diff --git a/core/modules/locale/lib/Drupal/locale/Tests/LocaleCompareTest.php b/core/modules/locale/lib/Drupal/locale/Tests/LocaleCompareTest.php
index 97af1fc..9b8432f 100644
--- a/core/modules/locale/lib/Drupal/locale/Tests/LocaleCompareTest.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocaleCompareTest.php
@@ -45,7 +45,11 @@ function setUp() {
   }
 
   /**
-   * @todo
+   * Set the value of the default translations directory.
+   *
+   * @param string $path
+   *   Path of the translations directory relative to the drupal installation
+   *   directory.
    */
   private function setTranslationsDirectory($path) {
     $this->tranlations_directory = $path;
@@ -54,7 +58,16 @@ private function setTranslationsDirectory($path) {
   }
 
   /**
-   * @todo
+   * Creates a translation file and test its timestamp.
+   *
+   * @param string $path
+   *   Path of the file relative to the public file path.
+   * @param string $filename
+   *   Name of the file to create.
+   * @param string $timestamp
+   *   Timestamp to set the file to. Defaults to current time.
+   * @param string $data
+   *   Translation data to put into the file. Po header data will be added.
    */
   private function makePoFile($path, $filename, $timestamp = NULL, $data = '') {
     $timestamp = $timestamp ? $timestamp : REQUEST_TIME;
@@ -135,7 +148,25 @@ function testLocaleCompare() {
   /**
    * Checks if local or remote translation sources are detected.
    *
-   * @todo Describe the test strategy.
+   * This test requires a simulated environment for local and remote files.
+   * Normally remote files are located at a remote server (e.g. ftp.drupal.org).
+   * For testing we can not rely on this. A directory in the file system of the
+   * test site is designated for remote files and is addressed using an absolute
+   * URL. Because drupal does not allow file with a po extension to be accessed
+   * (denied in .htaccess) the translation files  get a txt extension. An other
+   * directory is designated for local translation files.
+   *
+   * The translation status process by default checks the status of the
+   * installed projects. For testing purpose a predefined set of modules with
+   * fixed file names and release versions is used. Using a
+   * hook_locale_translation_projects_alter implementation in the locale_test
+   * module this custom project definition is applied.
+   *
+   * This test generates a set of local and remote translation files in their
+   * respective local and remote translation directory. The test check whether
+   * the most recent files are selected in the different check scenario's: check
+   * for local files only, check for remote files only, check for both local and
+   * remote files.
    */
   function testCompareCheckLocal() {
     $config = config('locale.settings');
@@ -165,6 +196,7 @@ function testCompareCheckLocal() {
     // locale_test_locale_translation_projects_alter().
     $this->makePoFile('local', 'contrib_module_one-8.x-1.1.de.txt', $timestamp_old);
     $this->makePoFile('local', 'contrib_module_two-8.x-2.0-beta4.de.txt', $timestamp_new);
+    $this->makePoFile('local', 'custom_module_one.de.po', $timestamp_new);
 
     //debug(file_scan_directory(variable_get('file_public_path', conf_path() . '/files') . '/local', '/.*\.*/', array('recurse' => TRUE)));
     //debug(file_scan_directory(variable_get('file_public_path', conf_path() . '/files') . '/remote', '/.*\.*/', array('recurse' => TRUE)));
@@ -188,7 +220,8 @@ function testCompareCheckLocal() {
     $this->assertEqual($result['contrib_module_one']['de']->timestamp, $timestamp_old, 'Translation timestamp found');
     $this->assertEqual($result['contrib_module_two']['de']->type, 'local', 'Translation of contrib_module_two found');
     $this->assertEqual($result['contrib_module_two']['de']->timestamp, $timestamp_new, 'Translation timestamp found');
-    $this->assertEqual($result['locale_test']['de']->type, 'local', 'Translation of test.de.po found');
+    $this->assertEqual($result['locale_test']['de']->type, 'local', 'Translation of locale_test found');
+    $this->assertEqual($result['custom_module_one']['de']->type, 'local', 'Translation of custom_module_one found');
 
