How do i correctly extend a TCPSegment class? ( INET )

[Emanuele]

Hello everyone. My name is Emanuele, and i am an university student from Rome. I have a weird bug involving the INET framework and i hope
some of you can help me with it. I need to use an extended version of the inet::tcp::TCPSegment class for a project, but i seem to miss some steps of the
process because all i get is a crash. ( i get no compilation error by the way )

The crash appens in a client<-->router<-->server  very basic network. More precisely, the crash occours when the client tries to connect the server ( so the crash is not right at the start ).

Here are the steps of my code:

I have a TCP2 class that extends from TCP. I have a TCP2.ned  file that is used as transport protocol in a StandardHost module.
Here i explain my c++ code. ( i will omit all the #includes)

/// header file

namespace inet{
namespace tcp{

class TCP2: public TCP {
protected:
     /// Override of the TCPConnection class factory
     TCPConnection *createConnection(int appGateIndex, int connId) override;
};

} /// end of tcp namespace
} /// end of inet namespace

/// surce file

namespace inet{
namespace tcp{
...

Define_Module(TCP2);

...

TCPConnection *TCP2::createConnection(int appGateIndex, int connId)
{
    /// return my custom connection class ( constructor is identical to super's one)
    return new TCPConnection2(this, appGateIndex, connId);
};

} /// end of tcp namespace
} /// end of inet namespace

The reason i override the createConnection function is because i need to use an edited version of TCPConnection class, i called it TCPConnection2:

/// header file


namespace inet{
namespace tcp{

class TCPConnection2: public TCPConnection {

public:
    /// Call contructor and super constructor
    XCPConnection(TCP *_mod, int _appGateIndex, int _connId) :
        // inheritance constructor queue
        TCPConnection(_mod, _appGateIndex, _connId){}

    /// used to return an edited TCP segment
    virtual TCPSegment *createTCPSegment(const char *name) override;
};

} /// end of tcp namespace
} /// end of inet namespace


/// surce file


namespace inet{
namespace tcp{

TCPSegment *TCPConnection2::createTCPSegment(const char * name)
{
    /// TCPSegment2 extends TCPSegment   
    return new TCPSegment2(name);
};


} /// end of tcp namespace
} /// end of inet namespace

This is clearly used to createTCPSegment2 instances, instead of the stdandard ones:

/// header file


namespace inet{
namespace tcp{

class TCPSegment2 : public TCPSegment
{
public:
   TCPSegment2(const char * name, int kind = 0) : TCPSegment(name, kind){}


... here i added some fields with getters and setters, nothing more ...

}


} /// end of tcp namespace
} /// end of inet namespace

The source file of TCPSegment2 just contains some getters and setters for the fields i added to the class, so i will avoid writing it.

Since i experienced the bug, i restored the code of TCPConnection2::createTCPSegment to the original one, for debug porpouse. Let me be super clear about this:
I didnt erease the override function in my TCPConnection2 class. My override function still appears in the source file, but the code is the exact one of the mother class. As a matter of fact, basically, is a pointless override:

/// surce file ( debug version )

namespace inet{
namespace tcp{

TCPSegment *TCPConnection2::createTCPSegment(const char * name)
{
    /// This is the original line of code of the TCPConnection::createTCPSegment(const char * name) function 
    return new TCPSegment(name);
};


} /// end of tcp namespace
} /// end of inet namespace

Now, here i'll explain why i call this bug weird:
If i use the code as it is now, the simulation will crash. If i erease completely my override, so that my TCPConnection2 does call implicitly the mother class function createTCPSegment, then the code will work.
Isn't this weird? The same line of code works if called by the mother class, but fails if called by the child class.

Anyway, my problem is just figure out how can i extend and use a TCPSegment2 class.
Does anybody have an intuition, or an idea?

Thanks in advice.

PS:
Any idea on the reason of the bug i explained?

[Emanuele]

So i solved the problem myself. I update this question so other who might need it will find the solution. It would seem that any class in the cMessage hierarchy needs to implement his
own dup() function and xxx( xxx& other) constructor.

Another thing i did was complete reinstall of omnet and inet. Install with as admin is corrupted, use normal istall instead. Regargs.