IssueTracker

Great! Thanks a lot, I'll look for the live updates soon!

This has been addressed internally and will be available in the Activity 1.9.2 release.

Activity 1.9.2 is scheduled for September 4th, but you can try out the fix now with snapshots.

Snapshots are always the latest things available internally. So the 1.10.0-SNAPSHOT will contain the change as well.

Do you have a sample project that reproduces this issue? Without enableOnBackInvokedCallback enabled the only thing that gets called is popBackStack so the stacktrace should come from that.

We're also seeing this crash without setting android:enableOnBackInvokedCallback in AndroidManifest.xml. I cannot provide a sample project, because I've not been able to reproduce this issue (with or without enableOnBackInvokedCallback).

I haven't been able to test 1.10.0-SNAPSHOT since I'm not able to reproduce the issue, but I'm fairly certain the commit linked above (https://issuetracker.google.com/issues/340202286#comment8) doesn't address the issue. When enabled switches to false, only the channel is closed, but the CoroutineScope in which the lambda run is still active. Since the Channel is buffered, it will deliver remaining events. Also the lambda in question does not have a suspension point before currentBackStack is accessed. So even if the scope were cancelled, the code would still execute.

That said, wouldn't the easiest solution be to add

if (currentBackStack.size < 2) return

to the start of the PredictiveBackHandler lambda in https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:navigation/navigation-compose/src/main/java/androidx/navigation/compose/NavHost.kt;l=514-530?q=navhost.kt. AFAICT there is no difference between PredictiveBackHandler being disabled and it returning immediately.

For us Activity 1.9.2 didn't fix the issue.

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

• androidx.activity:activity-compose:1.9.2
• androidx.activity:activity-compose:1.10.0-alpha02

Fatal Exception: java.lang.IndexOutOfBoundsException
Index -1 out of bounds for length 1
jdk.internal.util.Preconditions.outOfBounds (Preconditions.java:64)
jdk.internal.util.Preconditions.outOfBoundsCheckIndex (Preconditions.java:70)
jdk.internal.util.Preconditions.checkIndex (Preconditions.java:266)
java.util.Objects.checkIndex (Objects.java:359)
java.util.ArrayList.get (ArrayList.java:434)
androidx.navigation.compose.NavHostKt$NavHost$25$1.invokeSuspend (NavHost.kt:518)
androidx.navigation.compose.NavHostKt$NavHost$25$1.invoke (NavHost.kt:13)
androidx.navigation.compose.NavHostKt$NavHost$25$1.invoke (NavHost.kt:13)
androidx.activity.compose.OnBackInstance$job$1.invokeSuspend (PredictiveBackHandler.kt:160)
kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith (ContinuationImpl.kt:33)
kotlinx.coroutines.DispatchedTask.run (DispatchedTask.kt:104)
androidx.compose.ui.platform.AndroidUiDispatcher.performTrampolineDispatch (AndroidUiDispatcher.android.kt:81)
androidx.compose.ui.platform.AndroidUiDispatcher.access$performTrampolineDispatch (AndroidUiDispatcher.android.kt:41)
androidx.compose.ui.platform.AndroidUiDispatcher$dispatchCallback$1.run (AndroidUiDispatcher.android.kt:57)
android.os.Handler.handleCallback (Handler.java:942)
android.os.Handler.dispatchMessage (Handler.java:99)
android.os.Looper.loopOnce (Looper.java:240)
android.os.Looper.loop (Looper.java:351)
android.app.ActivityThread.main (ActivityThread.java:8436)
java.lang.reflect.Method.invoke (Method.java)
com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:568)
com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1013)

