diff -u b/core/modules/locale/lib/Drupal/locale/Tests/LocaleContentTest.php b/core/modules/locale/lib/Drupal/locale/Tests/LocaleContentTest.php
--- b/core/modules/locale/lib/Drupal/locale/Tests/LocaleContentTest.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocaleContentTest.php
@@ -182,11 +182,11 @@
 
     // Check if English node does not have lang tag.
     $this->drupalGet('node/' . $nodes['en']->id());
-    $pattern = '|class="[^"]*node--' . $nodes['en']->id() . '[^"]*"[^<>]*lang="en"|';    
+    $pattern = '|class="[^"]*node--' . $nodes['en']->id() . '[^"]*"[^<>]*lang="en"|';
     $this->assertNoPattern($pattern, 'The lang tag has not been assigned to the English node.');
 
     // Check if English node does not have dir tag.
-    $pattern = '|class="[^"]*node--' . $nodes['en']->id() . '[^"]*"[^<>]*dir="ltr"|';    
+    $pattern = '|class="[^"]*node--' . $nodes['en']->id() . '[^"]*"[^<>]*dir="ltr"|';
     $this->assertNoPattern($pattern, 'The dir tag has not been assigned to the English node.');
 
     // Check if Arabic node has lang="ar" & dir="rtl" tags.
@@ -200,7 +200,7 @@
     $this->assertPattern($pattern, 'The lang tag has been assigned correctly to the Spanish node.');
 
     // Check if Spanish node does not have dir="ltr" tag.
-    $pattern = '|class="[^"]*node--' . $nodes['es']->id() . '[^"]*"[^<>]*lang="es" dir="ltr"|';    
+    $pattern = '|class="[^"]*node--' . $nodes['es']->id() . '[^"]*"[^<>]*lang="es" dir="ltr"|';
     $this->assertNoPattern($pattern, 'The dir tag has not been assigned to the Spanish node.');
   }
 
diff -u b/core/modules/node/lib/Drupal/node/Tests/NodeFieldMultilingualTestCase.php b/core/modules/node/lib/Drupal/node/Tests/NodeFieldMultilingualTestCase.php
--- b/core/modules/node/lib/Drupal/node/Tests/NodeFieldMultilingualTestCase.php
+++ b/core/modules/node/lib/Drupal/node/Tests/NodeFieldMultilingualTestCase.php
@@ -133,7 +133,7 @@
     // Check if node body is showed.
     $this->drupalGet('node/' . $node->id());
      $body = $this->xpath('//article[contains(concat(" ", normalize-space(@class), " "), :node-class)]//div[@class=:content-class]/descendant::p', array(
-      ':node-class' => 'node--' . $node->id(), 
+      ':node-class' => 'node--' . $node->id(),
       ':content-class' => 'node--content',
     ));
     $this->assertEqual(current($body), $node->body->value, 'Node body found.');
diff -u b/core/modules/node/node.module b/core/modules/node/node.module
--- b/core/modules/node/node.module
+++ b/core/modules/node/node.module
@@ -646,7 +646,7 @@
   $variables['name'] = drupal_render($username);
   $variables['url'] = $node->url();
 
-  $variables['label'] = $variables['elements']['title'];
+  $variables['label'] = isset($variables['elements']['title']) ? $variables['elements']['title'] : '';
   unset($variables['elements']['title']);
   $variables['page'] = $variables['view_mode'] == 'full' && node_is_page($node);