Fixes a Pressflow bug. Fatal error happens if drupal_add_js() is called during install.

pressflow_drupal_add_js.diff

--- a/includes/common.inc
+++ b/includes/common.inc
@@ -2221,7 +2221,7 @@ function drupal_add_js($data = NULL, $type = 'module', $scope = 'header', $defer
       // We never cache authenticated user pages, so if they are logged in we
       // allow setting of the has_js cookie so batch API functions use the JS
       // version.
-      if (!user_is_anonymous()) {
+      if (function_exists('user_is_anonymous') && !user_is_anonymous()) {
         $javascript['footer']['inline'][] = array('code' => "document.cookie = 'has_js=1; path=/';", 'defer' => TRUE);
       }
     }
@@ -2733,7 +2733,7 @@ function page_set_cache() {
         'created' => $_SERVER['REQUEST_TIME'],
         'headers' => array(),
       );
-    
+
       // Restore preferred header names based on the lower-case names returned
       // by drupal_get_header().
       $header_names = _drupal_set_preferred_header_name();