perf(tagging multiple): transform tagging item only once when filtering

src/uiSelectMultipleDirective.js

@@ -308,7 +308,7 @@ uis.directive('uiSelectMultiple', ['uiSelectMinErr','$timeout', function(uiSelec
             // verify the new tag doesn't match the value of a possible selection choice or an already selected item.
             if (
               stashArr.some(function (origItem) {
-                 return angular.equals(origItem, $select.tagging.fct($select.search));
+                 return angular.equals(origItem, newItem);
               }) ||
               $select.selected.some(function (origItem) {
                 return angular.equals(origItem, newItem);

test/select.spec.js

@@ -212,6 +212,12 @@ describe('ui-select tests', function() {
     scope.$digest();
   }
 
+  function showChoicesForSearch(el, search) {
+    setSearchText(el, search);
+    el.scope().$select.searchInput.trigger('keyup');
+    scope.$digest();
+  }
+
 
   // Tests
   //uisRepeatParser
@@ -2206,6 +2212,25 @@ describe('ui-select tests', function() {
       expect(el.scope().$select.multiple).toBe(true);
     });
 
+    it('should not call tagging function needlessly', function() {
+      scope.slowTaggingFunc = function (name) {
+        // for (var i = 0; i < 100000000; i++);
+        return {name: name};
+      };
+      spyOn(scope, 'slowTaggingFunc').and.callThrough();
+
+      var el = createUiSelectMultiple({tagging: 'slowTaggingFunc'});
+
+      showChoicesForSearch(el, 'Foo');
+      expect(el.find('.ui-select-choices-row-inner').size()).toBe(6);
+
+      showChoicesForSearch(el, 'a');
+      expect(el.find('.ui-select-choices-row-inner').size()).toBe(9);
+
+      expect(scope.slowTaggingFunc.calls.count()).toBe(2);
+      expect(scope.slowTaggingFunc.calls.count()).not.toBe(15);
+    });
+
     it('should allow paste tag from clipboard', function() {
       scope.taggingFunc = function (name) {
         return {