Program: 188019
Project: 188019
Buggy source:
public void appendParam(DefaultMutableTreeNode treenode,MyFolder parent){
  final JTextField name=new JTextField();
  name.addAncestorListener(new AncestorListener(){
    @Override public void ancestorRemoved(    AncestorEvent arg0){
    }
    @Override public void ancestorMoved(    AncestorEvent arg0){
    }
    @Override public void ancestorAdded(    AncestorEvent arg0){
      name.requestFocusInWindow();
    }
  }
);
  JTextField value=new JTextField();
  JPanel p=getPropPanel(name,value);
  int r=(Integer)CustomDialog.showDialog(p,JOptionPane.PLAIN_MESSAGE,JOptionPane.OK_CANCEL_OPTION,panel,"String_Node_Str",null);
  if (r == JOptionPane.OK_OPTION && (!(name.getText() + value.getText()).equals("String_Node_Str"))) {
    MyParam param=new MyParam();
    Element rootElement=doc.createElement("String_Node_Str");
    parent.getNode().getParentNode().getParentNode().appendChild(rootElement);
    Node refs=null;
    try {
      refs=parent.getNode().getParentNode().getParentNode().getFirstChild().getNextSibling().getNextSibling().getNextSibling();
    }
 catch (    Exception e) {
      refs=null;
    }
    if (refs == null) {
      parent.getNode().getParentNode().getParentNode().appendChild(rootElement);
    }
 else {
      parent.getNode().getParentNode().getParentNode().insertBefore(rootElement,refs);
    }
    Element tname=doc.createElement("String_Node_Str");
    rootElement.appendChild(tname);
    Node node=doc.createTextNode(name.getText());
    param.setName(node);
    tname.appendChild(node);
    Element tvalue=doc.createElement("String_Node_Str");
    rootElement.appendChild(tvalue);
    node=doc.createTextNode(value.getText());
    param.setValue(node);
    tvalue.appendChild(node);
    DefaultMutableTreeNode temp=new DefaultMutableTreeNode(param,true);
    ((DefaultTreeModel)tree.getModel()).insertNodeInto(temp,treenode,0);
    writeXML();
    uploadFile();
  }
}

Fixed version (ground truth):
public void appendParam(DefaultMutableTreeNode treenode,MyFolder parent){
  final JTextField name=new JTextField();
  name.addAncestorListener(new AncestorListener(){
    @Override public void ancestorRemoved(    AncestorEvent arg0){
    }
    @Override public void ancestorMoved(    AncestorEvent arg0){
    }
    @Override public void ancestorAdded(    AncestorEvent arg0){
      name.requestFocusInWindow();
    }
  }
);
  JTextField value=new JTextField();
  JPanel p=getPropPanel(name,value);
  int r=(Integer)CustomDialog.showDialog(p,JOptionPane.PLAIN_MESSAGE,JOptionPane.OK_CANCEL_OPTION,panel,"String_Node_Str",null);
  if (r == JOptionPane.OK_OPTION) {
    if (name.getText().equals("String_Node_Str")) {
      CustomDialog.showInfo(JOptionPane.WARNING_MESSAGE,main,"String_Node_Str","String_Node_Str");
      return;
    }
    for (int i=0; i < treenode.getChildCount(); i++) {
      Object node=((DefaultMutableTreeNode)treenode.getChildAt(i)).getUserObject();
      if (node.getClass() == MyParam.class) {
        if (((MyParam)node).getName().getNodeValue().equals(name.getText())) {
          CustomDialog.showInfo(JOptionPane.WARNING_MESSAGE,main,"String_Node_Str","String_Node_Str");
          return;
        }
      }
    }
    MyParam param=new MyParam();
    Element rootElement=doc.createElement("String_Node_Str");
    parent.getNode().getParentNode().getParentNode().appendChild(rootElement);
    Node refs=null;
    try {
      refs=parent.getNode().getParentNode().getParentNode().getFirstChild().getNextSibling().getNextSibling().getNextSibling();
    }
 catch (    Exception e) {
      refs=null;
    }
    if (refs == null) {
      parent.getNode().getParentNode().getParentNode().appendChild(rootElement);
    }
 else {
      parent.getNode().getParentNode().getParentNode().insertBefore(rootElement,refs);
    }
    Element tname=doc.createElement("String_Node_Str");
    rootElement.appendChild(tname);
    Node node=doc.createTextNode(name.getText());
    param.setName(node);
    tname.appendChild(node);
    Element tvalue=doc.createElement("String_Node_Str");
    rootElement.appendChild(tvalue);
    node=doc.createTextNode(value.getText());
    param.setValue(node);
    tvalue.appendChild(node);
    DefaultMutableTreeNode temp=new DefaultMutableTreeNode(param,true);
    ((DefaultTreeModel)tree.getModel()).insertNodeInto(temp,treenode,0);
    writeXML();
    uploadFile();
  }
}