Short Description: Fix to potential crash, Accounting GUI, Display Groups
Bug Number: 5002
Release notes (y/n): Yes (6.0.2)
For Release Nums: 6.0.2 and 6.1

Gnats 5002: Potential Crash: Display Group RootSelection item callbacks; 
 Seen in Purify.

This is a fix to a potential crash in RiverWare 6.0.1 (and earlier versions)
and in RiverWare 6.1 development, when deleting Account or Supply Display 
Groups (generally when clearing the model or exiting RiverWare) from a
loaded RiverWare Accounting model.

An old coding error in the "special" issuing of SIMOBJ_ACCOUNT_DELETED to 
the CallbackReceiverMgr prevented: (1) the flagging of Account and Supply 
Groups as "invalidated" AND (2) the removal of "effective" callback 
registrations with regard to a deleted Account. This resulted, later on, 
in a memory error -- calling methods on the previously deleted Account.

The fix is in Sim/SimObj.Acct.cpp, in method SimObj::deleteAccount().
The call to CallbackReceiverMgr::invoke (const Root* object, CallbackType, 
CallbackData*) had been passing the account pointer to the first parameter.
That method should have passed the 'this' (SimObj*) pointer to the first
parameter.

The problem was detected using Purify and with diagnostic trace code at the
site of the memory error, in the [Sim] CallbackReceiver::_helpAccountCallbacks
method (when trying to discover the SimObj of an Account which no longer 
exists but which is still in the RootSelection).

See also other notes:
 https://cadswes2.colorado.edu/~philw/2010/bugs/5002/

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