Program: 17552
Project: 17552
Buggy source:
/** 
 * <code>handleClosingTag</code> - Handles a closing tag in the document
 * @return true - everything okay, false - error during parsing.
 * @param match the match that's a closer
 * @param matchStack - the stack of matched items
 */
protected boolean handleClosingTag(ParseItemMatch match,Stack matchStack){
  String closerName=match.match;
  if (closerName.toLowerCase().indexOf("String_Node_Str") != -1) {
    closerName=closerName.substring(4,closerName.length() - 1);
    DocItem topItem=(DocItem)matchStack.pop();
    if (topItem instanceof TagItem) {
      try {
        TagItem tempItem=new TagItem(match.lineNumber,match.startPos,match.endPos + 1,match.match);
        ((TagItem)topItem).setMatchingItem(tempItem);
      }
 catch (      Exception e) {
        System.err.println("String_Node_Str" + e.getMessage());
        e.printStackTrace();
      }
    }
    if (topItem.getName().compareToIgnoreCase(closerName) == 0) {
      DocItem parentItem=(DocItem)matchStack.pop();
      try {
        parentItem.addChild(topItem);
      }
 catch (      Exception excep) {
        excep.printStackTrace();
        throw (RuntimeException)excep.fillInStackTrace();
      }
      matchStack.push(parentItem);
    }
 else {
      ParseItemMatch tempMatch=new ParseItemMatch(match.match,match.startPos,match.endPos,getLineNumber(match.startPos),MATCHER_NOTHING);
      userMessage(matchStack.size(),"String_Node_Str","String_Node_Str" + match.match + "String_Node_Str"+ topItem.getName()+ "String_Node_Str",USRMSG_ERROR,tempMatch);
      return false;
    }
  }
  return true;
}

Fixed version (ground truth):
/** 
 * <code>handleClosingTag</code> - Handles a closing tag in the document
 * @return true - everything okay, false - error during parsing.
 * @param match the match that's a closer
 * @param matchStack - the stack of matched items
 */
protected boolean handleClosingTag(ParseItemMatch match,Stack matchStack){
  String closerName=match.match;
  if (closerName.toLowerCase().indexOf("String_Node_Str") != -1) {
    closerName=closerName.substring(2,closerName.length() - 1);
    DocItem topItem=(DocItem)matchStack.pop();
    if (topItem instanceof TagItem) {
      try {
        TagItem tempItem=new TagItem(match.lineNumber,match.startPos,match.endPos + 1,match.match);
        ((TagItem)topItem).setMatchingItem(tempItem);
      }
 catch (      Exception e) {
        System.err.println("String_Node_Str" + e.getMessage());
        e.printStackTrace();
      }
    }
    if (topItem.getName().compareToIgnoreCase(closerName) == 0) {
      DocItem parentItem=(DocItem)matchStack.pop();
      try {
        parentItem.addChild(topItem);
      }
 catch (      Exception excep) {
        excep.printStackTrace();
        throw (RuntimeException)excep.fillInStackTrace();
      }
      matchStack.push(parentItem);
    }
 else {
      ParseItemMatch tempMatch=new ParseItemMatch(match.match,match.startPos,match.endPos,getLineNumber(match.startPos),MATCHER_NOTHING);
      userMessage(matchStack.size(),"String_Node_Str","String_Node_Str" + match.match + "String_Node_Str"+ topItem.getName()+ "String_Node_Str",USRMSG_ERROR,tempMatch);
      return false;
    }
  }
  return true;
}