public Properties getChangedProperties() {
    Properties ret = new Properties();
    Properties newProp = getAllProperties();

    for (Object one : newProp.keySet()) {
      String oneProp = (String) one;
      String oldValue = origProp.getProperty(oneProp);
      if (!StringUtils.equals(oldValue, newProp.getProperty(oneProp))) {
        ret.setProperty(oneProp, newProp.getProperty(oneProp));
      }
    }
    return (ret);
  }
Overlays ConfVar properties with non-null values
common/src/java/org/apache/hadoop/hive/conf/HiveConf.java