[postgis-tickets] [PostGIS] #2825: ST_Intersection broken with Z coordinates

[PostGIS]

#2825: ST_Intersection broken with Z coordinates
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 Reporter:  TBL      |       Owner:  pramsey      
     Type:  defect   |      Status:  new          
 Priority:  medium   |   Milestone:  PostGIS 2.1.4
Component:  postgis  |     Version:  2.1.x        
 Keywords:           |  
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Comment(by TBL):

 I just posted that on freenode:
 {{{
 with linestring as (select ST_GeomFromText('LINESTRING Z (-1 -1 0, -0.5
 -0.5 1, 0 0 2, 0.5 0.5 3, 1 1 4, 1.5 1.5 5, 2 2 6)', 4326) as geom),
      polygon as (select ST_GeomFromText('POLYGON((0 0, 0 1, 1 1, 1 0, 0
 0))', 4326) as geom)
 select st_astext(st_intersection(linestring.geom, polygon.geom)) from
 linestring, polygon
 }}}
 Result is as expected: "LINESTRING Z (0 0 2,0.5 0.5 3,1 1 4)"

 But with a slightly longer linestring:
 {{{
 with linestring as (select ST_GeomFromText('LINESTRING Z (-20.00 -20.00 0,
 -19.95 -19.95 1, [...], 19.990 19.990 7998, 19.995 19.995 7999)', 4326) as
 geom),
      polygon as (select ST_GeomFromText('POLYGON((0 0, 0 1, 1 1, 1 0, 0
 0))', 4326) as geom)
 select st_astext(st_intersection(linestring.geom, polygon.geom)) from
 linestring, polygon
 }}}
 "MULTILINESTRING Z ((0 0 400,0.005 0.005 2200.55),(0.005 0.005
 2200.55,0.01 0.01 2201.1),(0.01 0.01 2201.1,0.015 0.015 2201.65),(0.015
 0.015 2201.65,0.02 0.02 2202.2),(0.02 0.02 2202.2,0.025 0.025
 2202.75),(0.025 0.025 2202.75,0.03 0.03 2203.3),(0.03 0.03 2 (...)"

 The z coordinates of the result are somehow mixed up, while the x/y
 coordinates seem to be right (the z at 0 0 should be 4000, at 0.005 0.005
 it should be 4001 ...). The returned values don't make any sense in my
 eyes.

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/2825#comment:2>
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