From 091b5fbe30db874255eda41dc3903d3bb93540fa Mon Sep 17 00:00:00 2001
From: John-David Dalton <john.david.dalton@gmail.com>
Date: Mon, 11 Apr 2016 17:30:15 -0700
Subject: [PATCH] Make `_.head` avoid accessing array when its length is `0`.

---
 lodash.js    | 2 +-
 test/test.js | 7 +++----
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/lodash.js b/lodash.js
index aadced73d..fd2667dac 100644
--- a/lodash.js
+++ b/lodash.js
@@ -6415,7 +6415,7 @@
      * // => undefined
      */
     function head(array) {
-      return array ? array[0] : undefined;
+      return (array && array.length) ? array[0] : undefined;
     }
 
     /**
diff --git a/test/test.js b/test/test.js
index 4a1866d19..a3f58b219 100644
--- a/test/test.js
+++ b/test/test.js
@@ -7386,10 +7386,9 @@
     QUnit.test('should return `undefined` when querying empty arrays', function(assert) {
       assert.expect(1);
 
-      var array = [];
-      array['-1'] = 1;
-
-      assert.strictEqual(_.head(array), undefined);
+      arrayProto[0] = 1;
+      assert.strictEqual(_.head([]), undefined);
+      arrayProto.length = 0;
     });
 
     QUnit.test('should work as an iteratee for methods like `_.map`', function(assert) {