From 78bf554eb2306b87abc426aa6e6c5e95975af3b2 Mon Sep 17 00:00:00 2001
From: Daniel Jones <dcjones@cs.washington.edu>
Date: Thu, 15 May 2014 22:47:07 -0700
Subject: [PATCH] Correctly check for undefined in getScroll. Fixes #219

---
 src/mouse.js | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/mouse.js b/src/mouse.js
index eeadd98..d159ca3 100644
--- a/src/mouse.js
+++ b/src/mouse.js
@@ -27,7 +27,11 @@ Snap.plugin(function (Snap, Element, Paper, glob) {
     },
     getScroll = function (xy) {
         var name = xy == "y" ? "scrollTop" : "scrollLeft";
-        return glob.doc.documentElement[name] || glob.doc.body[name];
+        if (name in glob.doc.documentElement) {
+            return glob.doc.documentElement[name];
+        } else {
+            return glob.doc.body[name];
+        }
     },
     preventDefault = function () {
         this.returnValue = false;