diff -u b/core/lib/Drupal/Core/Config/Config.php b/core/lib/Drupal/Core/Config/Config.php
--- b/core/lib/Drupal/Core/Config/Config.php
+++ b/core/lib/Drupal/Core/Config/Config.php
@@ -71,6 +71,9 @@
   /**
    * The current runtime data.
    *
+   * The configuration data from storage merged with language, module and
+   * settings overrides.
+   *
    * @var array
    */
   protected $overriddenData;
@@ -129,7 +132,7 @@
    *   An event dispatcher instance to use for configuration events.
    * @param \Drupal\Core\Config\TypedConfigManager $typed_config
    *   The typed configuration manager service.
-   * @param Drupal\Core\Language\Language $language
+   * @param \Drupal\Core\Language\Language $language
    *   The language object used to override configuration data.
    */
   public function __construct($name, StorageInterface $storage, EventDispatcher $event_dispatcher, TypedConfigManager $typed_config, Language $language = NULL) {
@@ -308,7 +311,7 @@
   }
 
   /**
-   * Sets settings.php overrides this configuration object.
+   * Sets settings.php overrides for this configuration object.
    *
    * The overridden data only applies to this configuration object.
    *
@@ -330,7 +333,7 @@
    * @param array $data
    *   The overridden values of the configuration data.
    *
-   * @return Drupal\Core\Config\Config
+   * @return \Drupal\Core\Config\Config
    *   The configuration object.
    */
   public function setModuleOverride(array $data) {
@@ -345,7 +348,7 @@
    * @param array $data
    *   The overridden values of the configuration data.
    *
-   * @return Drupal\Core\Config\Config
+   * @return \Drupal\Core\Config\Config
    *   The configuration object.
    */
   public function setLanguageOverride(array $data) {
@@ -357,10 +360,10 @@
   /**
    * Sets the current data for this configuration object.
    *
-   * Configuration overrides operate at three distinct layers: locale, modules
-   * and settings.php, with the last of these winning. Overrides in
-   * settings.php win over values provided by modules. Overrides provided by
-   * modules win over locale.
+   * Configuration overrides operate at three distinct layers: language, modules
+   * and settings.php, with the last of these taking precedence. Overrides in
+   * settings.php take precedence over values provided by modules. Overrides
+   * provided by modules take precedence over language.
    *
    * @return \Drupal\Core\Config\Config
    *   The configuration object.
@@ -665,19 +668,4 @@
   }
 
-  /**
-   * Get configuration name for this language.
-   *
-   * It will be the same name with a prefix depending on language code:
-   * language.config.LANGCODE.NAME
-   *
-   * @return string
-   *   The localized config name.
-   */
-  public function getLanguageConfigName() {
-    if (!isset($this->language)) {
-      throw new ConfigException("No language set, cannot return language config name for '{$this->name}'");
-    }
-    return 'language.config.' . $this->language->id . '.' . $this->getName();
-  }
 }
 
diff -u b/core/lib/Drupal/Core/Config/ConfigFactory.php b/core/lib/Drupal/Core/Config/ConfigFactory.php
--- b/core/lib/Drupal/Core/Config/ConfigFactory.php
+++ b/core/lib/Drupal/Core/Config/ConfigFactory.php
@@ -7,9 +7,7 @@
 
 namespace Drupal\Core\Config;
 
-use Drupal\Core\Config\TypedConfigManager;
 use Drupal\Core\Language\Language;
-use Drupal\Core\Config\ConfigModuleOverridesEvent;
 use Symfony\Component\EventDispatcher\EventDispatcher;
 
 /**
@@ -28,6 +26,11 @@
 class ConfigFactory {
 
   /**
+   * Prefix for all language configuration files.
+   */
+  const LANGUAGE_CONFIG_PREFIX = 'language.config';
+
+  /**
    * A storage controller instance for reading and writing configuration data.
    *
    * @var \Drupal\Core\Config\StorageInterface
@@ -51,14 +54,14 @@
   /**
    * The language object used to override configuration data.
    *
-   * @var Drupal\Core\Language\Language
+   * @var \Drupal\Core\Language\Language
    */
   protected $language;
 
   /**
    * Cached configuration objects.
    *
-   * @var array
+   * @var \Drupal\Core\Config\Config[]
    */
   protected $cache = array();
 
@@ -79,7 +82,9 @@
    * @param \Drupal\Core\Config\TypedConfigManager $typed_config
    *   The typed configuration manager.
    * @param \Drupal\Core\Language\Language
-   *   The language for this configuration.
+   *   (optional) The language for this configuration. If a language is set then
+   *   the config factory will use it to override configuration data is
+   *   overrides are available.
    */
   public function __construct(StorageInterface $storage, EventDispatcher $event_dispatcher, TypedConfigManager $typed_config, Language $language = NULL) {
     $this->storage = $storage;
@@ -157,16 +162,16 @@
     // Pre-load remaining configuration files.
     if (!empty($names)) {
       if ($this->useOverrides) {
+        $moduleOverrides = $this->loadModuleOverrides($names);
         // In order to make just one call to storage, add in language names.
         // Keep track of them separately, so we can get language override data
         // returned from storage and set it on new Config objects.
         $language_names = $this->getLanguageConfigNames($names);
         $storage_data = $this->storage->readMultiple(array_merge($names, array_values($language_names)));
-        $moduleOverrides = $this->loadModuleOverrides($names);
       }
       else {
-        $language_names = array();
         $moduleOverrides = array();
+        $language_names = array();
         $storage_data = $this->storage->readMultiple($names);
       }
 
@@ -311,11 +316,14 @@
   }
 
   /**
-   * Set the language to be injected in to Config objects.
+   * Set the language to be used in configuration overrides.
    *
-   * @param Language $language
+   * @param \Drupal\Core\Language\Language $language
+   *   The language object to be set on the config factory. Used to override
+   *   configuration by language.
    *
-   * @return ConfigFactory
+   * @return \Drupal\Core\Config\ConfigFactory
+   *   The config factory object.
    */
   public function setLanguage(Language $language = NULL) {
     $this->language = $language;
@@ -323,7 +331,7 @@
   }
 