     // Get status of translation sources at both local and remote the locations.
     $config->set('translation.check_mode', LOCALE_TRANSLATION_CHECK_ALL)->save();
@@ -200,6 +233,7 @@ function testCompareCheckLocal() {
     $this->assertEqual($result['contrib_module_two']['de']->timestamp, $timestamp_new, 'Translation timestamp found');
     $this->assertEqual($result['contrib_module_three']['de']->type, 'remote', 'Translation of contrib_module_three found');
     $this->assertEqual($result['contrib_module_three']['de']->timestamp, $timestamp_old, 'Translation timestamp found');
-    $this->assertEqual($result['locale_test']['de']->type, 'local', 'Translation of test.de.po found');
+    $this->assertEqual($result['locale_test']['de']->type, 'local', 'Translation of locale_test found');
+    $this->assertEqual($result['custom_module_one']['de']->type, 'local', 'Translation of custom_module_one. found');
   }
 }
diff --git a/core/modules/locale/locale.api.php b/core/modules/locale/locale.api.php
index 91b9cda..ea1085f 100644
--- a/core/modules/locale/locale.api.php
+++ b/core/modules/locale/locale.api.php
@@ -28,7 +28,18 @@
  * the module's folder.
  * @code
  * interface translation project = example_module
- * interface translation server pattern = sites/example.com/modules/custom/example_module/%project-%version.%language.po
+ * interface translation server pattern = sites/all/modules/custom/example_module/%project-%version.%language.po
+ * @endcode
+ *
+ * Streamwrappers can be used in the server pattern definition. The interface
+ * translations directory (Configuration > Media > File system) can be addressed
+ * using the "translations://" streamwrapper. But also other streamwrappers can
+ * be used.
+ * @code
+ * interface translation server pattern = translations://%project-%version.%language.po
+ * @endcode
+ * @code
+ * interface translation server pattern = public://translations/%project-%version.%language.po
  * @endcode
  *
  * Multiple custom modules or themes sharing the same po file should have
diff --git a/core/modules/locale/locale.batch.inc b/core/modules/locale/locale.batch.inc
index c6e30a2..adfebf5 100644
--- a/core/modules/locale/locale.batch.inc
+++ b/core/modules/locale/locale.batch.inc
@@ -2,7 +2,7 @@
 
 /**
  * @file
- *   @todo
+ *   Batch proces to check the availability of remote Gettext .po files.
  */
 
 /**
@@ -26,22 +26,16 @@ function locale_translation_batch_status_build($sources) {
     $operations[] = array('locale_translation_batch_status_fetch_remote', array($source));
   }
 
-  // Only fetch local data if it's configured to do so.
-  // @todo We should make an exception for modules without remote source.
-  //       But this requires a flag per project to be set when the .info data is parsed.
-  $check_mode = config('locale.settings')->get('translation.check_mode');
-  if ($check_mode == LOCALE_TRANSLATION_CHECK_ALL || $check_mode == LOCALE_TRANSLATION_CHECK_LOCAL) {
-    $operations[] = array('locale_translation_batch_status_fetch_local', array($sources));
-  }
-
-  // Compare results of local and remote and store the most recent.
+  // Check for local sources, compare the results of local and remote and store
+  // the most recent.
+  $operations[] = array('locale_translation_batch_status_fetch_local', array($sources));
   $operations[] = array('locale_translation_batch_status_compare', array());
 
