diff --git a/core/modules/system/lib/Drupal/system/Tests/Common/UrlTest.php b/core/modules/system/lib/Drupal/system/Tests/Common/UrlTest.php
index a241a31e9496889f3b81828a365283a6e59a39f6..346b5b7dd4f6710eaa662540276f6729812706e4 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Common/UrlTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Common/UrlTest.php
@@ -336,4 +336,153 @@ function testExternalUrls() {
     $result = url($url, array('query' => $query));
     $this->assertEqual($url . '&' . http_build_query($query, '', '&'), $result, 'External URL query string can be extended with a custom query string in $options.');
   }
+
+  /**
+   * Tests the variable processing within l().
+   */
+  function testLStructure() {
+    $options = array('render' => FALSE);
+
+    // Build some $texts to check.
+    $texts = array(
+      array(
+        'input' => 'foo',
+        'input_name' => 'plain text',
+        'expected_sanitized' => 'foo',
+        'expected_unsanitized' => 'foo',
+      ),
+      array(
+        'input' => '<script>',
+        'input_name' => 'script tag',
+        'expected_sanitized' => '&lt;script&gt;',
+        'expected_unsanitized' => '<script>',
+      ),
+      array(
+        'input' => '<div>',
+        'input_name' => 'div tag',
+        'expected_sanitized' => '&lt;div&gt;',
+        'expected_unsanitized' => '<div>',
+      ),
+    );
+
+    // l() has a 'html' flag that alters how $text is sanitized so we have to
+    // check each input/output twice.
+    foreach($texts as $text) {
+      $options['html'] = FALSE;
+      $sanitized_structure = l($text['input'], '', $options);
+      $message = 'For $text of type "' . $text['input_name'] . '" for l() the sanitized text was "' . $text['expected_sanitized'] . '".';
+      $this->assertIdentical($sanitized_structure['text'], $text['expected_sanitized'], check_plain($message));
+
+      $options['html'] = TRUE;
+      $unsanitized_structure = l($text['input'], '', $options);
+      $message = 'For $text of type "' . $text['input_name'] . '" for l() the unsanitized text was "' . $text['expected_unsanitized'] . '".';
+      $this->assertIdentical($unsanitized_structure['text'], $text['expected_unsanitized'], check_plain($message));
+    }
+    unset($options['html']);
+
+    // Build some $paths to check.
+    global $base_path;
+    $paths = array(
+      array(
+        'input' => 'foo',
+        'input_name' => 'internal path',
+        'expected' => $base_path . 'foo',
+      ),
+      array(
+        'input' => 'foo',
+        'query' => array('a' => 'b'),
+        'input_name' => 'internal path with query',
+        'expected' => $base_path . 'foo?a=b',
+      ),
+      array(
+        'input' => '<script>',
+        'input_name' => 'script tag',
+        'expected' => $base_path . urlencode('<script>'),
+      ),
+      array(
+        'input' => 'javascript:alert(\'foo\');',
+        'input_name' => 'javascript in url',
+        'expected' => $base_path . urlencode('javascript:alert(\'foo\');'),
+      ),
+      array(
+        'input' => '<div>',
+        'input_name' => 'div tag',
+        'expected' => $base_path . urlencode('<div>'),
+      ),
+      array(
+        'input' => '<front>',
+        'input_name' => '<front>',
+        'expected' => $base_path,
+      ),
+      array(
+        'input' => '<front>',
+        'query' => array('a' => 'b'),
+        'input_name' => '<front> with query',
+        'expected' => $base_path . '?a=b',
+      ),
+      array(
+        'input' => 'http://drupal.org',
+        'input_name' => 'http absolute URL',
+        'expected' => 'http://drupal.org',
+      ),
+      array(
+        'input' => 'http://drupal.org',
+        'query' => array('a' => 'b'),
+        'input_name' => 'http absolute URL with query',
+        'expected' => 'http://drupal.org?a=b',
+      ),
+      array(
+        'input' => 'https://drupal.org',
+        'input_name' => 'https absolute URL',
+        'expected' => 'https://drupal.org',
+      ),
+    );
+
+    foreach($paths as $path) {
+      // Set query option if appropriate.
+      if(isset($path['query'])) {
+        $options['query'] = $path['query'];
+      }
+      $structure = l('', $path['input'], $options);
+      $message = 'For $path of type "' . $path['input_name'] . '" for l() the processed url was "' . $path['expected'] . '".';
+      $this->assertIdentical($structure['url'], $path['expected'], check_plain($message));
+
+      $message = 'For $path of type "' . $path['input_name'] . '" for l() the processed path is equal to the input path.';
+      $this->assertIdentical($structure['path'], $path['input'], check_plain($message));
+
+      // Reset query option.
+      unset($options['query']);
+    }
+
+    // Check that language in is language out.
+    $options['language'] = 'fr';
+    $structure = l('', '', $options);
+    $this->assertIdentical($structure['options']['language'], $options['language'], 'Language variable is preserved in the structure returned by l().');
+    unset($options['language']);
+
+    // Check that url_is_active() works.
+    $current_path = current_path();
+    $structure = l('', $current_path, $options);
+    $this->assertIdentical($structure['url_is_active'], TRUE, 'url_is_active is TRUE for the current path in the structure returned by l().');
+
+    // We can't easily compare $structure['options']['attributes'] directly to
+    // strings as it is a Drupal Attribute object and will only stringify each
+    // HTML attribute it represents once.
+    $attribute_string = (string) $structure['options']['attributes'];
+    $this->assertIdentical($attribute_string, ' class="active"', 'The active class attribute is built for the current path in the structure returned by l().');
+
+    $random_path = uniqid();
+    $structure = l('', $random_path, $options);
+    $this->assertIdentical($structure['url_is_active'], FALSE, 'url_is_active is FALSE for a string that is not the current path in the structure returned by l().');
+
+    $attribute_string = (string) $structure['options']['attributes'];
+    $this->assertIdentical($attribute_string, '', 'The active class attribute is not built for a string that is not the current path in the structure returned by l().');
+
+    // Check that passed in attributes work.
+    $options['attributes'] = array('arbitrary'=>array('attribute'));
+    $structure = l('', '', $options);
+    $attribute_string = (string) $structure['options']['attributes'];
+    $this->assertIdentical($attribute_string, ' arbitrary="attribute"', 'Arbitrary attributes are handled correctly in the structure returned by l().');
+
+  }
 }