Program: 69727
Project: 69727
Buggy source:
/** 
 * Build fail resprocessing: Adjust score to 0 (if single correct mode)  and set hints, solutions and fail feedback when any blank is answered  wrong
 * @param resprocessingXML
 * @param isSingleCorrect
 */
private void buildRespcondition_fail(Element resprocessingXML,boolean isSingleCorrect){
  Element respcondition_fail=resprocessingXML.addElement("String_Node_Str");
  respcondition_fail.addAttribute("String_Node_Str","String_Node_Str");
  respcondition_fail.addAttribute("String_Node_Str","String_Node_Str");
  Element conditionvar=respcondition_fail.addElement("String_Node_Str");
  Element or=conditionvar.addElement("String_Node_Str");
  for (Iterator i=getResponses().iterator(); i.hasNext(); ) {
    FIBResponse tmpResponse=(FIBResponse)i.next();
    if (!tmpResponse.getType().equals(FIBResponse.TYPE_BLANK)) {
      continue;
    }
    String[] correctFIBs=tmpResponse.getCorrectBlank().split("String_Node_Str");
    Element not=or.addElement("String_Node_Str");
    Element orVal=not.addElement("String_Node_Str");
    for (int j=0; j < correctFIBs.length; j++) {
      String correctFIB=correctFIBs[j];
      if (correctFIB.length() > 0) {
        Element varequal=orVal.addElement("String_Node_Str");
        varequal.addAttribute("String_Node_Str",tmpResponse.getIdent());
        varequal.addAttribute("String_Node_Str",tmpResponse.getCaseSensitive());
        varequal.addCDATA(correctFIB);
      }
    }
  }
  if (isSingleCorrect) {
    Element setvar=respcondition_fail.addElement("String_Node_Str");
    setvar.addAttribute("String_Node_Str","String_Node_Str");
    setvar.addAttribute("String_Node_Str","String_Node_Str");
    setvar.addText("String_Node_Str");
  }
  QTIEditHelper.addFeedbackFail(respcondition_fail);
  QTIEditHelper.addFeedbackHint(respcondition_fail);
  QTIEditHelper.addFeedbackSolution(respcondition_fail);
  if (or.element("String_Node_Str") == null)   resprocessingXML.remove(respcondition_fail);
}

Fixed version (ground truth):
/** 
 * Build fail resprocessing: Adjust score to 0 (if single correct mode)  and set hints, solutions and fail feedback when any blank is answered  wrong
 * @param resprocessingXML
 * @param isSingleCorrect
 */
private void buildRespcondition_fail(Element resprocessingXML,boolean isSingleCorrect){
  Element respcondition_fail=resprocessingXML.addElement("String_Node_Str");
  respcondition_fail.addAttribute("String_Node_Str","String_Node_Str");
  respcondition_fail.addAttribute("String_Node_Str","String_Node_Str");
  Element conditionvar=respcondition_fail.addElement("String_Node_Str");
  Element or=conditionvar.addElement("String_Node_Str");
  for (Iterator<Response> i=getResponses().iterator(); i.hasNext(); ) {
    FIBResponse tmpResponse=(FIBResponse)i.next();
    if (!tmpResponse.getType().equals(FIBResponse.TYPE_BLANK)) {
      continue;
    }
    String[] correctFIBs=tmpResponse.getCorrectBlank().split("String_Node_Str");
    if (correctFIBs.length > 1) {
      Element not=or.addElement("String_Node_Str");
      Element orVal=not.addElement("String_Node_Str");
      for (int j=0; j < correctFIBs.length; j++) {
        String correctFIB=correctFIBs[j];
        if (correctFIB.length() > 0) {
          Element varequal=orVal.addElement("String_Node_Str");
          varequal.addAttribute("String_Node_Str",tmpResponse.getIdent());
          varequal.addAttribute("String_Node_Str",tmpResponse.getCaseSensitive());
          varequal.addCDATA(correctFIB);
        }
      }
    }
  }
  if (isSingleCorrect) {
    Element setvar=respcondition_fail.addElement("String_Node_Str");
    setvar.addAttribute("String_Node_Str","String_Node_Str");
    setvar.addAttribute("String_Node_Str","String_Node_Str");
    setvar.addText("String_Node_Str");
  }
  QTIEditHelper.addFeedbackFail(respcondition_fail);
  QTIEditHelper.addFeedbackHint(respcondition_fail);
  QTIEditHelper.addFeedbackSolution(respcondition_fail);
  if (or.element("String_Node_Str") == null)   resprocessingXML.remove(respcondition_fail);
}