From 2ea10b46780cb470218e64e4b530f5a411276a7b Mon Sep 17 00:00:00 2001
From: Minh-Quan TRAN <account@itscaro.me>
Date: Wed, 30 Jan 2019 18:01:47 +0100
Subject: [PATCH] Raise deprecation notice when the controller definition
 starts with \

Signed-off-by: Minh-Quan TRAN <account@itscaro.me>
---
 .../HttpKernel/Controller/ContainerControllerResolver.php      | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/Symfony/Component/HttpKernel/Controller/ContainerControllerResolver.php b/src/Symfony/Component/HttpKernel/Controller/ContainerControllerResolver.php
index 4f80921cf58f4..af9f3264c26fa 100644
--- a/src/Symfony/Component/HttpKernel/Controller/ContainerControllerResolver.php
+++ b/src/Symfony/Component/HttpKernel/Controller/ContainerControllerResolver.php
@@ -54,6 +54,9 @@ protected function instantiateController($class)
         try {
             return parent::instantiateController($class);
         } catch (\Error $e) {
+            if (0 === strpos($class, '\\')) {
+                @trigger_error(sprintf('The controller definition "%s" must not begin with "\"', $class), E_USER_DEPRECATED);
+            }
         }
 
         $this->throwExceptionIfControllerWasRemoved($class, $e);