From b1cecccb578c412b85c1d082a30fe31def090829 Mon Sep 17 00:00:00 2001
From: Michael Telatynski <7t3chguy@gmail.com>
Date: Tue, 13 Sep 2022 13:34:35 +0100
Subject: [PATCH] Fix thumbnail generation when offscreen canvas fails (#9272)

---
 src/utils/image-media.ts | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/utils/image-media.ts b/src/utils/image-media.ts
index b768133382..1f1db27727 100644
--- a/src/utils/image-media.ts
+++ b/src/utils/image-media.ts
@@ -92,9 +92,8 @@ export async function createThumbnail(
     context.drawImage(element, 0, 0, targetWidth, targetHeight);
 
     let thumbnailPromise: Promise<Blob>;
-
-    if (window.OffscreenCanvas) {
-        thumbnailPromise = (canvas as OffscreenCanvas).convertToBlob({ type: mimeType });
+    if (canvas instanceof window.OffscreenCanvas) {
+        thumbnailPromise = canvas.convertToBlob({ type: mimeType });
     } else {
         thumbnailPromise = new Promise<Blob>(resolve => (canvas as HTMLCanvasElement).toBlob(resolve, mimeType));
     }