   $batch = array(
     'operations' => $operations,
     'title' => t('Checking available translations'),
     'finished' => 'locale_translation_batch_status_finished',
-    'error_message' => t('Error checking available translation updates.'),
+    'error_message' => t('Error checking available interface translation updates.'),
     'file' => drupal_get_path('module', 'locale') . '/locale.batch.inc',
   );
   return $batch;
@@ -63,19 +57,19 @@ function locale_translation_batch_status_build($sources) {
 function locale_translation_batch_status_fetch_remote($source, &$context) {
   // Check the translation file at the remote server and update the source
   // data with the remote status.
-  $result = locale_translation_http_check($source->url);
-  if ($result && !empty($result->updated)) {
-
-    // Modify the source object with the result data.
-    // There may have been redirects so we store the resulting url.
-    $source->type = 'remote';
-    $source->fileurl = isset($result->redirect_url) ? $result->redirect_url : $source->url;
-    unset($source->url);
-    $source->timestamp = $result->updated;
+  if (isset($source->files['remote'])) {
+    $remote_file = $source->files['remote'];
+    $result = locale_translation_http_check($remote_file->url);
+
+    // Update the file object with the result data. In case of a redirect we
+    // we store the resulting url.
+    if ($result && !empty($result->updated)) {
+      $remote_file->url = isset($result->redirect_url) ? $result->redirect_url : $remote_file->url;
+      $remote_file->timestamp = $result->updated;
+      $source->files['remote'] = $remote_file;
+    }
+    $context['results'][$source->name][$source->language] = $source;
   }
-
-  // Store the source data in the context for later processing.
-  $context['results'][$source->name][$source->language]['remote'] = $source;
 }
 
 /**
@@ -84,6 +78,11 @@ function locale_translation_batch_status_fetch_remote($source, &$context) {
  * Checks the presence and creation time of po files in the local file system.
  * The file path and the timestamp are stored.
  *
+ * We check local files if the site is configured to check local or both local
+ * and remote files. But also we also check local sources if no remote file is
+ * defined for this source. For example for custom modules which
+ * bring their own po file and don't have a remote translation file.
+ *
  * @param array $sources
  *   Array of translation source objects of projects for which to check the
  *   state of local po files.
@@ -93,25 +92,36 @@ function locale_translation_batch_status_fetch_remote($source, &$context) {
  */
 function locale_translation_batch_status_fetch_local($sources, &$context) {
   module_load_include('compare.inc', 'locale');
+  $check_mode = config('locale.settings')->get('translation.check_mode');
+  $check_local = $check_mode == LOCALE_TRANSLATION_CHECK_ALL || $check_mode == LOCALE_TRANSLATION_CHECK_LOCAL;
+  $check_remote = $check_mode == LOCALE_TRANSLATION_CHECK_REMOTE;
 
+  // Get the status of local translation files and store the result data in the
+  // batch results for later processing.
   foreach ($sources as $source) {
-    // Get the status of local translation source and update the source data
-    // with this.
-    locale_translation_source_check_file($source);
+    if (isset($source->files['local'])) {
+      if ($check_local || ($check_remote && !isset($source->files['remote']))) {
+        locale_translation_source_check_file($source);
+      }
 
-    // Store the source data in the context for later processing.
-    $context['results'][$source->name][$source->language]['local'] = $source;
+      // If remote data was collected before, we merge it into the newly
+      // collected result.
+      if (isset($context['results'][$source->name][$source->language])) {
+        $source->files['remote'] = $context['results'][$source->name][$source->language]->files['remote'];
+      }
+      $context['results'][$source->name][$source->language] = $source;
+    }
   }
 }
 
 /**
  * Batch operation callback: Compare states and store the result.
  *
- * Compare the collected results of local and remote sources and store the most
- * recent one. The collected result are stored in the 'results' element of the
- * batch context parameter.
- * The results are stored in the 'locale_translation_status' state. Other
- * processes can collect this data once the batch is completed.
+ * In the preceding batch processes data of remote and local translation sources
+ * is collected. Here we compare the collected results and update the source
+ * object with the data of the most recent translation file. The end result is
+ * stored in the 'locale_translation_status' state variable. Other
+ * processes can collect this data after the batch process is completed.
  *
  * @param array $context
  *   The batch context array. The 'results' element contains a structured array
@@ -122,11 +132,17 @@ function locale_translation_batch_status_compare(&$context) {
   $results = array();
 
