From 2db78f33ddd734a6c168225529b3c853cd3f04d9 Mon Sep 17 00:00:00 2001
From: Jesse van Assen <jesse.v.assen@gmail.com>
Date: Mon, 21 Aug 2023 15:29:13 +0200
Subject: [PATCH] Only trigger attributeChangedCallback on toggleAttribute if
 the value changed

---
 .../src/scoped-custom-element-registry.js                    | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/packages/scoped-custom-element-registry/src/scoped-custom-element-registry.js b/packages/scoped-custom-element-registry/src/scoped-custom-element-registry.js
index bbed0154..861a7e13 100644
--- a/packages/scoped-custom-element-registry/src/scoped-custom-element-registry.js
+++ b/packages/scoped-custom-element-registry/src/scoped-custom-element-registry.js
@@ -354,7 +354,10 @@ if (!ShadowRoot.prototype.createElement) {
           const old = this.getAttribute(name);
           toggleAttribute.call(this, name, force);
           const newValue = this.getAttribute(name);
-          attributeChangedCallback.call(this, name, old, newValue);
+
+          if (old !== newValue) {
+            attributeChangedCallback.call(this, name, old, newValue);
+          }
         } else {
           toggleAttribute.call(this, name, force);
         }