Program: 119374
Project: 119374
Buggy source:
@Override protected void addFieldsListeners(){
  ftpUsernameText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setUsername(ftpUsernameText.getText());
      checkFieldsValue();
    }
  }
);
  ftpPasswordText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setPassword(ftpPasswordText.getText());
      checkFieldsValue();
    }
  }
);
  ftpPortText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setPort(ftpPortText.getText());
      checkFieldsValue();
    }
  }
);
  ftpHostText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setHost(ftpHostText.getText());
      checkFieldsValue();
    }
  }
);
  proxyUsernameText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setProxyuser(proxyUsernameText.getText());
    }
  }
);
  proxyPasswordText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setProxypassword(proxyPasswordText.getText());
    }
  }
);
  proxyPortText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setProxyport(proxyPortText.getText());
    }
  }
);
  proxyHostText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setProxyhost(proxyHostText.getText());
    }
  }
);
  keyFileText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setKeystoreFile(keyFileText.getText());
    }
  }
);
  keyPasswordText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setKeystorePassword(keyPasswordText.getText());
    }
  }
);
  connModelCombo.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setMode(connModelCombo.getText());
    }
  }
);
  encodeCombo.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setEcoding(encodeCombo.getText());
      if (getConnection().getEcoding().equals("String_Node_Str")) {
        customText.setVisible(true);
        customText.setText("String_Node_Str");
        getConnection().setCustomEncode(customText.getText());
      }
 else {
        getConnection().setCustomEncode(getConnection().getEcoding());
        customText.setVisible(false);
      }
    }
  }
);
  customText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setCustomEncode(customText.getText());
    }
  }
);
  methodCombo.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setMethod(methodCombo.getText());
      if (getConnection().getMethod().equals("String_Node_Str")) {
        privatekeyText.setVisible(true);
        passphraseText.setVisible(true);
        privatekeyText.setText(getConnection().getPrivatekey() != null ? getConnection().getPrivatekey() : "String_Node_Str");
        passphraseText.setText(getConnection().getPassphrase() != null ? getConnection().getPassphrase() : "String_Node_Str");
        getConnection().setPrivatekey(privatekeyText.getText());
        getConnection().setPassphrase(passphraseText.getText());
      }
 else {
        getConnection().setPrivatekey(getConnection().getPrivatekey());
        getConnection().setPassphrase(getConnection().getPassphrase());
        privatekeyText.setVisible(false);
        passphraseText.setVisible(false);
      }
      checkFieldsValue();
    }
  }
);
}

Fixed version (ground truth):
@Override protected void addFieldsListeners(){
  ftpUsernameText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setUsername(ftpUsernameText.getText());
      checkFieldsValue();
    }
  }
);
  ftpPasswordText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setPassword(ftpPasswordText.getText());
      checkFieldsValue();
    }
  }
);
  ftpPortText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setPort(ftpPortText.getText());
      checkFieldsValue();
    }
  }
);
  ftpHostText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setHost(ftpHostText.getText());
      checkFieldsValue();
    }
  }
);
  proxyUsernameText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setProxyuser(proxyUsernameText.getText());
    }
  }
);
  proxyPasswordText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setProxypassword(proxyPasswordText.getText());
    }
  }
);
  proxyPortText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setProxyport(proxyPortText.getText());
    }
  }
);
  proxyHostText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setProxyhost(proxyHostText.getText());
    }
  }
);
  keyFileText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setKeystoreFile(keyFileText.getText());
    }
  }
);
  keyPasswordText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setKeystorePassword(keyPasswordText.getText());
    }
  }
);
  connModelCombo.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setMode(connModelCombo.getText());
    }
  }
);
  encodeCombo.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setEcoding(encodeCombo.getText());
      if (CUSTOM.equals(getConnection().getEcoding())) {
        customText.setVisible(true);
        customText.setText(ENCODING);
        getConnection().setCustomEncode(customText.getText());
      }
 else {
        getConnection().setCustomEncode(getConnection().getEcoding());
        customText.setVisible(false);
      }
    }
  }
);
  customText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setCustomEncode(customText.getText());
    }
  }
);
  methodCombo.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setMethod(methodCombo.getText());
      if (PUBLIC_KEY.equals(getConnection().getMethod())) {
        privatekeyText.setVisible(true);
        passphraseText.setVisible(true);
        privatekeyText.setText(getConnection().getPrivatekey() != null ? getConnection().getPrivatekey() : "String_Node_Str");
        passphraseText.setText(getConnection().getPassphrase() != null ? getConnection().getPassphrase() : "String_Node_Str");
        getConnection().setPrivatekey(privatekeyText.getText());
        getConnection().setPassphrase(passphraseText.getText());
      }
 else {
        getConnection().setPrivatekey(getConnection().getPrivatekey());
        getConnection().setPassphrase(getConnection().getPassphrase());
        privatekeyText.setVisible(false);
        passphraseText.setVisible(false);
      }
      checkFieldsValue();
    }
  }
);
  privatekeyText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setPrivatekey(privatekeyText.getText());
    }
  }
);
  passphraseText.addModifyListener(new ModifyListener(){
    @Override public void modifyText(    ModifyEvent e){
      getConnection().setPassphrase(passphraseText.getText());
    }
  }
);
}