Navigation component app:clearTask and app:launchSingleTop crash

Component used: Navigation Version used: alpha01, alpha02 Devices/Android versions reproduced on: All

App crash when using app:clearTask=“true” or app:launchSingleTop=“true” in nav_graph.xml

Some times crash is gone after second app start. Some times it crashes on second call to this action (for example I opened fragment with app:launchSingleTop=“true” then go back using findNavController().navigateUp() and opened it again -> crash)

java.lang.IllegalArgumentException: navigation destination indicaonline.delivery:id/action_mainFragment_to_orderDetailsFragment is unknown to this NavController
        at androidx.navigation.NavController.navigate(NavController.java:633)
        at androidx.navigation.NavController.navigate(NavController.java:592)
        at androidx.navigation.NavController.navigate(NavController.java:654)
        at package.ui.main.MainFragment.openOrderDetails(MainFragment.kt:215)
        at package.ui.main.MainFragment.onItemClick(MainFragment.kt:203)
        at eu.davidea.viewholders.FlexibleViewHolder.onClick(FlexibleViewHolder.java:122)
        at android.view.View.performClick(View.java:6597)
        at android.view.View.performClickInternal(View.java:6574)
        at android.view.View.access$3100(View.java:778)
        at android.view.View$PerformClick.run(View.java:25881)
        at android.os.Handler.handleCallback(Handler.java:873)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6649)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:826)

<action
            android:id="@+id/action_mainFragment_to_orderDetailsFragment"
            app:destination="@id/orderDetailsFragment"
            app:launchSingleTop="true">
            <argument
                android:name="orderId"
                android:defaultValue="-1" />
        </action>

this is single activity app

to open fragment I use

viewModel.someLiveData.observe(this, EventObserver {
            findNavController().navigate(R.id.action_assignFragment_to_registerPinFragment)
        })

or

btnButton.setOnClickListener {
            val email = etEmail.text.toString()
            val action = LoginFragmentDirections
                    .action_loginFragment_to_forgotPasswordFragment().setEmail(email)
            findNavController().navigate(action)
        }

[mahmoudhabib91]

Issue still exists in alpha03

[searchy2]

Since clearTask is deprecated, this issue can be closed?

However, the problem still persists in that the current Navigation RC01 library does not clear the back stack using PopUpTo if you are trying to clear a nested graph.

If you are in a nested graph, you can’t pop to a destination outside the nested graph and only the start destination.