ST_ConcaveHull 2.1 regres failure compared to 2.0.3

[robe]

This worked in 2.0.3

SELECT ST_ConcaveHull('SRID=4326;MULTIPOINTM(-71.0821 42.3036 1,-71.0821 67.3036 1,-56.0821 42.3036 1,-56.0821 67.3036 1,-41.0821 42.3036 1,-41.0821 67.3036 1,-26.0821 42.3036 1,-26.0821 67.3036 1,-11.0821 42.3036 1,-11.0821 67.3036 1,3.9179 42.3036 1,3.9179 67.3036 1,18.9179 42.3036 1,18.9179 67.3036 1,33.9179 42.3036 1,33.9179 67.3036 1,48.9179 42.3036 1,48.9179 67.3036 1,-71.0821 42.3036 2,-71.0821 67.3036 2,-56.0821 42.3036 2,-56.0821 67.3036 2,-41.0821 42.3036 2,-41.0821 67.3036 2,-26.0821 42.3036 2,-26.0821 67.3036 2,-11.0821 42.3036 2,-11.0821 67.3036 2,3.9179 42.3036 2,3.9179 67.3036 2,18.9179 42.3036 2,18.9179 67.3036 2,33.9179 42.3036 2,33.9179 67.3036 2,48.9179 42.3036 2,48.9179 67.3036 2)'::geometry
, 0.5,false)

and gave answer:

-- The ST_AsEWKT output 
-- PostgreSQL 9.2.4, compiled by Visual C++ build 1600, 32-bit POSTGIS="2.0.3 r11132" GEOS="3.5.0dev-CAPI-1.9.0 r0" PROJ="Rel. 4.8.0, 6 March 2012" GDAL="GDAL 1.10.0, released 2013/04/24" LIBXML="2.7.8" LIBJSON="UNKNOWN" RASTER

SRID=4326;POLYGON((-71.0821 42.3036,-71.0821 67.3036,48.9179 67.3036,48.9179 42.3036,-71.0821 42.3036))

Which makes sense if we drop the M as I would expect it to.

In 2.1.0 branch

-- PostgreSQL 9.2.4, compiled by Visual C++ build 1600, 32-bit POSTGIS="2.1.0rc3 r11766" GEOS="3.5.0dev-CAPI-1.9.0 r0" PROJ="Rel. 4.8.0, 6 March 2012" GDAL="GDAL 1.10.0, released 2013/04/24" LIBXML="2.7.8" LIBJSON="UNKNOWN" RASTER


ERROR:  Operation on mixed SRID geometries
CONTEXT:  PL/pgSQL function st_concavehull(geometry,double precision,boolean) line 63 at assignment
********** Error **********

This could be a bug in my code I suppose that it might be missing resetting the SRID but why it worked in 2.0.3 and not in 2.1.0 is a bit troubling.

[nicklas]

In trunk version something happens when there is more than 3 points.

SELECT st_astext(ST_ConcaveHull(
'SRID=1;MULTIPOINT(1 1, 2 2, 2 1)'::geometry,
 0.5,false));

gives the same answer in both 2.0 and trunk:

POLYGON((1.004 1.004,1.996 1.004,1.996 1.996,2 2,2 1,1 1,1.004 1.004))

but

SELECT st_astext(ST_ConcaveHull(
'SRID=1;MULTIPOINT(1 1, 2 2, 2 1, 2 0)'::geometry,
 0.5,false))

gives the "mixed SRID" error in trunk. In 2.0 it returns:

POLYGON((2 0,1 1,2 2,2 0))

which doesn't seem to "shrink" the polygon like the 3-point answer does.