From 673fcd7927a31ad39ebe6208731e351f2574d1e3 Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov@git.wordpress.org>
Date: Fri, 28 Aug 2020 13:10:29 +0000
Subject: [PATCH] Comments: Check if reply heading text node exists before
 accessing its property in `comment-reply.js`.

Follow-up to [47506], [48876].

Props johannadevos, mailnew2ster.
Fixes #38009.

git-svn-id: https://develop.svn.wordpress.org/trunk@48904 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/js/_enqueues/lib/comment-reply.js | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/js/_enqueues/lib/comment-reply.js b/src/js/_enqueues/lib/comment-reply.js
index d86403bbeb..698e894304 100644
--- a/src/js/_enqueues/lib/comment-reply.js
+++ b/src/js/_enqueues/lib/comment-reply.js
@@ -175,11 +175,14 @@ window.addComment = ( function( window ) {
 		var headingText = temporaryElement.textContent;
 		temporaryElement.parentNode.replaceChild( respondElement, temporaryElement );
 		cancelLink.style.display = 'none';
-		var replyHeadingElement = getElementById( config.commentReplyTitleId );
+
+		var replyHeadingElement  = getElementById( config.commentReplyTitleId );
 		var replyHeadingTextNode = replyHeadingElement && replyHeadingElement.firstChild;
+
 		if ( replyHeadingTextNode && replyHeadingTextNode.nodeType === Node.TEXT_NODE && headingText ) {
 			replyHeadingTextNode.textContent = headingText;
 		}
+
 		event.preventDefault();
 	}
 
@@ -314,7 +317,7 @@ window.addComment = ( function( window ) {
 		var postIdField     = getElementById( config.postIdFieldId );
 		var element, cssHidden, style;
 
-		var replyHeading = getElementById( config.commentReplyTitleId );
+		var replyHeading         = getElementById( config.commentReplyTitleId );
 		var replyHeadingTextNode = replyHeading && replyHeading.firstChild;
 
 		if ( ! addBelowElement || ! respondElement || ! parentIdField ) {
@@ -337,9 +340,11 @@ window.addComment = ( function( window ) {
 
 		cancelElement.style.display = '';
 		addBelowElement.parentNode.insertBefore( respondElement, addBelowElement.nextSibling );
-		if ( replyHeadingTextNode.nodeType === Node.TEXT_NODE ) {
+
+		if ( replyHeadingTextNode && replyHeadingTextNode.nodeType === Node.TEXT_NODE ) {
 			replyHeadingTextNode.textContent = replyTo;
 		}
+
 		/*
 		 * This is for backward compatibility with third party commenting systems
 		 * hooking into the event using older techniques.