[postgis-devel] [PostGIS] #922: Have ST_Union aggregate use UnaryUnion from GEOS-3.0.0

[PostGIS]

#922: Have ST_Union aggregate use UnaryUnion from GEOS-3.0.0
-------------------------+--------------------------------------------------
 Reporter:  strk         |       Owner:  pramsey      
     Type:  enhancement  |      Status:  new          
 Priority:  medium       |   Milestone:  PostGIS 2.0.0
Component:  postgis      |     Version:  trunk        
 Keywords:               |  
-------------------------+--------------------------------------------------

Comment(by pramsey):

 I've got this implemented, but it has a single regression "failure" in
 topology.
 {{{

 --- regress/legacy_query_expected       2012-01-25 09:31:33.000000000
 -0800
 +++ /var/folders/vQ/vQpcmrOZEXuINbyg+7Jj4k+++TI/-Tmp-//test_5_out
 2012-02-06 14:54:43.000000000 -0800
 @@ -41,7 +41,7 @@
  E25|7|MULTILINESTRING((9 35,13 35))
  R1a|8|MULTILINESTRING((9 14,21 14,35 14))
  S1S2|MULTIPOINT(21 14,35 14)
 -R1R2|MULTILINESTRING((36 38,38 35,41 34,42 33,45 32,47 28,50 28,52 32,57
 33,57 36,59 39,61 38,62 41,47 42,45 40,41 40),(9 14,21 14,35 14))
 +R1R2|MULTILINESTRING((9 14,21 14,35 14),(36 38,38 35,41 34,42 33,45 32,47
 28,50 28,52 32,57 33,57 36,59 39,61 38,62 41,47 42,45 40,41 40))
  R4|MULTILINESTRING((25 30,25 35))
  P1P2|MULTIPOLYGON(((21 6,9 6,9 14,9 22,21 22,35 22,35 14,35 6,21 6)))
  P3P4|MULTIPOLYGON(((47 14,47 6,35 6,35 14,35 22,47 22,47 14)),((25 30,17
 30,17 40,31 40,31 30,25 30)))
 }}}
 As you can see this isn't really a regression failure. Unfortunately, the
 topology regression suite is so tightly coupled together it's quite hard
 for me to exempt this case while also allowing this functionality to be
 conditional on GEOS 3.3. Basically if GEOS 3.3 is present the test will
 fail, if not it will pass. Or the reverse if I change the expected.

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/922#comment:1>
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