Program: 124317
Project: 124317
Buggy source:
@Override public void run(){
  if (selectedNode != null) {
    IInputValidator validataor=new IInputValidator(){
      public String isValid(      String newText){
        String xpath=XmlMapUtil.getXPath(((TreeNode)selectedNode.eContainer()).getXpath(),newText,selectedNode.getNodeType());
        EList<TreeNode> children=((TreeNode)selectedNode.eContainer()).getChildren();
        boolean exist=false;
        for (        TreeNode child : children) {
          if (child.getNodeType().equals(selectedNode.getNodeType())) {
            if (child.getXpath() != null && child.getXpath().equals(xpath) && !child.equals(selectedNode)) {
              exist=true;
              break;
            }
          }
        }
        if (exist) {
          if (selectedNode.getNodeType().equals(NodeType.ATTRIBUT)) {
            return "String_Node_Str" + newText + "String_Node_Str";
          }
 else           if (selectedNode.getNodeType().equals(NodeType.ELEMENT)) {
            return "String_Node_Str" + newText + "String_Node_Str";
          }
 else           if (selectedNode.getNodeType().equals(NodeType.NAME_SPACE)) {
            return "String_Node_Str" + newText + "String_Node_Str";
          }
        }
        return null;
      }
    }
;
    InputDialog dialog=new InputDialog(null,"String_Node_Str","String_Node_Str",selectedNode.getName(),validataor);
    if (dialog.open() == Window.OK) {
      selectedNode.setName(dialog.getValue());
      XmlMapData externalEmfData=(XmlMapData)mapperManager.getCopyOfMapData();
      XmlMapUtil.updateXPathAndExpression(externalEmfData,selectedNode,dialog.getValue(),XmlMapUtil.getXPathLength(selectedNode.getXpath()),true);
      TabFolderEditors tabFolderEditors=mapperManager.getMapperUI().getTabFolderEditors();
      if (tabFolderEditors != null) {
        if (selectedNode instanceof OutputTreeNode) {
          tabFolderEditors.getOutputTreeSchemaEditor().refresh();
        }
 else         if (selectedNode instanceof TreeNode) {
          tabFolderEditors.getInputTreeSchemaEditor().refresh();
        }
      }
    }
  }
}

Fixed version (ground truth):
@Override public void run(){
  if (selectedNode != null) {
    IInputValidator validataor=new IInputValidator(){
      public String isValid(      String newText){
        String xpath=XmlMapUtil.getXPath(((TreeNode)selectedNode.eContainer()).getXpath(),newText,selectedNode.getNodeType());
        EList<TreeNode> children=((TreeNode)selectedNode.eContainer()).getChildren();
        boolean exist=false;
        for (        TreeNode child : children) {
          if (child.getNodeType().equals(selectedNode.getNodeType())) {
            if (child.getXpath() != null && child.getXpath().equals(xpath) && !child.equals(selectedNode)) {
              exist=true;
              break;
            }
          }
        }
        if (exist) {
          if (selectedNode.getNodeType().equals(NodeType.ATTRIBUT)) {
            return "String_Node_Str" + newText + "String_Node_Str";
          }
 else           if (selectedNode.getNodeType().equals(NodeType.ELEMENT)) {
            return "String_Node_Str" + newText + "String_Node_Str";
          }
        }
        return null;
      }
    }
;
    InputDialog dialog=new InputDialog(null,"String_Node_Str","String_Node_Str",selectedNode.getName(),validataor);
    if (dialog.open() == Window.OK) {
      selectedNode.setName(dialog.getValue());
      XmlMapData externalEmfData=(XmlMapData)mapperManager.getCopyOfMapData();
      XmlMapUtil.updateXPathAndExpression(externalEmfData,selectedNode,dialog.getValue(),XmlMapUtil.getXPathLength(selectedNode.getXpath()),true);
      TabFolderEditors tabFolderEditors=mapperManager.getMapperUI().getTabFolderEditors();
      if (tabFolderEditors != null) {
        if (selectedNode instanceof OutputTreeNode) {
          tabFolderEditors.getOutputTreeSchemaEditor().refresh();
        }
 else         if (selectedNode instanceof TreeNode) {
          tabFolderEditors.getInputTreeSchemaEditor().refresh();
        }
      }
    }
  }
}