From 06227c7075c1312974baf9062d87d502f003ae32 Mon Sep 17 00:00:00 2001
From: Nikolay Oleynikov <oleynikovny@mail.ru>
Date: Tue, 20 Nov 2018 01:09:03 +0300
Subject: [PATCH] Fixes #16648: Html::strtolower() was corrupting UTF-8 strings

---
 framework/CHANGELOG.md               |  1 +
 framework/helpers/BaseHtml.php       |  3 +-
 tests/framework/helpers/HtmlTest.php | 52 ++++++++++++++++++++++++++++
 3 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/framework/CHANGELOG.md b/framework/CHANGELOG.md
index e348d9bc34..fa67dea0ff 100644
--- a/framework/CHANGELOG.md
+++ b/framework/CHANGELOG.md
@@ -4,6 +4,7 @@ Yii Framework 2 Change Log
 2.0.16 under development
 ------------------------
 
+- Bug #16648: Html::strtolower() was corrupting UTF-8 strings (Kolyunya)
 - Bug #13977: Skip validation if file input does not exist (RobinKamps, s1lver)
 - Bug #16183: Fixed when `yii\helpers\BaseFileHelper` sometimes returned wrong value (samdark, SilverFire, OndrejVasicek)
 - Bug #13932: Fix number validator attributes comparison (uaoleg, s1lver)
diff --git a/framework/helpers/BaseHtml.php b/framework/helpers/BaseHtml.php
index 911bda6ff7..5b0440b291 100644
--- a/framework/helpers/BaseHtml.php
+++ b/framework/helpers/BaseHtml.php
@@ -2295,7 +2295,8 @@ class BaseHtml
      */
     public static function getInputId($model, $attribute)
     {
-        $name = strtolower(static::getInputName($model, $attribute));
+        $charset = Yii::$app ? Yii::$app->charset : 'UTF-8';
+        $name = mb_strtolower(static::getInputName($model, $attribute), $charset);
         return str_replace(['[]', '][', '[', ']', ' ', '.'], ['', '-', '-', '', '-', '-'], $name);
     }
 
diff --git a/tests/framework/helpers/HtmlTest.php b/tests/framework/helpers/HtmlTest.php
index 5f6c81227e..8e1846e10a 100644
--- a/tests/framework/helpers/HtmlTest.php
+++ b/tests/framework/helpers/HtmlTest.php
@@ -1778,6 +1778,19 @@ EOD;
         $this->assertSame($expected, $actual);
     }
 
+    /**
+     * @dataProvider testGetInputIdDataProvider
+     */
+    public function testGetInputId($attributeName, $inputIdExpected)
+    {
+        $model = new DynamicModel();
+        $model->defineAttribute($attributeName);
+
+        $inputIdActual = Html::getInputId($model, $attributeName);
+
+        $this->assertSame($inputIdExpected, $inputIdActual);
+    }
+
     public function testEscapeJsRegularExpression()
     {
         $expected = '/[a-z0-9-]+/';
@@ -1858,6 +1871,45 @@ HTML;
 
         $this->assertContains('placeholder="My placeholder: Name"', $html);
     }
+
+    public function testGetInputIdDataProvider()
+    {
+        return [
+            [
+                'foo',
+                'dynamicmodel-foo',
+            ],
+            [
+                'FooBar',
+                'dynamicmodel-foobar',
+            ],
+            [
+                'Foo_Bar',
+                'dynamicmodel-foo_bar',
+            ],
+            [
+                'foo[]',
+                'dynamicmodel-foo',
+            ],
+            [
+                'foo[bar][baz]',
+                'dynamicmodel-foo-bar-baz',
+            ],
+
+            [
+                'foo.bar',
+                'dynamicmodel-foo-bar',
+            ],
+            [
+                'bild_groß_dateiname',
+                'dynamicmodel-bild_groß_dateiname',
+            ],
+            [
+                'ФуБарБаз',
+                'dynamicmodel-фубарбаз',
+            ],
+        ];
+    }
 }
 
 /**