FIX: java.lang.ClassCastException on Variant Objects (260280)

MORE INFORMATION

Steps to Reproduce Behavior

import com.ms.com.*;

public class Class1 implements NoAutoMarshaling { 
  static Object m_obj;
  static Variant m_variant;
  static Variant m_cloned_variant;
  
  public static void main (String[] args) { 
    // COM hostable thread
    ComLib.declareMessagePumpThread();
    
    // force creation of Java/COM wrapper for instance
    // of Class1
    m_obj = ComLib.makeProxyRef(new Class1());
    
    // invoke Thread1.run() on new thread
    Thread t1 = new Thread(new Thread1());
    t1.start();
    
    // pump messages for COM
    PumpMessages();
  }
  
  public static class Thread1 implements Runnable { 
    // marshals m_obj to this thread, and stores instance
    // in m_variant
    public void run() { 
      // COM hostable thread
      ComLib.declareMessagePumpThread();
      
      // Force virtual machine to marshal m_obj
      // to this thread
      int nPtr = ComLib.unknownToPtr(m_obj, 
                                     ComLib.IID_IUnknown);
      Object objProxy = 
                       ComLib.ptrToUnknown(IUnknown.class, 
                                           nPtr,
                                           false);
      
      // Store proxy to m_obj in a variant.
      // Note that COM proxy (objProxy) is only valid 
      // on this thread:
      // --performing any COM operation on this proxy 
      // will cause a COM error
      m_variant = new Variant(Variant.VariantObject, 
                              objProxy);
      
      // Invoke Thread2.run() on a new thread
      Thread t2 = new Thread(new Thread2());
      t2.start();
      
      PumpMessages();
    }
  }

  public static class Thread2 implements Runnable { 
    // Calls Variant.clone() on m_variant and performs COM
    // QueryInterface on internal COM object
    public void run() { 
      // COM hostable thread
      ComLib.declareMessagePumpThread();
      try {
        // Clone m_variant
        m_cloned_variant = 
                          (Variant)m_variant.clone();
        
        System.out.println("after clone");
        
        // Get COM proxy to m_obj from cloned 
        // variant
        Object obj = m_cloned_variant.getObject();
        
        System.out.println("after getObject");
        
        // Try to perform COM QueryInterface on 
        // COM proxy. This fails with a 
        // ClassCastException because the COM
        // proxy is being invoked on the wrong 
        // thread
        boolean b = ComLib.supportsInterface(obj, 
                                             ComLib.IID_IDispatch);
        System.out.println("supportsInterface "+b);
      }
      catch (Exception e) {
        e.printStackTrace();
      }
      
      try {
        System.out.print("Please press enter "+
                         "to exit..");
        System.in.read();
      }
      catch (Exception e) {
      }
      System.exit(0);
    }
  }
  
  // standard Win32 message pump
  public static void PumpMessages() { 
    com.ms.win32.MSG msg = new com.ms.win32.MSG();

    while( com.ms.win32.User32.GetMessage( msg, 0, 0, 0 ) ) { 
      com.ms.win32.User32.TranslateMessage( msg );
      com.ms.win32.User32.DispatchMessage( msg );
    }
  }
}