diff --git a/modules/simpletest/tests/form.test b/modules/simpletest/tests/form.test
index 2f5a9cd..a41e396 100644
--- a/modules/simpletest/tests/form.test
+++ b/modules/simpletest/tests/form.test
@@ -587,7 +587,7 @@ class FormValidationTestCase extends DrupalWebTestCase {
    */
   function testValidateLimitErrors() {
     $edit = array(
-      'test' => 'invalid', 
+      'test' => 'invalid',
       'test_numeric_index[0]' => 'invalid',
       'test_substring[foo]' => 'invalid',
     );
@@ -1168,6 +1168,51 @@ class FormStateValuesCleanTestCase extends DrupalWebTestCase {
 }
 
 /**
+ * Tests $form_state clearance with form elements having buttons.
+ */
+class FormStateValuesCleanAdvancedTestCase extends DrupalWebTestCase {
+  /**
+   * An image file path for uploading.
+   */
+  protected $image;
+
+  public static function getInfo() {
+    return array(
+      'name' => 'Form state values clearance (advanced)',
+      'description' => 'Test proper removal of submitted form values using form_state_values_clean() when having forms with elements containing buttons like "managed_file".',
+      'group' => 'Form API',
+    );
+  }
+
+  function setUp() {
+    parent::setUp('form_test');
+  }
+
+  /**
+   * Tests form_state_values_clean().
+   */
+  function testFormStateValuesCleanAdvanced() {
+
+    // Get an image for uploading.
+    $image_files = $this->drupalGetTestFiles('image');
+    $this->image = current($image_files);
+
+    // Check if the physical file is there.
+    $this->assertTrue(is_file($this->image->uri), t("The image file we're going to upload exists."));
+
+    // "Browse" for the desired file.
+    $edit = array('files[image]' => drupal_realpath($this->image->uri));
+
+    // Post the form.
+    $this->drupalPost('form_test/form-state-values-clean-advanced', $edit, t('Submit'));
+
+    // Expecting a 200 HTTP code.
+    $this->assertResponse(200, t('Received a 200 response for posted test file.'));
+    $this->assertRaw(t('You WIN!'), t('Found the success message.'));
+  }
+}
+
+/**
  * Tests form rebuilding.
  *
  * @todo Add tests for other aspects of form rebuilding.
diff --git a/modules/simpletest/tests/form_test.module b/modules/simpletest/tests/form_test.module
index 43a6cbe..df2db30 100644
--- a/modules/simpletest/tests/form_test.module
+++ b/modules/simpletest/tests/form_test.module
@@ -99,6 +99,14 @@ function form_test_menu() {
     'type' => MENU_CALLBACK,
   );
 
+  $items['form_test/form-state-values-clean-advanced'] = array(
+    'title' => 'Form state values clearance advanced test',
+    'page callback' => 'drupal_get_form',
+    'page arguments' => array('form_test_form_state_values_clean_advanced_form'),
+    'access arguments' => array('access content'),
+    'type' => MENU_CALLBACK,
+  );
+
   $items['form-test/checkbox'] = array(
     'title' => t('Form test'),
     'page callback' => 'drupal_get_form',
@@ -873,6 +881,33 @@ function form_test_form_state_values_clean_form_submit($form, &$form_state) {
 }
 
 /**
+ * Form constructor for the form_state_values_clean() test.
+ */
+function form_test_form_state_values_clean_advanced_form($form, &$form_state) {
+  // Build an example form containing a managed file and a submit form element.
+  $form['image'] = array(
+    '#type' => 'managed_file',
+    '#title' => t('Image'),
+    '#upload_location' => 'public://',
+    '#default_value' => 0,
+  );
+  $form['submit'] = array(
+    '#type' => 'submit',
+    '#value' => t('Submit'),
+  );
+  return $form;
+}
+
+/**
+ * Form submission handler for form_test_form_state_values_clean_advanced_form().
+ */
+function form_test_form_state_values_clean_advanced_form_submit($form, &$form_state) {
+  form_state_values_clean($form_state);
+  print t('You WIN!');
+  exit;
+}
+
+/**
  * Build a form to test a checkbox.
  */
 function _form_test_checkbox($form, &$form_state) {