diff --git a/core/modules/language/language.admin.inc b/core/modules/language/language.admin.inc
index 35363b0..ebc3b16 100644
--- a/core/modules/language/language.admin.inc
+++ b/core/modules/language/language.admin.inc
@@ -156,14 +156,15 @@ function language_admin_overview_form_submit($form, &$form_state) {
     $language->weight = $form_state['values']['languages'][$langcode]['weight'];
 
     if ($language->default || $old_default->langcode == $langcode) {
-      // Automatically enable the default language and the language
-      // which was default previously (because we will not get the
-      // value from that disabled checkbox).
+      // Automatically enable the default language and the language which was
+      // default previously (because we will not get the value from that
+      // disabled checkbox).
       $form_state['values']['languages'][$langcode]['enabled'] = 1;
     }
     $language->enabled = (int) !empty($form_state['values']['languages'][$langcode]['enabled']);
 
-    // If a language is disabled take sure
+    // If the interface language has been disabled make sure that the form
+    // redirect includes the new default language as a query parameter.
     if ($language->enabled == FALSE && $langcode == $GLOBALS['language_interface']->langcode) {
       $form_state['redirect'] = array('admin/config/regional/language', array('language' => $languages[$form_state['values']['site_default']]));
     }
@@ -284,7 +285,7 @@ function _language_admin_common_controls(&$form, $language = NULL) {
     '#required' => TRUE,
     '#description' => t('Direction that text in this language is presented.'),
     '#default_value' => @$language->direction,
-    '#options' => array(LANGUAGE_LTR => t('Left to right'), LANGUAGE_RTL => t('Right to left'))
+    '#options' => array(LANGUAGE_LTR => t('Left to right'), LANGUAGE_RTL => t('Right to left')),
   );
   return $form;
 }
@@ -372,7 +373,7 @@ function language_admin_edit_form_validate($form, &$form_state) {
  * Process the language editing form submission.
  */
 function language_admin_edit_form_submit($form, &$form_state) {
-  // Prepare a language object for saving
+  // Prepare a language object for saving.
   $languages = language_list();
   $langcode = $form_state['values']['langcode'];
   $language = $languages[$langcode];
@@ -393,7 +394,7 @@ function language_admin_delete_form($form, &$form_state, $language) {
     drupal_goto('admin/config/regional/language');
   }
 
-  // For other languages, warn user that data loss is ahead.
+  // For other languages, warn the user that data loss is ahead.
   $languages = language_list();
 
   if (!isset($languages[$langcode])) {
@@ -568,7 +569,6 @@ function theme_language_negotiation_configure_form($variables) {
 
   foreach ($form['#language_types'] as $type) {
     $rows = array();
-    $info = $form['#language_types_info'][$type];
     $title = '<label>' . $form[$type]['#title'] . '</label>';
     $description = '<div class="description">' . $form[$type]['#description'] . '</div>';
 
@@ -703,7 +703,7 @@ function language_negotiation_configure_url_form($form, &$form_state) {
       '#title' => t('%language (%langcode) path prefix', array('%language' => $language->name, '%langcode' => $language->langcode)),
       '#maxlength' => 64,
       '#default_value' => isset($prefixes[$langcode]) ? $prefixes[$langcode] : '',
-      '#field_prefix' => url('', array('absolute' => TRUE)) . (variable_get('clean_url', 0) ? '' : '?q=')
+      '#field_prefix' => url('', array('absolute' => TRUE)) . (variable_get('clean_url', 0) ? '' : '?q='),
     );
     $form['domain'][$langcode] = array(
       '#type' => 'textfield',
@@ -732,7 +732,6 @@ function language_negotiation_configure_url_form($form, &$form_state) {
 function language_negotiation_configure_url_form_validate($form, &$form_state) {
   // Get the enabled languages only.
   $languages = language_list(TRUE);
-  $default = language_default();
 
