Program: 86153
Project: 86153
Buggy source:
@Override public ReservationResult reservation(DetailledItem item,Account account,int useraction,String selection) throws IOException {
  String html=httpGet(opac_url + "String_Node_Str" + item.getId()+ "String_Node_Str"+ sessid,ENCODING,false,cookieStore);
  Document doc=Jsoup.parse(html);
  if (doc.select("String_Node_Str").size() > 0) {
    List<NameValuePair> nameValuePairs=new ArrayList<>(2);
    nameValuePairs.add(new BasicNameValuePair("String_Node_Str",account.getName()));
    nameValuePairs.add(new BasicNameValuePair("String_Node_Str",account.getPassword()));
    nameValuePairs.add(new BasicNameValuePair("String_Node_Str",sessid));
    nameValuePairs.add(new BasicNameValuePair("String_Node_Str","String_Node_Str"));
    nameValuePairs.add(new BasicNameValuePair("String_Node_Str","String_Node_Str" + item.getId()));
    html=httpPost(opac_url + "String_Node_Str",new UrlEncodedFormEntity(nameValuePairs),ENCODING);
    doc=Jsoup.parse(html);
    if (doc.select("String_Node_Str").size() > 0) {
      return new ReservationResult(MultiStepResult.Status.ERROR,doc.select("String_Node_Str").text());
    }
  }
  if (doc.select("String_Node_Str").size() > 0) {
    if (selection != null) {
      List<NameValuePair> nameValuePairs=new ArrayList<>(2);
      nameValuePairs.add(new BasicNameValuePair("String_Node_Str",item.getId()));
      nameValuePairs.add(new BasicNameValuePair("String_Node_Str",selection));
      nameValuePairs.add(new BasicNameValuePair("String_Node_Str",sessid));
      nameValuePairs.add(new BasicNameValuePair("String_Node_Str","String_Node_Str"));
      html=httpPost(opac_url + "String_Node_Str",new UrlEncodedFormEntity(nameValuePairs),ENCODING);
      doc=Jsoup.parse(html);
    }
 else {
      List<Map<String,String>> options=new ArrayList<>();
      for (      Element input : doc.select("String_Node_Str")) {
        Element label=doc.select("String_Node_Str" + input.id() + "String_Node_Str").first();
        Map<String,String> selopt=new HashMap<>();
        selopt.put("String_Node_Str",input.attr("String_Node_Str"));
        selopt.put("String_Node_Str",label.text());
        options.add(selopt);
      }
      ReservationResult res=new ReservationResult(MultiStepResult.Status.SELECTION_NEEDED);
      res.setSelection(options);
      return res;
    }
  }
  if (doc.select("String_Node_Str").size() > 0) {
    String text=doc.select("String_Node_Str").text();
    return new ReservationResult(MultiStepResult.Status.ERROR,text);
  }
  String text=doc.select("String_Node_Str").text();
  if (text.contains("String_Node_Str")) {
    return new ReservationResult(MultiStepResult.Status.OK,text);
  }
 else {
    return new ReservationResult(MultiStepResult.Status.ERROR,text);
  }
}

Fixed version (ground truth):
@Override public ReservationResult reservation(DetailedItem item,Account account,int useraction,String selection) throws IOException {
  String html=httpGet(opac_url + "String_Node_Str" + item.getId()+ "String_Node_Str"+ sessid,ENCODING,false,cookieStore);
  Document doc=Jsoup.parse(html);
  if (doc.select("String_Node_Str").size() > 0) {
    List<NameValuePair> nameValuePairs=new ArrayList<>(2);
    nameValuePairs.add(new BasicNameValuePair("String_Node_Str",account.getName()));
    nameValuePairs.add(new BasicNameValuePair("String_Node_Str",account.getPassword()));
    nameValuePairs.add(new BasicNameValuePair("String_Node_Str",sessid));
    nameValuePairs.add(new BasicNameValuePair("String_Node_Str","String_Node_Str"));
    nameValuePairs.add(new BasicNameValuePair("String_Node_Str","String_Node_Str" + item.getId()));
    html=httpPost(opac_url + "String_Node_Str",new UrlEncodedFormEntity(nameValuePairs),ENCODING);
    doc=Jsoup.parse(html);
    if (doc.select("String_Node_Str").size() > 0) {
      return new ReservationResult(MultiStepResult.Status.ERROR,doc.select("String_Node_Str").text());
    }
  }
  if (doc.select("String_Node_Str").size() > 0) {
    if (selection != null) {
      List<NameValuePair> nameValuePairs=new ArrayList<>(2);
      nameValuePairs.add(new BasicNameValuePair("String_Node_Str",item.getId()));
      nameValuePairs.add(new BasicNameValuePair("String_Node_Str",selection));
      nameValuePairs.add(new BasicNameValuePair("String_Node_Str",sessid));
      nameValuePairs.add(new BasicNameValuePair("String_Node_Str","String_Node_Str"));
      html=httpPost(opac_url + "String_Node_Str",new UrlEncodedFormEntity(nameValuePairs),ENCODING);
      doc=Jsoup.parse(html);
    }
 else {
      List<Map<String,String>> options=new ArrayList<>();
      for (      Element input : doc.select("String_Node_Str")) {
        Element label=doc.select("String_Node_Str" + input.id() + "String_Node_Str").first();
        Map<String,String> selopt=new HashMap<>();
        selopt.put("String_Node_Str",input.attr("String_Node_Str"));
        selopt.put("String_Node_Str",label.text());
        options.add(selopt);
      }
      ReservationResult res=new ReservationResult(MultiStepResult.Status.SELECTION_NEEDED);
      res.setSelection(options);
      return res;
    }
  }
  if (doc.select("String_Node_Str").size() > 0) {
    String text=doc.select("String_Node_Str").text();
    return new ReservationResult(MultiStepResult.Status.ERROR,text);
  }
  String text=doc.select("String_Node_Str").text();
  if (text.contains("String_Node_Str")) {
    return new ReservationResult(MultiStepResult.Status.OK,text);
  }
 else {
    return new ReservationResult(MultiStepResult.Status.ERROR,text);
  }
}