From e4c4300a064b9bf21bfcf112088fe9cd0f46a049 Mon Sep 17 00:00:00 2001
From: Chris Baynes <binaryexp+github@gmail.com>
Date: Sat, 31 Mar 2012 11:05:47 +0200
Subject: [PATCH] Allow sortBy to handle undefined values.

---
 underscore.js | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/underscore.js b/underscore.js
index 44226a07c..00ca13d4a 100644
--- a/underscore.js
+++ b/underscore.js
@@ -270,6 +270,8 @@
       };
     }).sort(function(left, right) {
       var a = left.criteria, b = right.criteria;
+      if (_.isUndefined(a)) return 1;
+      if (_.isUndefined(b)) return -1;
       return a < b ? -1 : a > b ? 1 : 0;
     }), 'value');
   };