Program: 78387
Project: 78387
Buggy source:
/** 
 * inizializza le componenti dell'interfaccia
 */
private void initComponent(){
  setTitle("String_Node_Str");
  setSize(WIDTH,HEIGHT);
  setLocation((screenSize.width - getWidth()) / 2,(screenSize.height - getHeight()) / 2);
  setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
  setResizable(false);
  ActionListener registration=new ActionListener(){
    @Override public void actionPerformed(    ActionEvent registrationAe){
      if (registrationAe.getActionCommand().equals("String_Node_Str")) {
        if (textName.getText().equals("String_Node_Str") || textWeight.getText().equals("String_Node_Str")) {
          JOptionPane.showMessageDialog(new JFrame(),"String_Node_Str","String_Node_Str",JOptionPane.ERROR_MESSAGE);
        }
 else {
          boolean add=addNewDog();
          if (add) {
            JOptionPane.showMessageDialog(new JFrame(),"String_Node_Str","String_Node_Str",JOptionPane.INFORMATION_MESSAGE);
            dispose();
          }
        }
      }
      if (registrationAe.getActionCommand().equals("String_Node_Str")) {
        dispose();
      }
    }
  }
;
  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);
  panelDate.setLayout(new GridLayout(1,3,5,5));
  panelDate.add(dayList);
  panelDate.add(monthList);
  panelDate.add(yearList);
  panelData.setLayout(new GridLayout(4,2,10,10));
  panelData.setBorder(BorderFactory.createTitledBorder("String_Node_Str"));
  panelData.add(labelName);
  panelData.add(textName);
  panelData.add(labelBreed);
  panelData.add(breedList);
  panelData.add(labelWeight);
  panelData.add(textWeight);
  panelData.add(labelDate);
  panelData.add(panelDate);
  panelButton.setLayout(new GridLayout(1,2,5,5));
  panelButton.setBorder(BorderFactory.createEmptyBorder(15,90,10,90));
  buttonAdd.addActionListener(registration);
  buttonCancel.addActionListener(registration);
  panelButton.add(buttonAdd);
  panelButton.add(buttonCancel);
  panelOut.setBorder(BorderFactory.createEmptyBorder(5,15,5,15));
  panelOut.setLayout(new BorderLayout());
  panelOut.add(panelData,BorderLayout.NORTH);
  panelOut.add(panelButton,BorderLayout.SOUTH);
  add(panelOut);
}

Fixed version (ground truth):
/** 
 * inizializza le componenti dell'interfaccia
 */
private void initComponent(){
  setTitle("String_Node_Str");
  setSize(WIDTH,HEIGHT);
  setLocation((screenSize.width - getWidth()) / 2,(screenSize.height - getHeight()) / 2);
  setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
  setResizable(false);
  ActionListener registration=new ActionListener(){
    @Override public void actionPerformed(    ActionEvent registrationAe){
      if (registrationAe.getActionCommand().equals("String_Node_Str")) {
        if (textName.getText().equals("String_Node_Str") || textWeight.getText().equals("String_Node_Str")) {
          JOptionPane.showMessageDialog(new JFrame(),"String_Node_Str","String_Node_Str",JOptionPane.ERROR_MESSAGE);
        }
 else {
          boolean add=addNewDog();
          if (add) {
            JOptionPane.showMessageDialog(new JFrame(),"String_Node_Str","String_Node_Str",JOptionPane.INFORMATION_MESSAGE);
            guiAddDog.dispatchEvent(new WindowEvent(guiAddDog,WindowEvent.WINDOW_CLOSING));
            guiDogs.dispatchEvent(new WindowEvent(guiDogs,WindowEvent.WINDOW_CLOSING));
          }
        }
      }
      if (registrationAe.getActionCommand().equals("String_Node_Str")) {
        guiAddDog.dispatchEvent(new WindowEvent(guiAddDog,WindowEvent.WINDOW_CLOSING));
      }
    }
  }
;
  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);
  panelDate.setLayout(new GridLayout(1,3,5,5));
  panelDate.add(dayList);
  panelDate.add(monthList);
  panelDate.add(yearList);
  panelData.setLayout(new GridLayout(4,2,10,10));
  panelData.setBorder(BorderFactory.createTitledBorder("String_Node_Str"));
  panelData.add(labelName);
  panelData.add(textName);
  panelData.add(labelBreed);
  panelData.add(breedList);
  panelData.add(labelWeight);
  panelData.add(textWeight);
  panelData.add(labelDate);
  panelData.add(panelDate);
  panelButton.setLayout(new GridLayout(1,2,5,5));
  panelButton.setBorder(BorderFactory.createEmptyBorder(15,90,10,90));
  buttonAdd.addActionListener(registration);
  buttonCancel.addActionListener(registration);
  panelButton.add(buttonAdd);
  panelButton.add(buttonCancel);
  panelOut.setBorder(BorderFactory.createEmptyBorder(5,15,5,15));
  panelOut.setLayout(new BorderLayout());
  panelOut.add(panelData,BorderLayout.NORTH);
  panelOut.add(panelButton,BorderLayout.SOUTH);
  add(panelOut);
}