From b94fadac9739b1f1ab4d1534c5aa191789de1769 Mon Sep 17 00:00:00 2001
From: Gaming4JC <g4jc@hyperbola.info>
Date: Sat, 4 Jan 2020 22:04:13 -0500
Subject: [PATCH] Bug 1315885 - Part 2: Avoid rethrowing exception in
 CustomElementCallback::Call.

Tag UXP Issue #1344
---
 dom/base/CustomElementRegistry.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/dom/base/CustomElementRegistry.cpp b/dom/base/CustomElementRegistry.cpp
index bd48f3c071..249162c380 100644
--- a/dom/base/CustomElementRegistry.cpp
+++ b/dom/base/CustomElementRegistry.cpp
@@ -55,6 +55,10 @@ CustomElementCallback::Call()
         mArgs.name, mArgs.oldValue, mArgs.newValue, rv);
       break;
   }
+
+  // If callbacks throw exceptions, it'll be handled and reported in
+  // Lifecycle*Callback::Call function.
+  rv.SuppressException();
 }
 
 void