Program: 78370
Project: 78370
Buggy source:
/** 
 * Initialize the GUI components.
 */
private void initComponents(){
  panelData.setLayout(new GridLayout(4,1,70,20));
  panelData.setBorder(BorderFactory.createTitledBorder("String_Node_Str"));
  panelOut.add(panelData,BorderLayout.NORTH);
  panelOut.add(panelButton,BorderLayout.SOUTH);
  panelButton.setLayout(new GridLayout(1,2,5,5));
  panelButton.setBorder(BorderFactory.createEmptyBorder(30,90,10,90));
  panelButton.add(buttonConfirm,BorderLayout.SOUTH);
  for (int years=1930; years <= Calendar.getCurrentYear(); years++) {
    years_tmp.add(years + "String_Node_Str");
  }
  dayList=new JComboBox<>(day);
  monthList=new JComboBox<>(month);
  yearList=new JComboBox(years_tmp.toArray());
  HashSet<String> breedSet=proxy.getDogsBreedsList();
  breed=new String[breedSet.size()];
  int i=0;
  for (  String breedStr : breedSet) {
    breed[i]=breedStr;
    i++;
  }
  breedList=new JComboBox<>(breed);
  panelData.add(labelDogsName);
  panelData.add(textDogsName);
  panelData.add(labelDogBreed);
  panelData.add(breedList);
  panelData.add(labelDogsWeight);
  panelData.add(textDogsWeight);
  panelData.add(labelDogsAge);
  panelDate.setLayout(new GridLayout(1,3,5,5));
  panelDate.add(dayList);
  panelDate.add(monthList);
  panelDate.add(yearList);
  panelData.add(panelDate);
  add(panelOut);
  ActionListener registration=new ActionListener(){
    @Override public void actionPerformed(    ActionEvent registrationAe){
      if (registrationAe.getActionCommand().equals("String_Node_Str")) {
        if (textDogsName.getText().equals("String_Node_Str") || textDogsWeight.getText().equals("String_Node_Str")) {
          JOptionPane.showMessageDialog(new JFrame(),"String_Node_Str","String_Node_Str",JOptionPane.ERROR_MESSAGE);
        }
 else         if (checkNumber(textDogsWeight.getText())) {
          boolean add=newDog();
          if (add) {
            JOptionPane.showMessageDialog(new JFrame(),"String_Node_Str","String_Node_Str",JOptionPane.INFORMATION_MESSAGE);
            guiCustomerLabel.dispatchEvent(new WindowEvent(guiCustomerLabel,WindowEvent.WINDOW_CLOSING));
            GUILogin guiLogin=new GUILogin();
            guiLogin.setVisible(true);
          }
        }
      }
    }
  }
;
  buttonConfirm.addActionListener(registration);
}

Fixed version (ground truth):
/** 
 * Initialize the GUI components.
 */
private void initComponents(){
  panelData.setLayout(new GridLayout(4,1,70,20));
  panelData.setBorder(BorderFactory.createTitledBorder("String_Node_Str"));
  panelOut.add(panelData,BorderLayout.NORTH);
  panelOut.add(panelButton,BorderLayout.SOUTH);
  panelButton.setLayout(new GridLayout(1,2,5,5));
  panelButton.setBorder(BorderFactory.createEmptyBorder(30,90,10,90));
  panelButton.add(buttonConfirm,BorderLayout.SOUTH);
  for (int years=1930; years <= Calendar.getCurrentYear(); years++) {
    years_tmp.add(years + "String_Node_Str");
  }
  dayList=new JComboBox<>(day);
  monthList=new JComboBox<>(month);
  yearList=new JComboBox(years_tmp.toArray());
  HashSet<String> breedSet=proxy.getDogsBreedsList();
  breed=new String[breedSet.size()];
  int i=0;
  for (  String breedStr : breedSet) {
    breed[i]=breedStr;
    i++;
  }
  breedList=new JComboBox<>(breed);
  panelData.add(labelDogsName);
  panelData.add(textDogsName);
  panelData.add(labelDogBreed);
  panelData.add(breedList);
  panelData.add(labelDogsWeight);
  panelData.add(textDogsWeight);
  panelData.add(labelDogsAge);
  panelDate.setLayout(new GridLayout(1,3,5,5));
  panelDate.add(dayList);
  panelDate.add(monthList);
  panelDate.add(yearList);
  panelData.add(panelDate);
  add(panelOut);
  ActionListener registration=new ActionListener(){
    @Override public void actionPerformed(    ActionEvent registrationAe){
      if (registrationAe.getActionCommand().equals("String_Node_Str")) {
        if (textDogsName.getText().equals("String_Node_Str") || textDogsWeight.getText().equals("String_Node_Str")) {
          JOptionPane.showMessageDialog(new JFrame(),"String_Node_Str","String_Node_Str",JOptionPane.ERROR_MESSAGE);
        }
 else         if (checkNumber(textDogsWeight.getText())) {
          boolean add=newDog();
          if (add) {
            JOptionPane.showMessageDialog(new JFrame(),"String_Node_Str","String_Node_Str",JOptionPane.INFORMATION_MESSAGE);
            guiCustomerLabel.dispatchEvent(new WindowEvent(guiCustomerLabel,WindowEvent.WINDOW_CLOSING));
            guiSignUp.dispatchEvent(new WindowEvent(guiSignUp,WindowEvent.WINDOW_CLOSING));
          }
        }
      }
    }
  }
;
  buttonConfirm.addActionListener(registration);
}