Program: 51141
Project: 51141
Buggy source:
private void connectButtonActionPerformed(java.awt.event.ActionEvent evt){
  File sfile=null;
  try {
    JInternalFrame sf=null;
    String sfname=(String)schemaList.getSelectedItem();
    Iterator it=schemaWindowMap.entrySet().iterator();
    while (it.hasNext()) {
      Map.Entry elem=(Map.Entry)it.next();
      if (((JMenuItem)elem.getValue()).getText().equals(sfname)) {
        sf=(JInternalFrame)elem.getKey();
        break;
      }
    }
    if (sf == null) {
      JOptionPane.showMessageDialog(this,getResourceConverter().getString("String_Node_Str","String_Node_Str"),getResourceConverter().getString("String_Node_Str","String_Node_Str"),JOptionPane.ERROR_MESSAGE);
      return;
    }
    SchemaExplorer se=(SchemaExplorer)sf.getContentPane().getComponent(0);
    if (se.isNewFile()) {
      JOptionPane.showMessageDialog(this,getResourceConverter().getString("String_Node_Str","String_Node_Str"),getResourceConverter().getString("String_Node_Str","String_Node_Str"),JOptionPane.WARNING_MESSAGE);
      sf.setSelected(true);
      return;
    }
    sfile=se.getSchemaFile();
    PropertyList list=new PropertyList();
    list.put("String_Node_Str","String_Node_Str");
    list.put("String_Node_Str",se.getJdbcConnectionUrl());
    list.put("String_Node_Str",se.getSchemaFile().toURL().toString());
    if (se.getJdbcUsername() != null && se.getJdbcUsername().length() > 0) {
      list.put("String_Node_Str",se.getJdbcUsername());
    }
    if (se.getJdbcPassword() != null && se.getJdbcPassword().length() > 0) {
      list.put("String_Node_Str",se.getJdbcPassword());
    }
    Connection con=DriverManager.getConnection(list,null);
    if (con != null) {
      connection=con;
      queryMenuItem.setText(getResourceConverter().getFormattedString("String_Node_Str","String_Node_Str",new String[]{Integer.toString(windowMenuIndex),se.getSchemaFile().getName()}));
      Component o=this;
      while (o != null) {
        if (o.getClass() == JInternalFrame.class) {
          ((JInternalFrame)o).setTitle(getResourceConverter().getFormattedString("String_Node_Str","String_Node_Str",new String[]{se.getSchemaFile().getName()}));
          break;
        }
        o=o.getParent();
      }
      JOptionPane.showMessageDialog(this,"String_Node_Str",getResourceConverter().getString("String_Node_Str","String_Node_Str"),JOptionPane.INFORMATION_MESSAGE);
    }
 else {
      JOptionPane.showMessageDialog(this,getResourceConverter().getFormattedString("String_Node_Str","String_Node_Str",new String[]{se.getSchemaFile().getName()}),getResourceConverter().getString("String_Node_Str","String_Node_Str"),JOptionPane.ERROR_MESSAGE);
    }
  }
 catch (  Exception ex) {
    LOGGER.error("String_Node_Str" + ex.getMessage(),ex);
    JOptionPane.showMessageDialog(this,getResourceConverter().getFormattedString("String_Node_Str","String_Node_Str",new String[]{sfile == null ? getResourceConverter().getString("String_Node_Str","String_Node_Str") : sfile.getName()}),getResourceConverter().getString("String_Node_Str","String_Node_Str"),JOptionPane.ERROR_MESSAGE);
  }
}

Fixed version (ground truth):
private void connectButtonActionPerformed(java.awt.event.ActionEvent evt){
  File sfile=null;
  try {
    JInternalFrame sf=null;
    String sfname=(String)schemaList.getSelectedItem();
    Iterator it=schemaWindowMap.entrySet().iterator();
    while (it.hasNext()) {
      Map.Entry elem=(Map.Entry)it.next();
      if (((JMenuItem)elem.getValue()).getText().equals(sfname)) {
        sf=(JInternalFrame)elem.getKey();
        break;
      }
    }
    if (sf == null) {
      JOptionPane.showMessageDialog(this,getResourceConverter().getString("String_Node_Str","String_Node_Str"),getResourceConverter().getString("String_Node_Str","String_Node_Str"),JOptionPane.ERROR_MESSAGE);
      return;
    }
    SchemaExplorer se=(SchemaExplorer)sf.getContentPane().getComponent(0);
    if (se.isNewFile()) {
      JOptionPane.showMessageDialog(this,getResourceConverter().getString("String_Node_Str","String_Node_Str"),getResourceConverter().getString("String_Node_Str","String_Node_Str"),JOptionPane.WARNING_MESSAGE);
      sf.setSelected(true);
      return;
    }
    sfile=se.getSchemaFile();
    PropertyList list=new PropertyList();
    list.put("String_Node_Str","String_Node_Str");
    list.put("String_Node_Str",se.getJdbcConnectionUrl());
    list.put("String_Node_Str",se.getSchemaFile().toURL().toString());
    if (se.getJdbcUsername() != null && se.getJdbcUsername().length() > 0) {
      list.put("String_Node_Str",se.getJdbcUsername());
    }
    if (se.getJdbcPassword() != null && se.getJdbcPassword().length() > 0) {
      list.put("String_Node_Str",se.getJdbcPassword());
    }
    Connection con=DriverManager.getConnection(list,null);
    AggregationManager.instance().getCacheControl(null).flushSchemaCache();
    if (con != null) {
      connection=con;
      queryMenuItem.setText(getResourceConverter().getFormattedString("String_Node_Str","String_Node_Str",new String[]{Integer.toString(windowMenuIndex),se.getSchemaFile().getName()}));
      Component o=this;
      while (o != null) {
        if (o.getClass() == JInternalFrame.class) {
          ((JInternalFrame)o).setTitle(getResourceConverter().getFormattedString("String_Node_Str","String_Node_Str",new String[]{se.getSchemaFile().getName()}));
          break;
        }
        o=o.getParent();
      }
      JOptionPane.showMessageDialog(this,"String_Node_Str",getResourceConverter().getString("String_Node_Str","String_Node_Str"),JOptionPane.INFORMATION_MESSAGE);
    }
 else {
      JOptionPane.showMessageDialog(this,getResourceConverter().getFormattedString("String_Node_Str","String_Node_Str",new String[]{se.getSchemaFile().getName()}),getResourceConverter().getString("String_Node_Str","String_Node_Str"),JOptionPane.ERROR_MESSAGE);
    }
  }
 catch (  Exception ex) {
    LOGGER.error("String_Node_Str" + ex.getMessage(),ex);
    JOptionPane.showMessageDialog(this,getResourceConverter().getFormattedString("String_Node_Str","String_Node_Str",new String[]{sfile == null ? getResourceConverter().getString("String_Node_Str","String_Node_Str") : sfile.getName()}),getResourceConverter().getString("String_Node_Str","String_Node_Str"),JOptionPane.ERROR_MESSAGE);
  }
}