Existing Contact Address Data Values are Being Cleared Erroneously When Matching New User Reg Form is Submitted

When a new user registration is submitted and it matches an existing CiviCRM contact record - existing address block values (street, supplemental, city etc.) should only be updated if one or more non-blank address field values are submitted from the new registration profile form.

Currently, if you have a profile w/ street, city, state, zip - and you leave all fields blank on the new registration profile form - it will still clear field values in the linked contact record.

NOTE: The entire address block is a logical object - so if ANY new values are populated in the registration form, than the entire block SHOULD BE updated.

These behaviors should be tested in the context of the new 1.3 functionality which supports multiple location blocks in a profile form!