Program: 69356
Project: 69356
Buggy source:
@Override public void prepare(HttpServletResponse hres){
  String exportFolderName=translator.translate("String_Node_Str");
  if (hres != null) {
    String label=StringHelper.transformDisplayNameToFileSystemName(title);
    if (label != null && !label.toLowerCase().endsWith("String_Node_Str")) {
      label+="String_Node_Str";
    }
    String urlEncodedLabel=StringHelper.urlEncodeUTF8(label);
    hres.setHeader("String_Node_Str","String_Node_Str" + urlEncodedLabel);
    hres.setHeader("String_Node_Str",urlEncodedLabel);
  }
  try {
    ZipOutputStream zout=hres == null ? exportStream : new ZipOutputStream(hres.getOutputStream());
    zout.setLevel(9);
    List<AssessedMember> assessedMembers=new ArrayList<AssessedMember>();
    for (    Identity identity : identities) {
      String idDir=exportFolderName + "String_Node_Str" + DATA+ identity.getName();
      idDir=idDir.endsWith(SEP) ? idDir : idDir + SEP;
      createZipDirectory(zout,idDir);
      String userName=identity.getName();
      String firstName=identity.getUser().getProperty(UserConstants.FIRSTNAME,null);
      String lastName=identity.getUser().getProperty(UserConstants.LASTNAME,null);
      String memberEmail=identity.getUser().getProperty(UserConstants.EMAIL,null);
      AssessedMember assessedMember=new AssessedMember(userName,lastName,firstName,memberEmail,null);
      Long resourceId=courseEnv.getCourseResourceableId();
      String resourceDetail=courseNode.getIdent();
      Long resid=courseNode.getReferencedRepositoryEntry().getKey();
      List<QTIResultSet> resultSets=qtiResultManager.getResultSets(resourceId,resourceDetail,resid,identity);
      List<ResultDetail> assessments=new ArrayList<ResultDetail>();
      for (      QTIResultSet qtiResultSet : resultSets) {
        Long assessmentID=qtiResultSet.getAssessmentID();
        String idPath=idDir + translator.translate("String_Node_Str") + (resultSets.indexOf(qtiResultSet) + 1)+ SEP;
        createZipDirectory(zout,idPath);
        String linkToHTML=createHTMLfromQTIResultSet(idPath,idDir,zout,identity,qtiResultSet);
        ResultDetail resultDetail=new ResultDetail(createLink(String.valueOf(assessmentID),linkToHTML,true),assessmentDateFormat.format(qtiResultSet.getCreationDate()),displayDateFormat.format(new Date(qtiResultSet.getDuration())),qtiResultSet.getScore(),createPassedIcons(qtiResultSet.getIsPassed()),linkToHTML);
        assessments.add(resultDetail);
      }
      String oneUserHTML=createResultListingHTML(assessments,assessedMember);
      convertToZipEntry(zout,exportFolderName + "String_Node_Str" + DATA+ identity.getName()+ "String_Node_Str",oneUserHTML);
      String linkToUser=idDir.replace(exportFolderName + "String_Node_Str","String_Node_Str") + "String_Node_Str";
      AssessedMember member=new AssessedMember();
      member.setUsername(createLink(identity.getName(),linkToUser,false));
      member.setLastname(createLink(identity.getUser().getProperty(UserConstants.LASTNAME,null),linkToUser,false));
      member.setFirstname(createLink(identity.getUser().getProperty(UserConstants.FIRSTNAME,null),linkToUser,false));
      member.setTries(String.valueOf(resultSets.size()));
      assessedMembers.add(member);
    }
    String usersHTML=createMemberListingHTML(assessedMembers);
    convertToZipEntry(zout,exportFolderName + "String_Node_Str",usersHTML);
    File sasstheme=new File(WebappHelper.getContextRealPath("String_Node_Str"));
    fsToZip(zout,sasstheme.toPath(),exportFolderName + "String_Node_Str");
    File fontawesome=new File(WebappHelper.getContextRealPath("String_Node_Str"));
    fsToZip(zout,fontawesome.toPath(),exportFolderName + "String_Node_Str");
    if (hres != null) {
      zout.close();
    }
  }
 catch (  Exception e) {
    log.error("String_Node_Str",e);
  }
}

Fixed version (ground truth):
@Override public void prepare(HttpServletResponse hres){
  boolean hasServletResponse=hres != null;
  if (hasServletResponse) {
    String label=StringHelper.transformDisplayNameToFileSystemName(title);
    if (label != null && !label.toLowerCase().endsWith("String_Node_Str")) {
      label+="String_Node_Str";
    }
    String urlEncodedLabel=StringHelper.urlEncodeUTF8(label);
    hres.setHeader("String_Node_Str","String_Node_Str" + urlEncodedLabel);
    hres.setHeader("String_Node_Str",urlEncodedLabel);
  }
  try {
    createZipStream(hres,hasServletResponse);
  }
 catch (  Exception e) {
    log.error("String_Node_Str",e);
  }
}