Adding a Kotlin singleton to a compose state causes null pointers [170331371]

WAI

Bug

androidx-bug-bounty

Status Update

No update yet.

Description

b....@gmail.com

created issue #1

Oct 8, 2020 02:21AM

Jetpack Compose release version: alpha4

Android Studio Build: 4.2 Canary 13

Attached is a sample project.

Have a sealed class with a list in a companion object.

sealed class AppContent(val title: String, val content: @Composable () -> Unit) {
    object FirstPage: AppContent("First Page", { Text("First Page") })
    object SecondPage: AppContent("Second Page", { Text("Second Page") })
    companion object {
        val ALL = listOf(FirstPage, SecondPage)
    }
}

Add one of those objects in to a state variable

val screen = remember { mutableStateOf<AppContent>(AppContent.FirstPage) }

Try to iterate over the list

Column {
   AppContent.ALL.forEach { it.content() }
}

App crashes with a require non null assert failing

Process: com.bentrengrove.companionobjectbug, PID: 19774
    java.lang.NullPointerException: Attempt to invoke virtual method 'kotlin.jvm.functions.Function2 com.bentrengrove.companionobjectbug.AppContent.getContent()' on a null object reference
        at com.bentrengrove.companionobjectbug.MainActivity$onCreate$1$1$1.invoke(MainActivity.kt:28)
        at com.bentrengrove.companionobjectbug.MainActivity$onCreate$1$1$1.invoke(Unknown Source:10)
        at androidx.compose.runtime.internal.ComposableLambda.invoke(ComposableLambda.kt:144)
        at androidx.compose.runtime.internal.ComposableLambda.invoke(Unknown Source:10)
        at androidx.compose.runtime.AmbientKt.Providers(Ambient.kt:175)
        at androidx.compose.material.SurfaceKt$Surface$1.invoke(Surface.kt:107)
        at androidx.compose.material.SurfaceKt$Surface$1.invoke(Unknown Source:10)
        at androidx.compose.runtime.internal.ComposableLambda.invoke(ComposableLambda.kt:144)
        at androidx.compose.runtime.internal.ComposableLambda.invoke(Unknown Source:10)
        at androidx.compose.ui.LayoutKt.Layout(Layout.kt:677)
        at androidx.compose.material.SurfaceKt.SurfaceLayout(Surface.kt:129)
        at androidx.compose.material.SurfaceKt.Surface-biUpMIw(Surface.kt:97)
        at com.bentrengrove.companionobjectbug.MainActivity$onCreate$1$1.invoke(MainActivity.kt:26)
        at com.bentrengrove.companionobjectbug.MainActivity$onCreate$1$1.invoke(Unknown Source:10)
        at androidx.compose.runtime.internal.ComposableLambda.invoke(ComposableLambda.kt:144)
        at androidx.compose.runtime.internal.ComposableLambda.invoke(Unknown Source:10)
        at androidx.compose.runtime.AmbientKt.Providers(Ambient.kt:175)
        at androidx.compose.foundation.TextKt.ProvideTextStyle(Text.kt:238)
        at androidx.compose.material.MaterialThemeKt$MaterialTheme$1.invoke(MaterialTheme.kt:71)
        at androidx.compose.material.MaterialThemeKt$MaterialTheme$1.invoke(Unknown Source:10)
        at androidx.compose.runtime.internal.ComposableLambda.invoke(ComposableLambda.kt:144)
        at androidx.compose.runtime.internal.ComposableLambda.invoke(Unknown Source:10)
        at androidx.compose.runtime.AmbientKt.Providers(Ambient.kt:175)
        at androidx.compose.material.MaterialThemeKt.MaterialTheme(MaterialTheme.kt:65)
        at com.bentrengrove.companionobjectbug.ui.ThemeKt.CompanionObjectBugTheme(Theme.kt:38)
        at com.bentrengrove.companionobjectbug.MainActivity$onCreate$1.invoke(MainActivity.kt:24)
        at com.bentrengrove.companionobjectbug.MainActivity$onCreate$1.invoke(Unknown Source:10)
        at androidx.compose.runtime.internal.ComposableLambda.invoke(ComposableLambda.kt:144)
        at androidx.compose.runtime.internal.ComposableLambda.invoke(Unknown Source:10)
        at androidx.compose.runtime.AmbientKt.Providers(Ambient.kt:175)
        at androidx.compose.ui.platform.AmbientsKt.ProvideCommonAmbients(Ambients.kt:104)
        at androidx.compose.ui.platform.AndroidAmbientsKt$ProvideAndroidAmbients$3.invoke(AndroidAmbients.kt:105)
        at androidx.compose.ui.platform.AndroidAmbientsKt$ProvideAndroidAmbients$3.invoke(Unknown Source:10)
        at androidx.compose.runtime.internal.ComposableLambda.invoke(ComposableLambda.kt:144)
        at androidx.compose.runtime.internal.ComposableLambda.invoke(Unknown Source:10)
        at androidx.compose.runtime.AmbientKt.Providers(Ambient.kt:175)
        at androidx.compose.ui.platform.AndroidAmbientsKt.ProvideAndroidAmbients(AndroidAmbients.kt:97)
        at androidx.compose.ui.platform.WrappedComposition$setContent$1$1$1.invoke(Wrapper.kt:269)
        at androidx.compose.ui.platform.WrappedComposition$setContent$1$1$1.invoke(Unknown Source:10)
        at androidx.compose.runtime.internal.ComposableLambda.invoke(ComposableLambda.kt:144)
        at androidx.compose.runtime.internal.ComposableLambda.invoke(Unknown Source:10)
        at androidx.compose.runtime.AmbientKt.Providers(Ambient.kt:175)
        at androidx.compose.ui.platform.WrappedComposition$setContent$1$1.invoke(Wrapper.kt:268)
        at androidx.compose.ui.platform.WrappedComposition$setContent$1$1.invoke(Unknown Source:10)
        at androidx.compose.runtime.internal.ComposableLambda.invoke(ComposableLambda.kt:144)
2020-10-08 12:18:32.650 19774-19774/com.bentrengrove.companionobjectbug E/AndroidRuntime:     at androidx.compose.runtime.internal.ComposableLambda.invoke(Unknown Source:10)
        at androidx.compose.runtime.ComposerKt.invokeComposable(Composer.kt:2697)
        at androidx.compose.runtime.Composer.composeInitial(Composer.kt:1861)
        at androidx.compose.runtime.Recomposer.composeInitial$runtime_release(Recomposer.kt:241)
        at androidx.compose.runtime.CompositionImpl.setContent(Composition.kt:110)
        at androidx.compose.ui.platform.WrappedComposition$setContent$1.invoke(Wrapper.kt:262)
        at androidx.compose.ui.platform.WrappedComposition$setContent$1.invoke(Unknown Source:3)
        at androidx.compose.ui.platform.AndroidComposeView.onAttachedToWindow(AndroidComposeView.kt:579)
        at android.view.View.dispatchAttachedToWindow(View.java:19553)
        at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3430)
        at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3437)
        at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3437)
        at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3437)
        at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3437)
        at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3437)
        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2028)
        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1721)
        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7598)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:966)
        at android.view.Choreographer.doCallbacks(Choreographer.java:790)
        at android.view.Choreographer.doFrame(Choreographer.java:725)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:951)
        at android.os.Handler.handleCallback(Handler.java:883)
        at android.os.Handler.dispatchMessage(Handler.java:100)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)

