From 37d9e8bb8b22055be7bd1b13a0031f9572e58840 Mon Sep 17 00:00:00 2001
From: Kevin Ansfield <kevin@lookingsideways.co.uk>
Date: Thu, 24 Nov 2022 10:53:55 +0000
Subject: [PATCH] Fixed `Cannot set properties of null (setting 'scrollTop')`
 errors in `<GhHtmlIframe>`

closes sentry ADMIN-C7S

- we can't guarantee that the iframe being swapped to has rendered yet at the time we swap iframes so we need a guard around the `contentDocument.body` property existing before setting it's `scrollTop` value
---
 ghost/admin/app/components/gh-html-iframe.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/ghost/admin/app/components/gh-html-iframe.js b/ghost/admin/app/components/gh-html-iframe.js
index 0b84c24c3f..dce995497b 100644
--- a/ghost/admin/app/components/gh-html-iframe.js
+++ b/ghost/admin/app/components/gh-html-iframe.js
@@ -69,7 +69,9 @@ export default class GhHtmlIframeComponent extends Component {
             }
             this._lastPageId = this.args.pageId;
 
-            this.iframes[this.toRenderIframe].contentDocument.body.scrollTop = newScrollTop;
+            if (this.iframes[this.toRenderIframe].contentDocument.body) {
+                this.iframes[this.toRenderIframe].contentDocument.body.scrollTop = newScrollTop;
+            }
             this.iframes[this.toRenderIframe].style = this.visibleIframeStyle;
             this.renderedIframe = this.toRenderIframe;
             this.toRenderIframe = this.toRenderIframe === 0 ? 1 : 0;