From c07f33f5ade517fed808564576d3edd3c7289242 Mon Sep 17 00:00:00 2001
From: Kevin Ansfield <kevin@lookingsideways.co.uk>
Date: Wed, 19 Aug 2015 19:59:59 +0100
Subject: [PATCH] guard against missing $previewContent/ViewPort in
 gh-editor.scrollPosition

issue #5659
- fixes occasional issue with editor not rendering due to scrollPosition being requested before the relevant jquery elements have been set
---
 core/client/app/components/gh-editor.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/core/client/app/components/gh-editor.js b/core/client/app/components/gh-editor.js
index abe1845cb2..4172024c4f 100644
--- a/core/client/app/components/gh-editor.js
+++ b/core/client/app/components/gh-editor.js
@@ -41,7 +41,7 @@ export default Ember.Component.extend({
     // scrollPosition value such that when either scrolling or typing-at-the-end of the text editor the preview pane
     // stays in sync
     scrollPosition: Ember.computed('editorScrollInfo', 'height', function () {
-        if (!this.get('editorScrollInfo')) {
+        if (!this.get('editorScrollInfo') || !this.get('$previewContent') || !this.get('$previewViewPort')) {
             return 0;
         }