Handling setDisplayHomeAsUpEnabled with fragments

I have a fragment-based layout with two ListFragments (A and B) that are contained in an activity (called ListActivity 1). When the application starts, ListActivity 1 is called and depending on whether the device is in portrait or landscape view, only ListFragment A is displayed or both ListFragment lists are displayed.

When you click on an item in the Fragment ListView, then the Fragment B ListView is displayed. When you click on an item in the Fragment B ListView, go to the new action (Activity 1).

I use this code (called ListActivity 2) to determine whether to show ListFragment B on it alone or along with ListFragment A:

public class ListingActivity extends SherlockFragmentActivity  
{
    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {
            // If the screen is now in landscape mode, we can show the
            // dialog in-line so we don't need this activity.
            finish();
            return;
        }

        if (savedInstanceState == null) {
            // During initial setup, plug in the details fragment.
            final ListingFragment details = new ListingFragment();
            details.setArguments(getIntent().getExtras());

            getSupportFragmentManager().beginTransaction().add(android.R.id.content, details).commit();
        }
    }
}

1 setDisplayHomeAsUpEnabled, Actionbar "", , . , ListActivity 2, , ListActivity 1.

- , :

@Override
public boolean onOptionsItemSelected(final MenuItem item) 
{
    if (item.getItemId() == android.R.id.home) 
    {
        final Intent intent;

        if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE)
            intent = new Intent(this, ListingActivity1.class);
        else
            intent = new Intent(this, ListingActivity2.class);

        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
        startActivity(intent);
        return true;
    } else {
        return super.onOptionsItemSelected(item);
    }
}