From 27a1123c579ee8576019dcd0a1d88ec55600761b Mon Sep 17 00:00:00 2001
From: Beatrycze Volk <beatrycze.volk@slub-dresden.de>
Date: Fri, 31 May 2024 10:34:20 +0200
Subject: [PATCH] Check if core exists in registry array

---
 Classes/Common/Solr/Solr.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Classes/Common/Solr/Solr.php b/Classes/Common/Solr/Solr.php
index acd6e3a7f..c6eea82e4 100644
--- a/Classes/Common/Solr/Solr.php
+++ b/Classes/Common/Solr/Solr.php
@@ -301,7 +301,7 @@ public static function getInstance($core = null): Solr
         if (!empty($core)) {
             // Check if there is an instance in the registry already.
             if (
-                is_object(self::$registry[$core])
+                array_key_exists($core, self::$registry)
                 && self::$registry[$core] instanceof self
             ) {
                 // Return singleton instance if available.