From 29a27cdb87bb3c36b3ddb917fadfaa473ddfe83a Mon Sep 17 00:00:00 2001
From: Martin Stark <901824+martinstark@users.noreply.github.com>
Date: Tue, 14 Mar 2023 19:23:10 +0100
Subject: [PATCH] fix: mitigate uncaught type error in media_source_engine
 (#5069)

Fixes #4903
---
 lib/media/media_source_engine.js | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/lib/media/media_source_engine.js b/lib/media/media_source_engine.js
index 9aef7b1f7b..ced14a4160 100644
--- a/lib/media/media_source_engine.js
+++ b/lib/media/media_source_engine.js
@@ -375,7 +375,22 @@ shaka.media.MediaSourceEngine = class {
               shaka.media.Transmuxer.convertCodecs(contentType, mimeType);
         }
         const type = mimeType + this.config_.sourceBufferExtraFeatures;
-        const sourceBuffer = this.mediaSource_.addSourceBuffer(type);
+
+        this.destroyer_.ensureNotDestroyed();
+
+        let sourceBuffer;
+
+        try {
+          sourceBuffer = this.mediaSource_.addSourceBuffer(type);
+        } catch (exception) {
+          throw new shaka.util.Error(
+              shaka.util.Error.Severity.CRITICAL,
+              shaka.util.Error.Category.MEDIA,
+              shaka.util.Error.Code.MEDIA_SOURCE_OPERATION_THREW,
+              exception,
+              'The mediaSource_ status was' + this.mediaSource_.readyState +
+              'expected \'open\'');
+        }
 
         this.eventManager_.listen(
             sourceBuffer, 'error',