   // Count repeated values for uniqueness check.
   $count = array_count_values($form_state['values']['prefix']);
@@ -741,12 +740,14 @@ function language_negotiation_configure_url_form_validate($form, &$form_state) {
 
     if ($value === '') {
       if (!$language->default && $form_state['values']['language_negotiation_url_part'] == LANGUAGE_NEGOTIATION_URL_PREFIX) {
-        // Validation error if the prefix is blank for a non-default language, and value is for selected negotiation type.
+        // Throw a form error if the prefix is blank for a non-default language,
+        // although it is required for selected negotiation type.
         form_error($form['prefix'][$langcode], t('The prefix may only be left blank for the default language.'));
       }
     }
-    else if (isset($count[$value]) && $count[$value] > 1) {
-      // Validation error if there are two languages with the same domain/prefix.
+    elseif (isset($count[$value]) && $count[$value] > 1) {
+      // Throw a form error if there are two languages with the same
+      // domain/prefix.
       form_error($form['prefix'][$langcode], t('The prefix for %language, %value, is not unique.', array('%language' => $language->name, '%value' => $value)));
     }
   }
@@ -758,12 +759,14 @@ function language_negotiation_configure_url_form_validate($form, &$form_state) {
 
     if ($value === '') {
       if (!$language->default && $form_state['values']['language_negotiation_url_part'] == LANGUAGE_NEGOTIATION_URL_DOMAIN) {
-        // Validation error if the domain is blank for a non-default language, and value is for selected negotiation type.
+        // Throw a form error if the domain is blank for a non-default language,
+        // although it is required for selected negotiation type.
         form_error($form['domain'][$langcode], t('The domain may only be left blank for the default language.'));
       }
     }
-    else if (isset($count[$value]) && $count[$value] > 1) {
-      // Validation error if there are two languages with the same domain/domain.
+    elseif (isset($count[$value]) && $count[$value] > 1) {
+      // Throw a form error if there are two languages with the same
+      // domain/domain.
       form_error($form['domain'][$langcode], t('The domain for %language, %value, is not unique.', array('%language' => $language->name, '%value' => $value)));
     }
   }
@@ -772,11 +775,10 @@ function language_negotiation_configure_url_form_validate($form, &$form_state) {
   foreach ($languages as $langcode => $name) {
     $value = $form_state['values']['domain'][$langcode];
     if (!empty($value)) {
-      // Ensure we have a protocol but only one protocol in the setting for
-      // parse_url() checking against the hostname.
+      // Ensure we have exactly one protocol when checking the hostname.
       $host = 'http://' . str_replace(array('http://', 'https://'), '', $value);
       if (parse_url($host, PHP_URL_HOST) != $value) {
-        form_error($form['domain'][$langcode], t('The domain for %language may only contain the domain name, not a protocol and/or port.', array( '%language' => $name)));
+        form_error($form['domain'][$langcode], t('The domain for %language may only contain the domain name, not a protocol and/or port.', array('%language' => $name)));
       }
     }
   }
@@ -786,7 +788,6 @@ function language_negotiation_configure_url_form_validate($form, &$form_state) {
  * Saves the URL language negotiation method settings.
  */
 function language_negotiation_configure_url_form_submit($form, &$form_state) {
-
   // Save selected format (prefix or domain).
   variable_set('language_negotiation_url_part', $form_state['values']['language_negotiation_url_part']);
 
diff --git a/core/modules/language/language.negotiation.inc b/core/modules/language/language.negotiation.inc
index 367d116..f8d73ee 100644
--- a/core/modules/language/language.negotiation.inc
+++ b/core/modules/language/language.negotiation.inc
@@ -74,8 +74,8 @@ function language_from_browser($languages) {
   }
 
   // The Accept-Language header contains information about the language
-  // preferences configured in the user's browser / operating system.
-  // RFC 2616 (section 14.4) defines the Accept-Language header as follows:
+  // preferences configured in the user's browser / operating system. RFC 2616
+  // (section 14.4) defines the Accept-Language header as follows:
   //   Accept-Language = "Accept-Language" ":"
   //                  1#( language-range [ ";" "q" "=" qvalue ] )
   //   language-range  = ( ( 1*8ALPHA *( "-" 1*8ALPHA ) ) | "*" )
@@ -107,9 +107,9 @@ function language_from_browser($languages) {
     }
   }
 
