From bc50a7d3c6d8e03f99b64852c58ed8b7cc73a07c Mon Sep 17 00:00:00 2001
From: Moonchild <moonchild@palemoon.org>
Date: Sun, 19 Feb 2023 13:10:29 +0100
Subject: [PATCH] [DOM] Check whether module load request was already cancelled
 when a load fails

---
 dom/script/ModuleLoadRequest.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/dom/script/ModuleLoadRequest.cpp b/dom/script/ModuleLoadRequest.cpp
index ec924ea7a4..2abc6236e8 100644
--- a/dom/script/ModuleLoadRequest.cpp
+++ b/dom/script/ModuleLoadRequest.cpp
@@ -148,6 +148,11 @@ ModuleLoadRequest::LoadFailed()
   // We failed to load the source text or an error occurred unrelated to the
   // content of the module (e.g. OOM).
 
+  if (IsCanceled()) {
+    return;
+  }
+
+  MOZ_ASSERT(!IsReadyToRun());
   MOZ_ASSERT(!mModuleScript);
 
   Cancel();