From 660081ecd8eae86b9387af5caa35c7fa5019f2c4 Mon Sep 17 00:00:00 2001
From: Marlo Longley <mlongley@stanford.edu>
Date: Thu, 16 Jan 2025 11:49:04 -0500
Subject: [PATCH] Ensure viewerConfig exists in OpenSeadragonViewer condition

Fixes #4079
---
 src/components/OpenSeadragonViewer.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/components/OpenSeadragonViewer.js b/src/components/OpenSeadragonViewer.js
index 685375bc64..c3896110bf 100644
--- a/src/components/OpenSeadragonViewer.js
+++ b/src/components/OpenSeadragonViewer.js
@@ -104,7 +104,7 @@ export class OpenSeadragonViewer extends Component {
       }
     } else if (!isEqual(canvasWorld.layers, prevProps.canvasWorld.layers)) {
       this.refreshTileProperties();
-    } else if (viewerConfig !== prevProps.viewerConfig) {
+    } else if (viewerConfig && viewerConfig !== prevProps.viewerConfig) {
       const { viewport } = viewer;
 
       if (viewerConfig.x !== viewport.centerSpringX.target.value