[PostGIS] #5738: ST_OffsetCurve returns wrong geometry

[PostGIS]

#5738: ST_OffsetCurve returns wrong geometry
----------------------------+---------------------
 Reporter:  rkolka          |      Owner:  pramsey
     Type:  defect          |     Status:  new
 Priority:  medium          |  Milestone:
Component:  postgis         |    Version:  3.4.x
 Keywords:  st_offsetcurve  |
----------------------------+---------------------
 ST_OffsetCurve sometimes returns wrong geometry.
 Seems to happen when source geometry has 2 vertices very close.

 {{{

 CREATE TABLE public.offsetcurve_bug
 (
     id serial primary key,
         description text,
     geometry geometry(LineString)
 )
 ;
 CREATE INDEX offsetcurve_bug_geometry_x ON public.offsetcurve_bug USING
 gist (geometry);

 INSERT INTO public.offsetcurve_bug(
         description, geometry)
         VALUES
         ('original', 'LINESTRING(544237.894288877
 6588306.70972559,544226.9710250939 6588308.03375757,544220.8010926669
 6588309.418844438)'::geometry(LineString))
         ,
         ('original', 'LINESTRING(544172.354706179
 6588303.23414166,544174.671762133 6588304.55817364,544178.8093620511
 6588306.2132136)'::geometry(LineString))
 ;

 INSERT INTO public.offsetcurve_bug
         (description, geometry)
 SELECT
         'substring' as description,
         ST_LineSubstring(geometry, 0.35, 0.65) as geometry
 FROM
         public.offsetcurve_bug
 WHERE
         description = 'original'
 ;


 INSERT INTO public.offsetcurve_bug
         (description, geometry)
 SELECT
         'offset 6m' as description,
         ST_OffsetCurve(geometry, -6, 'quad_segs=4 join=mitre
 mitre_limit=1.1') as geometry
 FROM
         public.offsetcurve_bug
 WHERE
         description = 'substring'
 ;
 }}}

 POSTGIS=3.4.2
 GEOS=3.11.1-CAPI-1.17.1
-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/5738>
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