Program: 100632
Project: 100632
Buggy source:
@Override public void startElement(final String uri,final String localName,final String qName,final Attributes atts) throws SAXException {
  final int attsLen=atts.getLength();
  try {
    if (topicLevel != -1) {
      if (!hasProlog(atts) && startTopic && !hasWritten) {
        writeStartElement(TOPIC_PROLOG.localName,new AttributesBuilder().add(ATTRIBUTE_NAME_CLASS,TOPIC_PROLOG.toString()).build());
        writeStartElement(TOPIC_METADATA.localName,new AttributesBuilder().add(ATTRIBUTE_NAME_CLASS,TOPIC_METADATA.toString()).build());
        output.write(indexEntries);
        writeEndElement(TOPIC_METADATA.localName);
        writeEndElement(TOPIC_PROLOG.localName);
        hasPrologTillNow=true;
        hasWritten=true;
      }
    }
    if (!startTopic && !ELEMENT_NAME_DITA.equals(qName)) {
      if (atts.getValue(ATTRIBUTE_NAME_ID) != null) {
        topicIdList.add(atts.getValue(ATTRIBUTE_NAME_ID));
      }
 else {
        topicIdList.add("String_Node_Str");
      }
      if (topicIdList.size() >= matchList.size()) {
        startTopic=checkMatch();
      }
    }
    if (!hasMetadata(qName) && startTopic && !hasWritten) {
      writeStartElement(TOPIC_METADATA.localName,new AttributesBuilder().add(ATTRIBUTE_NAME_CLASS,TOPIC_METADATA.toString()).build());
      output.write(indexEntries);
      writeEndElement(TOPIC_METADATA.localName);
      hasMetadataTillNow=true;
      hasWritten=true;
    }
    writeStartElement(qName,atts);
    if (atts.getValue(ATTRIBUTE_NAME_CLASS) != null) {
      if (atts.getValue(ATTRIBUTE_NAME_CLASS).contains(TOPIC_METADATA.matcher) && startTopic && !hasWritten) {
        hasMetadataTillNow=true;
        output.write(indexEntries);
        hasWritten=true;
      }
      if (atts.getValue(ATTRIBUTE_NAME_CLASS).contains(TOPIC_PROLOG.matcher)) {
        hasPrologTillNow=true;
      }
    }
  }
 catch (  final Exception e) {
    logger.error(e.getMessage(),e);
  }
}

Fixed version (ground truth):
@Override public void startElement(final String uri,final String localName,final String qName,final Attributes atts) throws SAXException {
  try {
    if (topicLevel != -1) {
      if (!hasProlog(atts) && startTopic && !hasWritten) {
        writeStartElement(TOPIC_PROLOG.localName,new AttributesBuilder().add(ATTRIBUTE_NAME_CLASS,TOPIC_PROLOG.toString()).build());
        writeStartElement(TOPIC_METADATA.localName,new AttributesBuilder().add(ATTRIBUTE_NAME_CLASS,TOPIC_METADATA.toString()).build());
        output.write(indexEntries);
        writeEndElement(TOPIC_METADATA.localName);
        writeEndElement(TOPIC_PROLOG.localName);
        hasPrologTillNow=true;
        hasWritten=true;
      }
    }
    if (!startTopic && !ELEMENT_NAME_DITA.equals(qName)) {
      if (atts.getValue(ATTRIBUTE_NAME_ID) != null) {
        topicIdList.add(atts.getValue(ATTRIBUTE_NAME_ID));
      }
 else {
        topicIdList.add("String_Node_Str");
      }
      if (topicIdList.size() >= matchList.size()) {
        startTopic=checkMatch();
      }
    }
    if (!hasMetadata(qName) && startTopic && !hasWritten) {
      writeStartElement(TOPIC_METADATA.localName,new AttributesBuilder().add(ATTRIBUTE_NAME_CLASS,TOPIC_METADATA.toString()).build());
      output.write(indexEntries);
      writeEndElement(TOPIC_METADATA.localName);
      hasMetadataTillNow=true;
      hasWritten=true;
    }
    writeStartElement(qName,atts);
    if (atts.getValue(ATTRIBUTE_NAME_CLASS) != null) {
      if (atts.getValue(ATTRIBUTE_NAME_CLASS).contains(TOPIC_METADATA.matcher) && startTopic && !hasWritten) {
        hasMetadataTillNow=true;
        output.write(indexEntries);
        hasWritten=true;
      }
      if (atts.getValue(ATTRIBUTE_NAME_CLASS).contains(TOPIC_PROLOG.matcher)) {
        hasPrologTillNow=true;
      }
    }
  }
 catch (  final Exception e) {
    logger.error(e.getMessage(),e);
  }
}