[postgis-devel] [PostGIS] #1567: [raster] The SRID of the empty raster returned by ST_MapAlgebraExpr(rast, rast, 'intersection') should be 0

[PostGIS]

#1567: [raster] The SRID of the empty raster returned by ST_MapAlgebraExpr(rast,
rast, 'intersection') should be 0
---------------------+------------------------------------------------------
 Reporter:  pracine  |       Owner:  pracine      
     Type:  defect   |      Status:  new          
 Priority:  low      |   Milestone:  PostGIS 2.0.0
Component:  raster   |     Version:  trunk        
 Keywords:           |  
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Comment(by dustymugs):

 Replying to [comment:2 pracine]:
 > Hum. It might make sense.
 >
 > Does it make sense to give a SRID to en empty raster?
 >

 In this situation, I'd say yes since the output is based upon the input
 rasters.

 > Do empty geometries have a SRID?

 No.  The following returns NULL

 {{{
 SELECT ST_SRID(NULL::geometry(POINT, 4326))
 }}}

 >
 > Is it normal to be able to create and empty raster with SRID equal to
 -1? Should not SRID be clamped to 0?

 SRID < 0 is clamped to 0.

 So, change the empty raster's SRID to zero?

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/1567#comment:3>
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