FileSortOrderByName crash : Comparison method violates its general contract!

⚠️ Before posting ⚠️

This is a bug, not a question or an enhancement.
I've searched for similar issues and didn't find a duplicate.
I've written a clear and descriptive title for this issue, not just "Bug" or "Crash".
I agree to follow Nextcloud's Code of Conduct.

Steps to reproduce

Cause of error

Exception in thread "DefaultDispatcher-worker-5" java.lang.IllegalArgumentException: Comparison method violates its general contract!
    at java.util.TimSort.mergeHi(TimSort.java:903)
    at java.util.TimSort.mergeAt(TimSort.java:520)
    at java.util.TimSort.mergeForceCollapse(TimSort.java:461)
    at java.util.TimSort.sort(TimSort.java:254)
    at java.util.Arrays.sort(Arrays.java:1365)
    at java.util.ArrayList.sortRange(ArrayList.java:1834)
    at java.util.ArrayList.sort(ArrayList.java:1827)
    at java.util.Collections.sort(Collections.java:207)
    at kotlin.collections.CollectionsKt__MutableCollectionsJVMKt.sortWith(MutableCollectionsJVM.kt:42)
    at com.owncloud.android.utils.FileSortOrderByName.sortOnlyByName(FileSortOrderByName.kt:59)
    at com.owncloud.android.utils.FileSortOrderByName.sortCloudFiles(FileSortOrderByName.kt:32)
    at com.owncloud.android.ui.adapter.helper.OCFileListAdapterHelper$sortData$2.invokeSuspend(OCFileListAdapterHelper.kt:159)
    at com.owncloud.android.ui.adapter.helper.OCFileListAdapterHelper$sortData$2.invoke(OCFileListAdapterHelper.kt:8)
    at com.owncloud.android.ui.adapter.helper.OCFileListAdapterHelper$sortData$2.invoke(OCFileListAdapterHelper.kt:4)
    at kotlinx.coroutines.intrinsics.UndispatchedKt.startUndispatchedOrReturn(Undispatched.kt:42)
    at kotlinx.coroutines.BuildersKt__Builders_commonKt.withContext(Builders.common.kt:164)
    at kotlinx.coroutines.BuildersKt.withContext(dex-id-91442b47c60370bd28760623fdb31acd4f2c6112:1)
    at com.owncloud.android.ui.adapter.helper.OCFileListAdapterHelper.sortData(OCFileListAdapterHelper.kt:153)
    at com.owncloud.android.ui.adapter.helper.OCFileListAdapterHelper.prepareFileList(OCFileListAdapterHelper.kt:101)
    at com.owncloud.android.ui.adapter.helper.OCFileListAdapterHelper$prepareFileList$2.invokeSuspend(OCFileListAdapterHelper.kt:20)
    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:34)
    at kotlinx.coroutines.UndispatchedCoroutine.afterResume(CoroutineContext.kt:266)
    at kotlinx.coroutines.AbstractCoroutine.resumeWith(AbstractCoroutine.kt:100)
    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:47)
    at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:101)
    at kotlinx.coroutines.internal.LimitedDispatcher$Worker.run(LimitedDispatcher.kt:113)
    at kotlinx.coroutines.scheduling.TaskImpl.run(Tasks.kt:89)
    at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:589)
    at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:823)
    at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:720)
    at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:707)