   /**
-   * Get the language to be injected in to Config objects.
+   * Gets the language Used to override configuration.
    *
    * @return \Drupal\Core\Language\Language
    */
@@ -332,7 +340,7 @@
   }
 
   /**
-   * Get configuration names for this language.
+   * Gets configuration names for this language.
    *
    * It will be the same name with a prefix depending on language code:
    * language.config.LANGCODE.NAME
@@ -347,32 +355,34 @@
     $language_names = array();
     if (isset($this->language)) {
       foreach ($names as $name) {
-        if (strpos($name, 'lanuguage.config.') === 0) {
-          continue;
+        if ($language_name = $this->getLanguageConfigName($this->language->id, $name)) {
+          $language_names[$name] = $language_name;
         }
-        $language_names[$name] = 'language.config.' . $this->language->id . '.' . $name;
       }
     }
     return $language_names;
   }
 
   /**
-   * Get configuration name for this language.
+   * Gets configuration name for the provided language.
    *
-   * It will be the same name with a prefix depending on language code:
+   * The name will be the same name with a prefix depending on language code:
    * language.config.LANGCODE.NAME
    *
+   * @param string $langcode
+   *   The language code.
    * @param string $name
-   *   The name of the config object.
+   *   The name of the configuration object.
    *
-   * @return string
-   *   The localized config name.
+   * @return bool|string
+   *   The configuration name for configuration object providing overrides.
+   *   Returns false if the name already starts with the language config prefix.
    */
-  public function getLanguageConfigName($name) {
-    if (!isset($this->language) || strpos($name, 'language.config.') === 0) {
+  public function getLanguageConfigName($langcode, $name) {
+    if (strpos($name, static::LANGUAGE_CONFIG_PREFIX) === 0) {
       return FALSE;
     }
-    return 'language.config.' . $this->language->id . '.' . $name;
+    return static::LANGUAGE_CONFIG_PREFIX . '.' . $langcode . '.' . $name;
   }
 }
 
diff -u b/core/lib/Drupal/Core/Config/ConfigModuleOverridesEvent.php b/core/lib/Drupal/Core/Config/ConfigModuleOverridesEvent.php
--- b/core/lib/Drupal/Core/Config/ConfigModuleOverridesEvent.php
+++ b/core/lib/Drupal/Core/Config/ConfigModuleOverridesEvent.php
@@ -1,10 +1,19 @@
 <?php
 
+/**
+ * @file
+ * Contains \Drupal\Core\Config\ConfigModuleOverridesEvent.
+ */
+
 namespace Drupal\Core\Config;
 
-use Symfony\Component\EventDispatcher\Event;
+use Drupal\Component\Utility\NestedArray;
 use Drupal\Core\Language\Language;
+use Symfony\Component\EventDispatcher\Event;
 
+/**
+ * Event object to allow configuration to be overridden by modules.
+ */
 class ConfigModuleOverridesEvent extends Event {
 
   /**
@@ -24,7 +33,7 @@
   /**
    * The Language object used to override configuration data.
    *
-   * @var Drupal\Core\Language\Language
+   * @var \Drupal\Core\Language\Language
    */
   protected $language;
 
@@ -43,14 +52,20 @@
   }
 
   /**
-   * Get configuration names.
+   * Gets configuration names.
+   *
+   * @return array
+   *   The list of configuration names that can be overridden.
    */
   public function getNames() {
     return $this->names;
   }
 
   /**
-   * Get configuration language.
+   * Gets configuration language.
+   *
+   * @return \Drupal\Core\Language\Language
+   *   The configuration language object.
    */
   public function getLanguage() {
     return $this->language;
@@ -58,17 +73,35 @@
 
   /**
    * Get configuration overrides.
+   *
+   * @return array.
+   *   The array of configuration overrides.
    */
   public function getOverrides() {
     return $this->overrides;
   }
 
