[postgis-tickets] [PostGIS] #1926: ST_OffsetCurve creates a strange multi-linestring

[PostGIS]

#1926: ST_OffsetCurve creates a strange multi-linestring
---------------------+------------------------------------------------------
 Reporter:  lexman   |       Owner:  pramsey     
     Type:  defect   |      Status:  new         
 Priority:  medium   |   Milestone:  PostGIS GEOS
Component:  postgis  |     Version:  2.1.x       
 Keywords:           |  
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Changes (by jef):

  * version:  2.0.x => 2.1.x


Comment:

 A more recent and example using simpler geometry - a segment of the offset
 line is missing and turns it into a multiline string:

 {{{
 qgis=> select st_astext( st_offsetcurve( st_geomfromtext(
 'LINESTRING(436533.041 5755061.11,436420.979 5755061.071,436372.505
 5755061.054,436346.382 5755061.045)' ), -0.17 ) );
 st_astext
 -------------------------------------------------------------------------------------------------------------------------------------------------------------
 MULTILINESTRING((436420.97894038 5755061.24099999,436533.040940836
 5755061.27999999),(436346.381941431 5755061.21499999,436372.504941431
 5755061.22399999))
 (1 row)

 qgis=> select postgis_full_version();
 NOTICE: Function postgis_topology_scripts_installed() not found. Is
 topology support enabled and topology.sql installed?
 postgis_full_version
 --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 POSTGIS="2.1.3 r12547" GEOS="3.4.2-CAPI-1.8.2 r3921" PROJ="Rel. 4.8.0, 6
 March 2012" GDAL="GDAL 1.10.1, released 2013/08/26" LIBXML="2.9.1"
 LIBJSON="UNKNOWN" (core procs from "2.1.2 r12389" need upgrade) RASTER
 (raster procs from "2.1.2 r12389" need upgrade)
 (1 row)
 }}}

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/1926#comment:3>
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