Program: 139317
Project: 139317
Buggy source:
private void addItemElements(final List<Column> columns,int index){
  for (int i=0; i < columns.size(); i++) {
    final TdColumn column=(TdColumn)columns.get(i);
    final TreeItem treeItem=new TreeItem(tree,SWT.NONE,index);
    MetadataHelper.setDataminingType(DataminingType.NOMINAL,column);
    columnSetMultiValueList.add(index,column);
    String columnName=column.getName();
    treeItem.setImage(ImageLib.getImage(ImageLib.TD_COLUMN));
    treeItem.setText(0,columnName != null ? columnName + PluginConstant.SPACE_STRING + PluginConstant.PARENTHESIS_LEFT+ column.getSqlDataType().getName()+ PluginConstant.PARENTHESIS_RIGHT : "String_Node_Str");
    treeItem.setData(COLUMN_INDICATOR_KEY,column);
    TreeEditor delLabelEditor=new TreeEditor(tree);
    Label delLabel=new Label(tree,SWT.NONE);
    delLabel.setBackground(Display.getDefault().getSystemColor(SWT.COLOR_WHITE));
    delLabel.setImage(ImageLib.getImage(ImageLib.DELETE_ACTION));
    delLabel.setToolTipText(DefaultMessagesImpl.getString("String_Node_Str"));
    delLabel.pack();
    delLabel.addMouseListener(new MouseAdapter(){
      @Override public void mouseDown(      MouseEvent e){
        deleteColumnItems(column);
        removeItemBranch(treeItem);
      }
    }
);
    delLabelEditor.minimumWidth=delLabel.getImage().getBounds().width;
    delLabelEditor.horizontalAlignment=SWT.CENTER;
    delLabelEditor.setEditor(delLabel,treeItem,1);
    treeItem.setData(ITEM_EDITOR_KEY,new TreeEditor[]{delLabelEditor});
    delLabelEditor.layout();
    treeItem.setExpanded(true);
  }
  tree.layout();
  tree.redraw();
  this.setDirty(true);
  tree.forceFocus();
}

Fixed version (ground truth):
private void addItemElements(final List<Column> columns,int index){
  for (int i=0; i < columns.size(); i++) {
    final TdColumn column=(TdColumn)columns.get(i);
    final TreeItem treeItem=new TreeItem(tree,SWT.NONE,index);
    MetadataHelper.setDataminingType(DataminingType.NOMINAL,column);
    columnSetMultiValueList.add(index,column);
    String columnName=column.getName();
    treeItem.setImage(ImageLib.getImage(ImageLib.TD_COLUMN));
    treeItem.setText(0,columnName != null ? columnName + PluginConstant.SPACE_STRING + PluginConstant.PARENTHESIS_LEFT+ column.getSqlDataType().getName()+ PluginConstant.PARENTHESIS_RIGHT : "String_Node_Str");
    treeItem.setData(COLUMN_INDICATOR_KEY,column);
    TreeEditor delLabelEditor=new TreeEditor(tree);
    Label delLabel=new Label(tree,SWT.NONE);
    delLabel.setBackground(Display.getDefault().getSystemColor(SWT.COLOR_WHITE));
    delLabel.setImage(ImageLib.getImage(ImageLib.DELETE_ACTION));
    delLabel.setToolTipText(DefaultMessagesImpl.getString("String_Node_Str"));
    delLabel.pack();
    delLabel.addMouseListener(new MouseAdapter(){
      @Override public void mouseDown(      MouseEvent e){
        deleteColumnItems(column);
        removeItemBranch(treeItem);
        updateBindConnection(masterPage,tree);
      }
    }
);
    delLabelEditor.minimumWidth=delLabel.getImage().getBounds().width;
    delLabelEditor.horizontalAlignment=SWT.CENTER;
    delLabelEditor.setEditor(delLabel,treeItem,1);
    treeItem.setData(ITEM_EDITOR_KEY,new TreeEditor[]{delLabelEditor});
    delLabelEditor.layout();
    treeItem.setExpanded(true);
  }
  tree.layout();
  tree.redraw();
  this.setDirty(true);
  tree.forceFocus();
}