[geos-devel] Is Overlay-NG active?

Regina Obe lr at pcorp.us
Thu Oct 15 14:48:31 PDT 2020

> > Roger,
> >
> > I'll let Paul answer the question of when we can expect a 3.9 as he
> > probably has a better idea than anyone else. All I know is the plan is
> > we'll be releasing GEOS 3.9 and PostGIS 3.1 around the same time since
> > there is some functionality in PostGIS 3.1 that leverages GEOS 3.9 if
> > it is compiled with GEOS 3.9.
> >
> > As far as testing, on the PostGIS side to make the old Geos and new
> > Geos agree, I've been applying ST_Normalize
> >
> > Which looks to come from Geos CAPI - GEOSNormalize
> >
> > Can you use that to deal with the failures you are running into?  That
> > should make the wkt of both GEOS old and new agree.
> Thank you, yes, probably. However, both legacy overlay and Overlay-NG
> differ from GEOSNormalize() (as far as I can see from a simple test), so
> half-dozen package maintainers will need to go from legacy to normalized
> and then avoid having to condition on the GEOS version.
> Best wishes,
> Roger

Yah both legacy and NG both defer from GEOSNormalize, but the GEOSNormalize
of both is equivalent so what we do is


WKT(GeosNormalize(outputfromfunc)) = WKT(GeosNormalize(oldexpectedresult))

Not ideal I know and maybe much harder to do in your setup than it was on
our tests as it does require changing your wkt expected output to the
normalized version.

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