ListGrid sending request that causes Exception on server side

[csillag]

Sometimes, my ListGrid sends out DSRequests like this

{
    "actionURL":"http://127.0.0.1:8888/orgtel/sc/IDACall", 
    "showPrompt":true, 
    "prompt":"Az adatok betöltése folyamatban...", 
    "transport":"xmlHttpRequest", 
    "promptStyle":"dialog", 
    "bypassCache":true, 
    "data":{
        "criteria":{
        }, 
        "operationConfig":{
            "dataSource":"app_groups_auto", 
            "repo":null, 
            "operationType":"fetch", 
            "textMatchStyle":"substring"
        }, 
        "startRow":0, 
        "endRow":75, 
        "componentId":"isc_OID_46", 
        "appID":"builtinApplication", 
        "operation":{
            "ID":"app_groups_auto_fetch", 
            "dataSource":"app_groups_auto", 
            "type":"fetch", 
            "filterType":"paged", 
            "loadDataOnDemand":true, 
            "source":"auto"
        }, 
        "oldValues":{
        }
    }
}

This causes an exception on the server side:

java.lang.ClassCastException: org.apache.commons.collections.map.LinkedMap cannot be cast to java.lang.String
	at com.isomorphic.datasource.DSRequest.getOperation(DSRequest.java:469)
	at com.isomorphic.datasource.DSRequest.<init>(DSRequest.java:208)
	at com.isomorphic.datasource.DSRequest.<init>(DSRequest.java:344)
	at com.isomorphic.rpc.RPCManager.parseRequest(RPCManager.java:1283)
	at com.isomorphic.rpc.RPCManager.<init>(RPCManager.java:250)
	at com.isomorphic.servlet.IDACall.processRequest(IDACall.java:90)
	at com.isomorphic.servlet.IDACall.doPost(IDACall.java:54)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
	at com.isomorphic.servlet.BaseServlet.service(BaseServlet.java:152)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
	at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1097)
	at com.isomorphic.servlet.CompressionFilter.doFilter(CompressionFilter.java:259)
	at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1088)
	at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:360)
	at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
	at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
	at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:729)
	at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
	at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
	at org.mortbay.jetty.handler.RequestLogHandler.handle(RequestLogHandler.java:49)
	at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
	at org.mortbay.jetty.Server.handle(Server.java:324)
	at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:505)
	at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:843)
	at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:647)
	at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
	at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:380)
	at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:395)
	at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:488)

As far as I can tell, the only difference between the above DSRequest and the other successful ones is the "operation" part.

* * *

I am not yet sure what do I do to trigger this; will update post when I find out. (But this seems to be a bug, anyway.)