android - prevent same fragment multiple times in backstack

Hi guys here is my code

navigationView.setNavigationItemSelectedListener(new NavigationView
                .OnNavigationItemSelectedListener() {
            @Override public boolean onNavigationItemSelected(@NonNull MenuItem item) {
                if (item.isChecked()) {
                    //item already selected. Do nothing
                    drawerLayout.closeDrawer(GravityCompat.START);
                    return true;
                }
                switch (item.getItemId()) {
                    case R.id.home:
                        FragmentTransaction transaction = getSupportFragmentManager()
                                .beginTransaction();
                        transaction.replace(R.id.fragment, new HomeFragment())
                                .setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE).commit();
                        break;
                    case R.id.other:
                        transaction = getSupportFragmentManager().beginTransaction();
                        transaction.replace(R.id.fragment, new OtherFragment())
                                .addToBackStack(null).setTransition(FragmentTransaction
                                .TRANSIT_FRAGMENT_FADE).commit();
                        break;
                    default:
                        break;
                }
                drawerLayout.closeDrawer(GravityCompat.START);
                return true;
            }
        });

I basically only have 2 fragments and merely the HomeFragment should be added to the backstack. After switching between HomeFragment and OtherFragment for a while and clicking on the back button while on the HomeFragment, I end up with the HomeFragment getting displayed several times.
Within the HomeFragment lies a recyclerview. When I scroll up and down I can really see that the rows are displayed multiple times.
How can I make sure that the HomeFragment is added to the backstack only once.

Thanks

Answer

When you click on the Home menu item try to find out whether there is any fragment in the backstack or not. If yes, call popBackStack() or replace a fragment as you do now otherwise. Use this code:

if (getSupportFragmentManager().getBackStackEntryCount() > 0) {
getSupportFragmentManager().popBackStack();
}