[postgis-devel] Invalid output from ST_BuildArea()

[Kevin Neufeld]

Well now that is interesting.  That's what they say, eh?  Never assume. 
  I think the check is a good one to make.  I concur, loosen the checks 
to 2D for now (at least until the geos issue gets resolved).

What about raising a notice, warning the user that they may want to snap 
the endpoints of the ring before moving on?

Cheers,
Kevin

Mark Cave-Ayland wrote:
  > Ah. It's a polygon with a ring where the first point != last point. So
> in other words, it seems that the ST_BuildArea()/BuildArea() functions 
> are capable of producing invalid geometries :(
> 
> Given that it appears to be the Z coordinate which is incorrect, I'm 
> wondering if this is related to the "what does GEOS with the Z 
> coordinate?" discussion currently happening on the GEOS list. Maybe the 
> conversion checks from LWGEOM to WKT/WKB need to be loosened so that 
> they only make use of 2 dimensions?
> 
> 
> Thoughts?
> 
> Mark.
>