   foreach ($context['results'] as $project => $langcodes) {
-    foreach ($langcodes as $langcode => $sources) {
-      $local = isset($sources['local']) ? $sources['local']  : NULL;
-      $remote = $sources['remote'];
-      if ($result = _locale_translation_source_compare($local, $remote) < 0 ? $remote : $local) {
-        $results[$project][$langcode] = $result;
+    foreach ($langcodes as $langcode => $source) {
+      $local = isset($source->files['local']) ? $source->files['local'] : NULL;
+      $remote = isset($source->files['remote']) ? $source->files['remote'] : NULL;
+
+      // The available translation files are compare and data of the most recent
+      // file is used to update the source object.
+      $file = _locale_translation_source_compare($local, $remote) < 0 ? $remote : $local;
+      if (isset($file->timestamp)) {
+        $source->type = $file->type;
+        $source->timestamp = $file->timestamp;
+        $results[$project][$langcode] = $source;
       }
     }
   }
@@ -170,8 +186,6 @@ function locale_translation_batch_status_finished($success, $results) {
  *   Result object containing the HTTP request headers, response code, headers,
  *   data, redirect status and updated timestamp.
  */
-// @todo Replace this with a stream wrapper? May use ReadOnlyStreamWrapper:
-//       http://drupal.org/node/1308054
 function locale_translation_http_check($url, $headers = array()) {
   $result = drupal_http_request($url, array('headers' => $headers, 'method' => 'HEAD'));
   if ($result && $result->code == '200') {
diff --git a/core/modules/locale/locale.compare.inc b/core/modules/locale/locale.compare.inc
index 92b6238..a2c907a 100644
--- a/core/modules/locale/locale.compare.inc
+++ b/core/modules/locale/locale.compare.inc
@@ -227,10 +227,6 @@ function _locale_translation_prepare_project_list($data, $type) {
     if (isset($file->info['interface translation project'])) {
       $data[$name]->info['project'] = $file->info['interface translation project'];
     }
-    // @todo Here we could mark projects which do not have a 'project' and therefore should not
-    //       be checked for a remote translation. Unless explictly provided by 'interface translation server'.
-    //       Use file_uri_scheme() here?
-
   }
   return $data;
 }
@@ -260,7 +256,6 @@ function locale_translation_default_translation_server() {
  *   - "%version": Project version.
  *   - "%core": Project core version.
  *   - "%language": Language code.
- *   - "%filename": Project file name.
  *
  * @return string
  *   String with replaced placeholders.
@@ -271,7 +266,6 @@ function locale_translation_build_server_pattern($project, $template) {
     '%version' => $project->version,
     '%core' => $project->core,
     '%language' => isset($project->language) ? $project->language : '%language',
-    '%filename' => isset($project->filename) ? $project->filename : '%filename',
   );
   return strtr($template, $variables);
 }
@@ -303,10 +297,10 @@ function locale_translation_check_projects($projects, $langcodes = NULL) {
 }
 
 /**
- * Gets and stores the status and creation timestamp of remote po files.
+ * Gets and stores the status and timestamp of remote po files.
  *
- * A batch process is used to check for po files at remote locations and (if
- * configured) to check for po file in the local file system. The most recent
+ * A batch process is used to check for po files at remote locations and (when
+ * configured) to check for po files in the local file system. The most recent
  * translation source states are stored in the state variable
  * 'locale_translation_status'.
  *
@@ -322,7 +316,6 @@ function locale_translation_check_projects_batch($projects, $langcodes = NULL) {
     foreach ($langcodes as $langcode) {
       $project_clone = clone $project;
       $source = locale_translation_source_build($project_clone, $langcode);
-      $source->url = locale_translation_build_server_pattern($source, $source->server_pattern);
       $sources[] = $source;
     }
   }
@@ -334,20 +327,17 @@ function locale_translation_check_projects_batch($projects, $langcodes = NULL) {
 }
 
