[postgis-users] Changed bahaviour of PostGIS confuses MapServer

[Mark Cave-Ayland]

Peter Hopfgartner wrote:

> Dear MLs,
> 
> sorry for cross-posting to both, PostGIS and MS, but seems to rtouch both.
> 
> I've tried to install PostGIS 1.3.4 on a CentOS 5 server with MapServer 
> 5.2.1 and PostgreSQL 8.2.11.
> 
> the command:
> 
> shp2img -l prova -e 1587541 5116731 1591730 5120008 -m prova.map > 
> ../../public/technet/test-<pgis-version>.png
> 
> with 1.3.3 gave the result shown in figure test-postgis-1.3.3-4.png (a 
> simple line layer)
> 
> Upgrading to 1.3.4 the picture became as in test-postgis-1.3.4-1.png, an 
> empty picture.
> 
> The relevant mapfile fragment is Mapfile.frag.txt, the SQL table 
> definition is e405.sql, all objects are MULTILINESTRINGs [SELECT 
> DISTINCT geometrytype(the_geom) FROM public.e405 results in 
> MULTILINESTRING], the geometry column is registered as MULTILINESTRING 
> in geometry_columns.
> 
> Running the MapServer query:
> 
> SELECT 
> asbinary(force_collection(force_2d(the_geom)),'NDR'),common_uid::text 
> from public.e405 WHERE (tiplinapp is not null) and (the_geom && setSRID( 
> 'BOX3D(1587541 5116702.44897959,1591730 
> 5120036.55102041)'::BOX3D,find_srid('','public.e405','the_geom') ))
> 
> changed for better result readability into:
> 
> SELECT AsEWKT(force_collection(force_2d(the_geom))),common_uid::text 
> from public.e405 WHERE (tiplinapp is not null) and (the_geom && setSRID( 
> 'BOX3D(1587541 5116702.44897959,1591730 
> 5120036.55102041)'::BOX3D,find_srid('','public.e405','the_geom') ))
> 
> by hand gives slightly different results, as shown in the attached files.
> 
> To make a long story short, 1.3.4 seems to better preserve the 
> MULTILINESTRING, but this seems to confuse MapServer.
> 
> Regards,
> 
> Peter


Hi Peter,

This is likely the known issue with MULTILINESTRINGs in 1.3.4 causing 
segfaults :(  The patch you need is very simple and can be found here: 
http://postgis.refractions.net/pipermail/postgis-commits/2008-December/000866.html 
if you can't wait for a 1.3.5 release. Please let us know whether this 
resolves the problem for you.


HTH,

Mark.

-- 
Mark Cave-Ayland
Sirius Corporation - The Open Source Experts
http://www.siriusit.co.uk
T: +44 870 608 0063