From 3657c0e664bfb1a62f9fea9a898406909a1e130b Mon Sep 17 00:00:00 2001
From: Alan Poulain <contact@alanpoulain.eu>
Date: Tue, 24 Dec 2019 19:50:33 +0100
Subject: [PATCH] Use locale_parse for computing fallback locales

---
 .../Translation/Tests/TranslatorTest.php      | 31 ++++++++++++++++---
 .../Component/Translation/Translator.php      | 13 +++++++-
 2 files changed, 39 insertions(+), 5 deletions(-)

diff --git a/src/Symfony/Component/Translation/Tests/TranslatorTest.php b/src/Symfony/Component/Translation/Tests/TranslatorTest.php
index 77af7de33e..68122b2915 100644
--- a/src/Symfony/Component/Translation/Tests/TranslatorTest.php
+++ b/src/Symfony/Component/Translation/Tests/TranslatorTest.php
@@ -234,15 +234,38 @@ class TranslatorTest extends TestCase
         $this->assertEquals('bar', $translator->trans('foo', [], 'resources'));
     }
 
-    public function testTransWithFallbackLocaleBis()
+    /**
+     * @dataProvider getFallbackLocales
+     */
+    public function testTransWithFallbackLocaleBis($expectedLocale, $locale)
     {
-        $translator = new Translator('en_US');
+        $translator = new Translator($locale);
         $translator->addLoader('array', new ArrayLoader());
-        $translator->addResource('array', ['foo' => 'foofoo'], 'en_US');
-        $translator->addResource('array', ['bar' => 'foobar'], 'en');
+        $translator->addResource('array', ['foo' => 'foofoo'], $locale);
+        $translator->addResource('array', ['bar' => 'foobar'], $expectedLocale);
         $this->assertEquals('foobar', $translator->trans('bar'));
     }
 
+    public function getFallbackLocales()
+    {
+        $locales = [
+            ['en', 'en_US'],
+            ['en', 'en-US'],
+            ['sl_Latn_IT', 'sl_Latn_IT_nedis'],
+            ['sl_Latn', 'sl_Latn_IT'],
+        ];
+
+        if (\function_exists('locale_parse')) {
+            $locales[] = ['sl_Latn_IT', 'sl-Latn-IT-nedis'];
+            $locales[] = ['sl_Latn', 'sl-Latn-IT'];
+        } else {
+            $locales[] = ['sl-Latn-IT', 'sl-Latn-IT-nedis'];
+            $locales[] = ['sl-Latn', 'sl-Latn-IT'];
+        }
+
+        return $locales;
+    }
+
     public function testTransWithFallbackLocaleTer()
     {
         $translator = new Translator('fr_FR');
diff --git a/src/Symfony/Component/Translation/Translator.php b/src/Symfony/Component/Translation/Translator.php
index e72d20a86f..1bda62d1b1 100644
--- a/src/Symfony/Component/Translation/Translator.php
+++ b/src/Symfony/Component/Translation/Translator.php
@@ -412,8 +412,19 @@ EOF
             $locales[] = $fallback;
         }
 
-        if (false !== strrchr($locale, '_')) {
+        if (\function_exists('locale_parse')) {
+            $localeSubTags = locale_parse($locale);
+            if (1 < \count($localeSubTags)) {
+                array_pop($localeSubTags);
+                $fallback = locale_compose($localeSubTags);
+                if (false !== $fallback) {
+                    array_unshift($locales, $fallback);
+                }
+            }
+        } elseif (false !== strrchr($locale, '_')) {
             array_unshift($locales, substr($locale, 0, -\strlen(strrchr($locale, '_'))));
+        } elseif (false !== strrchr($locale, '-')) {
+            array_unshift($locales, substr($locale, 0, -\strlen(strrchr($locale, '-'))));
         }
 
         return array_unique($locales);