Fixes: U4-2989 Username & password must be changed if login credentials are invalid in order to submit again.

src/Umbraco.Web.UI.Client/src/views/common/dialogs/login.controller.js

@@ -16,6 +16,16 @@
     $scope.errorMsg = "";
     
     $scope.loginSubmit = function (login, password) {        
+        //if the login and password are not empty we need to automatically 
+        // validate them - this is because if there are validation errors on the server
+        // then the user has to change both username & password to resubmit which isn't ideal,
+        // so if they're not empty , we'l just make sure to set them to valid.
+        if (login && password && login.length > 0 && password.length > 0) {
+            $scope.loginForm.username.$setValidity('auth', true);
+            $scope.loginForm.password.$setValidity('auth', true);
+        }
+        
+        
         if ($scope.loginForm.$invalid) {
             return;
         }