diff --git a/core/includes/form.inc b/core/includes/form.inc
index 27f450e..45ec48e 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -588,7 +588,6 @@ function form_state_keys_no_cache() {
     'must_validate',
     'rebuild',
     'rebuild_info',
-    'redirect',
     'no_redirect',
     'temporary',
     // Internal properties defined by form processing.
diff --git a/core/modules/language/lib/Drupal/language/Tests/LanguageConfigurationTest.php b/core/modules/language/lib/Drupal/language/Tests/LanguageConfigurationTest.php
index b2d0bda..1fcec66 100644
--- a/core/modules/language/lib/Drupal/language/Tests/LanguageConfigurationTest.php
+++ b/core/modules/language/lib/Drupal/language/Tests/LanguageConfigurationTest.php
@@ -49,7 +49,7 @@ function testLanguageConfiguration() {
     );
     $this->drupalPost('admin/config/regional/language/add', $edit, 'Add language');
     $this->assertText('French');
-    $this->assertEqual($this->getUrl(), url('admin/config/regional/language', array('absolute' => TRUE)), 'Correct page redirection.');
+    $this->assertUrl('admin/config/regional/language');
 
     // Check if the Default English language has no path prefix.
     $this->drupalGet('admin/config/regional/language/detection/url');
@@ -68,14 +68,13 @@ function testLanguageConfiguration() {
     );
     $this->drupalPost(NULL, $edit, t('Save configuration'));
     $this->assertOptionSelected('edit-site-default-language', 'fr', 'Default language updated.');
-    $this->assertEqual($this->getUrl(), url('admin/config/regional/settings', array('absolute' => TRUE)), 'Correct page redirection.');
+    $this->assertUrl('admin/config/regional/language', 'Correct page redirection');
 
     // Check if a valid language prefix is added after changing the default
     // language.
     $this->drupalGet('admin/config/regional/language/detection/url');
     $this->assertFieldByXPath('//input[@name="prefix[en]"]', 'en', 'A valid path prefix has been added to the previous default language.');
     // Check if French still has a path prefix.
-    $this->drupalGet('admin/config/regional/language/detection/url');
     $this->assertFieldByXPath('//input[@name="prefix[fr]"]', 'fr', 'French still has a path prefix.');
 
     // Check that prefix can be changed.
@@ -83,6 +82,7 @@ function testLanguageConfiguration() {
       'prefix[fr]' => 'french',
     );
     $this->drupalPost(NULL, $edit, t('Save configuration'));
+    $this->drupalGet('admin/config/regional/language/detection/url');
     $this->assertFieldByXPath('//input[@name="prefix[fr]"]', 'french', 'French path prefix has changed.');
 
     // Check that prefix of non default language cannot be changed to