Operating systems 72% Android 13

Device states 0% background

57% Oppo 15% Motorola 14% Oppo 14% Vivo

Fatal Exception: java.lang.ArrayIndexOutOfBoundsException
length=10; index=-1
java.util.ArrayList.get (ArrayList.java:439)
androidx.navigation.compose.NavHostKt$NavHost$25$1.invokeSuspend (NavHost.kt:518)
androidx.navigation.compose.NavHostKt$NavHost$25$1.invoke (NavHost.kt:13)
androidx.navigation.compose.NavHostKt$NavHost$25$1.invoke (NavHost.kt:13)
androidx.activity.compose.OnBackInstance$job$1.invokeSuspend (PredictiveBackHandler.kt:160)
kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith (ContinuationImpl.kt:33)
kotlinx.coroutines.DispatchedTask.run (DispatchedTask.kt:104)
androidx.compose.ui.platform.AndroidUiDispatcher.performTrampolineDispatch (AndroidUiDispatcher.android.kt:81)
androidx.compose.ui.platform.AndroidUiDispatcher.access$performTrampolineDispatch (AndroidUiDispatcher.android.kt:41)
androidx.compose.ui.platform.AndroidUiDispatcher$dispatchCallback$1.run (AndroidUiDispatcher.android.kt:57)
android.os.Handler.handleCallback (Handler.java:790)
android.os.Handler.dispatchMessage (Handler.java:99)
android.os.Looper.loop (Looper.java:192)
android.app.ActivityThread.main (ActivityThread.java:6754)
java.lang.reflect.Method.invoke (Method.java)
com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:549)
com.android.internal.os.ZygoteInit.main (ZygoteInit.java:828)

Operating systems 75% Android 11

Device states 0% background

25% Vivo 25% Motorola 25% Samsung 25% Xiaomi

androidGradlePlugin = "8.6.0"

androidxActivity = "1.9.2"
androidxCore = "1.13.1"

androidxComposeBom = "2024.09.00"
androidxComposeMaterial3 = "1.3.0"
androidxComposeRuntimeTracing = "1.0.0-beta01"
androidxConstraintLayoutCompose = "1.0.1"
androidxHiltNavigationCompose = "1.2.0"
androidxNavigation = "2.8.0"

Re comment#22 - you'll want to open a new issue with a sample project that reproduces the issue if you are still seeing an issue.

Project: platform/frameworks/support
Branch: androidx-main
Author: Jeremy Woods <jbwoods@google.com>
Link:      https://android-review.googlesource.com/3285000

Fix failing PredictiveBackHandler enabled changes

Fix failing PredictiveBackHandler enabled changes

As part of asop/3164566 we attempted to fix an error with
PredictiveBackHandler by closing the internal onBackInstance when the
enabled status changed. This would have worked, except by the time we
made it to the LaunchedEffect the onBackInstance was always null, so we
weren't closing anything.

I believe the cause of this is that `onBackInstance` was a field of a
function and we couldn't reference it across different calls. Because we
needed to change it as part of the backCallback, it also could not be
remembered.

So instead of using the onBackInstance, we can just use the callback
`isEnabled` state directly by passing the callback to the
`OnBackInstance`. This ensures that we only fire the `onBack` callback
when the function is actually enabled.

Test: PredictiveBackHandlerTest, tested and confirmed in sample app
Bug: 365027664
Bug: 340202286
RelNote: "`PredictiveBackHandler` will no longer fire it's callback
after the handler has been disabled. This will fix an issue where
the `NavHost` from Navigation Compose would throw an
`IndexOutOfBoundsException`."

Change-Id: I3f75eb2415f39b914f18cf4b87bf4ed57bb5a483

This has been fixed internally and will be available in Activity 1.9.3 version.

This has been fixed internally and will be available in Activity 1.9.3 version.

So excited for that release, thank you for your persistence on this issue Jeremy!

Do we have a timeline for the Activity 1.9.3 release? comment#28

The release most likely will be October 16th if it is getting released in the next release cycle that andoidx libraries have (2 week release cycle) https://developer.android.com/jetpack/androidx/versions/all-channel

Activity 1.9.2 is scheduled for September 4th, but you can try out the fix now with snapshots. comment#11

If you'd like to try it out earlier, this commit is most likely in the snapshots

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

• androidx.activity:activity-compose:1.9.3

It seemed to address the crash on the 1.10.0 snapshot, will test 1.9.3 now that its in production and let the group know

Thanks for this update! This has been affecting our users using navigation-compose = "2.8.2" and activity-compose = "1.9.2".

That stacktrace indicates that we have somehow collected back events without ever starting them? Do you have a minimal sample project that can reproduce that error?

Please file a new bug with a minimal sample project that reproduces this error.

Same as above the stack trace changed but there is still a crash. Anyone know if its the same repro as before?

