Description of problem:
When calling Category.deleteCategoryAndRemap() for a category to which related
categories have been added with addRelatedCategory(), deletion of the "related
categories" association fails with a "IllegalArgumentException: No such object"
exception.


Version-Release number of selected component (if applicable):
6.0

How reproducible:
Always

Steps to Reproduce:
Replace the two category IDs in the attached JSP with actual values from your
cat_categories table and try to run the JSP.


Actual Results:  
java.lang.IllegalArgumentException: No such object:
[com.arsdigita.categorization.com_arsdigita_categorization_Category:parents::com_arsdigita_categorization_Category:related::Link:{parents=[com.arsdigita.categorization.Category:{id=147}],
related=[com.arsdigita.categorization.Category:{id=165}]}]
	at com.redhat.persistence.Session.fetchPropertyData(Session.java:787)
	at com.redhat.persistence.Session$1.onRole(Session.java:115)
	at com.redhat.persistence.metadata.Role.dispatch(Role.java:92)
	at com.redhat.persistence.Session.get(Session.java:113)
	at com.arsdigita.persistence.DataObjectImpl.get(DataObjectImpl.java:489)
	at com.arsdigita.persistence.DataObjectImpl.get(DataObjectImpl.java:200)
	at com.arsdigita.categorization.Category.deleteCategoryAndRemap(Category.java:923)


Additional info:

The cause for this error is the following while loop, which first deletes the
association and then tries to retrieve attributes from the link object it has
just deleted:

        while (cursor.next()) {
            DataObject link = cursor.getLink();
            remove(RELATED_CATEGORIES, cursor.getDataObject());
            if ("child".equals(link.get("relationType"))) {
                Category category = new Category(cursor.getDataObject());
                parent.addChild(category);
                if (Boolean.TRUE.equals(link.get("isDefault"))) {
                    category.setDefaultParentCategory(parent);
                }
            }
        }

One way to fix this:

        while (cursor.next()) {
            DataObject link = cursor.getLink();
	    String relationType = (String)link.get("relationType");
	    Boolean isDefault = (Boolean)link.get("isDefault");
            remove(RELATED_CATEGORIES, cursor.getDataObject());
            if ("child".equals(relationType)) {
                Category category = new Category(cursor.getDataObject());
                parent.addChild(category);
                if (Boolean.TRUE.equals(isDefault)) {
                    category.setDefaultParentCategory(parent);
                }
            }
        }