Fix header collection from array (#18883)

* Fixed HeaderCollection::fromArray() key case

* Added CHANGELOG.md line for #18883 (Fixed HeaderCollection::fromArray() key case)

framework/CHANGELOG.md

@@ -17,6 +17,7 @@ Yii Framework 2 Change Log
 - Bug #18842: Fix `yii\base\Controller::bindInjectedParams()` to not throw error when argument of `ReflectionUnionType` type is passed (bizley)
 - Enh #18858: Reduce memory usage in `yii\base\View::afterRender` method (LeoOnTheEarth)
 - Bug #18880: Fix `yii\helpers\ArrayHelper::toArray()` for `DateTime` objects in PHP >= 7.4 (rhertogh)
+- Bug #18883: Fix `yii\web\HeaderCollection::fromArray()` now ensures lower case keys (rhertogh)
 
 
 2.0.43 August 09, 2021

framework/web/HeaderCollection.php

@@ -180,7 +180,7 @@ class HeaderCollection extends BaseObject implements \IteratorAggregate, \ArrayA
      */
     public function fromArray(array $array)
     {
-        $this->_headers = $array;
+        $this->_headers = array_change_key_case($array, CASE_LOWER);
     }
 
     /**

tests/framework/web/HeaderCollectionTest.php

@@ -0,0 +1,27 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yiiunit\framework\web;
+
+use yii\web\HeaderCollection;
+use yiiunit\TestCase;
+
+/**
+ * @group web
+ */
+class HeaderCollectionTest extends TestCase
+{
+    public function testFromArray()
+    {
+        $headerCollection = new HeaderCollection();
+        $location = 'my-test-location';
+        $headerCollection->fromArray([
+            'Location' => [$location],
+        ]);
+        $this->assertEquals($location, $headerCollection->get('Location'));
+    }
+}