2.6.0-alpha05 NavController visibleEntries flow contains many wrong entries [288520638]

Fixed

Bug

Status Update

No update yet.

Description

th...@outlook.com

created issue #1

Jun 23, 2023 12:30PM

Component used: Navigation
Version used: 2.6.0-alpha05 and up (including 2.6.0 stable)
Devices/Android versions reproduced on: Any

In the sample project I try to determine if the home fragment is visible using NavController.visibleEntries. In library version alpha04 it always contains the correct entries, but in alpha05 the list is a hot mess because it keeps growing when navigating and even the host fragment and fragments that are not on the backstack are added to the list. This is not possible in the sample project.

The sample project logs the information for demonstration.

VisibleEntriesBugReport.zip

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Comments

il...@google.com <il...@google.com> Jun 23, 2023 10:07PM

Assigned to cl...@google.com.

th...@outlook.com <th...@outlook.com> #2Aug 30, 2023 09:57AM

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.

il...@google.com <il...@google.com> #3Aug 30, 2023 04:52PM

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

ap...@google.com <ap...@google.com> #4Sep 7, 2023 05:19PM

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:

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: https://github.com/Del-S/issues/blob/master/app/src/main/java/cz/dels/issues/SecondFragment.kt#L37.

cl...@google.com <cl...@google.com> #5Sep 7, 2023 05:25PM

Marked as fixed.

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.

na...@google.com <na...@google.com> #6Sep 20, 2023 07:16PM

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

th...@outlook.com <th...@outlook.com> #7Sep 21, 2023 08:48AM

Project: platform/frameworks/support
Branch: androidx-main

commit 6b358154b794a0456b089ac8e548bfb830dd6c22
Author: Clara Fok <clarafok@google.com>
Date: Tue Mar 14 17:56:12 2023

Fix missing non-nullable arg when rebuilding hierarchy

When navigating with NavDirections, args is populated with an empty bundle. This causes issue when we rebuild parent hierarchy while adding a new entry to NavBackStack. If the Entry being rebuilt contains a non-nullalbe arg, i.e. Long, this empty bundle will cause an exception.

Test: ./gradlew navigation:navigation-runtime:cC
Bug: 249988437
Change-Id: I5c8ce739ad9a3428c8a8de13eae391bfff0db5df

M navigation/navigation-runtime/src/androidTest/java/androidx/navigation/NavControllerTest.kt
M navigation/navigation-runtime/src/main/java/androidx/navigation/NavController.kt

https://android-review.googlesource.com/2488855

na...@google.com <na...@google.com> #8Jan 24, 2024 07:53PM

The following release(s) address this bug.It is possible this bug has only been partially addressed:

androidx.navigation:navigation-runtime:2.6.0-alpha08