I think it should be considered a separate bug. I agree that it would be good for the notification preferences page to, if the user sets an SMS number, ensure that the user also selects their carrier, but if they fail to do that, the current patch will still catch their mistake.
I think it should be considered a separate bug. I agree that it would be good for the notification preferences page to, if the user sets an SMS number, ensure that the user also selects their carrier, but if they fail to do that, the current patch will still catch their mistake.