[vtkusers] vtkSeedWidget bug FIXED!

[AGPX]

Ok, look like a bug. Look at the code of the file vtkSeedRepresentation.cxx:

/----------------------------------------------------------------------
void vtkSeedRepresentation::RemoveHandle( int n )
{
  // Remove nth handle
  
  if (n == this->ActiveHandle)
    {
    this->RemoveActiveHandle();
    return;
    }

  if (static_cast<int>(this->Handles->size()) <= n )
    {
    return;
    }

  vtkHandleListIterator iter = this->Handles->begin();
  vtkstd::advance( iter, n );

  
this->Handles->erase( iter );  
  ( *iter )->Delete();

}

//----------------------------------------------------------------------
void vtkSeedRepresentation::RemoveActiveHandle()
{
  if ( this->Handles->size() < 1 )
    {
    return;
    }
  if ( this->ActiveHandle >= 0 && this->ActiveHandle < static_cast<int>(this->Handles->size()) )
    {
    vtkHandleListIterator iter = this->Handles->begin();
    vtkstd::advance( iter, this->ActiveHandle );
    
    this->Handles->erase( iter );
    ( *iter )->Delete();
    this->ActiveHandle = -1;
    }


Basically the error are in the following lines:

this->Handles->erase( iter );
 ( *iter )->Delete();

You have to FIRST delete the object and THEN remove the handle! That is you have to swap the two lines:

 ( *iter )->Delete();
this->Handles->erase( iter );

Now the example no longer crash (and my application too!).

My two cents!

- AGPX




________________________________
Da: AGPX <agpxnet at yahoo.it>
A: vtk vtk <vtkusers at vtk.org>
Inviato: Ven 5 marzo 2010, 12:19:45
Oggetto: vtkSeedWidget bug?


Hi,

I have compiled the latest version of VTK (from CVS) and the WidgetsCxxTests.exe (debug mode) crashs when you run Test15 (vtkSeedWidget). The error reported is: "list iterator not dereferencable" and the debugger show the line:

( *iter )->Delete();

inside the vtkSeedRepresentation::RemoveHandle method. Basically the DeleteSeed seems doesn't work. I tested it on Microsoft Windows XP Pro with Visual Studio 2008 SP1. Any idea on how to fix? Thanks.

- AGPX


      
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