Comment 1 for bug 1803780

This was highlighted as a problem (identified) in an unrelated bug. The error was a red-herring there and probably simply an issue with our validation logic.

I'll poke at the code a little more closely here once I get back home. The core issue is in this for loop[0], and it looks like it's possibly mis-detecting the "next role ref" equivalency in the checked_role_ref list.

[0] https://github.com/openstack/keystone/blob/4b41fa4c8b17b2da510100e9c6cad98d1cd19b0c/keystone/assignment/core.py#L666-L673