Comment 5 for bug 808952

I think we want to rethink this issue. The context here is reading bug messages. All we ever promised was bug messages. bug messages are not threaded, though the underlying model does permit them to be, and the restful rules see that. The parent has always been exported on IMessage, so we cannot remove it. I think we want to ensure that parent is ignored.

We do not want to make links outside of the bug's context because this serialisation mechanism is making links that might contain a private object. Messages are subordinate to their artefact; users may get 403s if Lp wants to make a a link to something's message that the user is not permitted to access.