[postgis-users] ST_Union on empty polygon loses SRID

[Jonathan Schultz]

Hello,

I have found with a query that makes a union of geometries which 
includes an empty polygon produces a result without an SRID. For a 
trivial example:

 > => select ST_SRID(ST_Union(ST_GeomFromText('POLYGON EMPTY', 4283)));
 >  st_srid ---------
 >        0

This seems like a bug to me but maybe there is a good explanation?

Thanks,
Jonathan