If both country and state province have defaults set, profiles with address fields left blank will overwrite existing address info with blanks. New contacts created without address info will get an address record with just country and state

When both country and state province have a default defined in Admin => Localization => Languages, currency, location anything that creates or updates address where the address is left blank will result in an address record with only the country and state/province.  If it is an update via profiles, and I suspect import, the existing address info, street, city, zip will be wiped out.

The behavior is correct if only the country is defaulted.  The correct behavior should be to ignore any address update or creation where the only info is country and/or state/province.

To reproduce:

New Contact

1. Set defaults for both country and state/province
2. Create a new contact with just a name.  The new contact will end up with an address record with only the country and state.  You will see that on the contact form.

Profile

1. Set defaults for both country and state/province
2. Create a profile that includes address
3. Use that profile in a donation, event registration or other registrations.
4. Register or make a donation of an existing contact who has a full address but leave the address info blank when registering.  Insure the matching rule will match
5. The existing contact will end up having the address info that was there replaced with blanks.