The OGC Simple Feature spec says that the rings making up the boundaries of a polygon must be closed and simple, and its definition of "simple" includes that the ring may not pass through the same point more than once (except at the ends). However, Mapnik happily renders such polygons, for example (at the time of writing this) https://www.openstreetmap.org/way/447865387, [way 447865387][1], which uses node https://www.openstreetmap.org/node/4449293245 4449293245 twice. Should I fix my import pipeline to convert this into a multipolygon (or simply two polygons) before loading it into PostGIS, or should I fix the data to remove the self-intersection?self-intersection? [1]: https://www.openstreetmap.org/way/447865387

The OGC Simple Feature spec says that the rings making up the boundaries of a polygon must be closed and simple, and its definition of "simple" includes that the ring may not pass through the same point more than once (except at the ends). However, Mapnik happily renders such polygons, for example (at the time of writing this) https://www.openstreetmap.org/way/447865387, which uses node https://www.openstreetmap.org/node/4449293245 twice. Should I fix my import pipeline to convert this into a multipolygon (or simply two polygons) before loading it into PostGIS, or should I fix the data to remove the self-intersection?