Program: 86144
Project: 86144
Buggy source:
@Override public ReservationResult reservation(DetailledItem item,Account account,int useraction,String selection) throws IOException {
  String resinfo=item.getReservation_info();
  if (selection == null || selection.equals("String_Node_Str")) {
    String func=opacDir.contains("String_Node_Str") ? "String_Node_Str" : "String_Node_Str";
    String id=opacDir.contains("String_Node_Str") ? (resinfo.contains("String_Node_Str") ? resinfo.substring(5) + "String_Node_Str" + resinfo : resinfo + "String_Node_Str" + resinfo) : "String_Node_Str" + resinfo;
    String html=httpGet(opacUrl + "String_Node_Str" + opacDir+ "String_Node_Str"+ opacSuffix+ "String_Node_Str"+ func+ "String_Node_Str"+ id,getDefaultEncoding());
    Document doc=Jsoup.parse(html);
    newStyleReservations=doc.select("String_Node_Str" + resinfo.replace("String_Node_Str","String_Node_Str") + "String_Node_Str").val().length() > 4;
    Elements optionsElements=doc.select("String_Node_Str");
    if (optionsElements.size() > 0) {
      List<Map<String,String>> options=new ArrayList<>();
      for (      Element option : optionsElements) {
        if ("String_Node_Str".equals(option.attr("String_Node_Str"))) {
          continue;
        }
        Map<String,String> selopt=new HashMap<>();
        selopt.put("String_Node_Str",option.attr("String_Node_Str") + "String_Node_Str" + option.text());
        selopt.put("String_Node_Str",option.text());
        options.add(selopt);
      }
      if (options.size() > 1) {
        ReservationResult res=new ReservationResult(MultiStepResult.Status.SELECTION_NEEDED);
        res.setActionIdentifier(ReservationResult.ACTION_BRANCH);
        res.setSelection(options);
        return res;
      }
 else {
        return reservation(item,account,useraction,options.get(0).get("String_Node_Str"));
      }
    }
 else {
      ReservationResult res=new ReservationResult(MultiStepResult.Status.ERROR);
      res.setMessage("String_Node_Str");
      return res;
    }
  }
 else {
    List<NameValuePair> nameValuePairs=new ArrayList<>();
    nameValuePairs.add(new BasicNameValuePair("String_Node_Str","String_Node_Str"));
    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","String_Node_Str"));
    if (opacDir.contains("String_Node_Str")) {
      nameValuePairs.add(new BasicNameValuePair(resinfo.replace("String_Node_Str","String_Node_Str"),"String_Node_Str" + (newStyleReservations ? resinfo.replace("String_Node_Str","String_Node_Str") : "String_Node_Str")));
    }
    if (newStyleReservations) {
      nameValuePairs.add(new BasicNameValuePair("String_Node_Str",selection.split("String_Node_Str")[1]));
    }
    nameValuePairs.add(new BasicNameValuePair("String_Node_Str",selection.split("String_Node_Str")[0]));
    String html=httpPost(opacUrl + "String_Node_Str" + opacDir+ "String_Node_Str"+ opacSuffix,new UrlEncodedFormEntity(nameValuePairs),getDefaultEncoding());
    Document doc=Jsoup.parse(html);
    if (doc.select("String_Node_Str").text().contains("String_Node_Str")) {
      return new ReservationResult(MultiStepResult.Status.OK);
    }
 else {
      ReservationResult res=new ReservationResult(MultiStepResult.Status.ERROR);
      if (doc.select("String_Node_Str").size() > 0) {
        res.setMessage(doc.select("String_Node_Str").text());
      }
      return res;
    }
  }
}

Fixed version (ground truth):
@Override public ReservationResult reservation(DetailedItem item,Account account,int useraction,String selection) throws IOException {
  String resinfo=item.getReservation_info();
  if (selection == null || selection.equals("String_Node_Str")) {
    String func=opacDir.contains("String_Node_Str") ? "String_Node_Str" : "String_Node_Str";
    String id=opacDir.contains("String_Node_Str") ? (resinfo.contains("String_Node_Str") ? resinfo.substring(5) + "String_Node_Str" + resinfo : resinfo + "String_Node_Str" + resinfo) : "String_Node_Str" + resinfo;
    String html=httpGet(opacUrl + "String_Node_Str" + opacDir+ "String_Node_Str"+ opacSuffix+ "String_Node_Str"+ func+ "String_Node_Str"+ id,getDefaultEncoding());
    Document doc=Jsoup.parse(html);
    newStyleReservations=doc.select("String_Node_Str" + resinfo.replace("String_Node_Str","String_Node_Str") + "String_Node_Str").val().length() > 4;
    Elements optionsElements=doc.select("String_Node_Str");
    if (optionsElements.size() > 0) {
      List<Map<String,String>> options=new ArrayList<>();
      for (      Element option : optionsElements) {
        if ("String_Node_Str".equals(option.attr("String_Node_Str"))) {
          continue;
        }
        Map<String,String> selopt=new HashMap<>();
        selopt.put("String_Node_Str",option.attr("String_Node_Str") + "String_Node_Str" + option.text());
        selopt.put("String_Node_Str",option.text());
        options.add(selopt);
      }
      if (options.size() > 1) {
        ReservationResult res=new ReservationResult(MultiStepResult.Status.SELECTION_NEEDED);
        res.setActionIdentifier(ReservationResult.ACTION_BRANCH);
        res.setSelection(options);
        return res;
      }
 else {
        return reservation(item,account,useraction,options.get(0).get("String_Node_Str"));
      }
    }
 else {
      ReservationResult res=new ReservationResult(MultiStepResult.Status.ERROR);
      res.setMessage("String_Node_Str");
      return res;
    }
  }
 else {
    List<NameValuePair> nameValuePairs=new ArrayList<>();
    nameValuePairs.add(new BasicNameValuePair("String_Node_Str","String_Node_Str"));
    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","String_Node_Str"));
    if (opacDir.contains("String_Node_Str")) {
      nameValuePairs.add(new BasicNameValuePair(resinfo.replace("String_Node_Str","String_Node_Str"),"String_Node_Str" + (newStyleReservations ? resinfo.replace("String_Node_Str","String_Node_Str") : "String_Node_Str")));
    }
    if (newStyleReservations) {
      nameValuePairs.add(new BasicNameValuePair("String_Node_Str",selection.split("String_Node_Str")[1]));
    }
    nameValuePairs.add(new BasicNameValuePair("String_Node_Str",selection.split("String_Node_Str")[0]));
    String html=httpPost(opacUrl + "String_Node_Str" + opacDir+ "String_Node_Str"+ opacSuffix,new UrlEncodedFormEntity(nameValuePairs),getDefaultEncoding());
    Document doc=Jsoup.parse(html);
    if (doc.select("String_Node_Str").text().contains("String_Node_Str")) {
      return new ReservationResult(MultiStepResult.Status.OK);
    }
 else {
      ReservationResult res=new ReservationResult(MultiStepResult.Status.ERROR);
      if (doc.select("String_Node_Str").size() > 0) {
        res.setMessage(doc.select("String_Node_Str").text());
      }
      return res;
    }
  }
}