Using browseable API to update Interface object with empty attributes raises 400

[jathanism]

The attributes field should default to an empty object ({}) but it's blank. So if the attributes for an Interface object are unset, upon clicking "PUT" to update the instance, a 400 is raised from the browseable API:

PUT /api/sites/1/interfaces/foo14-ab01:s45/

HTTP 400 Bad Request
Allow: GET, PUT, PATCH, DELETE, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "error": {
        "message": {
            "attributes": "Expected dictionary but received <type 'NoneType'>"
        },
        "code": 400
    }
}

Strangely despite the error, any update still succeeds (such as if you're updating the description field). Also, if one puts {} into the attributes field and submits with the "PUT" button, the operation succeeds without any error.

There's something fishy going on here and appears to be two issues:

• The default value for the attributes field should be {} if the field is empty.
• The validation of the attributes field appears to block only update to that field and not update to the entire object.