Fixes #16648: Html::strtolower() was corrupting UTF-8 strings

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)

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);
     }
 

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',
+            ],
+        ];
+    }
 }
 
 /**