 /**
- * Check and store the status and creation timestamp of local po files.
+ * Check and store the status and timestamp of local po files.
  *
  * Only po files in the local file system and checked. Any remote translation
  * sources will be ignored. Results are stored in the state variable
  * 'locale_translation_status'.
  *
- * Projects may contain a server_pattern option containing the pattern of the
- * path to the po source files. If not defined the default translation directory
- * is scanned for presence of po files. If defined the specified location is
- * checked. The server_pattern can be set in the module's .info file or by
- * using hook_locale_translation_projects_alter().
- *
- * The time/date the po file was written (PHP: filemtime()) is used as
- * timestamp.
+ * Projects may contain a server_pattern option containing a pattern of the
+ * path to the po source files. If no server_pattern is defined the default
+ * translation directory is checked for the po file. When a server_pattern is
+ * defined the specified location is checked. The server_pattern can be set in
+ * the module's .info file or by using hook_locale_translation_projects_alter().
  *
  * @params array $projects
  *   Array of translatable projects.
@@ -358,11 +348,15 @@ function locale_translation_check_projects_local($projects, $langcodes = NULL) {
   $langcodes = $langcodes ? $langcodes : array_keys(locale_translatable_language_list());
   $results = array();
 
+  // For each project and each language we check if a local po file is
+  // available. When found the source object is updated with the appropriate
+  // type and timestamp of the po file.
   foreach ($projects as $name => $project) {
     foreach ($langcodes as $langcode) {
-      $project_clone = clone $project;
-      $source = locale_translation_source_build($project_clone, $langcode);
+      $source = locale_translation_source_build($project, $langcode);
       if (locale_translation_source_check_file($source)) {
+        $source->type = 'local';
+        $source->timestamp = $source->files['local']->timestamp;
         $results[$name][$langcode] = $source;
       }
     }
@@ -373,47 +367,53 @@ function locale_translation_check_projects_local($projects, $langcodes = NULL) {
 }
 
 /**
- * Check whether a po file exists in the filesystem.
+ * Check whether a po file exists in the local filesystem.
  *
  * It will search in the directory set in the translation source. Which defaults
- * to the files/translations directory as set in the variable
- * 'locale_translate_file_directory'.
+ * to the "translations://" stream wrapper path. The directory may contain any
+ * valid stream wrapper.
  *
- * It will search for a file name as set in the translation source. Which
- * defaults to LOCALE_TRANSLATION_DEFAULT_FILENAME. Per project this value
+ * The "local" files property of the source object contains the definition of a
+ * po file we are looking for. The file name defaults to
+ * LOCALE_TRANSLATION_DEFAULT_FILENAME. Per project this value
  * can be overridden using the server_pattern directive in the module's .info
  * file or by using hook_locale_translation_projects_alter().
  *
  * @param stdClass $source
- *   Translation file object.
+ *   Translation source object.
  *   @see locale_translation_source_build()
  *
  * @return stdClass
- *   File object (filename, basename, name) updated with data of the po file:
- *   - "type": Fixed value 'local'.
+ *   File object (filename, basename, name) updated with data of the po file.
+ *   On success the files property of the source object is updated.
+ *   files['local']:
  *   - "uri": File name and path.
- *   - "timestamp": Last updated time.
- *   NULL if failure.
+ *   - "timestamp": Last updated time of the po file.
+ *   FALSE if the file is not found.
  */
-// @todo incorporate translations:// streamwrapper. See http://drupal.org/node/1658842
 function locale_translation_source_check_file(&$source) {
-  $directory = $source->directory;
-  $filename = '/' . preg_quote($source->filename) . '$/';
-
-  // Get the time stamp and file date from file from the directory which matches
-  // the filename.
-  if ($files = file_scan_directory($directory, $filename, array('key' => 'name'))) {
-    $file = current($files);
-    $source->type = 'local';
-    $source->uri = $file->uri;
-    $source->timestamp = filemtime($file->uri);
-    return $file;
+  if (isset($source->files['local'])) {
+    $directory = $source->files['local']->directory;
+    $filename = '/' . preg_quote($source->files['local']->filename) . '$/';
+
+    // If the directory contains a streamwrapper, it is converted to a real
+    // path.
+    if ($scheme = file_uri_scheme($directory)) {
+      $directory = str_replace($scheme . '://', drupal_realpath($scheme . '://'), $directory);
+    }
+
+    if ($files = file_scan_directory($directory, $filename, array('key' => 'name'))) {
+      $file = current($files);
+      $source->files['local']->uri = $file->uri;
+      $source->files['local']->timestamp = filemtime($file->uri);
+      return $file;
+    }
   }
-  return NULL;
+  return FALSE;
 }
 