   /**
-   * Set a configuration override for the given name.
+   * Sets a configuration override for the given name.
+   *
+   * @param string $name
+   *   The configuration object name to override.
+   * @param array $values
+   *   The values in the configuration object to override.
+   *
+   * @return self
+   *   The ConfigModuleOverridesEvent object.
    */
-  public function setOverride($name, $value) {
+  public function setOverride($name, array $values) {
     if (in_array($name, $this->names)) {
-      $this->overrides[$name] = $value;
+      if (isset($this->overrides[$name])) {
+        // Existing overrides take precedence since these will have been added
+        // by events with a higher priority.
+        $this->overrides[$name] = NestedArray::mergeDeepArray(array($values, $this->overrides[$name]), TRUE);
+      }
+      else {
+        $this->overrides[$name] = $values;
+      }
     }
     return $this;
   }
diff -u b/core/lib/Drupal/Core/Form/ConfigFormBase.php b/core/lib/Drupal/Core/Form/ConfigFormBase.php
--- b/core/lib/Drupal/Core/Form/ConfigFormBase.php
+++ b/core/lib/Drupal/Core/Form/ConfigFormBase.php
@@ -69,12 +69,14 @@
   /**
    * {@inheritdoc}
+   *
+   * Overrides \Drupal\Core\Form\FormBase::config() so that configuration is
+   * returned override free. This ensures that overrides do not pollute saved
+   * configuration.
    */
   protected function config($name) {
-    if (!$this->configFactory) {
-      $container = $this->container();
-      $this->configFactory = $container->get('config.factory');
-      $this->configFactory->disableOverrides();
-    }
-    return $this->configFactory->get($name);
+    $this->configFactory->disableOverrides();
+    $config = $this->configFactory->get($name);
+    $this->configFactory->enableOverrides();
+    return $config;
   }
 }
diff -u b/core/modules/config/lib/Drupal/config/Tests/ConfigLocaleOverride.php /dev/null
--- b/core/modules/config/lib/Drupal/config/Tests/ConfigLocaleOverride.php
+++ /dev/null
@@ -1,66 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains \Drupal\config\Tests\ConfigLocaleOverride.
- */
-
-namespace Drupal\config\Tests;
-
-use Drupal\Core\Config\ConfigException;
-use Drupal\Core\Language\Language;
-use Drupal\simpletest\DrupalUnitTestBase;
-
-/**
- * Tests locale config override.
- */
-class ConfigLocaleOverride extends DrupalUnitTestBase {
-
-  /**
-   * Modules to enable.
-   *
-   * @var array
-   */
-  public static $modules = array('locale', 'config_test', 'user', 'language', 'system', 'field');
-
-  public static function getInfo() {
-    return array(
-      'name' => 'Locale override',
-      'description' => 'Confirm that locale overrides work',
-      'group' => 'Configuration',
-    );
-  }
-
-  public function setUp() {
-    parent::setUp();
-    config_install_default_config('module', 'config_test');
-    config_install_default_config('module', 'locale');
-    \Drupal::configFactory()->setLanguage(language_default());
-  }
-
-  /**
-   * Tests locale override based on language.
-   */
-  function testConfigLocaleLanguageOverride() {
-    $config = \Drupal::config('config_test.system');
-    $this->assertIdentical($config->get('foo'), 'en bar');
-
-    language_save(new Language(array(
-      'name' => 'French',
-      'id' => 'fr',
-    )));
-    language_save(new Language(array(
-      'name' => 'German',
-      'id' => 'de',
-    )));
-
-    \Drupal::configFactory()->setLanguage(language_load('fr'));
-    $config = \Drupal::config('config_test.system');
-    $this->assertIdentical($config->get('foo'), 'fr bar');
-
-    \Drupal::configFactory()->setLanguage(language_load('de'));
-    $config = \Drupal::config('config_test.system');
-    $this->assertIdentical($config->get('foo'), 'de bar');
-  }
-}
-
diff -u b/core/modules/config/lib/Drupal/config/Tests/ConfigModuleOverridesTest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigModuleOverridesTest.php
--- b/core/modules/config/lib/Drupal/config/Tests/ConfigModuleOverridesTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigModuleOverridesTest.php
@@ -7,14 +7,14 @@
 
 namespace Drupal\config\Tests;
 
-use Drupal\simpletest\WebTestBase;
+use Drupal\simpletest\DrupalUnitTestBase;
 
 /**
- * Tests importing configuration from files into active store.
+ * Tests module overrides of configuration using event subscribers.
  */
-class ConfigModuleOverridesTest extends WebTestBase {
+class ConfigModuleOverridesTest extends DrupalUnitTestBase {
 
-  public static $modules = array('config', 'config_test');
+  public static $modules = array('system', 'config', 'config_override');
 
   public static function getInfo() {
     return array(
@@ -32,16 +32,20 @@
+    $overridden_slogan = 'Yay for overrides!';
+    $non_overridden_slogan = 'Yay for defaults!';
     $config_factory = $this->container->get('config.factory');
     $config_factory
       ->get($name)
       ->set('name', $non_overridden_name)
+      ->set('slogan', $non_overridden_slogan)
       ->save();
 
     $config_factory->disableOverrides();
     $this->assertEqual($non_overridden_name, $config_factory->get('system.site')->get('name'));
+    $this->assertEqual($non_overridden_slogan, $config_factory->get('system.site')->get('slogan'));
 
     $config_factory->enableOverrides();
     $this->assertEqual($overridden_name, $config_factory->get('system.site')->get('name'));
+    $this->assertEqual($overridden_slogan, $config_factory->get('system.site')->get('slogan'));
 
     unset($GLOBALS['config_test_run_module_overrides']);
   }
 }
-
reverted:
--- b/core/modules/config/tests/config_test/config_test.services.yml
+++ /dev/null
@@ -1,6 +0,0 @@
-services:
-  config_test_config_subscriber:
-    class: Drupal\config_test\EventSubscriber\ConfigModuleOverrideSubscriber
-    tags:
-      - { name: event_subscriber }
-
reverted:
--- b/core/modules/config/tests/config_test/lib/Drupal/config_test/EventSubscriber/ConfigModuleOverrideSubscriber.php
+++ /dev/null
@@ -1,42 +0,0 @@
-<?Php
-
-/**
- * @file
- * Contains \Drupal\config_test\ConfigTestController.
- */
-
-namespace Drupal\config_test\EventSubscriber;
-
-use Drupal\Core\Config\ConfigModuleOverridesEvent;
-use Symfony\Component\EventDispatcher\EventSubscriberInterface;
-
-/**
- * Tests module overrides for configuration.
- */
-class ConfigModuleOverrideSubscriber implements EventSubscriberInterface {
-
-  public function onConfigLoadMultiple(ConfigModuleOverridesEvent $event) {
-    if (!empty($GLOBALS['config_test_run_module_overrides'])) {
-      $names = $event->getNames();
-      $language = $event->getLanguage();
-      $overrides = $event->getOverrides();
-      $overridden_name = 'ZOMG overridden site name';
-
-      if (in_array('system.site', $names)) {
-        $event->setOverride('system.site', array('name' => $overridden_name));
-      }
-    }
-  }
-
-  /**
-   * Registers the methods in this class that should be listeners.
-   *
-   * @return array
-   *   An array of event listener definitions.
-   */
-  static function getSubscribedEvents() {
-    $events['config.module.overrides'][] = array('onConfigLoadMultiple', 40);
-    return $events;
-  }
-}
-
diff -u b/core/modules/config_translation/lib/Drupal/config_translation/Form/ConfigTranslationFormBase.php b/core/modules/config_translation/lib/Drupal/config_translation/Form/ConfigTranslationFormBase.php
--- b/core/modules/config_translation/lib/Drupal/config_translation/Form/ConfigTranslationFormBase.php
+++ b/core/modules/config_translation/lib/Drupal/config_translation/Form/ConfigTranslationFormBase.php
@@ -214,7 +214,8 @@
     foreach ($this->mapper->getConfigNames() as $name) {
       // Set configuration values based on form submission and source values.
       $base_config = $this->config($name);
-      $translation_config = $this->config('locale.config.' . $this->language->id . '.' . $name);
+      $translation_config_name = $this->configFactory->getLanguageConfigName($this->language->id, $name);
+      $translation_config = $this->config($translation_config_name);
       $locations = $this->localeStorage->getLocations(array('type' => 'configuration', 'name' => $name));
 
