fixed return value of yii\web\Request::getPrefferedLanguage

framework/CHANGELOG.md

@@ -85,6 +85,7 @@ Yii Framework 2 Change Log
 - Bug #4672: Fixed issue with PostgreSQL handling of boolean values in queries, dropped support for using boolean value for integer columns (cebe)
 - Bug #4727: Fixed wrong Stylus definition in `\yii\web\AssetConverter` (samdark)
 - Bug #4813: Fixed MSSQL schema that was getting incorrect info about constraints (samdark, SerjRamone, o-rey)
+- Bug #4880: Return value of yii\web\Request::getPrefferedLanguage() was a normalized value instead of a valid language value from the input array (cebe)
 - Bug: Fixed inconsistent return of `\yii\console\Application::runAction()` (samdark)
 - Bug: URL encoding for the route parameter added to `\yii\web\UrlManager` (klimov-paul)
 - Bug: Fixed the bug that requesting protected or private action methods would cause 500 error instead of 404 (qiangxue)

framework/web/Request.php

@@ -1138,9 +1138,12 @@ class Request extends \yii\base\Request
         foreach ($this->getAcceptableLanguages() as $acceptableLanguage) {
             $acceptableLanguage = str_replace('_', '-', strtolower($acceptableLanguage));
             foreach ($languages as $language) {
-                $language = str_replace('_', '-', strtolower($language));
-                // en-us==en-us, en==en-us, en-us==en
-                if ($language === $acceptableLanguage || strpos($acceptableLanguage, $language . '-') === 0 || strpos($language, $acceptableLanguage . '-') === 0) {
+                $normalizedLanguage = str_replace('_', '-', strtolower($language));
+
+                if ($normalizedLanguage === $acceptableLanguage || // en-us==en-us
+                    strpos($acceptableLanguage, $normalizedLanguage . '-') === 0 || // en==en-us
+                    strpos($normalizedLanguage, $acceptableLanguage . '-') === 0) { // en-us==en
+
                     return $language;
                 }
             }

tests/unit/framework/web/RequestTest.php

@@ -11,8 +11,7 @@ use yii\web\Request;
 use yiiunit\TestCase;
 
 /**
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @since 2.0
+ * @group web
  */
 class RequestTest extends TestCase
 {
@@ -38,4 +37,45 @@ class RequestTest extends TestCase
             application/xml; version=2.0; x,
             text/x-dvi; q=0.8, text/x-c'));
     }
+
+    public function testPrefferedLanguage()
+    {
+        $this->mockApplication([
+            'language' => 'en',
+        ]);
+
+        $request = new Request();
+        $request->acceptableLanguages = [];
+        $this->assertEquals('en', $request->getPreferredLanguage());
+
+        $request = new Request();
+        $request->acceptableLanguages = ['de'];
+        $this->assertEquals('en', $request->getPreferredLanguage());
+
+        $request = new Request();
+        $request->acceptableLanguages = ['en-us', 'de', 'ru-RU'];
+        $this->assertEquals('en', $request->getPreferredLanguage(['en']));
+
+        $request = new Request();
+        $request->acceptableLanguages = ['en-us', 'de', 'ru-RU'];
+        $this->assertEquals('de', $request->getPreferredLanguage(['ru', 'de']));
+        $this->assertEquals('de-DE', $request->getPreferredLanguage(['ru', 'de-DE']));
+
+        $request = new Request();
+        $request->acceptableLanguages = ['en-us', 'de', 'ru-RU'];
+        $this->assertEquals('de', $request->getPreferredLanguage(['de', 'ru']));
+
+        $request = new Request();
+        $request->acceptableLanguages = ['en-us', 'de', 'ru-RU'];
+        $this->assertEquals('ru-ru', $request->getPreferredLanguage(['ru-ru']));
+
+        $request = new Request();
+        $request->acceptableLanguages = ['en-us', 'de'];
+        $this->assertEquals('ru-ru', $request->getPreferredLanguage(['ru-ru', 'pl']));
+        $this->assertEquals('ru-RU', $request->getPreferredLanguage(['ru-RU', 'pl']));
+
+        $request = new Request();
+        $request->acceptableLanguages = ['en-us', 'de'];
+        $this->assertEquals('pl', $request->getPreferredLanguage(['pl', 'ru-ru']));
+    }
 }