App information

ID: com.nextcloud.client
Version: 340000190
Build flavor: gplay

Device information

Brand: samsung
Device: e3q
Model: SM-S928U1
Id: BP4A.251205.006
Product: e3quew

Firmware

SDK: 36
Release: 16
Incremental: S928U1UES6DZF2

Expected behaviour

Cause of error

Exception in thread "DefaultDispatcher-worker-5" java.lang.IllegalArgumentException: Comparison method violates its general contract!
    at java.util.TimSort.mergeHi(TimSort.java:903)
    at java.util.TimSort.mergeAt(TimSort.java:520)
    at java.util.TimSort.mergeForceCollapse(TimSort.java:461)
    at java.util.TimSort.sort(TimSort.java:254)
    at java.util.Arrays.sort(Arrays.java:1365)
    at java.util.ArrayList.sortRange(ArrayList.java:1834)
    at java.util.ArrayList.sort(ArrayList.java:1827)
    at java.util.Collections.sort(Collections.java:207)
    at kotlin.collections.CollectionsKt__MutableCollectionsJVMKt.sortWith(MutableCollectionsJVM.kt:42)
    at com.owncloud.android.utils.FileSortOrderByName.sortOnlyByName(FileSortOrderByName.kt:59)
    at com.owncloud.android.utils.FileSortOrderByName.sortCloudFiles(FileSortOrderByName.kt:32)
    at com.owncloud.android.ui.adapter.helper.OCFileListAdapterHelper$sortData$2.invokeSuspend(OCFileListAdapterHelper.kt:159)
    at com.owncloud.android.ui.adapter.helper.OCFileListAdapterHelper$sortData$2.invoke(OCFileListAdapterHelper.kt:8)
    at com.owncloud.android.ui.adapter.helper.OCFileListAdapterHelper$sortData$2.invoke(OCFileListAdapterHelper.kt:4)
    at kotlinx.coroutines.intrinsics.UndispatchedKt.startUndispatchedOrReturn(Undispatched.kt:42)
    at kotlinx.coroutines.BuildersKt__Builders_commonKt.withContext(Builders.common.kt:164)
    at kotlinx.coroutines.BuildersKt.withContext(dex-id-91442b47c60370bd28760623fdb31acd4f2c6112:1)
    at com.owncloud.android.ui.adapter.helper.OCFileListAdapterHelper.sortData(OCFileListAdapterHelper.kt:153)
    at com.owncloud.android.ui.adapter.helper.OCFileListAdapterHelper.prepareFileList(OCFileListAdapterHelper.kt:101)
    at com.owncloud.android.ui.adapter.helper.OCFileListAdapterHelper$prepareFileList$2.invokeSuspend(OCFileListAdapterHelper.kt:20)
    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:34)
    at kotlinx.coroutines.UndispatchedCoroutine.afterResume(CoroutineContext.kt:266)
    at kotlinx.coroutines.AbstractCoroutine.resumeWith(AbstractCoroutine.kt:100)
    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:47)
    at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:101)
    at kotlinx.coroutines.internal.LimitedDispatcher$Worker.run(LimitedDispatcher.kt:113)
    at kotlinx.coroutines.scheduling.TaskImpl.run(Tasks.kt:89)
    at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:589)
    at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:823)
    at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:720)
    at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:707)

App information

ID: com.nextcloud.client
Version: 340000190
Build flavor: gplay

Device information

Brand: samsung
Device: e3q
Model: SM-S928U1
Id: BP4A.251205.006
Product: e3quew

Firmware

SDK: 36
Release: 16
Incremental: S928U1UES6DZF2

Actual behaviour

Cause of error

Exception in thread "DefaultDispatcher-worker-5" java.lang.IllegalArgumentException: Comparison method violates its general contract!
    at java.util.TimSort.mergeHi(TimSort.java:903)
    at java.util.TimSort.mergeAt(TimSort.java:520)
    at java.util.TimSort.mergeForceCollapse(TimSort.java:461)
    at java.util.TimSort.sort(TimSort.java:254)
    at java.util.Arrays.sort(Arrays.java:1365)
    at java.util.ArrayList.sortRange(ArrayList.java:1834)
    at java.util.ArrayList.sort(ArrayList.java:1827)
    at java.util.Collections.sort(Collections.java:207)
    at kotlin.collections.CollectionsKt__MutableCollectionsJVMKt.sortWith(MutableCollectionsJVM.kt:42)
    at com.owncloud.android.utils.FileSortOrderByName.sortOnlyByName(FileSortOrderByName.kt:59)
    at com.owncloud.android.utils.FileSortOrderByName.sortCloudFiles(FileSortOrderByName.kt:32)
    at com.owncloud.android.ui.adapter.helper.OCFileListAdapterHelper$sortData$2.invokeSuspend(OCFileListAdapterHelper.kt:159)
    at com.owncloud.android.ui.adapter.helper.OCFileListAdapterHelper$sortData$2.invoke(OCFileListAdapterHelper.kt:8)
    at com.owncloud.android.ui.adapter.helper.OCFileListAdapterHelper$sortData$2.invoke(OCFileListAdapterHelper.kt:4)
    at kotlinx.coroutines.intrinsics.UndispatchedKt.startUndispatchedOrReturn(Undispatched.kt:42)
    at kotlinx.coroutines.BuildersKt__Builders_commonKt.withContext(Builders.common.kt:164)
    at kotlinx.coroutines.BuildersKt.withContext(dex-id-91442b47c60370bd28760623fdb31acd4f2c6112:1)
    at com.owncloud.android.ui.adapter.helper.OCFileListAdapterHelper.sortData(OCFileListAdapterHelper.kt:153)
    at com.owncloud.android.ui.adapter.helper.OCFileListAdapterHelper.prepareFileList(OCFileListAdapterHelper.kt:101)
    at com.owncloud.android.ui.adapter.helper.OCFileListAdapterHelper$prepareFileList$2.invokeSuspend(OCFileListAdapterHelper.kt:20)
    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:34)
    at kotlinx.coroutines.UndispatchedCoroutine.afterResume(CoroutineContext.kt:266)
    at kotlinx.coroutines.AbstractCoroutine.resumeWith(AbstractCoroutine.kt:100)
    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:47)
    at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:101)
    at kotlinx.coroutines.internal.LimitedDispatcher$Worker.run(LimitedDispatcher.kt:113)
    at kotlinx.coroutines.scheduling.TaskImpl.run(Tasks.kt:89)
    at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:589)
    at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:823)
    at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:720)
    at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:707)