       $this->setConfig($this->language, $base_config, $translation_config, $form_values[$name], !empty($locations));
diff -u b/core/modules/locale/lib/Drupal/locale/LocaleConfigSubscriber.php /dev/null
--- b/core/modules/locale/lib/Drupal/locale/LocaleConfigSubscriber.php
+++ /dev/null
@@ -1,83 +0,0 @@
-<?php
-/**
- * @file
- * Contains \Drupal\locale\LocaleConfigSubscriber.
- */
-
-namespace Drupal\locale;
-
-use Drupal\Core\Config\ConfigFactory;
-use Drupal\Core\Config\StorageDispatcher;
-use Drupal\Core\Language\Language;
-use Drupal\Core\Language\LanguageManager;
-use Symfony\Component\HttpKernel\HttpKernelInterface;
-use Symfony\Component\HttpKernel\KernelEvents;
-use Symfony\Component\HttpKernel\Event\GetResponseEvent;
-use Symfony\Component\EventDispatcher\EventSubscriberInterface;
-
-/**
- * Locale Config helper
- *
- * $config is always a DrupalConfig object.
- */
-class LocaleConfigSubscriber implements EventSubscriberInterface {
-
-  /**
-   * The language manager.
-   *
-   * @var \Drupal\Core\Language\LanguageManager
-   */
-  protected $languageManager;
-
-  /**
-   * Constructs a LocaleConfigSubscriber object.
-   *
-   * @param \Drupal\Core\Language\LanguageManager $language_manager
-   *   The language manager service.
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
-   *   The configuration object factory.
-   */
-  public function __construct(LanguageManager $language_manager, ConfigFactory $config_factory) {
-    $this->languageManager = $language_manager;
-    $this->configFactory = $config_factory;
-  }
-
-  /**
-   * Sets the negotiated interface language on the configuration factory.
-   *
-   * @param \Symfony\Component\HttpKernel\Event\GetResponseEvent $event
-   *   Kernel event to respond to.
-   */
-  public function onKernelRequestSetDefaultConfigLanguage(GetResponseEvent $event) {
-    if ($this->languageManager->isMultiLingual()) {
-      $this->configFactory->setLanguage($this->languageManager->getLanguage());
-    }
-  }
-
-  /**
-   * Get configuration name for this language.
-   *
-   * It will be the same name with a prefix depending on language code:
-   * locale.config.LANGCODE.NAME
-   *
-   * @param string $name
-   *   The name of the config object.
-   * @param \Drupal\Core\Language\Language $language
-   *   The language object.
-   *
-   * @return string
-   *   The localized config name.
-   */
-  public function getLocaleConfigName($name, Language $language) {
-    return 'locale.config.' . $language->id . '.' . $name;
-  }
-
-  /**
-   * Implements EventSubscriberInterface::getSubscribedEvents().
-   */
-  static function getSubscribedEvents() {
-    $events[KernelEvents::REQUEST][] = array('onKernelRequestSetDefaultConfigLanguage', 48);
-    return $events;
-  }
-}
-
diff -u b/core/modules/locale/lib/Drupal/locale/Tests/LocaleConfigTranslationTest.php b/core/modules/locale/lib/Drupal/locale/Tests/LocaleConfigTranslationTest.php
--- b/core/modules/locale/lib/Drupal/locale/Tests/LocaleConfigTranslationTest.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocaleConfigTranslationTest.php
@@ -171,14 +171,15 @@
     $this->assertEqual($property->getValue(), $image_style_label, 'Got the right translation for image style name after translation');
 
     // Quick test to ensure translation file exists.
-    $this->assertEqual(\Drupal::config('locale.config.xx.image.style.medium')->get('label'), $image_style_label);
+    $language_config_name = \Drupal::configFactory()->getLanguageConfigName('xx', 'image.style.medium');
+    $this->assertEqual(\Drupal::config($language_config_name)->get('label'), $image_style_label);
 
     // Uninstall the module.
     $this->drupalPostForm('admin/modules/uninstall', array('uninstall[image]' => "image"), t('Uninstall'));
     $this->drupalPostForm(NULL, array(), t('Uninstall'));
 
     // Ensure that the translated configuration has been removed.
-    $this->assertFalse(\Drupal::config('locale.config.xx.image.style.medium')->get('label'), 'Translated configuration for image module removed.');
+    $this->assertFalse(\Drupal::config($language_config_name)->get('label'), 'Translated configuration for image module removed.');
 
     // Translate default category using the UI so configuration is refreshed.
     $category_label = $this->randomName(20);
diff -u b/core/modules/locale/locale.services.yml b/core/modules/locale/locale.services.yml
--- b/core/modules/locale/locale.services.yml
+++ b/core/modules/locale/locale.services.yml
@@ -1,9 +1,4 @@
 services:
-  locale_config_subscriber:
-    class: Drupal\locale\LocaleConfigSubscriber
-    tags:
-      - { name: event_subscriber }
-    arguments: ['@language_manager', '@config.factory']
   paramconverter.configentity_admin:
     class: Drupal\locale\ParamConverter\LocaleAdminPathConfigEntityConverter
     tags:
@@ -11,7 +6,7 @@
     arguments: ['@entity.manager', '@config.factory']
   locale.config.typed:
     class: Drupal\locale\LocaleConfigManager
-    arguments: ['@config.storage', '@config.storage.schema', '@config.storage.installer', '@locale.storage']
+    arguments: ['@config.storage', '@config.storage.schema', '@config.storage.installer', '@locale.storage', '@config.factory']
   locale.storage:
     class: Drupal\locale\StringDatabaseStorage
     arguments: ['@database']
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigLanguageOverride.php
@@ -0,0 +1,65 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\config\Tests\ConfigLanguageOverride.
+ */
+
+namespace Drupal\config\Tests;
+
+use Drupal\Core\Language\Language;
+use Drupal\simpletest\DrupalUnitTestBase;
+
+/**
+ * Tests language config override.
+ */
+class ConfigLanguageOverride extends DrupalUnitTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = array('config_test', 'user', 'language', 'system', 'field');
+
+  public static function getInfo() {
+    return array(
+      'name' => 'Language override',
+      'description' => 'Confirm that language overrides work',
+      'group' => 'Configuration',
+    );
+  }
+
+  public function setUp() {
+    parent::setUp();
+    config_install_default_config('module', 'config_test');
+    config_install_default_config('module', 'locale');
+    \Drupal::configFactory()->setLanguage(language_default());
+  }
+
+  /**
+   * Tests locale override based on language.
+   */
+  function testConfigLanguageOverride() {
+    $config = \Drupal::config('config_test.system');
+    $this->assertIdentical($config->get('foo'), 'en bar');
+
+    language_save(new Language(array(
+      'name' => 'French',
+      'id' => 'fr',
+    )));
+    language_save(new Language(array(
+      'name' => 'German',
+      'id' => 'de',
+    )));
+
+    \Drupal::configFactory()->setLanguage(language_load('fr'));
+    $config = \Drupal::config('config_test.system');
+    $this->assertIdentical($config->get('foo'), 'fr bar');
+
+    \Drupal::configFactory()->setLanguage(language_load('de'));
+    $config = \Drupal::config('config_test.system');
+    $this->assertIdentical($config->get('foo'), 'de bar');
+  }
+}
+
only in patch2:
unchanged:
--- a/core/modules/config/lib/Drupal/config/Tests/ConfigLocaleOverrideWebTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigLanguageOverrideWebTest.php
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Contains \Drupal\config\Tests\ConfigLocaleOverrideWebTest.
+ * Contains \Drupal\config\Tests\ConfigLanguageOverrideWebTest.
  */
 
 namespace Drupal\config\Tests;
@@ -12,14 +12,14 @@
 /**
  * Tests language overrides in configuration through the request.
  */
-class ConfigLocaleOverrideWebTest extends WebTestBase {
+class ConfigLanguageOverrideWebTest extends WebTestBase {
 
-  public static $modules = array('locale', 'language', 'system');
+  public static $modules = array('language', 'system');
 
   public static function getInfo() {
     return array(
-      'name' => 'Locale overrides through the request',
-      'description' => 'Tests locale overrides applied through the website.',
+      'name' => 'Language overrides through the request',
+      'description' => 'Tests language overrides applied through the website.',
       'group' => 'Configuration',
     );
   }
@@ -47,7 +47,8 @@ function testSiteNameTranslation() {
     $this->drupalPostForm('admin/config/regional/language/add', $edit, t('Add custom language'));
 
     // Save an override for the XX language.
-    \Drupal::config('locale.config.xx.system.site')->set('name', 'XX site name')->save();
+    $config_name = \Drupal::configFactory()->getLanguageConfigName('xx', 'system.site');
+    \Drupal::config($config_name)->set('name', 'XX site name')->save();
 
     $this->drupalLogout();
 
