Membership Price Set "Default" field setting ignored when user is logged in

When a renewing member with a current membership is logged in, the default field is not displayed correctly on membership select price sets.

Reproduced on demo site 11/30/2015:
http://d46.demo.civicrm.org/civicrm/contribute/transact?reset=1&id=2

1. Create a price set for memberships with two or more options: http://d46.demo.civicrm.org/civicrm/admin/price/field?reset=1&action=browse&sid=4
2. Choose the last option as the default (or just not the first option)
3. View the contribution page not logged in, the default is displayed correctly.
4. View the contribution page logged in as demo / demo, the default is not displayed rather the first option in the price set.

On our live site I have noticed that the default working or not has something to do with whether or not the user logged in has a current membership, but since I don't have access to that function on the demo site I can't really test it. All users (logged in, members or not) should see the default option selected i.e. it should be the 'default' for that price set regardless of user status.

This seems to be a regression of this bug: https://issues.civicrm.org/jira/browse/CRM-11491