[postgis-tickets] [PostGIS] #3835: ST_StraightSkeleton returns degenerate line segments

[PostGIS]

#3835: ST_StraightSkeleton returns degenerate line segments
---------------------+---------------------------
 Reporter:  wrog     |      Owner:  pramsey
     Type:  defect   |     Status:  new
 Priority:  medium   |  Milestone:  PostGIS 2.3.4
Component:  postgis  |    Version:  2.3.x
 Keywords:           |
---------------------+---------------------------
 This query
 {{{
 WITH bt(box) AS (
   SELECT st_makebox2d(st_point(1296000,202400),st_point(1297000,212400))
 )
 SELECT d.path[1], astext(d.geom)
 FROM bt, st_dump(
   st_straightskeleton(st_difference(st_buffer(box,2000,2),box))
 ) as d
 WHERE st_startpoint(d.geom) = st_endpoint(d.geom);
 }}}
 returns four zero-length line segments
 (out of 32; the other 28 all appear to make up a plausible straight
 skeleton for this shape).

 Versions of everything:
 POSTGIS="2.3.3 r15473"
 GEOS="3.5.1-CAPI-1.9.1 r4246"
 SFCGAL="1.3.0" PROJ="Rel. 4.9.3, 15 August 2016"
 GDAL="GDAL 2.1.2, released 2016/10/24"
 LIBXML="2.9.4"
 LIBJSON="0.12.1" (core procs from "2.3.2 r15302" need upgrade)
 TOPOLOGY
 RASTER (raster procs from "2.3.2 r15302" need upgrade)

 PostgreSQL 9.6.4 on x86_64-pc-linux-gnu,
 compiled by gcc (Debian 6.3.0-18) 6.3.0 20170516, 64-bit

 [I'm guessing this doesn't depend on LIBJSON or RASTER]

--
Ticket URL: <https://trac.osgeo.org/postgis/ticket/3835>
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