diff --git a/includes/common.inc b/includes/common.inc
index 72fcf76..8792d34 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -3959,36 +3959,41 @@ function drupal_add_js($data = NULL, $options = NULL) {
   $options['weight'] += count($javascript) / 1000;
 
   if (isset($data)) {
-    // Add jquery.js and drupal.js, as well as the basePath setting, the
-    // first time a JavaScript file is added.
+    // Set options for JavaScript settings.
     if (empty($javascript)) {
+      $javascript['settings'] = array(
+        'data' => array(),
+        'type' => 'setting',
+        'scope' => 'header',
+        'group' => JS_LIBRARY,
+        'every_page' => TRUE,
+        'weight' => 0,
+      );
+    }
+
+    // Add jquery.js, jquery.once.js and drupal.js, as well as basic settings
+    // such (basePath and pathPrefix), the first time JavaScript code is added.
+    // (Don't add these if only JavaScript settings have been added.)
+    if ($options['type'] != 'setting' && !isset($javascript['misc/drupal.js'])) {
       // url() generates the prefix using hook_url_outbound_alter(). Instead of
       // running the hook_url_outbound_alter() again here, extract the prefix
       // from url().
       url('', array('prefix' => &$prefix));
-      $javascript = array(
-        'settings' => array(
-          'data' => array(
-            array('basePath' => base_path()),
-            array('pathPrefix' => empty($prefix) ? '' : $prefix),
-          ),
-          'type' => 'setting',
-          'scope' => 'header',
-          'group' => JS_LIBRARY,
-          'every_page' => TRUE,
-          'weight' => 0,
-        ),
-        'misc/drupal.js' => array(
-          'data' => 'misc/drupal.js',
-          'type' => 'file',
-          'scope' => 'header',
-          'group' => JS_LIBRARY,
-          'every_page' => TRUE,
-          'weight' => -1,
-          'preprocess' => TRUE,
-          'cache' => TRUE,
-          'defer' => FALSE,
-        ),
+      $basic_settings = array(
+        array('basePath' => base_path()),
+        array('pathPrefix' => empty($prefix) ? '' : $prefix),
+      );
+      $javascript['settings']['data'] = array_merge($basic_settings, $javascript['settings']['data']);
+      $javascript['misc/drupal.js'] = array(
+        'data' => 'misc/drupal.js',
+        'type' => 'file',
+        'scope' => 'header',
+        'group' => JS_LIBRARY,
+        'every_page' => TRUE,
+        'weight' => -1,
+        'preprocess' => TRUE,
+        'cache' => TRUE,
+        'defer' => FALSE,
       );
       // Register all required libraries.
       drupal_add_library('system', 'jquery', TRUE);
diff --git a/modules/simpletest/tests/common.test b/modules/simpletest/tests/common.test
index 5f69673..5681e70 100644
--- a/modules/simpletest/tests/common.test
+++ b/modules/simpletest/tests/common.test
@@ -1202,6 +1202,12 @@ class JavaScriptTestCase extends DrupalWebTestCase {
    */
   function testAddSetting() {
     $javascript = drupal_add_js(array('drupal' => 'rocks', 'dries' => 280342800), 'setting');
+    $this->assertEqual(280342800, $javascript['settings']['data'][0]['dries'], t('JavaScript setting is set correctly.'));
+    $this->assertEqual('rocks', $javascript['settings']['data'][0]['drupal'], t('The other JavaScript setting is set correctly.'));
+
+    // When JavaScript code is added, the basePath and pathPrefix settings
+    // are prepended.
+    $javascript = drupal_add_js('jQuery(document).ready(function () { alert("Hello!"); });', 'inline');
     $this->assertEqual(280342800, $javascript['settings']['data'][2]['dries'], t('JavaScript setting is set correctly.'));
     $this->assertEqual('rocks', $javascript['settings']['data'][2]['drupal'], t('The other JavaScript setting is set correctly.'));
   }
@@ -1231,26 +1237,75 @@ class JavaScriptTestCase extends DrupalWebTestCase {
     drupal_add_js(array('commonTestArray' => array('key' => 'commonTestNewValue')), 'setting');
 
     $javascript = drupal_get_js('header');
-    $this->assertTrue(strpos($javascript, 'basePath') > 0, t('Rendered JavaScript header returns basePath setting.'));
-    $this->assertTrue(strpos($javascript, 'misc/jquery.js') > 0, t('Rendered JavaScript header includes jQuery.'));
-    $this->assertTrue(strpos($javascript, 'pathPrefix') > 0, t('Rendered JavaScript header returns pathPrefix setting.'));
 
-    // Test whether drupal_add_js can be used to override a previous setting.
+    // When adding only settings through drupal_add_js(), none of the basic
+    // JavaScript settings or basic JavaScript files should be added.
+    $this->assertTrue(strpos($javascript, 'basePath') === FALSE, t('Rendered JavaScript header does not return basePath setting.'));
+    $this->assertTrue(strpos($javascript, 'pathPrefix') === FALSE, t('Rendered JavaScript header does not return pathPrefix setting.'));
+    $this->assertTrue(strpos($javascript, 'misc/drupal.js') === FALSE, t('Rendered JavaScript header does not include Drupal\'s JavaScript library.'));
+    $this->assertTrue(strpos($javascript, 'misc/jquery.js') === FALSE, t('Rendered JavaScript header does not include jQuery.'));
+    $this->assertTrue(strpos($javascript, 'misc/jquery.once.js') === FALSE, t('Rendered JavaScript header does not include jQuery Once.'));
+
+    // Test whether drupal_add_js() can be used to override a previous setting.
     $this->assertTrue(strpos($javascript, 'commonTestShouldAppear') > 0, t('Rendered JavaScript header returns custom setting.'));
     $this->assertTrue(strpos($javascript, 'commonTestShouldNotAppear') === FALSE, t('drupal_add_js() correctly overrides a custom setting.'));
 