Either moving the ALL list to global scope or removing the state variable makes the problem go away.

CompanionObjectBug.zip

37 MB

Download

Comments

cl...@google.com <cl...@google.com> Oct 15, 2020 05:32PM

Assigned to le...@google.com.

le...@google.com <le...@google.com> #2Mar 16, 2021 11:03PM

Known issue, we cannot do anything because AGP doesn't provide an API to fetch Kotlin sources (specifically here https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:buildSrc/private/src/main/kotlin/androidx/build/java/JavaCompileInputs.kt;l=88), i failed to find an FR for it, so it must have been a chat conversation.

ya...@gmail.com <ya...@gmail.com> #3Mar 26, 2021 07:12PM

Would you be opposed to failing the build if we see a src/kotlin directory?

le...@google.com <le...@google.com> #4Mar 26, 2021 07:17PM

Status: Won't Fix (Intended Behavior)

No, go ahead if you want to add that check.

Issue 170331371

Description

Issue summary

Comments

cl...@google.com <cl...@google.com> Oct 15, 2020 05:32PM

le...@google.com <le...@google.com> #2Mar 16, 2021 11:03PM

ya...@gmail.com <ya...@gmail.com> #3Mar 26, 2021 07:12PM

le...@google.com <le...@google.com> #4Mar 26, 2021 07:17PM

Add comment

Issue metadata