From b54c4933ef78099e32b22418bfb4ac4d14f3c010 Mon Sep 17 00:00:00 2001
From: mantis <mantis@users.noreply.github.com>
Date: Fri, 25 Jan 2019 17:17:45 +0000
Subject: [PATCH] Fix: Deprecation: A tree builder without a root node is
 deprecated since symfony 4.2 (#1457)

* Fix: Deprecation: A tree builder without a root node is deprecated since Symfony 4.2 and will not be supported anymore in 5.0.

* Fix: Deprecation: A tree builder without a root node is deprecated since Symfony 4.2 and will not be supported anymore in 5.0.
---
 DependencyInjection/Configuration.php | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/DependencyInjection/Configuration.php b/DependencyInjection/Configuration.php
index c71e33000..a2cecf6a1 100644
--- a/DependencyInjection/Configuration.php
+++ b/DependencyInjection/Configuration.php
@@ -18,9 +18,16 @@ class Configuration implements ConfigurationInterface
 {
     public function getConfigTreeBuilder()
     {
-        $treeBuilder = new TreeBuilder();
-        $treeBuilder
-            ->root('nelmio_api_doc')
+        $treeBuilder = new TreeBuilder('nelmio_api_doc');
+
+        if (method_exists($treeBuilder, 'getRootNode')) {
+            $rootNode = $treeBuilder->getRootNode();
+        } else {
+            // symfony < 4.2 support
+            $rootNode = $treeBuilder->root('nelmio_api_doc');
+        }
+
+        $rootNode
             ->children()
                 ->scalarNode('name')->defaultValue('API documentation')->end()
                 ->arrayNode('exclude_sections')