App information

ID: com.nextcloud.client
Version: 340000190
Build flavor: gplay

Device information

Brand: samsung
Device: e3q
Model: SM-S928U1
Id: BP4A.251205.006
Product: e3quew

Firmware

SDK: 36
Release: 16
Incremental: S928U1UES6DZF2

Android version

16

Device brand and model

Samsung S24 Ultra

Stock or custom OS?

Stock

Nextcloud android app version

340000190

Nextcloud server version

00

Using a reverse proxy?

I don't know

Android logs

No response

Server error logs

Additional information

No response

Could you please provide a list of the file names associated with the crash, if available?

It's a one folder named S24 Ultra with 167 GB. Suliman Elhaj <http://facebook.com/elbagers> <http://linkedin.com/in/elbagers> <http://instagram.com/elbagers>

…

On Fri, Jul 24, 2026, 1:26 AM Ali Tarek Hrhera ***@***.***> wrote: *alihrhera* left a comment (nextcloud/android#17371) <#17371 (comment)> Could you please provide a list of the file names associated with the crash, if available? — Reply to this email directly, view it on GitHub <#17371?email_source=notifications&email_token=A223B55EORIRCOIOEYU4P7T5GLXPDA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTKMBWGY2DKMJWHA32M4TFMFZW63VGMF2XI2DPOKSWK5TFNZ2KYZTPN52GK4S7MNWGSY3L#issuecomment-5066451687>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A223B537Z25G5ISFBVSOGJ35GLXPDAVCNFSNUABEKJSXA33TNF2G64TZHM3DANJWGE4DGNB3JFZXG5LFHM2DSNRVGMZDKNJUHCQXMAQ> . You are receiving this because you authored the thread.Message ID: ***@***.***>

@elbagers

@elbagers Hey,

Once the QA APK generated from PR could you please try?

#17390

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FileSortOrderByName crash : Comparison method violates its general contract! #17371

⚠️ Before posting ⚠️

Steps to reproduce

Cause of error

App information

Device information

Firmware

Expected behaviour

Cause of error

App information

Device information

Firmware

Actual behaviour

Cause of error

App information

Device information

Firmware

Android version

Device brand and model

Stock or custom OS?

Nextcloud android app version

Nextcloud server version

Using a reverse proxy?

Android logs

Server error logs

Additional information

Metadata

Assignees

Labels

Type

Projects

Milestone

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Development

FileSortOrderByName crash : Comparison method violates its general contract! #17371

Description

⚠️ Before posting ⚠️

Steps to reproduce

Cause of error

App information

Device information

Firmware

Expected behaviour

Cause of error

App information

Device information

Firmware

Actual behaviour

Cause of error

App information

Device information

Firmware

Android version

Device brand and model

Stock or custom OS?

Nextcloud android app version

Nextcloud server version

Using a reverse proxy?

Android logs

Server error logs

Additional information

Activity

alihrhera commented on Jul 24, 2026

elbagers commented on Jul 24, 2026

alperozturk96 commented on Jul 28, 2026

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions