fix(datepicker): Today button should not set time

Fixes #1726
Closes #1808

src/datepicker/datepicker.js

@@ -442,7 +442,16 @@ function ($compile, $parse, $document, $position, dateFilter, datepickerPopupCon
       });
 
       scope.select = function( date ) {
-        scope.dateSelection( date === 'today' ? new Date() : date);
+        if (date === 'today') {
+          var today = new Date();
+          if (angular.isDate(ngModel.$modelValue)) {
+            date = new Date(ngModel.$modelValue);
+            date.setFullYear(today.getFullYear(), today.getMonth(), today.getDate());
+          } else {
+            date = new Date(today.setHours(0, 0, 0, 0));
+          }
+        }
+        scope.dateSelection( date );
       };
 
       var $popup = $compile(popupEl)(scope);

src/datepicker/test/datepicker.spec.js

@@ -1042,14 +1042,41 @@ describe('datepicker directive', function () {
           expect(dropdownEl.find('li').length).toBe(2);
         });
 
-        it('should have four buttons', function() {
+        it('should have three buttons', function() {
           expect(buttons.length).toBe(3);
 
           expect(buttons.eq(0).text()).toBe('Today');
           expect(buttons.eq(1).text()).toBe('Clear');
           expect(buttons.eq(2).text()).toBe('Done');
         });
 
+        it('should have a button to set today date without altering time part', function() {
+          var today = new Date();
+          buttons.eq(0).click();
+          expect($rootScope.date.getFullYear()).toBe(today.getFullYear());
+          expect($rootScope.date.getMonth()).toBe(today.getMonth());
+          expect($rootScope.date.getDate()).toBe(today.getDate());
+
+          expect($rootScope.date.getHours()).toBe(15);
+          expect($rootScope.date.getMinutes()).toBe(30);
+          expect($rootScope.date.getSeconds()).toBe(0);
+        });
+
+        it('should have a button to set today date if blank', function() {
+          $rootScope.date = null;
+          $rootScope.$digest();
+
+          var today = new Date();
+          buttons.eq(0).click();
+          expect($rootScope.date.getFullYear()).toBe(today.getFullYear());
+          expect($rootScope.date.getMonth()).toBe(today.getMonth());
+          expect($rootScope.date.getDate()).toBe(today.getDate());
+
+          expect($rootScope.date.getHours()).toBe(0);
+          expect($rootScope.date.getMinutes()).toBe(0);
+          expect($rootScope.date.getSeconds()).toBe(0);
+        });
+
         it('should have a button to clear value', function() {
           buttons.eq(1).click();
           expect($rootScope.date).toBe(null);