Hidden files on external storage with dotfiles crash the app

[kescherCode]

When enabling hidden files in settings and accessing an external storage (using SFTP) containing dotfiles, the Android app crashes.

Actual behaviour

• The app crashes

Expected behaviour

• The app should display a list of files

Steps to reproduce

1. Have the following list of files and folders in the directory defined as root on an SFTP external storage

Folders:

.apache2
.cache
.config
.local
.logs
.nano
.nginx
.script-credentials
.ssh
.subversion
.znc
------------------------------
Files:

.bash_aliases
.bash_history
.bash_logout
.bashrc
.feral_aliases
.mysql_history
.profile
.selected_editor
.wget-hsts

2. Enable hidden files in the Nextcloud app settings.

3. Access the external storage

Environment data

Android version: 8.1.2 or 7.0

Device model: Xiaomi Redmi Note 4 (mido), or also stock Samsung Galaxy A5 2016

Stock or customized system: Customized LineageOS 15.1, Stock "Samsung Experience".

Nextcloud app version: 3.3.2

Nextcloud server version: 14.0.3

Logs

Stacktrace

E/AndroidRuntime( 4641): FATAL EXCEPTION: main
E/AndroidRuntime( 4641): Process: com.nextcloud.client, PID: 4641
E/AndroidRuntime( 4641): java.lang.IllegalArgumentException: Comparison method violates its general contract!
E/AndroidRuntime( 4641): 	at java.util.TimSort.mergeHi(TimSort.java:899)
E/AndroidRuntime( 4641): 	at java.util.TimSort.mergeAt(TimSort.java:516)
E/AndroidRuntime( 4641): 	at java.util.TimSort.mergeCollapse(TimSort.java:441)
E/AndroidRuntime( 4641): 	at java.util.TimSort.sort(TimSort.java:245)
E/AndroidRuntime( 4641): 	at java.util.Arrays.sort(Arrays.java:1498)
E/AndroidRuntime( 4641): 	at java.util.ArrayList.sort(ArrayList.java:1470)
E/AndroidRuntime( 4641): 	at java.util.Collections.sort(Collections.java:201)
E/AndroidRuntime( 4641): 	at com.owncloud.android.utils.FileSortOrderByName.sortCloudFiles(FileSortOrderByName.java:52)
E/AndroidRuntime( 4641): 	at com.owncloud.android.ui.adapter.OCFileListAdapter.swapDirectory(OCFileListAdapter.java:513)
E/AndroidRuntime( 4641): 	at com.owncloud.android.ui.fragment.OCFileListFragment.listDirectory(OCFileListFragment.java:1080)
E/AndroidRuntime( 4641): 	at com.owncloud.android.ui.fragment.OCFileListFragment.onItemClicked(OCFileListFragment.java:809)
E/AndroidRuntime( 4641): 	at com.owncloud.android.ui.adapter.OCFileListAdapter.lambda$onBindViewHolder$0$OCFileListAdapter(OCFileListAdapter.java:276)
E/AndroidRuntime( 4641): 	at com.owncloud.android.ui.adapter.OCFileListAdapter$$Lambda$0.onClick(Unknown Source:4)
E/AndroidRuntime( 4641): 	at android.view.View.performClick(View.java:6294)
E/AndroidRuntime( 4641): 	at android.view.View$PerformClick.run(View.java:24770)
E/AndroidRuntime( 4641): 	at android.os.Handler.handleCallback(Handler.java:790)
E/AndroidRuntime( 4641): 	at android.os.Handler.dispatchMessage(Handler.java:99)
E/AndroidRuntime( 4641): 	at android.os.Looper.loop(Looper.java:164)
E/AndroidRuntime( 4641): 	at android.app.ActivityThread.main(ActivityThread.java:6494)
E/AndroidRuntime( 4641): 	at java.lang.reflect.Method.invoke(Native Method)
E/AndroidRuntime( 4641): 	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:440)
E/AndroidRuntime( 4641): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

Web server error log

Error log stays empty when reproducing the issue (and five minutes afterwards).

Nextcloud log (data/nextcloud.log)

Error log stays empty when reproducing the issue (and five minutes afterwards).

[nextcloud-android-bot]

GitMate.io thinks possibly related issues are #2529 (App crash), #31 (Removing file crashes app.), #41 (Crash on sharing to app), #2515 (Crash at files loading), and #2574 (crash on file delete).

[AndyScherzinger]

Hi @filthycoding, thanks a lot for the report. We merged a contribution for fixing the sorting implementation (for the next feature release). Could you give the Dev build a try -> https://f-droid.org/de/packages/com.nextcloud.android.beta/ to check if this version solves your problem?

[kescherCode]

Hi @AndyScherzinger, the latest dev build on F-Droid actually fixes the issue.

[AndyScherzinger]

I created another test case, see #3281 to have this covered in via continuous integration with every build