"wms_sld_body" "AUTO_TMPFILE" option

Okay, I have done a bit more analyzing and I think we can work around this by
using the following process:

1. generate CLASSes on the WMS layer like is done now
2. don't use "wms_sld_body" "AUTO"
3. use Mapscript function generateSLD to create the SLD from the classes
4. save this document on the webserver
5. set the "wms_sld_url" METADATA in the map file for the WMS layer

Apparently it is not the intention of Mapserver WMS client to automate this process?

Maybe a "wms_sld_body" "AUTO_TMPFILE" option could be added that would save the
SLD body to a temp file in the IMAGEPATH/IMAGEURL directory and use that as the
SLD URL in the GetMap request. 

Saving the SLD to a temporary file everytime implies that the remote server has
to download the SLD in a separate HTTP request for *every* map. OTOH if you
pregenerate it then the remote server can cache it (if it's smart enough to
cache it). It might be worth looking into not regenerating the SLD files if we
don't need to, a bit like we did for the HTML legend icons (temporary filename
based on class/layer info and timestamp of mapfile).

But I think that should be considered a future enhancement since you have found
a good workaround already.  ;)

Changed the summary to something more appropriate.