Hi,

This one has got me stumped, and I'm not sure if it's a bug with the core or if it's deliberate.  Hopefully someone will be able to advise which as I think it's the former!  This is for 4.7.1 and I haven't checked if the code is the same in 4.7.2 as yet - so that's my next task - but wanted to get this down before I do just in case.

There's a user control within a standard umbraco page template within the site which adds a new document thru SendToPublish. A user has been created to handle the document creation for tracking purposes, which has an id of 5.  All good so far.

When you first start the site up, it works fine and the nofication emails go out.  This'll go on for x period of time.  Eventually though, it gives up and fails to email the notification, with umbracoLog stating that there is a null reference exception:

Error in notification: System.NullReferenceException: Object reference not set to an instance of an object.     at umbraco.cms.businesslogic.workflow.Notification.sendNotification(User performingUser, User mailingUser, Document documentObject, IAction Action) in C:\Documents and Settings\Administrator\My Documents\Downloads\umbraco-92d7d98ea3fe\umbraco_92d7d98ea3fe\umbraco\cms\businesslogic\workflow\Notification.cs:line 129     at umbraco.cms.businesslogic.workflow.Notification.GetNotifications(CMSNode Node, User user, IAction Action) in C:\Documents and Settings\Administrator\My Documents\Downloads\umbraco-92d7d98ea3fe\umbraco_92d7d98ea3fe\umbraco\cms\businesslogic\workflow\Notification.cs:line 62

Tracking the issue through the source, ultimately it's these 2 sections causing the problem.  The first is in umbraco.BusinessLogic.Actions.Action where it attempts to find the current user:

// Run notification
            // Find current user
            User u;
            try
            {
                u = User.GetCurrent();
            }
            catch
            {
                u = User.GetUser(0);
            }
            Notification.GetNotifications(d, u, action);

With the actual cause of the problem happening within umbraco.BusinessLogic.User:

public static User GetCurrent()
        {
            if (umbraco.BasePages.BasePage.umbracoUserContextID != "")
                return BusinessLogic.User.GetUser(umbraco.BasePages.BasePage.GetUserId(umbraco.BasePages.BasePage.umbracoUserContextID));
            else
                return null;

        }

The problem stems from User.GetCurrent() returning a null value because 'umbraco.BasePages.BasePage.umbracoUserContextID is empty, which I presume is fine as the work to add the new document is being done in the backend via a non-logged in user id for the back office.

Even so, with the umbracoUserContextID being empty, the code for Action.cs implies that a null reference is perfectly valid, yet there's a try/catch wrapped around it to just get the default user Admin (0):

try
{
   u = User.GetCurrent();
}
catch
{
   u = User.GetUser(0);
}

The problem is, the null does not cause an exception in this block, therefore the u variable is always coming back as null - causing the subsequent line call to Notification.GetNotifications to fail, as u is passed through that ultimately to the method sendNotification in Notification.cs as the variable 'performingUser', which in a later line is just assumed to be populated (see bold):

string[] bodyVars = {
   mailingUser.Name, ui.Text(Action.Alias), documentObject.Text, performingUser.Name,
   HttpContext.Current.Request.ServerVariables["SERVER_NAME"] + ":" + 
   HttpContext.Current.Request.Url.Port.ToString() +
   IOHelper.ResolveUrl(SystemDirectories.Umbraco),
   documentObject.Id.ToString(), summary.ToString(), <snip>

This then causes the error, preventing the notication being emailed out to any of the subscribers.

I'm reasonably confident it's a bug, as if you login as a user to the back office, then run the form in the front-end, it works and sends out the notifications, as the cookie for the umbraco context is populated thus the call to User.GetCurrent returns a value.  As the user control is being called from 'normal' users with no back-office access, I'd expect SendToPublish to work.

Hope someone can help clear this up - either I'm very wrong (most likely!) or it's something I've done wrong during the call to SendToPublish.

Thanks in advance!

Tony