Program: 121662
Project: 121662
Buggy source:
@Override protected void handleDrop(){
  final Object object=TemplateTransfer.getInstance().getObject();
  if (object == null || !(object instanceof TransferedObject)) {
    return;
  }
  updateTargetRequest();
  updateTargetEditPart();
  DropContextAnalyzer analyzer=new DropContextAnalyzer((TransferedObject)object,(AbstractGraphicalEditPart)getTargetEditPart(),getDropLocation());
  if (analyzer.isDropValid()) {
    NodeType selectedNodeType=NodeType.ELEMENT;
    DropType dropType=analyzer.getDropType();
    if (dropType == DropType.DROP_OUTPUT_DOC_CHILD && getTargetEditPart() instanceof OutputTreeNodeEditPart) {
      OutputTreeNode targetOutputNode=(OutputTreeNode)((OutputTreeNodeEditPart)getTargetEditPart()).getModel();
      Shell shell=getViewer().getControl().getShell();
      boolean needPrompt=false;
      boolean hasSubTree=false;
      for (      Object o : ((TransferedObject)object).getToTransfer()) {
        if (o instanceof VarNodeEditPart) {
          needPrompt=true;
        }
 else         if (o instanceof TreeNodeEditPart) {
          TreeNode treeNode=(TreeNode)((TreeNodeEditPart)o).getModel();
          if (NodeType.ATTRIBUT.equals(treeNode.getNodeType())) {
            needPrompt=true;
          }
          if (NodeType.ELEMENT.equals(treeNode.getNodeType())) {
            if (treeNode.getChildren().isEmpty()) {
              needPrompt=true;
            }
 else {
              hasSubTree=true;
            }
          }
        }
      }
      if (needPrompt) {
        DragAndDrogDialog selectDialog=new DragAndDrogDialog(shell,!targetOutputNode.getChildren().isEmpty());
        int open=selectDialog.open();
        if (open == Window.OK) {
          if (DragAndDrogDialog.CREATE_AS_SUBELEMENT.equals(selectDialog.getSelectValue())) {
            selectedNodeType=NodeType.ELEMENT;
          }
 else           if (DragAndDrogDialog.CREATE_AS_ATTRIBUTE.equals(selectDialog.getSelectValue())) {
            selectedNodeType=NodeType.ATTRIBUT;
          }
 else           if (DragAndDrogDialog.CREATE_AS_SUBELEMENT.equals(selectDialog.getSelectValue())) {
            selectedNodeType=NodeType.NAME_SPACE;
          }
 else           if (DragAndDrogDialog.CREATE_AS_TEXT.equals(selectDialog.getSelectValue())) {
            dropType=DropType.DROP_EXPRESSION;
          }
        }
 else {
          return;
        }
      }
      if (dropType != DropType.DROP_EXPRESSION) {
        if (!targetOutputNode.getIncomingConnections().isEmpty() && ((selectedNodeType != NodeType.ATTRIBUT && selectedNodeType != NodeType.NAME_SPACE) || hasSubTree)) {
          boolean canContinue=MessageDialog.openConfirm(null,"String_Node_Str","String_Node_Str");
          if (canContinue) {
            MapperManager mapperManager=((XmlMapGraphicViewer)getViewer()).getMapperManager();
            if (mapperManager != null && mapperManager.getCopyOfMapData() != null) {
              XmlMapUtil.detachNodeConnections(targetOutputNode,mapperManager.getCopyOfMapData(),false);
            }
          }
 else {
            return;
          }
        }
      }
    }
    NewNodeCreationFactory factory=new NewNodeCreationFactory(dropType,selectedNodeType);
    getCreateRequest().setFactory(factory);
  }
  if (getTargetEditPart() != null) {
    Command command=getCommand();
    if (command != null && command.canExecute())     getViewer().getEditDomain().getCommandStack().execute(command);
 else     getCurrentEvent().detail=DND.DROP_NONE;
  }
 else   getCurrentEvent().detail=DND.DROP_NONE;
  selectAddedObject();
}

Fixed version (ground truth):
@Override protected void handleDrop(){
  final Object object=TemplateTransfer.getInstance().getObject();
  if (object == null || !(object instanceof TransferedObject)) {
    return;
  }
  updateTargetRequest();
  updateTargetEditPart();
  DropContextAnalyzer analyzer=new DropContextAnalyzer((TransferedObject)object,(AbstractGraphicalEditPart)getTargetEditPart(),getDropLocation());
  if (analyzer.isDropValid()) {
    NodeType selectedNodeType=NodeType.ELEMENT;
    DropType dropType=analyzer.getDropType();
    if (dropType == DropType.DROP_OUTPUT_DOC_CHILD && getTargetEditPart() instanceof OutputTreeNodeEditPart) {
      OutputTreeNode targetOutputNode=(OutputTreeNode)((OutputTreeNodeEditPart)getTargetEditPart()).getModel();
      Shell shell=getViewer().getControl().getShell();
      boolean needPrompt=false;
      boolean hasSubTree=false;
      for (      Object o : ((TransferedObject)object).getToTransfer()) {
        if (o instanceof VarNodeEditPart) {
          needPrompt=true;
        }
 else         if (o instanceof TreeNodeEditPart) {
          TreeNode treeNode=(TreeNode)((TreeNodeEditPart)o).getModel();
          if (NodeType.ATTRIBUT.equals(treeNode.getNodeType())) {
            needPrompt=true;
          }
          if (NodeType.ELEMENT.equals(treeNode.getNodeType())) {
            if (treeNode.getChildren().isEmpty()) {
              needPrompt=true;
            }
 else {
              hasSubTree=true;
            }
          }
        }
      }
      if (needPrompt) {
        DragAndDrogDialog selectDialog=new DragAndDrogDialog(shell,!targetOutputNode.getChildren().isEmpty());
        int open=selectDialog.open();
        if (open == Window.OK) {
          if (DragAndDrogDialog.CREATE_AS_SUBELEMENT.equals(selectDialog.getSelectValue())) {
            selectedNodeType=NodeType.ELEMENT;
          }
 else           if (DragAndDrogDialog.CREATE_AS_ATTRIBUTE.equals(selectDialog.getSelectValue())) {
            selectedNodeType=NodeType.ATTRIBUT;
          }
 else           if (DragAndDrogDialog.CREATE_AS_SUBELEMENT.equals(selectDialog.getSelectValue())) {
            selectedNodeType=NodeType.NAME_SPACE;
          }
 else           if (DragAndDrogDialog.CREATE_AS_TEXT.equals(selectDialog.getSelectValue())) {
            dropType=DropType.DROP_EXPRESSION;
          }
        }
 else {
          return;
        }
      }
      if (dropType != DropType.DROP_EXPRESSION) {
        if (!targetOutputNode.getIncomingConnections().isEmpty() && ((selectedNodeType != NodeType.ATTRIBUT && selectedNodeType != NodeType.NAME_SPACE) || hasSubTree)) {
          boolean canContinue=MessageDialog.openConfirm(null,"String_Node_Str","String_Node_Str");
          if (canContinue) {
            MapperManager mapperManager=((XmlMapGraphicViewer)getViewer()).getMapperManager();
            if (mapperManager != null && mapperManager.getCopyOfMapData() != null) {
              XmlMapUtil.detachNodeConnections(targetOutputNode,mapperManager.getCopyOfMapData(),false);
            }
          }
 else {
            return;
          }
        }
      }
    }
    NewNodeCreationFactory factory=new NewNodeCreationFactory(dropType,selectedNodeType);
    getCreateRequest().setFactory(factory);
  }
  if (getTargetEditPart() != null) {
    Command command=getCommand();
    if (command != null && command.canExecute()) {
      getViewer().getEditDomain().getCommandStack().execute(command);
    }
 else {
      getCurrentEvent().detail=DND.DROP_NONE;
    }
  }
 else {
    getCurrentEvent().detail=DND.DROP_NONE;
  }
  selectAddedObject();
}