From 024f47dfe74a188891423582649685a49c4d203b Mon Sep 17 00:00:00 2001
From: Andreas Plesch <andreasplesch@users.noreply.github.com>
Date: Mon, 18 Dec 2017 17:11:09 -0500
Subject: [PATCH] avoid type errors when checking

---
 nrrd.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/nrrd.js b/nrrd.js
index dae8e0d..f7d3a66 100644
--- a/nrrd.js
+++ b/nrrd.js
@@ -1128,7 +1128,9 @@ function checkNRRD(ret) {
     // TODO: Check space/orientation fields.
     
     // We should either have inline data or external data
-    if ((ret.data === undefined || ret.data.length === 0) && (ret.buffer === undefined || ret.buffer.byteLength === 0) && ret.dataFile === undefined) {
+    if ((ret.data === undefined || (ret.data && ret.data.length === 0)) && 
+        (ret.buffer === undefined || (ret.buffer && ret.buffer.byteLength === 0)) && 
+        ret.dataFile === undefined) {
         throw new Error("NRRD file has neither inline or external data!");
     }
 }