[Intl] Fixed support of Locale::getFallback

Author: lyrixx

Locale.php

@@ -67,21 +67,44 @@ public static function getDefaultFallback()
      */
     public static function getFallback($locale)
     {
-        if (false === $pos = strrpos($locale, '_')) {
-            if (self::$defaultFallback === $locale) {
-                return 'root';
-            }
+        if (function_exists('locale_parse')) {
+            $localeSubTags = locale_parse($locale);
+            if (1 === count($localeSubTags)) {
+                if (self::$defaultFallback === $localeSubTags['language']) {
+                    return 'root';
+                }
+
+                // Don't return default fallback for "root", "meta" or others
+                // Normal locales have two or three letters
+                if (strlen($locale) < 4) {
+                    return self::$defaultFallback;
+                }
 
-            // Don't return default fallback for "root", "meta" or others
-            // Normal locales have two or three letters
-            if (strlen($locale) < 4) {
-                return self::$defaultFallback;
+                return null;
             }
 
-            return;
+            array_pop($localeSubTags);
+
+            return locale_compose($localeSubTags);
+        }
+
+        if (false !== $pos = strrpos($locale, '_')) {
+            return substr($locale, 0, $pos);
         }
 
-        return substr($locale, 0, $pos);
+        if (false !== $pos = strrpos($locale, '-')) {
+            return substr($locale, 0, $pos);
+        }
+
+        if (self::$defaultFallback === $locale) {
+            return 'root';
+        }
+
+        // Don't return default fallback for "root", "meta" or others
+        // Normal locales have two or three letters
+        if (strlen($locale) < 4) {
+            return self::$defaultFallback;
+        }
     }
 
     /**

Tests/LocaleTest.php

@@ -0,0 +1,49 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Intl\Tests;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Intl\Locale;
+
+class LocaleTest extends TestCase
+{
+    public function provideGetFallbackTests()
+    {
+        $tests = array(
+            array('sl_Latn_IT', 'sl_Latn_IT_nedis'),
+            array('sl_Latn', 'sl_Latn_IT'),
+            array('fr', 'fr_FR'),
+            array('fr', 'fr-FR'),
+            array('en', 'fr'),
+            array('root', 'en'),
+            array(null, 'root'),
+        );
+
+        if (function_exists('locale_parse')) {
+            $tests[] = array('sl_Latn_IT', 'sl-Latn-IT-nedis');
+            $tests[] = array('sl_Latn', 'sl-Latn_IT');
+        } else {
+            $tests[] = array('sl-Latn-IT', 'sl-Latn-IT-nedis');
+            $tests[] = array('sl-Latn', 'sl-Latn-IT');
+        }
+
+        return $tests;
+    }
+
+    /**
+     * @dataProvider provideGetFallbackTests
+     */
+    public function testGetFallback($expected, $locale)
+    {
+        $this->assertSame($expected, Locale::getFallback($locale));
+    }
+}