-    // Test whether drupal_add_js can be used to add numerically indexed values
-    // to an array.
+    // Test whether drupal_add_js() can be used to add numerically indexed
+    // values to an array.
     $array_values_appear = strpos($javascript, 'commonTestValue0') > 0 && strpos($javascript, 'commonTestValue1') > 0 && strpos($javascript, 'commonTestValue2') > 0;
     $this->assertTrue($array_values_appear, t('drupal_add_js() correctly adds settings to the end of an indexed array.'));
 
-    // Test whether drupal_add_js can be used to override the entry for an
+    // Test whether drupal_add_js() can be used to override the entry for an
     // existing key in an associative array.
     $associative_array_override = strpos($javascript, 'commonTestNewValue') > 0 && strpos($javascript, 'commonTestOldValue') === FALSE;
     $this->assertTrue($associative_array_override, t('drupal_add_js() correctly overrides settings within an associative array.'));
   }
 
   /**
+   * Test drupal_add_js()'s behavior of adding the basic JavaScript only when
+   * code has been added (just adding settings should not trigger the addition
+   * of JavaScript files).
+   */
+  function testBasicJS() {
+    // When adding only settings through drupal_add_js(), none of the basic
+    // JavaScript settings or basic JavaScript files should be added.
+    drupal_add_js(array('foo' => 'bar'), 'setting');
+    $javascript = drupal_get_js('header');
+    $this->assertTrue(strpos($javascript, 'basePath') === FALSE, t('Rendered JavaScript header does not return basePath setting.'));
+    $this->assertTrue(strpos($javascript, 'pathPrefix') === FALSE, t('Rendered JavaScript header does not return pathPrefix setting.'));
+    $this->assertTrue(strpos($javascript, 'misc/drupal.js') === FALSE, t('Rendered JavaScript header does not include Drupal\'s JavaScript library.'));
+    $this->assertTrue(strpos($javascript, 'misc/jquery.js') === FALSE, t('Rendered JavaScript header does not include jQuery.'));
+    $this->assertTrue(strpos($javascript, 'misc/jquery.once.js') === FALSE, t('Rendered JavaScript header does not include jQuery Once.'));
+
+    // When adding at least one piece of JavaScript code (either 'inline',
+    // 'file' or 'external'), add the basic JavaScript settings and basic
+    // JavaScript files.
+    // Case: 'file'.
+    drupal_static_reset('drupal_add_js');
+    drupal_static_reset('drupal_add_library');
+    drupal_add_js('misc/collapse.js');
+    $javascript = drupal_get_js('header');
+    $this->assertTrue(strpos($javascript, 'basePath') > 0, t('Rendered JavaScript header does not return basePath setting.'));
+    $this->assertTrue(strpos($javascript, 'pathPrefix') > 0, t('Rendered JavaScript header does not return pathPrefix setting.'));
+    $this->assertTrue(strpos($javascript, 'misc/drupal.js') > 0, t('Rendered JavaScript header does not include Drupal\'s JavaScript library.'));
+    $this->assertTrue(strpos($javascript, 'misc/jquery.js') > 0, t('Rendered JavaScript header does not include jQuery.'));
+    $this->assertTrue(strpos($javascript, 'misc/jquery.once.js') > 0, t('Rendered JavaScript header does not include jQuery Once.'));
+    // Case: 'inline'.
+    drupal_static_reset('drupal_add_js');
+    drupal_static_reset('drupal_add_library');
+    drupal_add_js('jQuery(document).ready(function () { alert("Hello!"); });', 'inline');
+    $javascript = drupal_get_js('header');
+    $this->assertTrue(strpos($javascript, 'basePath') > 0, t('Rendered JavaScript header does not return basePath setting.'));
+    $this->assertTrue(strpos($javascript, 'pathPrefix') > 0, t('Rendered JavaScript header does not return pathPrefix setting.'));
+    $this->assertTrue(strpos($javascript, 'misc/drupal.js') > 0, t('Rendered JavaScript header does not include Drupal\'s JavaScript library.'));
+    $this->assertTrue(strpos($javascript, 'misc/jquery.js') > 0, t('Rendered JavaScript header does not include jQuery.'));
+    $this->assertTrue(strpos($javascript, 'misc/jquery.once.js') > 0, t('Rendered JavaScript header does not include jQuery Once.'));
+    file_put_contents('/htdocs/test.txt', print_r($javascript, TRUE));
+    // Case: 'external'.
+    // Not tested due to possible unavailability of internet connection.
+  }
+
+  /**
    * Test to see if resetting the JavaScript empties the cache.
    */
   function testReset() {