-  // Find the enabled language with the greatest qvalue, following the rules
-  // of RFC 2616 (section 14.4). If several languages have the same qvalue,
-  // prefer the one with the greatest weight.
+  // Find the enabled language with the greatest qvalue, following the rules of
+  // RFC 2616 (section 14.4). If several languages have the same qvalue, prefer
+  // the one with the greatest weight.
   $best_match_langcode = FALSE;
   $max_qvalue = 0;
   foreach ($languages as $langcode => $language) {
@@ -120,8 +120,8 @@ function language_from_browser($languages) {
     // language, if set, or is 0 (which will never match).
     $qvalue = isset($browser_langcodes['*']) ? $browser_langcodes['*'] : 0;
 
-    // Find the longest possible prefix of the browser-supplied language
-    // ('the language-range') that matches this site language ('the language tag').
+    // Find the longest possible prefix of the browser-supplied language ('the
+    // language-range') that matches this site language ('the language tag').
     $prefix = $langcode;
     do {
       if (isset($browser_langcodes[$prefix])) {
@@ -210,8 +210,8 @@ function language_from_url($languages) {
 
   switch (variable_get('language_negotiation_url_part', LANGUAGE_NEGOTIATION_URL_PREFIX)) {
     case LANGUAGE_NEGOTIATION_URL_PREFIX:
-      // $_GET['q'] might not be available at this time, because
-      // path initialization runs after the language bootstrap phase.
+      // $_GET['q'] might not be available at this time, because path
+      // initialization runs after the language bootstrap phase.
       list($language, $_GET['q']) = language_url_split_prefix(isset($_GET['q']) ? $_GET['q'] : NULL, $languages);
       if ($language !== FALSE) {
         $language_url = $language->langcode;
@@ -221,10 +221,10 @@ function language_from_url($languages) {
     case LANGUAGE_NEGOTIATION_URL_DOMAIN:
       $domains = language_negotiation_url_domains();
       foreach ($languages as $language) {
-        // Skip check if the language doesn't have a domain.
+        // Skip the check if the language doesn't have a domain.
         if (!empty($domains[$language->langcode])) {
-          // Only compare the domains not the protocols or ports.
-          // Remove protocol and add http:// so parse_url works
+          // Ensure that there is exactly one protocol in the url when checking
+          // the hostname.
           $host = 'http://' . str_replace(array('http://', 'https://'), '', $domains[$language->langcode]);
           $host = parse_url($host, PHP_URL_HOST);
           if ($_SERVER['HTTP_HOST'] == $host) {
diff --git a/core/modules/language/language.test b/core/modules/language/language.test
index a943bb0..6c64c29 100644
--- a/core/modules/language/language.test
+++ b/core/modules/language/language.test
@@ -41,8 +41,6 @@ class LanguageListTest extends DrupalWebTestCase {
     );
     $this->drupalPost('admin/config/regional/language/add', $edit, t('Add language'));
     $this->assertText('French', t('Language added successfully.'));
-    debug($this->getUrl());
-    debug(url('admin/config/regional/language', array('absolute' => TRUE)));
     $this->assertEqual($this->getUrl(), url('admin/config/regional/language', array('absolute' => TRUE)), t('Correct page redirection.'));
 
     // Add custom language.
diff --git a/core/modules/locale/locale.install b/core/modules/locale/locale.install
index bb590f5..c29e0d8 100644
--- a/core/modules/locale/locale.install
+++ b/core/modules/locale/locale.install
@@ -309,10 +309,10 @@ function locale_update_8005() {
   $plural_lids = array();
   foreach ($results as $row) {
     // Need to collect both LID and PLID. The LID for the first (singular)
-    // string can only be retrieved from the first plural's PLID given no
-    // other indication. The last plural variant is never referenced, so we
-    // need to store the LID directly for that. We never know whether we are
-    // on the last plural though, so we always remember LID too.
+    // string can only be retrieved from the first plural's PLID given no other
+    // indication. The last plural variant is never referenced, so we need to
+    // store the LID directly for that. We never know whether we are on the last
+    // plural though, so we always remember LID too.
     $plural_lids[] = $row->lid;
     $plural_lids[] = $row->plid;
   }
@@ -320,9 +320,9 @@ function locale_update_8005() {
 
   if (!empty($plural_lids)) {
     // Look up all translations for these source strings. Ordering by language
-    // will group the strings by language, the 'plid' order will get the
-    // strings in singular/plural order and 'plural' will get them in precise
-    // sequential order needed.
+    // will group the strings by language, the 'plid' order will get the strings
+    // in singular/plural order and 'plural' will get them in precise sequential
+    // order needed.
     $results = db_query("SELECT s.lid, s.source, t.translation, t.plid, t.plural, t.language FROM {locales_source} s LEFT JOIN {locales_target} t ON s.lid = t.lid WHERE s.lid IN (:lids) ORDER BY t.language, t.plid, t.plural", array(':lids' => $plural_lids));
 