 /**
- * Build abstract translation source, to be mapped to a file or a download.
+ * Build abstract translation source.
  *
  * @param stdClass $project
  *   Project object.
@@ -423,16 +423,26 @@ function locale_translation_source_check_file(&$source) {
  *   File name of translation file. May contains placeholders.
  *
  * @return object
- *   Source object, which may have these properties:
+ *   Source object:
  *   - "project": Project name.
+ *   - "name": Project name (inherited from project).
  *   - "language": Language code.
- *   - "type": Source type 'remote' or 'local'.
+ *   - "core": Core version (inherited from project).
+ *   - "version": Project version (inherited from project).
+ *   - "project_type": Project type (inherited from project).
+ *   - "files": Array of file objects containing properties of local and remote
+ *     translation files.
+ *   Other processes can add the following properties:
+ *   - "type": Most recent file type 'remote' or 'local'. Corresponding with
+ *     a key of the "files" array.
+ *   - "timestamp": Timestamp of the most recent translation file.
+ *   The "files" array contains file objects with the following properties:
  *   - "uri": Local file path.
- *   - "fileurl": Remote file URL for downloads.
+ *   - "url": Remote file URL for downloads.
  *   - "directory": Directory of the local po file.
  *   - "filename": File name.
- *   - "keep": TRUE to keep the downloaded file. //@todo Is this still applicable?
- *   - "timestamp": Last update time of the file.
+ *   - "timestamp": Timestamp of the file.
+ *   - "keep": TRUE to keep the downloaded file.
  */
 // @todo Move this file?
 function locale_translation_source_build($project, $langcode, $filename = NULL) {
@@ -442,24 +452,52 @@ function locale_translation_source_build($project, $langcode, $filename = NULL)
 
   $filename = $filename ? $filename : config('locale.settings')->get('translation.default_filename');
 
-  // If the server_pattern contains a remote file path we check for a
-  // corresponding local po file in the local translation directory. If the
-  // server_pattern is a local po file path we check for a po file using this
-  // pattern.
-  module_load_include('inc', 'file');
-  if (file_uri_scheme($source->server_pattern)) {
-    $source->directory = variable_get('locale_translate_file_directory', conf_path() . '/files/translations');
-    $source->filename = locale_translation_build_server_pattern($source, $filename);
+  // If the server_pattern contains a remote file path we will check both
+  // a remote and a local file. If the server_pattern is a local file path
+  // we will only check for a local file.
+  $files = array();
+  if (_locale_translation_file_is_remote($source->server_pattern)) {
+    $files['remote'] = (object) array(
+      'type' => 'remote',
+      'filename' => locale_translation_build_server_pattern($source, basename($source->server_pattern)),
+      'url' => locale_translation_build_server_pattern($source, $source->server_pattern),
+    );
+    $files['local'] = (object) array(
+      'type' => 'local',
+      'directory' => 'translations://',
+      'filename' => locale_translation_build_server_pattern($source, $filename),
+    );
   }
   else {
-    $source->directory = dirname($source->server_pattern);
-    $source->filename = locale_translation_build_server_pattern($source, basename($source->server_pattern));
+    $files['local'] = (object) array(
+      'type' => 'local',
+      'directory' => locale_translation_build_server_pattern($source, drupal_dirname($source->server_pattern)),
+      'filename' => locale_translation_build_server_pattern($source, basename($source->server_pattern)),
+    );
   }
+  $source->files = $files;
 
