Microsite domain paths are doubled with Domain Source

There's an additional unrelated problem, that I have to fix to do anything about this issue. In DomainMicrositePathProcessor::processOutbound(), there is a line:

$domain_source = array_shift(array_column($entity->get('field_domain_source')->getValue(), 'target_id'));

The argument for array_shift() is passed by reference, so it has to be a variable. The array_column() call has to be stored and then passed to array_shift().

$target_ids = array_column($entity->get('field_domain_source')->getValue(), 'target_id');
$domain_source = array_shift($target_ids);

Domain Source isn't dependent on Domain Access (at least it isn't anymore). I separated the changes made for the fields of each module so that it will work for either or both.

Fixed in 2.0.0-beta6.