[ns] Routing agent exchange

[Ulrich Herberg]

In an agent I would like to change the routing protocol agent of a
wireless node. I can successfully insert a new routing agent, but I
somehow get a segmentation fault from the old agent:

The following code is executed from the C++ agent (with tcl.evalf()):
       set ragent_(0) [new Agent/OLSR 0]
       $ns_ attach-agent $node_(0) $ragent_(0)
       $ragent_(0) start
       $node_(0) set ragent_ $ragent_(0)
       foreach dumbagent [Agent/DumbAgent info instances] {
            if { [$dumbagent id] == 0} { ;# note: dumbagent has been
modified to save the node id
                $dumbagent close
                $ns_ detach-agent $node_(0) $dumbagent
                break
            }}
       delete $dumbagent


The new OLSR agent sucessfully starts, however, the old dumbagent seems
not be completely deleted (or detached). Here is the gdb output:
       Program received signal SIGSEGV, Segmentation fault.
       0x00000000004224fc in PortClassifier::classify ()
       (gdb) bt
       #0  0x00000000004224fc in PortClassifier::classify ()
       #1  0x000000000041ca2d in Classifier::find ()
       #2  0x000000000041cb74 in Classifier::recv ()
       #3  0x00000000004f9d12 in DumbAgent::recv ()
       #4  0x000000000041cba6 in Classifier::recv ()
       #5  0x00000000004f9d12 in DumbAgent::recv ()
       #6  0x000000000041cba6 in Classifier::recv ()
       (...)

Thanks for your advice,

Ulrich