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigOverridesPriorityTest.php
@@ -0,0 +1,103 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\config\Tests\ConfigOverridesPriorityTest.
+ */
+
+namespace Drupal\config\Tests;
+
+use Drupal\Core\Language\Language;
+use Drupal\simpletest\DrupalUnitTestBase;
+
+/**
+ * Tests module overrides of configuration using event subscribers.
+ */
+class ConfigOverridesPriorityTest extends DrupalUnitTestBase {
+
+  public static $modules = array('system', 'config', 'config_override');
+
+  public static function getInfo() {
+    return array(
+      'name' => 'Override priority',
+      'description' => 'Tests that language, module and settings.php are applied in the correct order.',
+      'group' => 'Configuration',
+    );
+  }
+
+  public function testOverridePriorities() {
+    global $conf;
+    $GLOBALS['config_test_run_module_overrides'] = FALSE;
+
+    $non_overridden_mail =  'site@example.com';
+    $language_overridden_mail = 'french@example.com';
+
+    $language_overridden_name = 'French site name';
+    $module_overridden_name = 'ZOMG overridden site name';
+    $non_overridden_name = 'ZOMG this name is on disk mkay';
+
+    $module_overridden_slogan = 'Yay for overrides!';
+    $non_overridden_slogan = 'Yay for defaults!';
+
+    /** @var \Drupal\Core\Config\ConfigFactory $config_factory */
+    $config_factory = $this->container->get('config.factory');
+    $config_factory
+      ->get('system.site')
+      ->set('name', $non_overridden_name)
+      ->set('slogan', $non_overridden_slogan)
+      ->set('mail', $non_overridden_mail)
+      ->set('weight_select_max', 50)
+      ->save();
+
+    // Ensure that no overrides are applying.
+    $this->assertEqual($non_overridden_name, $config_factory->get('system.site')->get('name'));
+    $this->assertEqual($non_overridden_slogan, $config_factory->get('system.site')->get('slogan'));
+    $this->assertEqual($non_overridden_mail, $config_factory->get('system.site')->get('mail'));
+    $this->assertEqual(50, $config_factory->get('system.site')->get('weight_select_max'));
+
+    // Override using language.
+    $language = new Language(array(
+      'name' => 'French',
+      'id' => 'fr',
+    ));
+    $config_factory->setLanguage($language);
+    $language_config_name = $config_factory->getLanguageConfigName($language->id, 'system.site');
+    $config_factory
+      ->get($language_config_name)
+      ->set('name', $language_overridden_name)
+      ->set('mail', $language_overridden_mail)
+      ->save();
+
+    $this->assertEqual($language_overridden_name, $config_factory->get('system.site')->get('name'));
+    $this->assertEqual($non_overridden_slogan, $config_factory->get('system.site')->get('slogan'));
+    $this->assertEqual($language_overridden_mail, $config_factory->get('system.site')->get('mail'));
+    $this->assertEqual(50, $config_factory->get('system.site')->get('weight_select_max'));
+
+    // Enable module overrides. Do not override system.site:mail to prove that
+    // the language override still applies.
+    $GLOBALS['config_test_run_module_overrides'] = TRUE;
+    $config_factory->reset('system.site');
+    $this->assertEqual($module_overridden_name, $config_factory->get('system.site')->get('name'));
+    $this->assertEqual($module_overridden_slogan, $config_factory->get('system.site')->get('slogan'));
+    $this->assertEqual($language_overridden_mail, $config_factory->get('system.site')->get('mail'));
+    $this->assertEqual(50, $config_factory->get('system.site')->get('weight_select_max'));
+
+    // Configure a global override to simulate overriding using settings.php. Do
+    // not override system.site:mail or system.site:slogan to prove that the
+    // language and module overrides still apply.
+    $conf['system.site']['name'] = 'Site name global conf override';
+    $config_factory->reset('system.site');
+    $this->assertEqual('Site name global conf override', $config_factory->get('system.site')->get('name'));
+    $this->assertEqual($module_overridden_slogan, $config_factory->get('system.site')->get('slogan'));
+    $this->assertEqual($language_overridden_mail, $config_factory->get('system.site')->get('mail'));
+    $this->assertEqual(50, $config_factory->get('system.site')->get('weight_select_max'));
+
+    $config_factory->disableOverrides();
+    $this->assertEqual($non_overridden_name, $config_factory->get('system.site')->get('name'));
+    $this->assertEqual($non_overridden_slogan, $config_factory->get('system.site')->get('slogan'));
+    $this->assertEqual($non_overridden_mail, $config_factory->get('system.site')->get('mail'));
+    $this->assertEqual(50, $config_factory->get('system.site')->get('weight_select_max'));
+
+    unset($GLOBALS['config_test_run_module_overrides']);
+  }
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/config/tests/config_override/config_override.info.yml
@@ -0,0 +1,6 @@
+name: 'Configuration override test'
+type: module
+package: Testing
+version: VERSION
+core: 8.x
+hidden: true
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/config/tests/config_override/config_override.module
@@ -0,0 +1,6 @@
+<?php
+
+/**
+ * @file
+ * Provides Config module for testing overrides.
+ */
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/config/tests/config_override/config_override.services.yml
@@ -0,0 +1,9 @@
+services:
+  config_override_config_subscriber:
+    class: Drupal\config_override\EventSubscriber\ConfigModuleOverrideSubscriber
+    tags:
+      - { name: event_subscriber }
+  config_override_low_priority_config_subscriber:
+    class: Drupal\config_override\EventSubscriber\ConfigModuleLowPriorityOverrideSubscriber
+    tags:
+      - { name: event_subscriber }
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/config/tests/config_override/lib/Drupal/config_override/EventSubscriber/ConfigModuleLowPriorityOverrideSubscriber.php
@@ -0,0 +1,43 @@
+<?Php
+
+/**
+ * @file
+ * Contains \Drupal\config_override\EventSubscriber\ConfigModuleLowPriorityOverrideSubscriber.
+ */
+
+namespace Drupal\config_override\EventSubscriber;
+
+use Drupal\Core\Config\ConfigModuleOverridesEvent;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+/**
+ * Tests module overrides for configuration.
+ */
+class ConfigModuleLowPriorityOverrideSubscriber implements EventSubscriberInterface {
+
+  public function onConfigModuleOverride(ConfigModuleOverridesEvent $event) {
+    if (!empty($GLOBALS['config_test_run_module_overrides'])) {
+      $names = $event->getNames();
+      if (in_array('system.site', $names)) {
+        $event->setOverride('system.site', array(
+          'name' => 'Should not apply because of higher priority listener',
+          // This override should apply because it is not overridden by the
+          // higher priority listener.
+          'slogan' => 'Yay for overrides!',
+        ));
+      }
+    }
+  }
+
+  /**
+   * Registers the methods in this class that should be listeners.
+   *
+   * @return array
+   *   An array of event listener definitions.
+   */
+  static function getSubscribedEvents() {
+    $events['config.module.overrides'][] = array('onConfigModuleOverride', 35);
+    return $events;
+  }
+}
+
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/config/tests/config_override/lib/Drupal/config_override/EventSubscriber/ConfigModuleOverrideSubscriber.php
@@ -0,0 +1,38 @@
+<?Php
+
+/**
+ * @file
+ * Contains \Drupal\config_override\EventSubscriber\ConfigModuleOverrideSubscriber.
+ */
+
+namespace Drupal\config_override\EventSubscriber;
+
+use Drupal\Core\Config\ConfigModuleOverridesEvent;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+/**
+ * Tests module overrides for configuration.
+ */
+class ConfigModuleOverrideSubscriber implements EventSubscriberInterface {
+
+  public function onConfigModuleOverride(ConfigModuleOverridesEvent $event) {
+    if (!empty($GLOBALS['config_test_run_module_overrides'])) {
+      $names = $event->getNames();
+      if (in_array('system.site', $names)) {
+        $event->setOverride('system.site', array('name' => 'ZOMG overridden site name'));
+      }
+    }
+  }
+
+  /**
+   * Registers the methods in this class that should be listeners.
+   *
+   * @return array
+   *   An array of event listener definitions.
+   */
+  static function getSubscribedEvents() {
+    $events['config.module.overrides'][] = array('onConfigModuleOverride', 40);
+    return $events;
+  }
+}
+
only in patch2:
unchanged:
--- a/core/modules/config_translation/lib/Drupal/config_translation/Form/ConfigTranslationDeleteForm.php
+++ b/core/modules/config_translation/lib/Drupal/config_translation/Form/ConfigTranslationDeleteForm.php
@@ -137,7 +137,8 @@ public function buildForm(array $form, array &$form_state, Request $request = NU
    */
   public function submitForm(array &$form, array &$form_state) {
     foreach ($this->mapper->getConfigNames() as $name) {
-      $this->configStorage->delete('locale.config.' . $this->language->id . '.' . $name);
+      $config_name = $this->configFactory->getLanguageConfigName($this->language->id, $name);
+      $this->configStorage->delete($config_name);
     }
 
