[mapserver-users] MapServer as a WMS Client bug with GDAL

[Frank Warmerdam]

Folks,

Anyone uses MapServer as a client for remote WMS servers (ie. as a cascading
map server) should be aware there are some bugs in the handling of the output
results of remote WMS servers by the GDAL code in MapServer.

The problem only manifests if the GD support for the format returned by the
remote server is not available ... for instance, if you have mapserver with
only GD-PNG enabled, but get a .gif result from a remote server, the file
will be processed by GDAL instead of GD.

Then in cases that the file isn't needing transformation (reprojection) it
will not be handled properly.  Basically this is because the GDAL drawing
code does not properly handle complete georeferencing-less files.  That is
cases where the TRANSFORM flag is set to OFF or where there is no .wld
file for something like a gif or png files.

The workaround is to ensure that MapServer's GD is configured with
all formats you want to be able to read from remote mapservers (usually
gif and png).

The problem is fixed in MapServer CVS (or will be very shortly) and is
documented in:

   http://mapserver.gis.umn.edu/bugs/show_bug.cgi?id=163

This notice is just for your information.

Best regards,

-- 
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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