From 4ddc3b518bd74e9c10c2af161bbf32b62d3a3844 Mon Sep 17 00:00:00 2001
From: John-David Dalton <john.david.dalton@gmail.com>
Date: Tue, 8 Jul 2014 00:36:52 -0700
Subject: [PATCH] Optimize `_.shuffle`.

---
 lodash.js | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/lodash.js b/lodash.js
index f76bbb7ab..b481db01f 100644
--- a/lodash.js
+++ b/lodash.js
@@ -5242,13 +5242,16 @@
     function shuffle(collection) {
       collection = toIterable(collection);
 
-      var index = -1,
+      var index = 0,
           length = collection.length,
           result = Array(length);
 
+      if (length) {
+        result[index] = collection[index];
+      }
       while (++index < length) {
         var value = collection[index],
-            rand = baseRandom(0, index);
+            rand = baseRandom(0, index - 1);
 
         result[index] = result[rand];
         result[rand] = value;