operator overloading and inheritance

[tuli]

Hi,

So i am having troubles with operator overloading in inherited class. Basically, it doesnt work. Consider this:

class A
{
public:
	A()
	{
		x=0;
		z= new int;
	}
	~A()
	{
		delete z;
	}

	int x;
	int* z;

	A& operator=(A& a)
	{
		x = a.x;
		z = new int(*a.z);
		return *this;
	}
};

class  B : public A
{
public:
	B(){y=0;}
	B(B& b, int dummy) //pseudo-assignment constructor
	{
		operator=(b);
	}

	int y;

	B& operator=(B& b)
	{
		y = b.y;
		A::operator=(b);
		return *this;
	}
};


void somefunc(B& b)
{
	/*
	some how the copy constructor of a is improperly executed - the pointer is copied over, not re-created.
	As a result, the destructors crashes due to double-free.
	*/
	B bb = b; //doesnt work
	B bbb(b); //doesnt work
	B bbbb(b, 0); //works
}

Above code shows the problem well. The "official" copy-constructor wont work - it copies over the pointer directly, and doesnt create a new one as it should. However, if i provide my own pseudo-copy-constructor that works.
But ofcourse it's just a cheap work around - and wont actually work in real code (STL).

What's wrong? Strikes me as very odd...

compiler is VS2008SP1.

edit:
I have added a proper example, sorry.