Mobile app crashes when sorting on trying to upload files

[ddattee]

⚠️ 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

1. Open the app.
2. Go into a non synchronized folder.
3. Click on + then Files.
4. Sort files by more recent first (or any date sorting I've tested).
5. App crashed.

Expected behaviour

No crash and sorting work.

Actual behaviour

App crash with a Java exception when trying to sort files.

Android version

14

Device brand and model

Pixel 5

Stock or custom OS?

Stock

Nextcloud android app version

3.34.1

Nextcloud server version

31.0.10

Using a reverse proxy?

Yes

Android logs

Cause of error

Exception in thread "pool-17-thread-1" java.util.ConcurrentModificationException
    at java.util.ArrayList.sort(ArrayList.java:1823)
    at java.util.Collections.sort(Collections.java:207)
    at kotlin.collections.CollectionsKt__MutableCollectionsJVMKt.sortWith(MutableCollectionsJVM.kt:42)
    at com.owncloud.android.utils.FileSortOrderByName.sortLocalFiles(FileSortOrderByName.kt:60)
    at com.owncloud.android.ui.adapter.LocalFileListAdapter.lambda$setSortOrder$6(LocalFileListAdapter.java:392)
    at com.owncloud.android.ui.adapter.LocalFileListAdapter.$r8$lambda$WTDJyclhOx9wYl9P9c9Mv0A876o(Unknown Source:0)
    at com.owncloud.android.ui.adapter.LocalFileListAdapter$$ExternalSyntheticLambda3.run(D8$$SyntheticClass:0)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1156)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:651)
    at java.lang.Thread.run(Thread.java:1119)

App information

• ID: com.nextcloud.client
• Version: 30340190
• Build flavor: gplay

Device information

• Brand: google
• Device: redfin
• Model: Pixel 5
• Id: `redacted'
• Product: redfin

Firmware

• SDK: 34
• Release: 14
• Incremental: 11260668

Server error logs

Additional information

No response

[ddattee]

Might be related to #16250

[mab18]

Hi,
I confirm this bug :

Cause of error

Exception in thread "pool-21-thread-1" java.util.ConcurrentModificationException
    at java.util.ArrayList.sort(ArrayList.java:1823)
    at java.util.Collections.sort(Collections.java:207)
    at kotlin.collections.CollectionsKt__MutableCollectionsJVMKt.sortWith(MutableCollectionsJVM.kt:42)
    at com.owncloud.android.utils.FileSortOrderByDate.sortLocalFiles(FileSortOrderByDate.kt:51)
    at com.owncloud.android.ui.adapter.LocalFileListAdapter.lambda$setSortOrder$6(LocalFileListAdapter.java:392)
    at com.owncloud.android.ui.adapter.LocalFileListAdapter.$r8$lambda$WTDJyclhOx9wYl9P9c9Mv0A876o(Unknown Source:0)
    at com.owncloud.android.ui.adapter.LocalFileListAdapter$$ExternalSyntheticLambda3.run(D8$$SyntheticClass:0)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1156)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:651)
    at java.lang.Thread.run(Thread.java:1119)

### App information
* ID: `com.nextcloud.client`
* Version: `30340190`
* Build flavor: `gplay`

### Firmware
* SDK: `36`
* Release: `16`
* Incremental: `U.R4T3.4ab7733-29b231b-29b231a`

[Jellrin]

Cause of error

Exception in thread "pool-29-thread-1" java.util.ConcurrentModificationException
    at java.util.ArrayList.sort(ArrayList.java:1823)
    at java.util.Collections.sort(Collections.java:207)
    at kotlin.collections.CollectionsKt__MutableCollectionsJVMKt.sortWith(MutableCollectionsJVM.kt:42)
    at com.owncloud.android.utils.FileSortOrderByName.sortLocalFiles(FileSortOrderByName.kt:60)
    at com.owncloud.android.ui.adapter.LocalFileListAdapter.lambda$setSortOrder$6(LocalFileListAdapter.java:392)
    at com.owncloud.android.ui.adapter.LocalFileListAdapter.$r8$lambda$WTDJyclhOx9wYl9P9c9Mv0A876o(Unknown Source:0)
    at com.owncloud.android.ui.adapter.LocalFileListAdapter$$ExternalSyntheticLambda3.run(D8$$SyntheticClass:0)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1154)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:652)
    at java.lang.Thread.run(Thread.java:1563)

