Scope includes field values with value None

[mikhaz]

I have scoping on a location field for a user subset. They can only see data that belongs to locations that they are assigned to. However there are some cases where data is created without being assigned a location (while it is still a location specific model). I would like the location filtering to be able include the rows where location=None. There does not seem to be any way to do this but I may have missed something.

My only other option is to create a default location that I assign everyone to but I would like avoid this if possible.