[postgis-tickets] [PostGIS] #2638: geography ST_Intersects bugginess with Polygon/multilinestring M

[PostGIS]

#2638: geography ST_Intersects bugginess with Polygon/multilinestring M
---------------------+------------------------------------------------------
 Reporter:  robe     |       Owner:  pramsey      
     Type:  defect   |      Status:  new          
 Priority:  medium   |   Milestone:  PostGIS 2.0.5
Component:  postgis  |     Version:  2.1.x        
 Keywords:           |  
---------------------+------------------------------------------------------

Comment(by robe):

 Just tested by collapsing to 2D.


 {{{
 SELECT ST_Intersects(geog1, geog2) As g1_in_g2, ST_Intersects(geog2,geog1)
 As g2_in_g1
  , ST_Distance(geog1,geog2) As dist_g1_g2, ST_Distance(geog2,geog1) As
 dist_g2_g1
 FROM ST_GeogFromText('MULTILINESTRING((-71.0821 50.3036,50 -71),(-56.0821
 50.3036,50 -56),(-41.0821 50.3036,50 -41),(-26.0821 50.3036,50
 -26),(-11.0821 50.3036,50 -11),(3.9179 50.3036,50 4),(18.9179 50.3036,50
 19),(33.9179 50.3036,50 34),(48.9179 50.3036,50 49),(-71.0821 50.3036,50
 -71),(-56.0821 50.3036,50 -56),(-41.0821 50.3036,50 -41),(-26.0821
 50.3036,50 -26),(-11.0821 50.3036,50 -11),(3.9179 50.3036,50 4),(18.9179
 50.3036,50 19),(33.9179 50.3036,50 34),(48.9179 50.3036,50 49))') As
 geog1,
 ST_GeogFromText('MULTIPOLYGON(((0 0,10 0,10 10,0 10,0 0),(5 5,7 5,7 7,5
 7,5 5)))') As geog2;
 }}}


  The answers agree and intersect true always.


 {{{
  g1_in_g2 | g2_in_g1 | dist_g1_g2 | dist_g2_g1
 ----------+----------+------------+------------
  t        | t        |          0 |          0
 (1 row)
 }}}


 So somehow it seems the M is getting in the way when it really shouldn't
 be considered at all and is causing some sort of instability.

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/2638#comment:1>
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