[postgis-tickets] [PostGIS] #4015: ST_Covers may have bug

[PostGIS]

#4015: ST_Covers may have bug
---------------------+---------------------------
 Reporter:  petermj  |      Owner:  pramsey
     Type:  defect   |     Status:  new
 Priority:  medium   |  Milestone:  PostGIS 2.4.4
Component:  postgis  |    Version:  2.4.x
 Keywords:           |
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 The following code produces (for me) unexpected results.

 I have a large and a small tile (square polygon), and I believe the large
 should cover the small, but as a geography is does not, and as a geometry
 it does?

 The tiles share a corner point, and the neighbouring corners share either
 longitude or latitude.

 {{{
 SELECT
 ST_Covers(large.tile, small.tile),
 ST_Covers(large.tile::geography, small.tile::geography)
 FROM
         (SELECT 'POLYGON((-3.34216155333235
 55.3991017765333,-3.34058316886567 55.3991017765333,-3.34058316886567
 55.4,-3.34216155333235 55.4,-3.34216155333235
 55.3991017765333))'::geometry as tile) as large,
         (SELECT 'POLYGON((-3.34216155333235
 55.3999101776593,-3.34200371488568 55.3999101776593,-3.34200371488568
 55.4,-3.34216155333235 55.4,-3.34216155333235
 55.3999101776593))'::geometry as tile) as small

 ;
 }}}

 I'm happy to be told my knowledge of GIS is incomplete and this is a
 standard newbie error, but it felt wrong to my mind....?

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Ticket URL: <https://trac.osgeo.org/postgis/ticket/4015>
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