Hi Nagy:

You said:

> However, if I I call 
> context.documents.sorted('classprop') 
> where 'classprop' is a Class() with integer order property,
> then I still get 
>
> <class 'TypeError'>: '<' not supported between instances of 'NoneType' 
and 'str'.

by classprop do you mean classprop is a multilink to a Class?

From customizing.txt:

  Select a property of the class to be the order property. The order
  property is used whenever using a default sort order for the class,
  e.g., when grouping or sorting class A by a link to class B in the
  user interface, the order property of class B is used for sorting.

That is the only sorting that I see as mentioned in customizing.txt
that seems to sort of match what you stated.

I am having issues developing a test case for this code. I'll spend
another few hours of getting a test case put together. If I can't get 
something running, I'll commit the code.

Regarding issue2551122 (sorted method of MultilinkHTMLProperty does a 
string sort even if the property is an integer) still failing, I am not
sure. If my description of the 'classprop' case is correct, I'll update
and continue the discussion on that issue and close this issue.

I may need a more detailed test case for that issue as I expected
this patch would have (by accident) handled both cases.