     // Flush all persistent caches.
only in patch2:
unchanged:
--- a/core/modules/config_translation/lib/Drupal/config_translation/Tests/ConfigTranslationUiTest.php
+++ b/core/modules/config_translation/lib/Drupal/config_translation/Tests/ConfigTranslationUiTest.php
@@ -178,7 +178,8 @@ public function testSourceValueDuplicateSave() {
 
     // Read overridden file from active config.
     $file_storage = new FileStorage($this->configDirectories[CONFIG_ACTIVE_DIRECTORY]);
-    $config_parsed = $file_storage->read('locale.config.fr.system.site');
+    $language_config_name = \Drupal::configFactory()->getLanguageConfigName('fr', 'system.site');
+    $config_parsed = $file_storage->read($language_config_name);
 
     // Expect both name and slogan in language specific file.
     $expected = array(
@@ -199,7 +200,7 @@ public function testSourceValueDuplicateSave() {
     );
     $this->drupalPostForm(NULL, $edit, t('Save translation'));
     $this->assertRaw(t('Successfully updated @language translation.', array('@language' => 'French')));
-    $config_parsed = $file_storage->read('locale.config.fr.system.site');
+    $config_parsed = $file_storage->read($language_config_name);
 
     // Expect only slogan in language specific file.
     $expected = array('slogan' => 'FR ' . $site_slogan);
@@ -213,7 +214,7 @@ public function testSourceValueDuplicateSave() {
       'config_names[system.site][slogan][translation]' => $site_slogan,
     );
     $this->drupalPostForm(NULL, $edit, t('Save translation'));
-    $config_parsed = $file_storage->read('locale.config.fr.system.site');
+    $config_parsed = $file_storage->read($language_config_name);
 
     // Expect no language specific file.
     $this->assertFalse($config_parsed);
@@ -284,7 +285,8 @@ public function testContactConfigEntityTranslation() {
       $this->drupalPostForm($translation_page_url, $edit, t('Save translation'));
 
       // Expect translated values in language specific file.
-      $config_parsed = $file_storage->read('locale.config.'. $langcode . '.contact.category.feedback');
+      $language_config_name = \Drupal::configFactory()->getLanguageConfigName($langcode, 'contact.category.feedback');
+      $config_parsed = $file_storage->read($language_config_name);
       $expected = array(
         'label' => 'Website feedback - ' . $langcode,
         'reply' => 'Thank you for your mail - ' . $langcode,
@@ -347,7 +349,8 @@ public function testContactConfigEntityTranslation() {
       $this->assertNoLinkByHref("$translation_base_url/$langcode/delete");
 
       // Expect no language specific file present anymore.
-      $config_parsed = $file_storage->read('locale.config.'. $langcode . '.config.category.feedback');
+      $language_config_name = \Drupal::configFactory()->getLanguageConfigName($langcode, 'contact.category.feedback');
+      $config_parsed = $file_storage->read($language_config_name);
       $this->assertFalse($config_parsed);
     }
 
@@ -414,7 +417,8 @@ public function testDateFormatTranslation() {
       $this->drupalPostForm($translation_page_url, $edit, t('Save translation'));
 
       // Get translation and check we've got the right value.
-      $config_parsed = $file_storage->read('locale.config.fr.system.date_format.' . $id);
+      $language_config_name = \Drupal::configFactory()->getLanguageConfigName('fr', 'system.date_format.' . $id);
+      $config_parsed = $file_storage->read($language_config_name);
       $expected = array(
         'label' => $id . ' - FR',
         'pattern' => array('php' => 'D'),
only in patch2:
unchanged:
--- a/core/modules/language/language.services.yml
+++ b/core/modules/language/language.services.yml
@@ -5,3 +5,8 @@ services:
     tags:
       - { name: path_processor_inbound, priority: 300 }
       - { name: path_processor_outbound, priority: 100 }
+  language_config_subscriber:
+    class: Drupal\language\LanguageConfigSubscriber
+    tags:
+      - { name: event_subscriber }
+    arguments: ['@language_manager', '@config.factory']
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/language/lib/Drupal/language/LanguageConfigSubscriber.php
@@ -0,0 +1,68 @@
+<?php
+/**
+ * @file
+ * Contains \Drupal\language\LanguageConfigSubscriber.
+ */
+
+namespace Drupal\language;
+
+use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\StorageDispatcher;
+use Drupal\Core\Language\LanguageManager;
+use Symfony\Component\HttpKernel\KernelEvents;
+use Symfony\Component\HttpKernel\Event\GetResponseEvent;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+/**
+ * Language event subscriber to set language on configuration factory service.
+ */
+class LanguageConfigSubscriber implements EventSubscriberInterface {
+
+  /**
+   * The language manager.
+   *
+   * @var \Drupal\Core\Language\LanguageManager
+   */
+  protected $languageManager;
+
+  /**
+   * The configuration factory.
+   *
+   * @var \Drupal\Core\Config\ConfigFactory
+   */
+  protected $configFactory;
+
+  /**
+   * Constructs a LanguageConfigSubscriber object.
+   *
+   * @param \Drupal\Core\Language\LanguageManager $language_manager
+   *   The language manager service.
+   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   *   The configuration object factory.
+   */
+  public function __construct(LanguageManager $language_manager, ConfigFactory $config_factory) {
+    $this->languageManager = $language_manager;
+    $this->configFactory = $config_factory;
+  }
+
+  /**
+   * Sets the negotiated interface language on the configuration factory.
+   *
+   * @param \Symfony\Component\HttpKernel\Event\GetResponseEvent $event
+   *   Kernel event to respond to.
+   */
+  public function onKernelRequestSetDefaultConfigLanguage(GetResponseEvent $event) {
+    if ($this->languageManager->isMultiLingual()) {
+      $this->configFactory->setLanguage($this->languageManager->getLanguage());
+    }
+  }
+
+  /**
+   * Implements EventSubscriberInterface::getSubscribedEvents().
+   */
+  static function getSubscribedEvents() {
+    $events[KernelEvents::REQUEST][] = array('onKernelRequestSetDefaultConfigLanguage', 48);
+    return $events;
+  }
+}
+
only in patch2:
unchanged:
--- a/core/modules/locale/lib/Drupal/locale/LocaleConfigManager.php
+++ b/core/modules/locale/lib/Drupal/locale/LocaleConfigManager.php
@@ -10,6 +10,7 @@
 use Drupal\Core\Language\Language;
 use Drupal\Core\Config\TypedConfigManager;
 use Drupal\Core\Config\StorageInterface;
+use Drupal\Core\Config\ConfigFactory;
 