The steps to repro the first crash are somewhat tricky and require good timing

1. Start the app in debug mode (or use a really old phone). This seems to help to reproduce the crash because it creates a bigger window for clicking the back button at the right time
2. Navigate to a new screen while simultaneously or a split second later pressing the back button. I mash the back button right after clicking on a button to open a screen

    Fatal Exception: java.lang.IndexOutOfBoundsException: Index -1 out of bounds for length 1
       at jdk.internal.util.Preconditions.outOfBounds(Preconditions.java:64)
       at jdk.internal.util.Preconditions.outOfBoundsCheckIndex(Preconditions.java:70)
       at jdk.internal.util.Preconditions.checkIndex(Preconditions.java:266)
       at java.util.Objects.checkIndex(Objects.java:359)
       at java.util.ArrayList.get(ArrayList.java:434)
       at androidx.navigation.compose.NavHostKt$NavHost$28$1.invokeSuspend(NavHost.kt:611)
       at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
       at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:101)
       at androidx.compose.ui.platform.AndroidUiDispatcher.performTrampolineDispatch(AndroidUiDispatcher.android.kt:81)
       at androidx.compose.ui.platform.AndroidUiDispatcher.access$setScheduledFrameDispatch$p(AndroidUiDispatcher.android.kt:41)
       at androidx.compose.ui.platform.AndroidUiDispatcher.access$performTrampolineDispatch(AndroidUiDispatcher.android.kt:41)
       at androidx.compose.ui.platform.AndroidUiDispatcher$dispatchCallback$1.run(AndroidUiDispatcher.android.kt:57)
       at android.os.Handler.handleCallback(Handler.java:958)
       at android.os.Handler.dispatchMessage(Handler.java:99)
       at android.os.Looper.loopOnce(Looper.java:257)
       at android.os.Looper.loop(Looper.java:368)
       at android.app.ActivityThread.main(ActivityThread.java:8839)
       at java.lang.reflect.Method.invoke(Method.java)
       at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:572)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1049)

I have created a new issue in https://issuetracker.google.com/issues/375343407, as requested.

comment#41

I have created a new issue in https://issuetracker.google.com/issues/375343407, as requested.

Thanks for reporting this! Its my biggest crash by fare, hopefully we can resolve soon

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

• androidx.activity:activity-compose:1.10.0-alpha03

I also same issues, It was as though val previousEntry = currentBackStack[currentBackStack.size - 2], NavHost.kt, didn't guard this situation.

java.lang.IndexOutOfBoundsException: Index -1 out of bounds for length 1 at jdk.internal.util.Preconditions.outOfBounds(Preconditions.java:64) at jdk.internal.util.Preconditions.outOfBoundsCheckIndex(Preconditions.java:70) at jdk.internal.util.Preconditions.checkIndex(Preconditions.java:266) at java.util.Objects.checkIndex(Objects.java:359) at java.util.ArrayList.get(ArrayList.java:434) at androidx.navigation.compose.NavHostKt$NavHost$25$1.invokeSuspend(NavHost.kt:518) at androidx.navigation.compose.NavHostKt$NavHost$25$1.invoke(Unknown Source:8) at androidx.navigation.compose.NavHostKt$NavHost$25$1.invoke(Unknown Source:4) at androidx.activity.compose.OnBackInstance$job$1.invokeSuspend(PredictiveBackHandler.kt:121) at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33) at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:108) at androidx.compose.ui.platform.AndroidUiDispatcher.performTrampolineDispatch(AndroidUiDispatcher.android.kt:81) at androidx.compose.ui.platform.AndroidUiDispatcher.access$performTrampolineDispatch(AndroidUiDispatcher.android.kt:41) at androidx.compose.ui.platform.AndroidUiDispatcher$dispatchCallback$1.run(AndroidUiDispatcher.android.kt:57) at android.os.Handler.handleCallback(Handler.java:958) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loopOnce(Looper.java:230) at android.os.Looper.loop(Looper.java:319) at android.app.ActivityThread.main(ActivityThread.java:8919) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:578) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1103) Suppressed: kotlinx.coroutines.internal.DiagnosticCoroutineContextException: [androidx.compose.ui.platform.MotionDurationScaleImpl@5133892, androidx.compose.runtime.BroadcastFrameClock@757c263, StandaloneCoroutine{Cancelling}@92a1e60, AndroidUiDispatcher@a705f19]

Additional information activity-compose: 1.10.0-alpha03 navigation-compose: 2.9.0-alpha02

The resolution of this issue has unfortunately led to a new problem, which is now tracked under Issue https://issuetracker.google.com/issues/375343407. This new issue has quickly gained over 40 upvotes and is currently a top crash in numerous apps.

If there’s any way I can help get this new issue assigned to an owner or provide further information, please let me know.

W