Versions

Component used: Navigation

Version used: 2.5.3

Devices/Android versions reproduced on: any

Description

According to the documentation of [BackHandler], nested BackHandlers(https://developer.android.com/reference/kotlin/androidx/activity/compose/package-summary#top-level-functions) should take priority:

If this is called by nested composables, if enabled, the inner most composable will consume the call to system back and invoke its lambda. The call will continue to propagate up until it finds an enabled BackHandler.

However, this doesn't work correctly if the activity is paused and then resumed.

Steps to reproduce

1. Start the app
2. Click back button
3. Toast "Button clicked" shows
4. Minimize the app (by pressing home button)
5. Bring app to foreground (via recent apps menu)
6. Click back button Expected behavior: Toast "Button clicked" shows Actual behavior: Toast "This should never ever show!!!" shows

Code to demonstrate the issue

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            MaterialTheme {
                Surface(Modifier.fillMaxSize()) {
                    val context = LocalContext.current
                    BackHandler {
                        Toast.makeText(context, "This should never ever show!!!", Toast.LENGTH_SHORT).show()
                    }
                    SampleApp()
                }
            }
        }
    }
}

@Composable
fun SampleApp() {
    val navController = rememberNavController()
    NavHost(navController, "first") {
        composable("first") { Screen() }
    }
}

@Composable
fun Screen() {
    val context = LocalContext.current
    BackHandler {
        Toast.makeText(context, "Back clicked", Toast.LENGTH_SHORT).show()
    }
    Column {
        Text("First screen")
    }
}

A sample project is attached.