[postgis-users] ST_Envelope

[Sam Giffney]

On Postgis 1.3.2 (tested on Windows and Debian Lenny)

A LINESTRING which runs "parallel to the grid lines" (excuse my poor
GIS terminology) returns a LINESTRING instead of a POLYGON for the
envelope.

postgis=> select
ST_AsText(ST_Envelope(ST_GeomFromText('LINESTRING(-36.91410
174.90900,-36.91410 174.91017)')));
                    st_astext
-------------------------------------------------
 LINESTRING(-36.9141 174.909,-36.9141 174.91017)
(1 row)

The documentation states that ST_Envelope should return a POLYGON.
I think I understand why the LINESTRING is returned, but shouldn't the
documentation list that as an option?

Cheers,
Sam