   return $source;
 }
 
 /**
+ * Determine if the source file is a remote or a local file.
+ *
+ * @param string $url
+ *   The URL or URL pattern of the file.
+ *
+ * @return boolean
+ *   TRUE if the $url is a remote file location.
+ */
+function _locale_translation_file_is_remote($url) {
+  $scheme = file_uri_scheme($url);
+  if ($scheme) {
+    return !drupal_realpath($scheme . '://');
+  }
+  return FALSE;
+}
+
+/**
  * Compare two update sources, looking for the newer one.
  *
  * The timestamp property of the source objects are used to determine which is
diff --git a/core/modules/locale/locale.module b/core/modules/locale/locale.module
index 645e79a..b110016 100644
--- a/core/modules/locale/locale.module
+++ b/core/modules/locale/locale.module
@@ -16,7 +16,6 @@
 use Drupal\locale\StringDatabaseStorage;
 use Drupal\locale\TranslationsStream;
 use Drupal\Core\Database\Database;
-use Drupal\Core\Cache;
 
 /**
  * Regular expression pattern used to localize JavaScript strings.
@@ -113,10 +112,6 @@
  */
 const LOCALE_TRANSLATION_DEFAULT_FILENAME = '%project-%version.%language.po';
 
-
-// ---------------------------------------------------------------------------------
-// Hook implementations
-
 /**
  * Implements hook_help().
  */
@@ -290,9 +285,6 @@ function locale_language_delete($language) {
   cache()->delete('locale:' . $language->langcode);
 }
 
-// ---------------------------------------------------------------------------------
-// Locale translation core functionality
-
 /**
  * Returns list of translatable languages.
  *
@@ -301,7 +293,6 @@ function locale_language_delete($language) {
  *   unless its marked as translatable.
  */
 function locale_translatable_language_list() {
-//drupal_static_reset('language_list');
   $languages = language_list();
   if (!locale_translate_english()) {
     unset($languages['en']);
@@ -309,9 +300,6 @@ function locale_translatable_language_list() {
   return $languages;
 }
 
-// ---------------------------------------------------------------------------------
-// Locale core functionality
-
 /**
  * Provides interface translation services.
  *
diff --git a/core/modules/locale/tests/modules/locale_test/locale_test.module b/core/modules/locale/tests/modules/locale_test/locale_test.module
index 0fa485f..c22e307 100644
--- a/core/modules/locale/tests/modules/locale_test/locale_test.module
+++ b/core/modules/locale/tests/modules/locale_test/locale_test.module
@@ -27,7 +27,14 @@ function locale_test_system_info_alter(&$info, $file, $type) {
 /**
  * Implements hook_locale_translation_projects_alter().
  *
- * @todo Describe what role this alter plays in the test.
+ * The translation status process by default checks the status of the installed
+ * projects. This function replaces the data of the installed modules by a
+ * predefined set of modules with fixed file names and release versions. Project
+ * names, versions, timestamps etc must be fixed because they must match the
+ * files created by the test script.
+ *
+ * The "locale_translation_test_projects" state variable must be set by the
+ * test script in order for this hook to take effect.
  */
 function locale_test_locale_translation_projects_alter(&$projects) {
   if (state()->get('locale_translation_test_projects')) {
@@ -109,7 +116,23 @@ function locale_test_locale_translation_projects_alter(&$projects) {
           'interface translation server pattern' => 'core/modules/locale/tests/test.%language.po',
           'package' => 'Other',
           'version' => NULL,
-          'project' => 'ttest',
+          'project' => 'locale_test',
+          '_info_file_ctime' => 1348767306,
+          'datestamp' => 0,
+        ),
+        'datestamp' => 0,
+        'project_type' => 'module',
+        'project_status' => TRUE,
+      ),
+      'custom_module_one' => array (
+        'name' => 'custom_module_one',
+        'info' => array (
+          'name' => 'Custom module one',
+          'interface translation project' => 'custom_module_one',
+          'interface translation server pattern' => 'translations://custom_module_one.%language.po',
+          'package' => 'Other',
+          'version' => NULL,
+          'project' => 'custom_module_one',
           '_info_file_ctime' => 1348767306,
           'datestamp' => 0,
         ),