ST_MapAlgebra -- I think we have a memory leak

[robe]

I tried to do this on my test elephant

-- its a single tile -- I forget the size O

ALTER TABLE ch13.pele ADD column map_rast raster;
UPDATE ch13.pele 
SET map_rast = ST_MapAlgebra(rast,'CASE WHEN rast BETWEEN 100 and 250 THEN 1 WHEN rast = 252 THEN 2 WHEN rast BETWEEN 253 and 254 THEN 3 ELSE 0 END', '2BUI') ; 

and it crashes the server after about 13 seconds.

This is on Windows XP latest trunk.