From d8a587631ba96773dbe7f49ede3714add63f0d8c Mon Sep 17 00:00:00 2001
From: Tom MacWright <tom@macwright.org>
Date: Wed, 16 Jan 2013 17:37:57 -0500
Subject: [PATCH] Fix TypeError from race condition between resetting and using
 transforms.

---
 js/id/renderer/map.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/js/id/renderer/map.js b/js/id/renderer/map.js
index 9d80676f4..9bb695747 100644
--- a/js/id/renderer/map.js
+++ b/js/id/renderer/map.js
@@ -123,7 +123,7 @@ iD.Map = function() {
         projection
             .translate(d3.event.translate)
             .scale(d3.event.scale);
-        if (fast) {
+        if (fast && translateStart) {
             var a = d3.event.translate,
                 b = translateStart,
                 translate = 'translate(' + ~~(a[0] - b[0]) + 'px,' +