Selection not cleared server-side

[gBecker]

When using the AjaxViewer and trying to clear a selection then this selection is not cleared server-side. This is related to MGOS 2.6 and the preview release of MGOS 3.0.

Steps to reproduce the Problem:

1. Preview an existing MapDefinition with Maestro
   
2. Select a feature
   
3. Deselect the feature via toolbar or context menu
   
4. Go to the "MapAgent Test Pages"
   
5. Under "Rendering" service perform a "MAPIMAGE"-Request of the area where you formerly selected the feature.
   
6. The selection is rendering with the map Image.
   

I turned on the browsers network analysis and detected a "silent" error when you are deselecting features. The request that should probably clear the selection returns a 559 http-error:

Request to mapagent.fcgi (POST):

OPERATION=QUERYMAPFEATURES&VERSION=2.6.0&PERSIST=1&MAXFEATURES=-1&MAPNAME=da766655-a6f1-4981-916f-356b5e605b9f&SESSION=44ec47c2-c636-11e4-8000-a0d3c14fb893_en_MTI3LjAuMC4x0B600B5F0B5E&SEQ=0.5484117435160211&CLIENTAGENT=Ajax%20Viewer&LAYERATTRIBUTEFILTER=0&REQUESTDATA=8&FEATUREFILTER=

return this error:

Argument is null.

- MgRenderingServiceHandler.ProcessOperation() line 83 file c:\working\build_area\mapguide\2.6.0\x64\mgdev\server\src\services\rendering\RenderingServiceHandler.cpp
- MgOpQueryFeatures.Execute() line 125 file c:\working\build_area\mapguide\2.6.0\x64\mgdev\server\src\services\rendering\OpQueryFeatures.cpp
- MgServerRenderingService.QueryFeatures() line 853 file c:\working\build_area\mapguide\2.6.0\x64\mgdev\server\src\services\rendering\ServerRenderingService.cpp
- MgServerRenderingService.RenderForSelection() line 1187 file c:\working\build_area\mapguide\2.6.0\x64\mgdev\server\src\services\rendering\ServerRenderingService.cpp

[jng]

Fixed trunk (r8567) and 2.6 (r8615)