[postgis-tickets] [PostGIS] #3823: ST_MinimumBoundingCircle creates invalid geometries

[PostGIS]

#3823: ST_MinimumBoundingCircle creates invalid geometries
--------------------------------------+---------------------------
 Reporter:  cswingle                  |      Owner:  pramsey
     Type:  defect                    |     Status:  new
 Priority:  medium                    |  Milestone:  PostGIS 2.3.4
Component:  postgis                   |    Version:  2.3.x
 Keywords:  ST_MinimumBoundingCircle  |
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 Certain combinations of PostGIS 2.3.3 and dependent libraries cause
 ST_MinimumBoundingCircle to create invalid geometries.

 For example on an Ubuntu Xenial, AMD64 system (with ubuntugis-unstable):

 {{{
 POSTGIS="2.3.3 r15473"
 GEOS="3.5.1-CAPI-1.9.1 r4246"
 PROJ="Rel. 4.9.2, 08 September 2015"
 GDAL="GDAL 1.11.3, released 2015/09/16"
 LIBXML="2.9.3"
 LIBJSON="0.11.99" RASTER

 SELECT ST_IsValid(ST_MinimumBoundingCircle(ST_GeomFromText(
     'MULTIPOINT(-150.646548 69.6052122,
                 -150.641227 69.578776,
                 -150.641227 69.578776,
                 -150.659938 69.575257)')));
 NOTICE:  IllegalArgumentException: Points of LinearRing do not form a
 closed linestring
  st_isvalid
  ------------
   f
 }}}

 The same SQL is successful on several other identical versions of PostGIS,
 but with different libraries.  These are two example systems where it
 works (Debian stretch and Debian jessie, AMD64):

 {{{
 POSTGIS="2.3.3 r15473"
 GEOS="3.5.1-CAPI-1.9.1 r4246"
 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" RASTER

 POSTGIS="2.3.3 r15473"
 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="0.11.99" RASTER
 }}}

 Since it's the same version of PostGIS each time, it seems likely that
 it's another library causing the issue but I don't know enough about these
 interactions to identify a culprit or a solution for my Xenial system.

--
Ticket URL: <https://trac.osgeo.org/postgis/ticket/3823>
PostGIS <http://trac.osgeo.org/postgis/>
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