commit 012b05e197f250a7ba09d95bdaba91ff0a27a175
Author: Erik Stielstra <info@erikstielstra.nl>
Date:   Mon Sep 16 15:28:51 2013 +0200

    #30

diff --git a/core/modules/system/lib/Drupal/system/Tests/Installer/InstallerTranslationVersionUnitTest.php b/core/modules/system/lib/Drupal/system/Tests/Installer/InstallerTranslationVersionUnitTest.php
new file mode 100644
index 0000000..371cdf1
--- /dev/null
+++ b/core/modules/system/lib/Drupal/system/Tests/Installer/InstallerTranslationVersionUnitTest.php
@@ -0,0 +1,114 @@
+<?php
+
+/**
+ * @file
+ * Contains Drupal\system\Tests\Installer\InstallerTranslationVersionUnitTest.
+ */
+
+namespace Drupal\system\Tests\Installer;
+
+use Drupal\simpletest\DrupalUnitTestBase;
+
+/**
+ * Tests translation release version fallback.
+ */
+class InstallerTranslationVersionUnitTest extends DrupalUnitTestBase {
+
+  public static function getInfo() {
+    return array(
+      'name' => 'Installer translation version fallback',
+      'description' => 'Tests the translation version fallback used during site installation to determine available translation files.',
+      'group' => 'Installer',
+    );
+  }
+
+  protected function setUp() {
+    parent::setUp();
+    require_once DRUPAL_ROOT . '/core/includes/install.core.inc';
+  }
+
+  /**
+   * Asserts version fallback results of install_get_localization_release().
+   *
+   * @param $version
+   *   Version string for which to determine version fallbacks.
+   * @param $required_results
+   *   Version fallback results ordered for most to least significant.
+   * @param string $message
+   *   (optional) A message to display with the assertion.
+   * @param string $group
+   *   (optional) The group this message is in.
+   *
+   * @return bool
+   *   TRUE if the assertion succeeded, FALSE otherwise.
+   */
+  protected function assertVersionFallback($version, $required_results, $message = '', $group = 'Other') {
+    $equal = TRUE;
+    $results = install_get_localization_release($version);
+    if (count($required_results) == count($results)) {
+      foreach($results as $key => $result) {
+        $equal &= $result['version'] == $required_results[$key];
+        list($major_release) = explode('.', $required_results[$key]);
+        $equal &= $result['core'] == $major_release . '.x';
+      }
+    }
+    else {
+      $equal = FALSE;
+    }
+    $message = $message ? $message : t('Version fallback for @version.', array('@version' => $version));
+    return $this->assert((bool) $equal, $message, $group);
+  }
+
+  /**
+   * Tests version fallback of install_get_localization_release().
+   */
+  public function testVersionFallback() {
+    $version = '8.0';
+    $result = array('8.0', '8.0-rc1', '7.0');
+    $this->assertVersionFallback($version, $result);
+
+    $version = '8.1';
+    $result = array('8.1', '8.0', '7.0'); // @todo Add 'rc1'?; Remove '7.0' ?
+    $this->assertVersionFallback($version, $result);
+
+    $version = '8.12';
+    $result = array('8.12', '8.11', '7.0'); // @todo Add '8.0'; Remove '7.0' ?
+    $this->assertVersionFallback($version, $result);
+
+    $version = '8.0-dev';
+    $result = array('7.0'); // @todo Add 'alpha1', 'beta1', 'rc1'
+    $this->assertVersionFallback($version, $result);
+
+    $version = '8.0-alpha3';
+    $result = array('7.0'); // @todo Add 'alpha2', 'alpha1'
+    $this->assertVersionFallback($version, $result);
+
+    $version = '8.0-alpha1';
+    $result = array('7.0');
+    $this->assertVersionFallback($version, $result);
+
+    $version = '8.0-beta2';
+    $result = array('7.0'); // @todo Add 'alpha1', 'beta1'
+    $this->assertVersionFallback($version, $result);
+
+    $version = '8.0-beta1';
+    $result = array('7.0');  // @todo Add 'alpha1'
+    $this->assertVersionFallback($version, $result);
+
+    $version = '8.0-rc8';
+    $result = array('8.0-rc8', '8.0-rc7', '7.0'); // @todo Add 'alpha1' ?, 'beta1', 'rc1'
+    $this->assertVersionFallback($version, $result);
+
+    $version = '8.0-rc1';
+    $result = array('8.0-rc1', '7.0'); // @todo Add 'alpha1', 'beta1'
+    $this->assertVersionFallback($version, $result);
+
+    $version = '8.0-foo2';
+    $result = array('7.0'); // @todo Add 'alpha1', 'beta1', 'rc1'
+    $this->assertVersionFallback($version, $result);
+
+    $version = '99.2';
+    $result = array('99.2', '99.1', '98.0');
+    $this->assertVersionFallback($version, $result);
+  }
+}
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