From 0ba19b4eed220c58bfa0a6094beda9d84d9eb681 Mon Sep 17 00:00:00 2001
From: Kevin Schaaf <kschaaf@google.com>
Date: Mon, 24 Jun 2019 17:04:20 -0700
Subject: [PATCH] Add a dirty check to showHideChildren

---
 lib/elements/dom-if.js | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/lib/elements/dom-if.js b/lib/elements/dom-if.js
index dd54017c4a..48fdc988c6 100644
--- a/lib/elements/dom-if.js
+++ b/lib/elements/dom-if.js
@@ -297,11 +297,12 @@ class DomIfFast extends DomIfBase {
    */
   _showHideChildren() {
     const hidden = this.__hideTemplateChildren__ || !this.if;
-    if (this.__instance) {
+    if (this.__instance && Boolean(this.__instance.__hidden) !== hidden) {
+      this.__instance.__hidden = hidden;
       showHideChildren(hidden, this.__instance.templateInfo.childNodes);
-    }
-    if (!hidden) {
-      this.__syncHostProperties();
+      if (!hidden) {
+        this.__syncHostProperties();
+      }
     }
   }
 }
@@ -397,7 +398,8 @@ class DomIfLegacy extends DomIfBase {
    */
   _showHideChildren() {
     const hidden = this.__hideTemplateChildren__ || !this.if;
-    if (this.__instance) {
+    if (this.__instance && Boolean(this.__instance.__hidden) !== hidden) {
+      this.__instance.__hidden = hidden;
       this.__instance._showHideChildren(hidden);
       if (!hidden) {
         this.__syncHostProperties();