IssueTracker

Oh I forgot to mention that I thought it might be connected to this issue: https://issuetracker.google.com/issues/243778589. But after trying 2.5.2 I can say that the issue persists.

Please provide a minimal sample project along with the minimal steps to recreate the issue in the project.

Sorry for the delay. I got a working example here: https://github.com/Del-S/issues. The project is set up to crash when navigating to ThirdFragment (nested nav graph) with poping the graph.

I poked into it a little bit and it seems to be connected to SafeArgs gradle plugin. When safe args is used to navigate to ThirdFragment (with nested graph poped) it will try to recreate te parent but there were no arguments passed so it crashes.

Steps to reproduce:

1. Navigate from Second Fragment to Child nav graph (with non-nullable parameters).
2. 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: https://github.com/Del-S/issues/blob/master/app/src/main/java/cz/dels/issues/SecondFragment.kt#L37.

Ups a typo: Navigate from Second First Fragment to Child nav graph (with non-nullable parameters).

Note: sorry for the spam but I am not able to edit my own comment.

This has been fixed and will be available in navigation 2.6.0-alpha08