jul 2009 16:57:59 -0000
@@ -28,7 +28,7 @@ function install_main() {
   // The user agent header is used to pass a database prefix in the request when
   // running tests. However, for security reasons, it is imperative that no
   // installation be permitted using such a prefix.
-  if (preg_match("/^simpletest\d+$/", $_SERVER['HTTP_USER_AGENT'])) {
+  if (isset($_SERVER['HTTP_USER_AGENT']) && preg_match("/^simpletest\d+$/", $_SERVER['HTTP_USER_AGENT'])) {
     header($_SERVER['SERVER_PROTOCOL'] . ' 403 Forbidden');
     exit;
   }
Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.925
diff -u -p -r1.925 common.inc
--- includes/common.inc	18 Jun 2009 21:19:01 -0000	1.925
+++ includes/common.inc	2 Jul 2009 16:58:06 -0000
@@ -552,7 +552,7 @@ function drupal_http_request($url, array
   // user-agent is used to ensure that multiple testing sessions running at the
   // same time won't interfere with each other as they would if the database
   // prefix were stored statically in a file or database variable.
-  if (preg_match("/simpletest\d+/", $db_prefix, $matches)) {
+  if (isset($_SERVER['HTTP_USER_AGENT']) && preg_match("/^simpletest\d+/", $_SERVER['HTTP_USER_AGENT'], $matches)) {
     $options['headers']['User-Agent'] = $matches[0];
   }
 
@@ -809,7 +809,7 @@ function _drupal_log_error($error, $fata
 
   // When running inside the testing framework, we relay the errors
   // to the tested site by the way of HTTP headers.
-  if (preg_match("/^simpletest\d+/", $_SERVER['HTTP_USER_AGENT']) && !headers_sent() && (!defined('SIMPLETEST_COLLECT_ERRORS') || SIMPLETEST_COLLECT_ERRORS)) {
+  if (isset($_SERVER['HTTP_USER_AGENT']) && preg_match("/^simpletest\d+/", $_SERVER['HTTP_USER_AGENT']) && !headers_sent() && (!defined('SIMPLETEST_COLLECT_ERRORS') || SIMPLETEST_COLLECT_ERRORS)) {
     // $number does not use drupal_static as it should not be reset
     // as it uniquely identifies each PHP error.
     static $number = 0;