Comment 1 for bug 504102

I suspect some global state in the format registry is being tweaked by an earlier test.

This is comparing:

a= the bzrdir format for this instance of the parameterized test
b= the actual format observed when opening this transport

so what we see here would be consistent with

1- opening the format not setting the network name
2- the network name being put into the format as a bzrdir instance is initialized; or the network name being set in the parameterization of this test