From ded886bcfea5fa29c13e2cda23c60b22a3b375a3 Mon Sep 17 00:00:00 2001
From: "stefan.heinze" <stefan.heinze@zeiss.com>
Date: Thu, 7 Mar 2024 13:32:26 +0100
Subject: [PATCH] patch error while loading an image as tiled image where the
 highest zoom level can not be determined

---
 src/tiledimage.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/tiledimage.js b/src/tiledimage.js
index 20fa2ebf..0c666f1e 100644
--- a/src/tiledimage.js
+++ b/src/tiledimage.js
@@ -1299,6 +1299,10 @@ $.extend($.TiledImage.prototype, $.EventSource.prototype, /** @lends OpenSeadrag
             ))
         );
 
+        if (!highestLevel) {
+            highestLevel = 0;
+        }
+
         // Calculations for the interval of levels to draw
         // can return invalid intervals; fix that here if necessary
         highestLevel = Math.max(highestLevel, this.source.minLevel || 0);