// The configuration file name has has the executable name
// but with the ".config" extension.
//
wxFileName configFileName(wxStandardPaths::Get().GetExecutablePath());
configFileName.SetExt("config");

// The config object uses the above file name, and captures the defaults.
//
wxFileConfig * pConfig = new wxFileConfig(wxEmptyString,
                                          wxEmptyString,
                                          wxEmptyString,
                                          configFileName.GetFullPath(),
                                          wxCONFIG_USE_GLOBAL_FILE);
pConfig->SetRecordDefaults();    // to capture the defaults
wxFileConfig::Set(pConfig);      // to be globally accessible

// One of the configuration values is the file name for the exported
// values (the app.exe functionality, unrelated to the config file name).
// It uses a subdirectory with the name built out of the exe path, its name
// without the extension, with the "_OUTPUT" appended.
// For example, "some/path/App.exe" should produce "some/path/App_OUTPUT".
// The file name is again constructed from the bare app name with
// the ".txt" extension.
//
wxFileName outfname(configFileName.GetPath());            // same as the exe path
outfname.AppendDir(configFileName.GetName() + "_OUTPUT"); // the subdir
outfname.SetName(configFileName.GetName());               // same name as app has
outfname.SetExt("txt");                                   // with the .txt extension
outfname.Normalize();  // actually, my real path contains also ".."

// The above constructed filename is the default for the "output" key.
// I expect to be recorded into the pConfig because of the above
// pConfig->SetRecordDefaults();   Is my expectation correct?
//
m_output_filename = pConfig->Read("output", outfname.GetFullPath());

if (! configFileName.Exists())
{
    pConfig->??? What should be called?
}

if ( !IsDirty() || !m_fnLocalFile.GetFullPath() )
    return true;

wxFileConfig * pConfig = new wxFileConfig(wxEmptyString,
                                          wxEmptyString,
                                          configFileName.GetFullPath(),
                                          wxEmptyString,
                                          wxCONFIG_USE_LOCAL_FILE);