I have the following maven2 project hierarchy:

B <------ C

So there is no circular dependency. This works nicely unless, C is a module of
A, i.e.:
a/pom.xml
a/c/pom.xml
b/pom.xml

and A lists C as module.

In Hudson, project A has B listed as both upstream and downstrean dependency,
which results in an infinite build loop. However, I think this is a legal setup
in Maven2, as there is no circular dependency. I haven't investigated this
thoroughly, but it might be that modules are considered downstream projects even
they aren't.

I'll attach a test project demonstrating the bug. Just adding A and B to Hudson
should cause the loop. If not, committing something should do it.