fix(ngRepeat): attempt to simplify and improve existing fix for #933

I'm keeping this in for future reference. The issue with this solution
is that if we shift() the first item in the array, the whole repeater
DOM will be rebuilt from scratch, we need to do better than that.

src/apis.js

@@ -98,12 +98,12 @@ HashQueueMap.prototype = {
       }
     }
   },
-  
+
   /**
    * return the first item without deleting it
    */
   peek: function(key) {
-    var array = this[key = hashKey(key)];
+    var array = this[hashKey(key)];
     if (array) {
     return array[0];
     }

src/ng/directive/ngRepeat.js

@@ -88,7 +88,7 @@ var ngRepeatDirective = ngDirective({
       // We need an array of these objects since the same object can be returned from the iterator.
       // We expect this to be a rare case.
       var lastOrder = new HashQueueMap();
-      var indexValues = [];
+
       scope.$watch(function ngRepeatWatch(scope){
         var index, length,
             collection = scope.$eval(rhs),
@@ -119,18 +119,14 @@ var ngRepeatDirective = ngDirective({
           key = (collection === array) ? index : array[index];
           value = collection[key];
 
-          // if collection is array and value is object, it can be shifted to allow for position change
-          // if collection is array and value is not object, need to first check whether index is same to
-          // avoid shifting wrong value
-          // if collection is not array, need to always check index to avoid shifting wrong value
-          if (lastOrder.peek(value)) {
-            last = collection === array ?
-              ((isObject(value)) ? lastOrder.shift(value) :
-                (index === lastOrder.peek(value).index ? lastOrder.shift(value) : undefined)) :
-              (index === lastOrder.peek(value).index ? lastOrder.shift(value) : undefined);
-          } else {
-            last = undefined;
-          }
+          // if value is object, it can be shifted to allow for position change
+          // if is not object, need to first check whether index is same to avoid shifting wrong val
+          last = isObject(value)
+              ? lastOrder.shift(value)
+              : (last = lastOrder.peek(value)) && (index === last.index)
+                  ? lastOrder.shift(value)
+                  : undefined;
+
 
           if (last) {
             // if we have already seen this object, then we need to reuse the
@@ -151,12 +147,6 @@ var ngRepeatDirective = ngDirective({
               cursor = last.element;
             }
           } else {
-            if (indexValues.hasOwnProperty(index) && collection !== array) {
-              var preValue = indexValues[index];
-              var v = lastOrder.shift(preValue);
-              v.element.remove();
-              v.scope.$destroy();
-            }
             // new item which we don't know about
             childScope = scope.$new();
           }
@@ -178,16 +168,10 @@ var ngRepeatDirective = ngDirective({
                   index: index
                 };
               nextOrder.push(value, last);
-              indexValues[index] = value;
             });
           }
         }
 
-        var i, l;
-        for (i = 0, l = indexValues.length - length; i < l; i++) {
-          indexValues.pop();
-        }
-
         //shrink children
         for (key in lastOrder) {
           if (lastOrder.hasOwnProperty(key)) {