diff --git a/includes/common.inc b/includes/common.inc
index f6171cf..87912e7 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -4155,7 +4155,18 @@ function drupal_add_js($data = NULL, $options = NULL) {
       case 'setting':
         // All JavaScript settings are placed in the header of the page with
         // the library weight so that inline scripts appear afterwards.
-        $javascript['settings']['data'][] = $data;
+        if ($options['once']) {
+          foreach ($javascript['settings']['data'] as $setting) {
+            foreach (array_keys($setting) as $key) {
+              if (isset($data[$key])) {
+                unset($data[$key]);
+              }
+            }
+          }
+        }
+        if (!empty($data)) {
+          $javascript['settings']['data'][] = $data;
+        }
         break;
 
       case 'inline':
@@ -4192,6 +4203,7 @@ function drupal_js_defaults($data = NULL) {
     'preprocess' => TRUE,
     'version' => NULL,
     'data' => $data,
+    'once' => FALSE,
   );
 }
 
diff --git a/modules/user/user.module b/modules/user/user.module
index c1c7ec2..f1f772e 100644
--- a/modules/user/user.module
+++ b/modules/user/user.module
@@ -3577,11 +3577,7 @@ function user_form_process_password_confirm($element) {
 
   $element['#attached']['js'][] = drupal_get_path('module', 'user') . '/user.js';
   // Ensure settings are only added once per page.
-  static $already_added = FALSE;
-  if (!$already_added) {
-    $already_added = TRUE;
-    $element['#attached']['js'][] = array('data' => $js_settings, 'type' => 'setting');
-  }
+  $element['#attached']['js'][] = array('data' => $js_settings, 'type' => 'setting', 'once' => TRUE);
 
   return $element;
 }