Locked files: not enough infos for end user, too much for admin

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

When someone tries to move/delete/edit a locked file, he/she gets an incomplete notification while admin get errors as if something were abnormal.

Steps to reproduce

1. try to delete a locked file
2. see the error popup "action failed: deleting file" (or something like that, my interface is in french)
3. go to the logs and see the Locked Exception thrown: Sabre\DAV\Exception\Locked error

Expected behavior

• End user should see a complete warning : "action failed: file is locked by [...]" (and it could be a simple warning like "this file is locked, you cannot {action} it", rather than an error)
• Logs should not be spammed with this message which is not an error in the admin pov but a simple information about a user trying to edit a locked file, which is ok

Nextcloud Server version

30

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.3

Web server

Nginx

Database engine version

MariaDB

Is this bug present after an update or on a fresh install?

None

Are you using the Nextcloud Server Encryption module?

None

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Start by tracing locked-file delete, move, and edit handling around the Sabre\DAV\Exception\Locked entry point, then follow how the result reaches the user notification and administrator logs. Done means users receive a clear locked-file warning and this expected condition is no longer logged as an abnormal error.