     // Collect the strings into an array and combine values as we go.
@@ -352,9 +352,9 @@ function locale_update_8005() {
         // formulas.
         $utmost_parent['translation'][] = str_replace('@count[' . $child->plural .']', '@count', $child->translation);
         if (count($utmost_parent['source']) < 2) {
-          // Append source to the utmost parent's source string only if it is the
-          // plural variant. Further Drupal specific plural variants are not to be
-          // retained for source strings.
+          // Append source to the utmost parent's source string only if it is
+          // the plural variant. Further Drupal specific plural variants are not
+          // to be retained for source strings.
           $utmost_parent['source'][] = $child->source;
         }
 
@@ -369,10 +369,10 @@ function locale_update_8005() {
     foreach ($strings as $langcode => $translations) {
       foreach($translations as $lid => $translation) {
         if (!in_array($lid, $updated_sources)) {
-          // Only update source string if not yet updated. We merged these within
-          // the translation lookups because plural information was only avilable
-          // with the translation, but we don't need to save it again for every
-          // language.
+          // Only update source string if not yet updated. We merged these
+          // within the translation lookups because plural information was only
+          // avilable with the translation, but we don't need to save it again
+          // for every language.
           db_update('locales_source')
             ->fields(array(
             'source' => implode(LOCALE_PLURAL_DELIMITER, $translation['source']),
@@ -420,7 +420,11 @@ function locale_update_8005() {
  * Convert language_negotiation_* variables to use the new callbacks.
  */
 function locale_update_8006() {
-  $variable_names = array('language_negotiation_language_interface', 'language_negotiation_language_content', 'language_negotiation_language_url');
+  $variable_names = array(
+    'language_negotiation_language_interface',
+    'language_negotiation_language_content',
+    'language_negotiation_language_url'
+  );
   $callback_map = array(
     'locale_language_from_url' => 'language_from_url',
     'locale_language_switcher_url' =>  'language_switcher_url',
@@ -469,11 +473,11 @@ function locale_update_8006() {
  * Convert the variable locale_language_negotiation_url_part, locale_language_negotiation_url_domains.
  */
 function locale_update_8007() {
-  $value = variable_get('locale_language_negotiation_url_part',0);
+  $value = variable_get('locale_language_negotiation_url_part', 0);
   variable_set('language_negotiation_url_part', $value);
   variable_del('locale_language_negotiation_url_part');
 
-  $value = variable_get('locale_language_negotiation_url_domains',0);
+  $value = variable_get('locale_language_negotiation_url_domains', 0);
   variable_set('language_negotiation_url_domains', $value);
   variable_del('locale_language_negotiation_url_domains');
 }
@@ -485,9 +489,7 @@ function locale_update_8008() {
   $block_tables = array('block', 'block_node_type', 'block_role');
   foreach ($block_tables as $table) {
     db_update($table)
-      ->fields(array(
-        'module' => 'language',
-      ))
+      ->fields(array('module' => 'language'))
       ->condition('module', 'locale')
       ->execute();
   }
diff --git a/core/modules/locale/locale.test b/core/modules/locale/locale.test
index 108db1e..893cc35 100644
--- a/core/modules/locale/locale.test
+++ b/core/modules/locale/locale.test
@@ -3008,8 +3008,6 @@ class LocaleLanguageNegotiationInfoFunctionalTest extends DrupalWebTestCase {
     $this->languageNegotiationUpdate();
     $type = LANGUAGE_TYPE_CONTENT;
     $language_types = variable_get('language_types', language_types_get_default());
-    debug($language_types);
-    debug($type);
     $this->assertTrue($language_types[$type], t('Content language type is configurable.'));
 
     // Enable some core and custom language negotiation methods. The test