diff -r'upF^func' ../drupal-6.0-rc2/includes/install.mysqli.inc ./includes/install.mysqli.inc
--- ../drupal-6.0-rc2/includes/install.mysqli.inc	2007-12-19 12:25:47.000000000 +0100
+++ ./includes/install.mysqli.inc	2008-01-17 11:54:46.000000000 +0100
@@ -29,7 +29,7 @@ function drupal_test_mysqli($url, &$succ
 
   // Decode url-encoded information in the db connection string.
   $url['user'] = urldecode($url['user']);
-  $url['pass'] = isset($url['pass']) ? urldecode($url['pass']) : NULL;
+  $url['pass'] = isset($url['pass']) ? urldecode($url['pass']) : '';
   $url['host'] = urldecode($url['host']);
   $url['path'] = urldecode($url['path']);
 
diff -r'upF^func' ../drupal-6.0-rc2/includes/install.mysql.inc ./includes/install.mysql.inc
--- ../drupal-6.0-rc2/includes/install.mysql.inc	2007-12-08 15:06:20.000000000 +0100
+++ ./includes/install.mysql.inc	2008-01-17 11:55:58.000000000 +0100
@@ -29,7 +29,7 @@ function drupal_test_mysql($url, &$succe
 
   // Decode url-encoded information in the db connection string.
   $url['user'] = urldecode($url['user']);
-  $url['pass'] = urldecode($url['pass']);
+  $url['pass'] = isset($url['pass']) ? urldecode($url['pass']) : '';
   $url['host'] = urldecode($url['host']);
   $url['path'] = urldecode($url['path']);