Program: 143558
Project: 143558
Buggy source:
public void initDragNDrop(FormController formController,int clientDesignYOffset){
  this.yOffset=clientDesignYOffset;
  boolean enableDragDrop=false;
  if (cellview instanceof Portal) {
    Portal cellviewPortal=(Portal)cellview;
    enableDragDrop=(cellviewPortal.getOnDragMethodID() > 0 || cellviewPortal.getOnDragEndMethodID() > 0 || cellviewPortal.getOnDragOverMethodID() > 0 || cellviewPortal.getOnDropMethodID() > 0);
  }
 else {
    Form form=fc.getForm();
    enableDragDrop=(form.getOnDragMethodID() > 0 || form.getOnDragEndMethodID() > 0 || form.getOnDragOverMethodID() > 0 || form.getOnDropMethodID() > 0);
  }
  if (enableDragDrop) {
    setDragEnabled(true);
    setTransferHandler(FormDataTransferHandler.getInstance());
    new DropTarget(this,(DropTargetListener)FormDataTransferHandler.getInstance());
    addHierarchyListener(new HierarchyListener(){
      public void hierarchyChanged(      HierarchyEvent e){
        JComponent changedParent=(JComponent)e.getChangedParent();
        if (changedParent != null && e.getChanged() == TableView.this && (e.getChangeFlags() & HierarchyEvent.PARENT_CHANGED) == HierarchyEvent.PARENT_CHANGED) {
          changedParent.setTransferHandler(FormDataTransferHandler.getInstance());
          new DropTarget(changedParent,(DropTargetListener)FormDataTransferHandler.getInstance());
          DragStartTester dragTester=new DragStartTester();
          changedParent.addMouseListener(dragTester);
          changedParent.addMouseMotionListener(dragTester);
          TableView.this.removeHierarchyListener(this);
        }
      }
    }
);
  }
}

Fixed version (ground truth):
public void initDragNDrop(FormController formController,int clientDesignYOffset){
  this.yOffset=clientDesignYOffset;
  boolean enableDragDrop=false;
  if (cellview instanceof Portal) {
    Portal cellviewPortal=(Portal)cellview;
    enableDragDrop=(cellviewPortal.getOnDragMethodID() > 0 || cellviewPortal.getOnDragEndMethodID() > 0 || cellviewPortal.getOnDragOverMethodID() > 0 || cellviewPortal.getOnDropMethodID() > 0);
  }
 else {
    Form form=fc.getForm();
    enableDragDrop=(form.getOnDragMethodID() > 0 || form.getOnDragEndMethodID() > 0 || form.getOnDragOverMethodID() > 0 || form.getOnDropMethodID() > 0);
  }
  if (enableDragDrop && !GraphicsEnvironment.isHeadless()) {
    setDragEnabled(true);
    setTransferHandler(FormDataTransferHandler.getInstance());
    new DropTarget(this,(DropTargetListener)FormDataTransferHandler.getInstance());
    addHierarchyListener(new HierarchyListener(){
      public void hierarchyChanged(      HierarchyEvent e){
        JComponent changedParent=(JComponent)e.getChangedParent();
        if (changedParent != null && e.getChanged() == TableView.this && (e.getChangeFlags() & HierarchyEvent.PARENT_CHANGED) == HierarchyEvent.PARENT_CHANGED) {
          changedParent.setTransferHandler(FormDataTransferHandler.getInstance());
          new DropTarget(changedParent,(DropTargetListener)FormDataTransferHandler.getInstance());
          DragStartTester dragTester=new DragStartTester();
          changedParent.addMouseListener(dragTester);
          changedParent.addMouseMotionListener(dragTester);
          TableView.this.removeHierarchyListener(this);
        }
      }
    }
);
  }
}