Handle loginModel.RedirectUrl in Login partial (#5587)

src/Umbraco.Web.UI/Umbraco/PartialViewMacros/Templates/Login.cshtml

@@ -1,4 +1,4 @@
-@using System.Web.Mvc.Html
+@using System.Web.Mvc.Html
 @using ClientDependency.Core.Mvc
 @using Umbraco.Web
 @using Umbraco.Web.Models
@@ -7,6 +7,7 @@
 
 @{
     var loginModel = new LoginModel();
+    loginModel.RedirectUrl = HttpContext.Current.Request.Url.AbsolutePath;
 
     Html.EnableClientValidation();
     Html.EnableUnobtrusiveJavaScript();
@@ -20,6 +21,7 @@
 
 @using (Html.BeginUmbracoForm<UmbLoginController>("HandleLogin"))
 {
+    @Html.HiddenFor(m => loginModel.RedirectUrl)
     <fieldset>
         <legend>Login</legend>