ST_AsGeoJSONRow: Invalid output for null geometry

[jtojnar]

According to the GeoJSON RFC, ​the `type` member of Geometry must be one of seven geometry type names. This is not the case when a row containing a NULL geometry column is converted to GeoJSON Feature:

postgres=# select ST_AsGeoJSON(r.*) from (values (null::geometry)) as r(geom);
                           st_asgeojson                            
-------------------------------------------------------------------
 {"type": "Feature", "geometry": {"type": null}, "properties": {}}
(1 row)

The proper representation is "geometry": null, see ​section 3.2.

This can be ​trivially fixed but I am not sure whether it would be an acceptable BC break.

[robe]

Probably safer to just put in 3.5.0 where we allow breaking changes, just in case someone is actually relying on this non-standard behavior.

[robe]

jtojnar if you want to provide a patch for this, I think it's fine to go into 3.5.0. 3.4 or lower we'd have to seriously think about it. I doubt anyone is relying on the old representation of null geometries in older versions but who knows.

[Paul Ramsey <pramsey@…>]

In 2962a36/git:

ST_AsGeoJSON, produce correct output in null geometry case, closes #5597