commit 284c4cdb5f524d9bab14e851d2fddd87c75d84fd (HEAD, 2003892-date-format)
Author: Tim Plunkett <git@plnktt.com>
Date:   Wed Jun 5 00:19:54 2013 -0700

    Restore locked functionality.

diff --git a/core/modules/system/config/system.date_format.html_date.yml b/core/modules/system/config/system.date_format.html_date.yml
index 72ec3b2..9098f3e 100644
--- a/core/modules/system/config/system.date_format.html_date.yml
+++ b/core/modules/system/config/system.date_format.html_date.yml
@@ -5,3 +5,4 @@ pattern:
   intl: 'yyyy-MM-dd'
 status: '1'
 langcode: en
+locked: '1'
diff --git a/core/modules/system/config/system.date_format.html_datetime.yml b/core/modules/system/config/system.date_format.html_datetime.yml
index 8f2c382..20df544 100644
--- a/core/modules/system/config/system.date_format.html_datetime.yml
+++ b/core/modules/system/config/system.date_format.html_datetime.yml
@@ -5,3 +5,4 @@ pattern:
   intl: 'yyyy-MM-dd''T''kk:mm:ssZZ'
 status: '1'
 langcode: en
+locked: '1'
diff --git a/core/modules/system/config/system.date_format.html_month.yml b/core/modules/system/config/system.date_format.html_month.yml
index a82eb59..5b7d31d 100644
--- a/core/modules/system/config/system.date_format.html_month.yml
+++ b/core/modules/system/config/system.date_format.html_month.yml
@@ -5,3 +5,4 @@ pattern:
   intl: 'Y-MM'
 status: '1'
 langcode: en
+locked: '1'
diff --git a/core/modules/system/config/system.date_format.html_time.yml b/core/modules/system/config/system.date_format.html_time.yml
index a890cd3..8de6fc0 100644
--- a/core/modules/system/config/system.date_format.html_time.yml
+++ b/core/modules/system/config/system.date_format.html_time.yml
@@ -5,3 +5,4 @@ pattern:
   intl: 'H:mm:ss'
 status: '1'
 langcode: en
+locked: '1'
diff --git a/core/modules/system/config/system.date_format.html_week.yml b/core/modules/system/config/system.date_format.html_week.yml
index e820bff..ab59e37 100644
--- a/core/modules/system/config/system.date_format.html_week.yml
+++ b/core/modules/system/config/system.date_format.html_week.yml
@@ -5,3 +5,4 @@ pattern:
   intl: 'Y-''W''WW'
 status: '1'
 langcode: en
+locked: '1'
diff --git a/core/modules/system/config/system.date_format.html_year.yml b/core/modules/system/config/system.date_format.html_year.yml
index 9bf4a5e..9e07384 100644
--- a/core/modules/system/config/system.date_format.html_year.yml
+++ b/core/modules/system/config/system.date_format.html_year.yml
@@ -5,3 +5,4 @@ pattern:
   intl: 'Y'
 status: '1'
 langcode: en
+locked: '1'
diff --git a/core/modules/system/config/system.date_format.html_yearless_date.yml b/core/modules/system/config/system.date_format.html_yearless_date.yml
index f2a6bde..69f5e22 100644
--- a/core/modules/system/config/system.date_format.html_yearless_date.yml
+++ b/core/modules/system/config/system.date_format.html_yearless_date.yml
@@ -5,3 +5,4 @@ pattern:
   intl: 'MM-d'
 status: '1'
 langcode: en
+locked: '1'
diff --git a/core/modules/system/lib/Drupal/system/DateFormatEditFormController.php b/core/modules/system/lib/Drupal/system/DateFormatEditFormController.php
index e24f555..6fc2f3c 100644
--- a/core/modules/system/lib/Drupal/system/DateFormatEditFormController.php
+++ b/core/modules/system/lib/Drupal/system/DateFormatEditFormController.php
@@ -7,6 +7,8 @@
 
 namespace Drupal\system;
 
+use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
+
 /**
  * @todo.
  */
@@ -15,6 +17,15 @@ class DateFormatEditFormController extends DateFormatFormControllerBase {
   /**
    * {@inheritdoc}
    */
+  protected function prepareEntity() {
+    if ($this->entity->isLocked()) {
+      throw new AccessDeniedHttpException();
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function form(array $form, array &$form_state) {
     $form = parent::form($form, $form_state);
 
diff --git a/core/modules/system/lib/Drupal/system/DateFormatInterface.php b/core/modules/system/lib/Drupal/system/DateFormatInterface.php
index ae35fae..eb456a4 100644
--- a/core/modules/system/lib/Drupal/system/DateFormatInterface.php
+++ b/core/modules/system/lib/Drupal/system/DateFormatInterface.php
@@ -54,4 +54,9 @@ public function getLocales();
    */
   public function hasLocales();
 
+  /**
+   * @return bool
+   */
+  public function isLocked();
+
 }
diff --git a/core/modules/system/lib/Drupal/system/DateFormatListController.php b/core/modules/system/lib/Drupal/system/DateFormatListController.php
index bc86400..737f5ac 100644
--- a/core/modules/system/lib/Drupal/system/DateFormatListController.php
+++ b/core/modules/system/lib/Drupal/system/DateFormatListController.php
@@ -18,6 +18,15 @@ class DateFormatListController extends ConfigEntityListController {
   /**
    * {@inheritdoc}
    */
+  public function load() {
+    return array_filter(parent::load(), function ($entity) {
+      return !$entity->isLocked();
+    });
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function buildHeader() {
     $header['id'] = t('Machine name');
     $header['label'] = t('Name');
diff --git a/core/modules/system/lib/Drupal/system/Form/DateFormatDeleteForm.php b/core/modules/system/lib/Drupal/system/Form/DateFormatDeleteForm.php
index e1597a7..d0613ad 100644
--- a/core/modules/system/lib/Drupal/system/Form/DateFormatDeleteForm.php
+++ b/core/modules/system/lib/Drupal/system/Form/DateFormatDeleteForm.php
@@ -12,6 +12,7 @@
 use Drupal\Core\Config\ConfigFactory;
 use Drupal\system\DateFormatInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
 
 /**
  * Builds a form to delete a date format.
@@ -86,6 +87,9 @@ protected function getCancelPath() {
    *   The date format ID.
    */
   public function buildForm(array $form, array &$form_state, DateFormatInterface $date_format = NULL) {
+    if ($date_format->isLocked()) {
+      throw new AccessDeniedHttpException();
+    }
     $this->format = $date_format;
 
     return parent::buildForm($form, $form_state);
diff --git a/core/modules/system/lib/Drupal/system/Plugin/Core/Entity/DateFormat.php b/core/modules/system/lib/Drupal/system/Plugin/Core/Entity/DateFormat.php
index 7cb8a3f..98c8080 100644
--- a/core/modules/system/lib/Drupal/system/Plugin/Core/Entity/DateFormat.php
+++ b/core/modules/system/lib/Drupal/system/Plugin/Core/Entity/DateFormat.php
@@ -153,4 +153,11 @@ public function addLocale($locale) {
     return $this;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function isLocked() {
+    return (bool) $this->locked;
+  }
+
 }