From 2c5661ebb30461d7a004372318617ded7a332ae7 Mon Sep 17 00:00:00 2001
From: John-David Dalton <john.david.dalton@gmail.com>
Date: Tue, 6 Dec 2011 01:16:56 -0500
Subject: [PATCH] underscore: Avoid regression and cleanup comments. [jddalton]

---
 test/objects.js |  2 +-
 underscore.js   | 13 +++++++------
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/test/objects.js b/test/objects.js
index 5edea3710..73c56376d 100644
--- a/test/objects.js
+++ b/test/objects.js
@@ -262,7 +262,7 @@ $(document).ready(function($, undefined) {
     ok(!_.isEqual({a: 1}, {a: 1, b: 2}), "Commutative equality is implemented for objects");
     ok(!_.isEqual({x: 1, y: undefined}, {x: 1, z: 2}), "Objects with identical keys and different values are not equivalent");
 
-    // Objects with shadowing properties
+    // Objects with properties that shadow non-enumerable ones.
     ok(!_.isEqual({}, {toString: 1}), "Object with custom toString is not equal to {}");
     ok(_.isEqual({toString: 1, valueOf: 2}, {toString: 1, valueOf: 2}), "Objects with equivalent shadow properties");
 
diff --git a/underscore.js b/underscore.js
index c6587c99b..34fd319d5 100644
--- a/underscore.js
+++ b/underscore.js
@@ -25,8 +25,8 @@
 
   // Create quick reference variables for speed access to core prototypes.
   var concat           = ArrayProto.concat,
+      push             = ArrayProto.push,
       slice            = ArrayProto.slice,
-      unshift          = ArrayProto.unshift,
       toString         = ObjProto.toString,
       hasOwnProperty   = ObjProto.hasOwnProperty;
 
@@ -85,7 +85,7 @@
       var i = -1;
       var l = obj.length;
 
-      // We optimized for common use by only binding a context when it's passed
+      // We optimize for common use by only binding a context when it's passed.
       if (context) {
         iterator = function() { return fn.call(context, obj[i], i, obj); };
       }
@@ -100,7 +100,7 @@
     }
   };
 
-  // A simple each, for dealing with non-sparse arrays and arguments objects
+  // A simple each, for dealing with non-sparse arrays and arguments objects.
   var simpleEach = function(obj, iterator, index) {
     index || (index = 0);
     for (var l = obj.length; index < l; index++) {
@@ -114,7 +114,7 @@
     'toLocaleString', 'toString', 'valueOf'
   ];
 
-  // IE < 9 makes properties, shadowing non-enumerable ones, non-enumerable too
+  // IE < 9 makes properties, shadowing non-enumerable ones, non-enumerable too.
   var forShadowed = !{valueOf:0}.propertyIsEnumerable('valueOf') &&
     function(obj, iterator) {
       // Because IE < 9 can't set the `[[Enumerable]]` attribute of an existing
@@ -1021,8 +1021,9 @@
   // A method to easily add functions to the OOP wrapper.
   var addToWrapper = function(name, func) {
     wrapper.prototype[name] = function() {
-      unshift.call(arguments, this._wrapped);
-      return result(func.apply(_, arguments), this._chain);
+      var args = [this._wrapped];
+      push.apply(args, arguments);
+      return result(func.apply(_, args), this._chain);
     };
   };