[postgis-users] Self-intersecting polygon gives ST_IsSimple=true

[Jukka Rahkonen]

Jukka Rahkonen kirjoitti 2017-05-08 17:33:
> Jukka Rahkonen kirjoitti 2017-05-08 15:48:

> I can still find the same comments about polygon validity in
> https://github.com/locationtech/jts/blob/master/modules/core/src/main/java/org/locationtech/jts/operation/IsSimpleOp.java
> beginning from line 205
> 
>  /**
>    * Computes simplicity for polygonal geometries.
>    * Polygonal geometries are simple if and only if
>    * all of their component rings are simple.
>    *
>    * @param geom a Polygonal geometry
>    * @return true if the geometry is simple
>    */
> 


I was remembering that JTS list is a bit slow with answers so I compiled 
JTS from master https://github.com/locationtech/jts.
IsSimple with POLYGON ((320 620, 460 620, 460 500, 320 620, 320 500, 180 
500, 180 620, 320 620)) gives false so JTS and GEOS have different 
behavior.

I am new with PostGIS project, do the developers consider this as a bug 
and do you want me to file an issue? If yes, would it be a GEOS bug  
https://trac.osgeo.org/geos/newticket?

-Jukka Rahkonen-