There is a bug in the Image / File widget, that will manifest itself when we import or export documents through XML. Today it's a problem for Image portlets I/O, but it would be a problem if we did any other content I/O for documents.
The problem is that in an attached File object (also true for Images), we store two things: the filename in the id field, and a title in the title field.
But we really shouldn't change the id, Zope needs an invariant where the id known by an object is the same as the id that the container of the object knows. That's not the case here.
So we have to modify the Image and File widget, to lose one piece of information. We'll keep the title field, we have to decide what to put in it:
- original filename
- user title
