[postgis-devel] Should EMPTY be spatially equal to self ?

[Paul Ramsey]

You might need to untease it further, as there is no such thing as an
empty box (in our code, notionally there is)... but right you could
just have the ~= operator implement the right semantic. OK.

Having it always be true is fine w/ me.
Note this, warning, warning.

'POINT EMPTY'::geometry::wkb::geometry = 'MULTIPOINT EMPTY'

Sowwy.

P.

On Wed, Jan 11, 2012 at 9:48 AM, Sandro Santilli <strk at keybit.net> wrote:
> I was doing this nice round-trip WKB test:
>
>  SELECT ST_Equals(g, g::wkb::geometry)
>
> ... when I got a few FALSE returns.
>
> WKB Reader or Writer bug ?
> NO, it is that EMPTY isn't equal to itself !
>
> So, what do you think ? Should it be equal ?
>
> The box of an EMPTY geometry is an EMPTY box.
> Is the EMPTY box equal to self ? I think it is.
>
> See also http://trac.osgeo.org/postgis/ticket/1453
>
> --strk;
>
>  ()   Free GIS & Flash consultant/developer
>  /\   http://strk.keybit.net/services.html
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