Fixes #5001: yii\rest\CreateAction, yii\rest\UpdateAction and yii\rest\DeleteAction should throw 500 error if the model operation returns false without validation errors

framework/web/ServerErrorHttpException.php

@@ -0,0 +1,28 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\web;
+
+/**
+ * ServerErrorHttpException represents an "Internal Server Error" HTTP exception with status code 500.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @since 2.0
+ */
+class ServerErrorHttpException extends HttpException
+{
+    /**
+     * Constructor.
+     * @param string $message error message
+     * @param integer $code error code
+     * @param \Exception $previous The previous exception used for the exception chaining.
+     */
+    public function __construct($message = null, $code = 0, \Exception $previous = null)
+    {
+        parent::__construct(500, $message, $code, $previous);
+    }
+}