Program: 34757
Project: 34757
Buggy source:
private static String jsonifyTraceAndMessage(int maxFieldLength,String wlpUserDir,String serverName,String hostName,String eventType,Object event,String[] tags){
  GenericData genData=(GenericData)event;
  StringBuilder sb=new StringBuilder();
  boolean isFirstField=true;
  ArrayList<Pair> pairs=genData.getPairs();
  KeyValuePair kvp=null;
  String key=null;
  String value=null;
  sb.append("String_Node_Str");
  isFirstField=CollectorJsonHelpers.addCommonFields(sb,hostName,wlpUserDir,serverName,isFirstField,eventType);
  for (  Pair p : pairs) {
    if (p instanceof KeyValuePair) {
      kvp=(KeyValuePair)p;
      key=kvp.getKey();
      value=kvp.getValue();
      if (!(key.equals(LogFieldConstants.LOGLEVEL))) {
      }
 else       if (key.equals(LogFieldConstants.MESSAGE)) {
        String formattedValue=CollectorJsonHelpers.formatMessage(value,maxFieldLength);
        isFirstField=isFirstField & !CollectorJsonHelpers.addToJSON(sb,key,formattedValue,false,true,false,isFirstField,kvp.isNumber());
      }
 else       if (key.equals(LogFieldConstants.IBM_THREADID)) {
        key=LogFieldConstants.THREADID;
        isFirstField=isFirstField & !CollectorJsonHelpers.addToJSON(sb,key,DataFormatHelper.padHexString(Integer.parseInt(value),8),false,true,false,isFirstField,kvp.isNumber());
      }
 else       if (key.equals(LogFieldConstants.IBM_DATETIME)) {
        key=LogFieldConstants.DATETIME;
        String datetime=CollectorJsonHelpers.dateFormatTL.get().format(Long.parseLong(value));
        isFirstField=isFirstField & !CollectorJsonHelpers.addToJSON(sb,key,datetime,false,true,false,isFirstField,kvp.isNumber());
      }
 else       if (key.equals(LogFieldConstants.MODULE)) {
        key=LogFieldConstants.LOGGERNAME;
        isFirstField=isFirstField & !CollectorJsonHelpers.addToJSON(sb,key,value,false,true,false,isFirstField,kvp.isNumber());
      }
 else {
        if (key.contains(LogFieldConstants.IBM_TAG)) {
          key=CollectorJsonHelpers.removeIBMTag(key);
        }
        isFirstField=isFirstField & !CollectorJsonHelpers.addToJSON(sb,key,value,false,true,false,isFirstField,kvp.isNumber());
      }
    }
  }
  if (tags != null) {
    addTagNameForVersion(sb).append(CollectorJsonHelpers.jsonifyTags(tags));
  }
  sb.append("String_Node_Str");
  return sb.toString();
}

Fixed version (ground truth):
private static String jsonifyTraceAndMessage(int maxFieldLength,String wlpUserDir,String serverName,String hostName,String eventType,Object event,String[] tags){
  GenericData genData=(GenericData)event;
  StringBuilder sb=new StringBuilder();
  boolean isFirstField=true;
  ArrayList<Pair> pairs=genData.getPairs();
  KeyValuePair kvp=null;
  String key=null;
  String value=null;
  sb.append("String_Node_Str");
  isFirstField=CollectorJsonHelpers.addCommonFields(sb,hostName,wlpUserDir,serverName,isFirstField,eventType);
  for (  Pair p : pairs) {
    if (p instanceof KeyValuePair) {
      kvp=(KeyValuePair)p;
      key=kvp.getKey();
      value=kvp.getValue();
      if (key.equals(LogFieldConstants.LOGLEVEL)) {
      }
 else       if (key.equals(LogFieldConstants.MESSAGE)) {
        String formattedValue=CollectorJsonHelpers.formatMessage(value,maxFieldLength);
        isFirstField=isFirstField & !CollectorJsonHelpers.addToJSON(sb,key,formattedValue,false,true,false,isFirstField,kvp.isNumber());
      }
 else       if (key.equals(LogFieldConstants.IBM_THREADID)) {
        key=LogFieldConstants.THREADID;
        isFirstField=isFirstField & !CollectorJsonHelpers.addToJSON(sb,key,DataFormatHelper.padHexString(Integer.parseInt(value),8),false,true,false,isFirstField,kvp.isNumber());
      }
 else       if (key.equals(LogFieldConstants.IBM_DATETIME)) {
        key=LogFieldConstants.DATETIME;
        String datetime=CollectorJsonHelpers.dateFormatTL.get().format(Long.parseLong(value));
        isFirstField=isFirstField & !CollectorJsonHelpers.addToJSON(sb,key,datetime,false,true,false,isFirstField,kvp.isNumber());
      }
 else       if (key.equals(LogFieldConstants.MODULE)) {
        key=LogFieldConstants.LOGGERNAME;
        isFirstField=isFirstField & !CollectorJsonHelpers.addToJSON(sb,key,value,false,true,false,isFirstField,kvp.isNumber());
      }
 else {
        if (key.contains(LogFieldConstants.IBM_TAG)) {
          key=CollectorJsonHelpers.removeIBMTag(key);
        }
        isFirstField=isFirstField & !CollectorJsonHelpers.addToJSON(sb,key,value,false,true,false,isFirstField,kvp.isNumber());
      }
    }
  }
  if (tags != null) {
    addTagNameForVersion(sb).append(CollectorJsonHelpers.jsonifyTags(tags));
  }
  sb.append("String_Node_Str");
  return sb.toString();
}