Null value accepted from action property, but not model property when throwExceptionOnFailure=true

In this project, we experiment with setting struts.el.throwExceptionOnFailure=true to catch errors.

We use <s:property value="myprop" /> in our JSP.

Occasionally, the property thus referenced is null. We want struts to insert an empty string in that case.
This it duely does, when either struts.el.throwExceptionOnFailure=false or when the property is from an action object.

However, if the property is from a model object and struts.el.throwExceptionOnFailure=true, this bombs out.