[Bug]: Custom Public Link containing underscores "_" stopped working on upgrade to 31.0.2

[kr4z33]

⚠️ 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

custom public links containing underscores are borked, apparently after upgrade to version 31.0.2

Steps to reproduce

1. Create a custom public link, including an underscore charachter
2. Attempt to access it
3. read error "This directory is unavailable, please check the logs or contact the administrator"
4. check the logs, observe things like the following on each access attempt:

[webdav] Error: Requested uri (/public.php/dav/files/20250316_D) is out of base uri (/public.php/dav/files/20250316/)
	PROPFIND /public.php/dav/files/20250316_D
	from <ip address> by ? at Mar 25, 2025, 3:39:06 PM

Expected behavior

Custom public links continue working. I now have a bunch of broken links that I have distributed which used underscores to make the links prettier.

Nextcloud Server version

31

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.2

Web server

Apache (supported)

Database engine version

MariaDB

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

Updated from a MINOR version (ex. 32.0.1 to 32.0.2)

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

Configuration report

{
    "system": {
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "***REMOVED SENSITIVE VALUE***",
            "***REMOVED SENSITIVE VALUE***"
        ],
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "overwrite.cli.url": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "mysql",
        "version": "31.0.2.1",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "logtimezone": "UTC",
        "installed": true,
        "maintenance": false,
        "theme": "",
        "loglevel": 2,
        "memcache.local": "\\OC\\Memcache\\APCu",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "filelocking.enabled": "true",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": 0,
            "timeout": 0,
            "password": "***REMOVED SENSITIVE VALUE***",
            "dbindex": 0
        },
        "htaccess.RewriteBase": "\/",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpmode": "sendmail",
        "mail_smtpauthtype": "LOGIN",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "3325",
        "mail_smtpauth": 1,
        "mail_smtpsecure": "tls",
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "mail_sendmailmode": "smtp",
        "updater.release.channel": "stable",
        "mysql.utf8mb4": true,
        "default_phone_region": "US",
        "app_install_overwrite": [
            "gpxedit"
        ],
        "simpleSignUpLink.shown": false,
        "maintenance_window_start": 1
    }
}

List of activated Apps

Enabled:
  - activity: 4.0.0
  - admin_audit: 1.21.0
  - announcementcenter: 7.1.0
  - app_api: 5.0.2
  - appointments: 2.4.1
  - bruteforcesettings: 4.0.0
  - calendar: 5.2.0
  - cfg_share_links: 7.0.1
  - circles: 31.0.0
  - cloud_federation_api: 1.14.0
  - comments: 1.21.0
  - contacts: 7.0.4
  - contactsinteraction: 1.12.0
  - dashboard: 7.11.0
  - dav: 1.33.0
  - deck: 1.15.0
  - event_update_notification: 2.6.1
  - federatedfilesharing: 1.21.0
  - federation: 1.21.0
  - files: 2.3.1
  - files_downloadlimit: 4.0.0
  - files_external: 1.23.0
  - files_pdfviewer: 4.0.0
  - files_reminders: 1.4.0
  - files_sharing: 1.23.1
  - files_trashbin: 1.21.0
  - files_versions: 1.24.0
  - firstrunwizard: 4.0.0
  - forms: 5.0.4
  - gpoddersync: 3.12.0
  - gpxpod: 7.0.4
  - groupfolders: 19.0.4
  - groupquota: 0.2.2
  - imageconverter: 2.0.5
  - impersonate: 2.0.0
  - logreader: 4.0.0
  - lookup_server_connector: 1.19.0
  - metadata: 0.22.0
  - nextcloud_announcements: 3.0.0
  - notes: 4.11.0
  - notifications: 4.0.0
  - oauth2: 1.19.1
  - password_policy: 3.0.0
  - phonetrack: 0.8.2
  - photos: 4.0.0-dev.1
  - polls: 7.4.1
  - previewgenerator: 5.8.0
  - privacy: 3.0.0
  - profile: 1.0.0
  - provisioning_api: 1.21.0
  - quota_warning: 1.21.0
  - recommendations: 4.0.0
  - related_resources: 2.0.0
  - serverinfo: 3.0.0
  - settings: 1.14.0
  - sharebymail: 1.21.0
  - spreed: 21.0.1
  - support: 3.0.0
  - survey_client: 3.0.0
  - suspicious_login: 9.0.1
  - systemtags: 1.21.1
  - tasks: 0.16.1
  - text: 5.0.0
  - theming: 2.6.1
  - theming_customcss: 1.18.0
  - timemanager: 0.3.18
  - twofactor_backupcodes: 1.20.0
  - updatenotification: 1.21.0
  - user_status: 1.11.0
  - user_usage_report: 2.0.0
  - viewer: 4.0.0
  - weather_status: 1.11.0
  - webhook_listeners: 1.2.0
  - workflowengine: 2.13.0
Disabled:
  - camerarawpreviews: 0.8.6 (installed 0.8.6)
  - encryption: 2.19.0
  - files_markdown: 2.4.1 (installed 2.4.1)
  - files_readmemd: 3.0.2 (installed 3.0.2)
  - files_rightclick: 0.15.1 (installed 1.6.0)
  - gpgmailer: 0.0.4 (installed 0.0.3)
  - gpxedit: 0.0.14 (installed 0.0.14)
  - gpxmotion: 0.1.0 (installed 0.1.0)
  - registration: 2.6.0 (installed 2.6.0)
  - sensorlogger: 0.1.4 (installed 0.1.4)
  - sms_relentless: 1.4.2 (installed 1.4.2)
  - stt_whisper: 1.0.8 (installed 1.0.8)
  - twofactor_nextcloud_notification: 5.0.0
  - twofactor_totp: 13.0.0-dev.0
  - user_ldap: 1.22.0
  - video_converter: 1.0.6 (installed 1.0.6)

Nextcloud Signing status

No errors have been found.

Nextcloud Logs

see under 'steps to reproduce'

Additional info

No response

[solracsf]

On which NC version was this link created?

[kr4z33]

Thanks for the quick attention - I have been creating custom links with underscores for a while now (since dashes were outlawed, when custom links were made via 3rd party app). Share links with underscore can still be created in my v. 31.0.2 without complaint from Nextcloud.