[Mapserver-dev] msLookupHashTable: Hash table error

[Frank Warmerdam]

Howard Butler wrote:
> And finally, when it comes up to draw, it throws this error (with Python 
> MapScript).
> 
> Traceback (most recent call last):
>   File "/usr/local/apache/cgi-bin/dataview.py", line 294, in ?
>     img = map.draw()
>   File "/usr/local/lib/python2.3/site-packages/mapscript.py", line 1150, 
> in draw
>     def draw(*args): return _mapscript.mapObj_draw(*args)
> _mapscript.MapServerError: msLookupHashTable: Hash table error. Invalid 
> hash table or key
> 
> If I turn off the layer, the rest of the map draws fine.  This is with 
> today's (an hour ago's) CVS.  Other WMS requests (to TerraServer) work 
> fine.  I have never seen this error, and some searching on the list for 
> previous tracking showed that this is related to the CONFIG option (Sean 
> and Frank were talking a bit about it).  Is this error masking something 
> else, or is it really the error?  If so, is it related to a Metadata 
> option that is missing (other WMS requests to TerraServer have the same 
> options and work fine)?

Howard,

The "Invalid Hash table or key" error occures if an effort is made to lookup
a NULL key or lookup a value on a NULL hash.  I setup the following mapfile
and run shp2img on it, but things worked fine:


MAP
NAME  "w2qpgi5qsg4k"
DEBUG on
SIZE 800 600
EXTENT 363411 4564460 365246 4565842

LAYER
   NAME cir
   METADATA
     "wms_title" "Iowa CIR"
     "wms_srs"   "EPSG:26915"
   END
   STATUS DEFAULT
   TYPE RASTER
   DEBUG ON
   MAXSCALE 100000
   CONNECTIONTYPE WMS
   CONNECTION "http://cairo.gis.iastate.edu/cgi-bin/server.cgi?wmtver=1.0.0&layers=doqqs&format=jpg"
   PROJECTION
     "init=epsg:26915"
   END
END

END

One difference is that my .map file is not having to go through the resampling
code yours is ... presumably because you are generating a map in a different
coordinate system than the input data.  If you can provide a mapfile that allows
me to reproduce the error with shp2img or with python mapscript then I will see
what I can do to fix this issue.  If there is a bug I would like to fix it
before the release snapshot to happen *very* soon.

Best regards,
-- 
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent