Program: 125107
Project: 125107
Buggy source:
public boolean isMetadataExsit(Object node,DatabaseConnection connection){
  TableNode columnNode=null;
  if (node == null) {
    return false;
  }
  if (node instanceof TableNode) {
    columnNode=(TableNode)node;
  }
  if (columnNode.getType() == TableNode.COLUMN) {
    TableNode columnFamilyNode=columnNode.getParent();
    TableNode tableNode=null;
    String tableName=null;
    String columnFamilyName=null;
    String columnName=columnNode.getValue();
    if (columnFamilyNode != null) {
      columnFamilyName=columnFamilyNode.getValue();
      tableNode=columnFamilyNode.getParent();
      if (tableNode != null) {
        tableName=tableNode.getValue();
      }
    }
    List<MetadataTable> tables=ConnectionHelper.getTablesWithOrders(connection);
    for (    MetadataTable table : tables) {
      if (table instanceof TdTable) {
        TdTable tdTable=(TdTable)table;
        if (tdTable.getLabel().equals(tableName)) {
          List<MetadataColumn> columns=tdTable.getColumns();
          for (          MetadataColumn column : columns) {
            if (column.getLabel().equals(columnName)) {
              List<TaggedValue> tagValues=column.getTaggedValue();
              for (              TaggedValue tv : tagValues) {
                String tag=tv.getTag();
                String value=tv.getValue();
                if (tag != null && tag.equals(COLUMN_FAMILY)) {
                  if (value != null && value.equals(columnFamilyName)) {
                    columns.remove(column);
                    return true;
                  }
                }
              }
            }
          }
        }
      }
    }
  }
  return false;
}

Fixed version (ground truth):
@Override public boolean isMetadataExsit(Object node,DatabaseConnection connection){
  TableNode columnNode=null;
  if (node == null) {
    return false;
  }
  if (node instanceof TableNode) {
    columnNode=(TableNode)node;
  }
  if (columnNode.getType() == TableNode.COLUMN) {
    TableNode columnFamilyNode=columnNode.getParent();
    TableNode tableNode=null;
    String tableName=null;
    String columnFamilyName=null;
    String columnName=columnNode.getValue();
    if (columnFamilyNode != null) {
      columnFamilyName=columnFamilyNode.getValue();
      tableNode=columnFamilyNode.getParent();
      if (tableNode != null) {
        tableName=tableNode.getValue();
      }
    }
    List<MetadataTable> tables=ConnectionHelper.getTablesWithOrders(connection);
    for (    MetadataTable table : tables) {
      if (table instanceof TdTable) {
        TdTable tdTable=(TdTable)table;
        if (tdTable.getLabel().equals(tableName)) {
          List<MetadataColumn> columns=tdTable.getColumns();
          for (          MetadataColumn column : columns) {
            if (column.getLabel().equals(columnName)) {
              List<TaggedValue> tagValues=column.getTaggedValue();
              for (              TaggedValue tv : tagValues) {
                String tag=tv.getTag();
                String value=tv.getValue();
                if (tag != null && tag.equals(COLUMN_FAMILY)) {
                  if (value != null && value.equals(columnFamilyName)) {
                    columns.remove(column);
                    return true;
                  }
                }
              }
            }
          }
        }
      }
    }
  }
  return false;
}