NavController.navigate() with launchSingleTop crashes with nested navigation containing same nested routes [294408596]

Fixed

Bug

Status Update

No update yet.

Description

ma...@vonforell.de

created issue #1

Aug 4, 2023 05:37PM

Component used: Navigation

Version used: androidx.navigation:navigation-compose:2.7.0-rc01 (same issue occurs with 2.6.0)

Devices/Android versions reproduced on: Pixel 6 / Android 13

Calling NavController.navigate() { launchSingleTop = true } when using two nested navigations graphs that both contain a node with the same nested route crashes with this stack trace:

type: crash
osVersion: google/oriole/oriole:13/TQ3A.230705.001/2023072600:user/release-keys
package: com.example.navigationtest:1
process: com.example.navigationtest
processUptime: 1300 + 73 ms

java.util.NoSuchElementException: ArrayDeque is empty.
	at kotlin.collections.ArrayDeque.removeLast(ArrayDeque.kt:163)
	at androidx.navigation.NavController.launchSingleTopInternal(NavController.kt:1868)
	at androidx.navigation.NavController.navigate(NavController.kt:1829)
	at androidx.navigation.NavController.navigate(NavController.kt:1792)
	at androidx.navigation.NavController.navigate(NavController.kt:2193)
	at androidx.navigation.NavController.navigate$default(NavController.kt:2188)
	at androidx.navigation.NavController.navigate(NavController.kt:2173)
	at com.example.navigationtest.MainActivityKt$MyNavBar$1$1$1.invoke(MainActivity.kt:81)
	at com.example.navigationtest.MainActivityKt$MyNavBar$1$1$1.invoke(MainActivity.kt:76)
	at androidx.compose.foundation.ClickablePointerInputNode$pointerInput$3.invoke-k-4lQ0M(Clickable.kt:895)
	at androidx.compose.foundation.ClickablePointerInputNode$pointerInput$3.invoke(Clickable.kt:889)
	at androidx.compose.foundation.gestures.TapGestureDetectorKt$detectTapAndPress$2$1.invokeSuspend(TapGestureDetector.kt:255)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)

I have attached a sample project, here's the interesting part of it:

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            MyNavHost()
        }
    }
}

@Composable
fun MyNavHost(navController: NavHostController = rememberNavController()) {
    Scaffold(
        bottomBar = { MyNavBar(navController) }
    ) { innerPadding ->
        NavHost(
            modifier = Modifier.padding(innerPadding),
            navController = navController,
            startDestination = "left",
        ) {
            navigation(
                route = "left",
                startDestination = "foo",
            ) {
                composable(route = "foo") {
                    Text("Left")
                }
            }

            navigation(
                route = "right",
                startDestination = "foo",
            ) {
                composable(route = "foo") {
                    Text("Right")
                }
            }
        }
    }
}

@Composable
fun MyNavBar(navController: NavController) {
    val screens = listOf("left", "right")
    val navBackStackEntry by navController.currentBackStackEntryAsState()
    val currentDestination = navBackStackEntry?.destination

    NavigationBar {
        screens.forEach { screen ->
            val selected = currentDestination?.hierarchy?.any { it.route == screen } == true
            NavigationBarItem(
                icon = { Icon(Icons.Default.Info, contentDescription = "") },
                selected = selected,
                label = { Text("text") },
                onClick = {
                    navController.navigate(screen) {
                        launchSingleTop = true
                    }
                }
            )
        }
    }
}

navigation_test.zip

103 KB

Download

Comments

il...@google.com <il...@google.com> Aug 24, 2023 05:57PM

Assigned to cl...@google.com.

al...@gmail.com <al...@gmail.com> #2May 13, 2024 01:10AM

Could you please provide a minimal sample that reproduces this issue?

cl...@google.com <cl...@google.com> Jun 20, 2024 11:07PM

Accepted by cl...@google.com.

ap...@google.com <ap...@google.com> #3Jul 3, 2024 10:54PM

Yes, of course

@Composable
private fun DemoNavHost() {
    val controller = rememberNavController()
    NavHost(
        navController = controller,
        startDestination = "mainRoute",
        modifier = Modifier.fillMaxSize()
    ) {

        composable("mainRoute") {
            Surface() {
                Box(Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
                    Button(
                        onClick = {
                            controller.navigate("demoDialog")
                            controller.navigate("demoDialog")   // Simulate a quick click by the user
                        }
                    ) {
                        Text(text = "show dialog")
                    }
                }
            }
        }

        dialog("demoDialog") {
            val context = LocalContext.current
            val lifecycle = LocalLifecycleOwner.current
            Surface() {
                Column() {
                    Text(text = "I'm demo dialog")
                    Button(
                        onClick = {
                            Toast
                                .makeText(
                                    context,
                                    "${lifecycle.lifecycle.currentState}",
                                    Toast.LENGTH_SHORT
                                )
                                .show()
                        }
                    ) {
                        Text(text = "check lifecycle")
                    }
                    Button(onClick = controller::popBackStack) {
                        Text(text = "close")
                    }
                }
            }
        }
    }
}

Steps:

Step 1: Click the show dialog button on mainRoute

Step 2: Because 2 pop-up windows pop up, we close the top one

Step 3: Click the check lifecycle button on the pop-up window, you can see STARTED instead of RESUMED

I have also checked the cause, which is consistent with the description in my question.

cl...@google.com <cl...@google.com> #4Jul 3, 2024 11:40PM

Marked as fixed.

In fact, I found another problem. When the tester frequently clicks the button, the button event is to display a Dialog, Dialog is set to be destroyed by external click, so Dialog is always displayed and destroyed

Interesting thing, because it may be too fast, causing DialogHost to not notice that Dialog appears and disappears, but it has actually joined NavController#_visibleEntries

But because NavHost#DialogHost did not process DisposableEffect, it will not execute dialogNavigator#onTransitionComplete, so it will not be removed from NavController#_visibleEntries, and a NavBackStackEntry leak occurs

The reason may be that the pop-up window appears and disappears within one frame

na...@google.com <na...@google.com> #5Jul 10, 2024 05:10PM

Hi, can you please file a separate bug for the issue you see in comment#4?

On initial bug - when multiple dialogs are open at the same time and the top one is dismissed, the second dialog in backstack is marked as transitioning to hold it in STARTED state until the top dialog has completed transitioning. But the second dialog was not marked as complete when composed so it stays in STARTED state instead of moving to expected RESUMED state.