From e8ba15ed27d080ac3385292d3b57ce3621e987bf Mon Sep 17 00:00:00 2001
From: Thomas Calvet <calvet.thomas@gmail.com>
Date: Fri, 31 Jan 2020 12:46:11 +0100
Subject: [PATCH] [Config][XmlReferenceDumper] Prevent potential \TypeError

---
 .../Component/Config/Definition/Dumper/XmlReferenceDumper.php   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Symfony/Component/Config/Definition/Dumper/XmlReferenceDumper.php b/src/Symfony/Component/Config/Definition/Dumper/XmlReferenceDumper.php
index ff8c35388870d..da0a971213ee7 100644
--- a/src/Symfony/Component/Config/Definition/Dumper/XmlReferenceDumper.php
+++ b/src/Symfony/Component/Config/Definition/Dumper/XmlReferenceDumper.php
@@ -91,7 +91,7 @@ private function writeNode(NodeInterface $node, int $depth = 0, bool $root = fal
                 }
 
                 if ($prototype instanceof PrototypedArrayNode) {
-                    $prototype->setName($key);
+                    $prototype->setName($key ?? '');
                     $children = [$key => $prototype];
                 } elseif ($prototype instanceof ArrayNode) {
                     $children = $prototype->getChildren();