GeoQuerySet.perimeter returns invalid results on geometry fields with geodetic coordinate systems

[jbronn]

The method GeoQuerySet.perimeter returns Distance objects with erroneous values when called on a geometry field that has a geodetic coordinate system (e.g., srid=4326). The values in the returned distance objects are really perimeter measurements in degrees of latitude/longitude, rather than meters.

Here's an example using the models and data from the ​GeoDjango tutorial:

>>> from world.models import WorldBorders
>>> us = WorldBorders.objects.perimeter().get(name='United States')
>>> print us.perimeter
771.493229562 m

Obviously, the perimeter of the United States is greater than a kilometer. To fix, the helper method GeoQuerySet._distance_attribute needs to be modified to raise an exception or return a raw numeric value when attempting to calculate perimeters on geodetic coordinate systems.

[Aymeric Augustin]

Change UI/UX from NULL to False.

[Aymeric Augustin]

Change Easy pickings from NULL to False.

[Tim Graham]

A resolution for the test failure on Oracle is needed.

[Tim Graham <timograham@…>]

In 00cb9e13:

Fixed #15165 -- Prevented wrong results with perimeter on geodetic fields.