From f831662fdd4954149628a913a7d57b2117408438 Mon Sep 17 00:00:00 2001
From: Andreas Richter <andy@selfstudy.com>
Date: Wed, 26 Jun 2019 11:06:00 -0400
Subject: [PATCH] Allow html to stay on preview page.

---
 src/js/easymde.js | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/js/easymde.js b/src/js/easymde.js
index 445fbd3..c8d2272 100644
--- a/src/js/easymde.js
+++ b/src/js/easymde.js
@@ -791,7 +791,10 @@ function toggleSideBySide(editor) {
     }
 
     var sideBySideRenderingFunction = function () {
-        preview.innerHTML = editor.options.previewRender(editor.value(), preview);
+        var newValue = editor.options.previewRender(editor.value(), preview);
+        if (newValue != null) {
+            preview.innerHTML = newValue;
+        }
     };
 
     if (!cm.sideBySideRenderingFunction) {
@@ -799,7 +802,10 @@ function toggleSideBySide(editor) {
     }
 
     if (useSideBySideListener) {
-        preview.innerHTML = editor.options.previewRender(editor.value(), preview);
+        var newValue = editor.options.previewRender(editor.value(), preview);
+        if (newValue != null) {
+            preview.innerHTML = newValue;
+        }
         cm.on('update', cm.sideBySideRenderingFunction);
     } else {
         cm.off('update', cm.sideBySideRenderingFunction);