fix(select): placeholder (empty option) is lost in IE9

src/ng/directive/select.js

@@ -394,10 +394,6 @@ var selectDirective = ['$compile', '$parse', function($compile,   $parse) {
 
           if (multiple) {
             selectedSet = new HashMap(modelValue);
-          } else if (modelValue === null || nullOption) {
-            // if we are not multiselect, and we are null then we have to add the nullOption
-            optionGroups[''].push({selected:modelValue === null, id:'', label:''});
-            selectedSet = true;
           }
 
           // We now build up the list of options we need (we merge later)
@@ -422,9 +418,14 @@ var selectDirective = ['$compile', '$parse', function($compile,   $parse) {
               selected: selected                   // determine if we should be selected
             });
           }
-          if (!multiple && !selectedSet) {
-            // nothing was selected, we have to insert the undefined item
-            optionGroups[''].unshift({id:'?', label:'', selected:true});
+          if (!multiple) {
+            if (nullOption || modelValue === null) {
+              // insert null option if we have a placeholder, or the model is null
+              optionGroups[''].unshift({id:'', label:'', selected:!selectedSet});
+            } else if (!selectedSet) {
+              // option could not be found, we have to insert the undefined item
+              optionGroups[''].unshift({id:'?', label:'', selected:true});
+            }
           }
 
           // Now we need to update the list of DOM nodes to match the optionGroups we computed above
@@ -468,7 +469,8 @@ var selectDirective = ['$compile', '$parse', function($compile,   $parse) {
                 if (existingOption.id !== option.id) {
                   lastElement.val(existingOption.id = option.id);
                 }
-                if (existingOption.element.selected !== option.selected) {
+                // lastElement.prop('selected') provided by jQuery has side-effects
+                if (lastElement[0].selected !== option.selected) {
                   lastElement.prop('selected', (existingOption.selected = option.selected));
                 }
               } else {

test/ng/directive/selectSpec.js

@@ -977,6 +977,19 @@ describe('select', function() {
         expect(option.attr('id')).toBe('road-runner');
         expect(option.attr('custom-attr')).toBe('custom-attr');
       });
+
+      it('should be selected, if it is available and no other option is selected', function() {
+        // selectedIndex is used here because jqLite incorrectly reports element.val()
+        scope.$apply(function() {
+          scope.values = [{name: 'A'}];
+        });
+        createSingleSelect(true);
+        // ensure the first option (the blank option) is selected
+        expect(element[0].selectedIndex).toEqual(0);
+        scope.$digest();
+        // ensure the option has not changed following the digest
+        expect(element[0].selectedIndex).toEqual(0);
+      });
     });
 
 
@@ -1099,6 +1112,21 @@ describe('select', function() {
         browserTrigger(element, 'change');
         expect(scope.selected).toEqual(['0']);
       });
+
+      it('should deselect all options when model is emptied', function() {
+        createMultiSelect();
+         scope.$apply(function() {
+          scope.values = [{name: 'A'}, {name: 'B'}];
+          scope.selected = [scope.values[0]];
+        });
+        expect(element.find('option')[0].selected).toEqual(true);
+
+        scope.$apply(function() {
+          scope.selected.pop();
+        });
+
+        expect(element.find('option')[0].selected).toEqual(false);
+      })
     });