Fixes #1844: Calling `Response::sendFile()` would cause sending the response twice

framework/CHANGELOG.md

@@ -24,6 +24,7 @@ Yii Framework 2 Change Log
 - Bug #1798: Fixed label attributes for array fields (zhuravljov)
 - Bug #1800: Better check for `$_SERVER['HTTPS']` in `yii\web\Request::getIsSecureConnection()` (ginus, samdark)
 - Bug #1827: Debugger toolbar is loaded twice if an action is calling `run()` to execute another action (qiangxue)
+- Bug #1844: Calling `Response::sendFile()` would cause sending the response twice (qiangxue)
 - Bug: Fixed `Call to a member function registerAssetFiles() on a non-object` in case of wrong `sourcePath` for an asset bundle (samdark)
 - Bug: Fixed incorrect event name for `yii\jui\Spinner` (samdark)
 - Bug: Json::encode() did not handle objects that implement JsonSerializable interface correctly (cebe)

framework/yii/web/Response.php

@@ -136,6 +136,10 @@ class Response extends \yii\base\Response
 	 */
 	public $version;
 	/**
+	 * @var boolean whether the response has been sent. If this is true, calling [[send()]] will do nothing.
+	 */
+	public $isSent = false;
+	/**
 	 * @var array list of HTTP status codes and the corresponding texts
 	 */
 	public static $httpStatuses = [
@@ -281,6 +285,11 @@ class Response extends \yii\base\Response
 	 */
 	public function send()
 	{
+		if ($this->isSent) {
+			return;
+		} else {
+			$this->isSent = true;
+		}
 		$this->trigger(self::EVENT_BEFORE_SEND);
 		$this->prepare();
 		$this->trigger(self::EVENT_AFTER_PREPARE);
@@ -300,6 +309,7 @@ class Response extends \yii\base\Response
 		$this->statusText = 'OK';
 		$this->data = null;
 		$this->content = null;
+		$this->isSent = false;
 	}
 
 	/**