Safe Args Kotlin fromBundle() method is being stripped by ProGuard [190082521]

Fixed

Bug

Status Update

No update yet.

Description

ia...@gmail.com

created issue #1

Jun 3, 2021 10:56PM

Component used: Navigation Safe Args Kotlin Plugin

Version used: 2.4.0-alpha02, AGP 4.2.0-beta03

After upgrading to Navigation 2.4.0-alpha02 and building a minified version of my app, my app crashed with an exception that said that the fromBundle method couldn't be found.

I use the by navArgs() extension, which uses reflection to access this method, so I depended on Navigation's included ProGuard keep rules to properly keep that method.

I found that I could work around this issue via this commit:

# Workaround for Kotlin Safe Args issue
-if public class ** implements androidx.navigation.NavArgs
-keepclassmembers public class <1> {
    public static ** Companion;
    ** fromBundle(android.os.Bundle);
}

Essentially just making sure that the Companion class is kept. After adding that ProGuard rule, the fromBundle() class was successfully kept. I'm not sure why that helped, since I'm pretty sure that the format of the fromBundle() didn't change since Navigation 2.3.5?

Reproduction steps:

Check out Muzei
Revert this commit
Add minifyEnabled true to the debug configuration
Run ./gradlew assembleDebug and analyze the resulting APK to verify that the ChooseProviderFragmentArgs.fromBundle() method exists (it won't) 4a) Alternatively, install Muzei, Activate it as your wallpaper, then select the 'Sources' screen. Muzei should not crash.

Comments

il...@google.com <il...@google.com> Jun 3, 2021 11:04PM

Assigned to il...@google.com.

il...@google.com <il...@google.com> #2Jun 10, 2021 12:06AM

Accepted by il...@google.com.

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.

ap...@google.com <ap...@google.com> #3Jun 10, 2021 01:18AM

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

il...@google.com <il...@google.com> #4Jun 10, 2021 03:28PM

Marked as fixed.

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.

Issue 190082521

Description

Issue summary

Comments

il...@google.com <il...@google.com> Jun 3, 2021 11:04PM

il...@google.com <il...@google.com> #2Jun 10, 2021 12:06AM

ap...@google.com <ap...@google.com> #3Jun 10, 2021 01:18AM

il...@google.com <il...@google.com> #4Jun 10, 2021 03:28PM

Add comment

Issue metadata