App information

• ID: com.nextcloud.client
• Version: 30340190
• Build flavor: gplay

Device information

• Brand: google
• Device: cheetah
• Model: Pixel 7 Pro
• Id: BP4A.251205.006
• Product: cheetah

Firmware

• SDK: 36
• Release: 16
• Incremental: 14401865

[susnux]

Cause of error

Exception in thread "pool-14-thread-1" java.util.ConcurrentModificationException
    at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:1111)
    at java.util.ArrayList$Itr.next(ArrayList.java:1064)
    at com.owncloud.android.utils.FileSortOrderBySize.sortLocalFiles(FileSortOrderBySize.kt:62)
    at com.owncloud.android.ui.adapter.LocalFileListAdapter.lambda$setSortOrder$6(LocalFileListAdapter.java:392)
    at com.owncloud.android.ui.adapter.LocalFileListAdapter.$r8$lambda$WTDJyclhOx9wYl9P9c9Mv0A876o(Unknown Source:0)
    at com.owncloud.android.ui.adapter.LocalFileListAdapter$$ExternalSyntheticLambda3.run(D8$$SyntheticClass:0)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1156)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:651)
    at java.lang.Thread.run(Thread.java:1119)

App information

• ID: com.nextcloud.client
• Version: 30340190
• Build flavor: generic

Device information

• Brand: samsung
• Device: dm1q
• Model: SM-S911B
• Id: BP2A.250605.031.A3
• Product: dm1qxeea

Firmware

• SDK: 36
• Release: 16
• Incremental: S911BXXS8EYK5

[gohrner]

I can confirm this, and it looks like a duplicate of #16250, but this issue here has better descriptions.

This happens since several months. Also, the list of files shown for upload is tagged as "Sorted" by the sorting indicator, but is actually in random order initially. (I think I'll report this as a separate bug.) Trying to sort it in most cases (> 90% in my experience) leads to this crash.

I noticed that the image thumbnails are loaded asynchronously - no idea whether this may be related.

Cause of error

Exception in thread "pool-18-thread-1" java.util.ConcurrentModificationException
    at java.util.ArrayList.sort(ArrayList.java:1823)
    at java.util.Collections.sort(Collections.java:207)
    at kotlin.collections.CollectionsKt__MutableCollectionsJVMKt.sortWith(MutableCollectionsJVM.kt:42)
    at com.owncloud.android.utils.FileSortOrderByDate.sortLocalFiles(FileSortOrderByDate.kt:51)
    at com.owncloud.android.ui.adapter.LocalFileListAdapter.lambda$setSortOrder$6(LocalFileListAdapter.java:392)
    at com.owncloud.android.ui.adapter.LocalFileListAdapter.$r8$lambda$WTDJyclhOx9wYl9P9c9Mv0A876o(Unknown Source:0)
    at com.owncloud.android.ui.adapter.LocalFileListAdapter$$ExternalSyntheticLambda3.run(D8$$SyntheticClass:0)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1154)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:652)
    at java.lang.Thread.run(Thread.java:1563)

App information

• ID: com.nextcloud.client
• Version: 30340190
• Build flavor: gplay

Device information

• Brand: Fairphone
• Device: FP5
• Model: FP5
• Id: AQ3A.240912.001
• Product: FP5

Firmware

• SDK: 35
• Release: 15
• Incremental: VT2F

[gohrner]

Oh dear:

• App crashes when sorting by newest when choosing files to upload #16192
• Crash while trying to order photos, to select which to upload #16013
• Bug when changing the file ordering criteria #15969
• Upload file does not show the latest file – regardless of which sorting option I choose #16190

This bug does not seem to have any priority for the developers... I wonder why, as it makes the file upload feature something between really inconvenient to use to basically useless... :-( I thought sharing files would be one of the core features of Nextcloud...