Strange behaviour after porting from VS2005 to VS2008

Mikel Luri <>
Wed, 09 Feb 2011 12:54:26 +0100
I'm trying to port my application from VS2005 to VS2008. After dealing
with some dependency issues and other minor things, I've been able to
build it and try to run it. But to my surprise, it didn't work, throwing
some assertions in the initialization. Those assertions are in my own
code and are a result of a bad initialization of some variables, which
is the real syptom.

So, I've been stepping through the initialization process and I've found
some strange things.

Here is what I have:

In my CDocument derived class I have a member of type CMyClass (name

CMyClass declares three members of class CMyVertex (which derives from
CPoint3D, which derives from CPoint2D):

class CPoint2D

     double m_X;
     double m_Y;

     CPoint2D(double X, double Y);
     CPoint2D(const CPoint2D& P);

     // More thints here
     // ...

class CPoint3D : public CPoint2D

     double m_Z;

     // Constructores/Destructores
     CPoint3D(double X, double Y, double Z);
     CPoint3D(const CPoint3D& P);
     CPoint3D(const CPoint2D& P);

     // More things here
     // ...


class CMyVertex : public CPoint3D
     BOOL m_Visible; // Punto Visible o no

     // Constructores y destructores
     CMyVertex(const CMyVertex& ver);
     CMyVertex(double x, double y, double z, BOOL visible = TRUE);
     CMyVertex(const CPoint3D& P, BOOL visible = TRUE);

     // More things
     // ...

class CMyClass : public CObject

    // ...

     CMyVertex m_Origen;
     CMyVertex m_LimiteInfIzq;
     CMyVertex m_LimiteSupDch;

     // ...

     // Constructores y destructores
     CMyClass(const CMyClass& CMyClass);
    virtual ~CMyClass();

    // Many more things
    // ...

class CMyDocument : public CDocument
// ...

     CMyClass m_MyObject;


(Let's ignore style issues, like wether member variables should be
public, protected or private for the moment, please)

The default constructors of CPoint2D and CPoint3D set m_X, m_Y and m_Z
to 0.0, and CMyVertex's sets m_Visible to TRUE:

CMyVertex::CMyVertex(void) : CPoint3D(), m_Visible(TRUE)

CPoint3D::CPoint3D(void) : CPoint2D(), m_Z(0.0)

CPoint2D::CPoint2D(void) : m_X(0.0), m_Y(0.0)

And the default constructor of CMyClass uses the default constructor of
CMyVertex. Of course, following the logic, the document's constructor
uses the default constructor of CMyClass.

So, when the document is created, those CMyVertex members should be set
to all 0.0 coordinates and m_Visible = TRUE. Right?

Well, here comes the weird part: they're not. They are initialized to:

m_X = 0
m_Y = -6.2774359784998866e+066 or -6.2774359784998874e+066 (which seems
to be cdcdcdcd00000000 or cdcdcdcd00000001 in memory)
m_Z = 0
m_Visible = 0 (FALSE)

I've stepped into the document's constructor and here's what happens:
The constructor of CMyClass sets the values correctly. I mean, when the
step-by-step cursor is on the closing brace of CMyClass' constructor all
the values are correct. As soon as I step out of that constructor, back
to CMyDocument's constructor, the values are messed up.

Looking into it in greater detail, I've found that inside the document's
constructor m_MyObject.m_Origen is at a certain address (e.g.
0x01714f28), but inside CMyClass's constructor m_Origen is at a
different one (0x01714f38), so it seem's that's why the values get
messed up.

By the way, as I was writing this, I've tested the release version and
it seems to work fine.

Any ideas on what's going on here?


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