[postgis-devel] [PostGIS] #1252: SRID appearing in ST_AsText for particular multipolygon

PostGIS trac at osgeo.org
Fri Oct 28 01:13:17 PDT 2011

#1252: SRID appearing in ST_AsText for particular multipolygon
 Reporter:  robe     |       Owner:  pramsey      
     Type:  defect   |      Status:  new          
 Priority:  medium   |   Milestone:  PostGIS 1.5.4
Component:  postgis  |     Version:  1.5.X        
 Keywords:           |  

Comment(by robe):

 Yes indeed: ST_AsEWKT of
 SELECT ST_AsEWKT(ST_Union(geom))
 FROM (SELECT (ST_Dump(geom)).geom
 FROM weird_mpoly) As foo ;

 SRID=4326;MULTIPOLYGON(SRID=4326;((-116.9937666 33.4711291,-116.9936485
 33.4698868,-116.992874 33.4689698,-116.9911977 33.4686095,-116.9889499
 33.4689424,-116.9865345 33.4688388,-116.9849953 33.4684547,-116.9832575

 SELECT ST_AsEWKT(geom) from weird_mpoly;
 {{{ SRID=4326;MULTIPOLYGON(((-116.9937666 33.4711291,-116.9936485
 33.4698868,-116.992874 33.4689698,-116.9911977 33.4686095...


 I'm not sure why it does it with just this geometry though.  dump/union is
 something I do all the time and with even more complex sets and this has
 never happened to my knowledge. I spot checked some of my others and they
 look fine.

 I fear this is something we introduced in 1.5.3, because like I said, I
 don't seem to be able to replicate it on my 1.5.2 install but can on a
 clean 1.5.3 install.  Granted my 1.5.2 has gone thru many upgrades.

 I'm not sure GEOS is the culprit or even Union since I am running GEOS
 3.3.1 (wlel maybe GEOS 3.3.0 on my 1.5.2). I have to check.

 I'm beginning to get suspicious of ST_Dump.  I'll check if we made changes
 to that in 1.5.3

 strk -- are you able to replicate it on your end with a 1.5.3 the
 weird_mpoly.sql I attached.  It oculd be a windows only issue.

 I don't see the behavior in 2.0, but it could be camouflaged by the the
 changes we've made so may be lurking in a different form.

Ticket URL: <http://trac.osgeo.org/postgis/ticket/1252#comment:7>
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