From de437e73d3c35b91892bcbd59828e22fb8eb4b72 Mon Sep 17 00:00:00 2001
From: phromo <phromo@phromo.se>
Date: Wed, 31 Oct 2018 09:10:47 +0100
Subject: [PATCH] fix null reference on empty cell. fixes #14

---
 lib/main.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/main.js b/lib/main.js
index c3fa9d2..4002709 100644
--- a/lib/main.js
+++ b/lib/main.js
@@ -183,7 +183,9 @@ class PythonKernelMod {
     // is indented the same amount. However, this only works if the first line
     // is indented. We therefore trim empty lines at the start of the executed
     // region.
-    code = code.replace(/^\n|\n$/g, '');
+    if (code != null) {
+      code = code.replace(/^\n|\n$/g, '');
+    }
 
     next.execute(code, (msg, channel) => {
       if (!makeReply && msg.parent_header) {