This is an internal error. (a null collection is not being returned)
I have seen this before, and it was caused by a bug in XDoclet where it would create an empty key-fields element in both roles. In the cvs I changed the deployment code to throw an exception if both key-fields elements of a foreign-key mapped relationship are empty, or if either side of a relation-table mapped relationship is empty.
The problem in xdoclet is that it can't distinguish between
"there are no key fields on this side of the relationship" and "I want Dain's code to generate everything automagically". I added a @jboss:auto-key-fields tag you can add to your cmr accessor markup so you can explicitly select the latter. This is in xdoclet cvs and should be in 1.1.2 coming out perhaps tomorrow.
Wow, a response right from the source. Thanks Dain! I bought your workbook. Very helpfull so far.
As far as this issue is concerned, merely downloading the latest CVS jboss-all should fix the problem right?
I don't know what "xdoclet" is, guess that makes me a newbie.