ST_XMax() and ST_YMax() return incorrect values

[mloskot]

For flipped-over 2D box with lower-left corner coordinates higher than coordinates of upper-right corner:

sistest=# SELECT ST_MakeBox2D(ST_Point(5, 5), ST_Point(0, 0));
  st_makebox2d
--------------
  BOX(5 5,0 0)

Min/Max functions report incorrect values:

sistest=# SELECT ST_XMin(ST_MakeBox2D(ST_Point(5, 5), ST_Point(0, 0)));
  st_xmin
---------
        5

sistest=# SELECT ST_XMax(ST_MakeBox2D(ST_Point(5, 5), ST_Point(0, 0)));
  st_xmax
---------
        0

Originally, I posted this issue to the mailing list asking if names of ST_MakeBox2D parameters are correct and eventually Mark confirmed that is a bug in Min/Max functions. It is in thread ​Name of ST_MakeBox2D parameters.

[mcayland]

Thanks Mateusz. This is now resolved in SVN trunk:

postgis=# SELECT ST_XMin(ST_MakeBox2D(ST_Point(5, 5), ST_Point(0, 0)));

st_xmin

---

0

(1 row)

postgis=# SELECT ST_XMax(ST_MakeBox2D(ST_Point(5, 5), ST_Point(0, 0)));

st_xmax

---

5

(1 row)

Due to the change in behaviour having the potential to effect existing applications, I don't intend to backport this to the 1.3 branch.

ATB,

Mark.