Status Update
Comments
ap...@google.com <ap...@google.com> #2
Oh I forgot to mention that I thought it might be connected to this issue:
jb...@google.com <jb...@google.com> #3
Please provide a minimal sample project along with the minimal steps to recreate the issue in the project.
ju...@google.com <ju...@google.com> #4
Sorry for the delay. I got a working example here:
I poked into it a little bit and it seems to be connected to
Steps to reproduce:
- Navigate from Second Fragment to Child nav graph (with non-nullable parameters).
- Navigate to Third fragment using SafeArgs and the app crashes.
Crash log:
Process: cz.dels.issues, PID: 1743
java.lang.NullPointerException: null cannot be cast to non-null type kotlin.Long
at androidx.navigation.NavType$Companion$LongType$1.get(NavType.kt:352)
at androidx.navigation.NavType$Companion$LongType$1.get(NavType.kt:342)
at androidx.navigation.NavArgument.verify(NavArgument.kt:76)
at androidx.navigation.NavDestination.addInDefaultArgs(NavDestination.kt:502)
at androidx.navigation.NavController.addEntryToBackStack(NavController.kt:1865)
at androidx.navigation.NavController.addEntryToBackStack$default(NavController.kt:1813)
at androidx.navigation.NavController$navigate$4.invoke(NavController.kt:1721)
at androidx.navigation.NavController$navigate$4.invoke(NavController.kt:1719)
at androidx.navigation.NavController$NavControllerNavigatorState.push(NavController.kt:287)
at androidx.navigation.fragment.FragmentNavigator.navigate(FragmentNavigator.kt:246)
at androidx.navigation.fragment.FragmentNavigator.navigate(FragmentNavigator.kt:162)
at androidx.navigation.NavController.navigateInternal(NavController.kt:260)
at androidx.navigation.NavController.navigate(NavController.kt:1719)
at androidx.navigation.NavController.navigate(NavController.kt:1545)
at androidx.navigation.NavController.navigate(NavController.kt:1472)
at androidx.navigation.NavController.navigate(NavController.kt:1930)
at cz.dels.issues.SecondFragment.onViewCreated$lambda-0(SecondFragment.kt:38)
at cz.dels.issues.SecondFragment.$r8$lambda$XDYnOS_cYrafiNQ5rcCu1WCn0IE(Unknown Source:0)
at cz.dels.issues.SecondFragment$$ExternalSyntheticLambda0.onClick(Unknown Source:2)
Note: If in step 2 SaveArgs is not used then navigation works correctly. More information is here:
Description
The reason for this is that if a fragment on the back stack is destroyed while it is still created, we ensure the entry makes it to destroyed, but failed to clear some associated state. The state remains around and prevents us from popping the Nav back stack during system back.