 /**
  * Manages localized configuration type plugins.
@@ -36,6 +37,13 @@ class LocaleConfigManager extends TypedConfigManager {
   protected $translations;
 
   /**
+   * The configuration factory.
+   *
+   * @var \Drupal\Core\Config\ConfigFactory
+   */
+  protected $configFactory;
+
+  /**
    * Creates a new typed configuration manager.
    *
    * @param \Drupal\Core\Config\StorageInterface $configStorage
@@ -47,12 +55,15 @@ class LocaleConfigManager extends TypedConfigManager {
    *   data.
    * @param \Drupal\locale\StringStorageInterface $localeStorage
    *   The locale storage to use for reading string translations.
+   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   *   The configuration factory
    */
-  public function __construct(StorageInterface $configStorage, StorageInterface $schemaStorage, StorageInterface $installStorage, StringStorageInterface $localeStorage) {
+  public function __construct(StorageInterface $configStorage, StorageInterface $schemaStorage, StorageInterface $installStorage, StringStorageInterface $localeStorage, ConfigFactory $config_factory) {
     // Note we use the install storage for the parent constructor.
     parent::__construct($configStorage, $schemaStorage);
     $this->installStorage = $installStorage;
     $this->localeStorage = $localeStorage;
+    $this->configFactory = $config_factory;
   }
 
   /**
@@ -119,7 +130,7 @@ protected function compareConfigData(array $default, $updated) {
    *   Configuration data to be saved, that will be only the translated values.
    */
   public function saveTranslationData($name, $langcode, array $data) {
-    $locale_name = self::localeConfigName($langcode, $name);
+    $locale_name = $this->configFactory->getLanguageConfigName($langcode, $name);
     $this->configStorage->write($locale_name, $data);
   }
 
@@ -132,7 +143,7 @@ public function saveTranslationData($name, $langcode, array $data) {
    *   Language code.
    */
   public function deleteTranslationData($name, $langcode) {
-    $locale_name = self::localeConfigName($langcode, $name);
+    $locale_name = $this->configFactory->getLanguageConfigName($langcode, $name);
     $this->configStorage->delete($locale_name);
   }
 
@@ -206,7 +217,7 @@ public function getStringNames(array $lids) {
    *   Language code to delete.
    */
   public function deleteLanguageTranslations($langcode) {
-    $locale_name = self::localeConfigName($langcode);
+    $locale_name = ConfigFactory::LANGUAGE_CONFIG_PREFIX . '.' . $langcode . '.';
     foreach ($this->configStorage->listAll($locale_name) as $name) {
       $this->configStorage->delete($name);
     }
@@ -291,24 +302,9 @@ public function translateString($name, $langcode, $source, $context) {
    *   A boolean indicating if a language has configuration translations.
    */
   public function hasTranslation($name, Language $language) {
-    $locale_name = static::localeConfigName($language->id, $name);
+    $locale_name = $this->configFactory->getLanguageConfigName($language->id, $name);
     $translation = $this->configStorage->read($locale_name);
     return !empty($translation);
   }
 
-  /**
-   * Provides configuration data location for given langcode and name.
-   *
-   * @param string $langcode
-   *   The language code.
-   * @param string|null $name
-   *   Name of the original configuration. Set to NULL to get the name prefix
-   *   for all $langcode overrides.
-   *
-   * @return string
-   */
-  public static function localeConfigName($langcode, $name = NULL) {
-    return rtrim('locale.config.' . $langcode . '.' . $name, '.');
-  }
-
 }
only in patch2:
unchanged:
--- a/core/modules/locale/lib/Drupal/locale/Tests/LocaleConfigManagerTest.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocaleConfigManagerTest.php
@@ -46,7 +46,8 @@ public function testHasTranslation() {
       $this->container->get('config.storage.installer'),
       $this->container->get('config.storage.schema'),
       $this->container->get('config.storage.installer'),
-      $this->container->get('locale.storage')
+      $this->container->get('locale.storage'),
+      $this->container->get('config.factory')
     );
 
     $language = new Language(array('id' => 'de'));
only in patch2:
unchanged:
--- a/core/modules/locale/locale.install
+++ b/core/modules/locale/locale.install
@@ -947,9 +947,9 @@ function locale_update_8016() {
   // Fetch all date types from {date_format_type}.
   $result = db_query('SELECT * FROM {date_format_locale}');
   foreach ($result as $format) {
-    $language = $format->language;
     // Create config objects for the language if not yet done.
-    \Drupal::config("locale.config.$language.system.date_format." . $format->type)
+    $config_name = \Drupal::configFactory()->getLanguageConfigName($format->language, 'system.date_format.' . $format->type);
+    \Drupal::config($config_name)
       ->set('pattern.php', $format->format)
       ->save();
   }