countSeenUsers() function returns wrong amount of LDAP active users

⚠️ 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 (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• Nextcloud Server is running on 64bit capable CPU, PHP and OS.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

The function countSeenUsers() seems to return the amount of users that have ever been registered, not only those active and registered currently:

public function countSeenUsers() {
	$queryBuilder = \OC::$server->getDatabaseConnection()->getQueryBuilder();
	$queryBuilder->select($queryBuilder->func()->count('*'))
		->from('preferences')
		->where($queryBuilder->expr()->eq('appid', $queryBuilder->createNamedParameter('login')))
		->andWhere($queryBuilder->expr()->eq('configkey', $queryBuilder->createNamedParameter('lastLogin')));

	$query = $queryBuilder->execute();

	$result = (int)$query->fetchOne();
	$query->closeCursor();

	return $result;
}

The following SQL statement to the Nextcloud database replicates the return value of this function:

SELECT COUNT(*)
FROM oc_preferences
WHERE appid = 'login' AND configkey = 'lastLogin';

The following SQL statement also outputs the displayName alongside the userid to better see which users are considered by countSeenUsers():

SELECT userid, configvalue
FROM oc_preferences
WHERE userid IN
    (SELECT userid
     FROM oc_preferences
     WHERE appid = 'login' AND configkey = 'lastLogin')
AND configkey = 'displayName';

The output of the SQL statement above includes already deleted LDAP accounts. So maybe this is a problem with the LDAP implementation of Nextcloud. Deleted users should not appear in the database.

Steps to reproduce

1. Execute the following SQL statement to replicate the users considered by countSeenUsers():

SELECT userid, configvalue
FROM oc_preferences
WHERE userid IN
    (SELECT userid
     FROM oc_preferences
     WHERE appid = 'login' AND configkey = 'lastLogin')
AND configkey = 'email';

2. Compare the output above with the output of php occ user:list

Expected behavior

The expected behaviour would be that the function countSeenUsers() returns the same amount of users as the OCC command php occ user:list. Deleted (LDAP) users should not appear in the database.

Installation method

Official All-in-One appliance

Nextcloud Server version

25

Operating system

Other

PHP engine version

PHP 8.0

Web server

Apache (supported)

Database engine version

PostgreSQL

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

Fresh Nextcloud Server install

Are you using the Nextcloud Server Encryption module?

Encryption is Disabled

What user-backends are you using?

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

Configuration report

{
    "system": {
        "profile.enabled": false,
        "enable_avatars": false,
        "memcache.distributed": "\\OC\\Memcache\\Redis"
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "memcache.local": "\\OC\\Memcache\\APCu",
        "apps_paths": [
            {
                "path": "\/var\/www\/html\/apps",
                "url": "\/apps",
                "writable": false
            },
            {
                "path": "\/var\/www\/html\/custom_apps",
                "url": "\/custom_apps",
                "writable": true
            }
        ],
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "password": "***REMOVED SENSITIVE VALUE***",
            "port": 6379
        },
        "overwritehost": "***REMOVED SENSITIVE VALUE***",
        "overwriteprotocol": "https",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "localhost",
            "***REMOVED SENSITIVE VALUE***"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "pgsql",
        "version": "25.0.7.1",
        "overwrite.cli.url": "https:\/\/***REMOVED SENSITIVE VALUE***\/",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "loglevel": "2",
        "log_type": "file",
        "logfile": "\/var\/www\/html\/data\/nextcloud.log",
        "log_rotate_size": "10485760",
        "log.condition": {
            "apps": [
                "admin_audit"
            ]
        },
        "preview_max_x": "2048",
        "preview_max_y": "2048",
        "jpeg_quality": "60",
        "enabledPreviewProviders": {
            "1": "OC\\Preview\\Image",
            "2": "OC\\Preview\\MarkDown",
            "3": "OC\\Preview\\MP3",
            "4": "OC\\Preview\\TXT",
            "5": "OC\\Preview\\OpenDocument",
            "6": "OC\\Preview\\Movie"
        },
        "enable_previews": true,
        "upgrade.disable-web": true,
        "mail_smtpmode": "smtp",
        "trashbin_retention_obligation": "auto, 30",
        "versions_retention_obligation": "auto, 30",
        "activity_expire_days": "30",
        "simpleSignUpLink.shown": false,
        "share_folder": "\/Freigaben\/",
        "tempdirectory": "\/mnt\/ncdata\/tmp\/",
        "one-click-instance": true,
        "one-click-instance.user-limit": 100,
        "one-click-instance.link": "https:\/\/nextcloud.com\/all-in-one\/",
        "htaccess.RewriteBase": "\/",
        "files_external_allow_create_new_local": true,
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "allow_local_remote_servers": true,
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_sendmailmode": "smtp",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpauthtype": "PLAIN",
        "mail_smtpsecure": "ssl",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpauth": 1,
        "mail_smtpport": "465",
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "ldapProviderFactory": "OCA\\User_LDAP\\LDAPProviderFactory",
        "maintenance": false,
        "default_language": "de",
        "default_locale": "de",
        "updatedirectory": "\/nc-updater",
    }
}

List of activated Apps

Enabled:
  - activity: 2.17.0
  - admin_audit: 1.15.0
  - appointments: 1.15.1
  - calendar: 4.3.4
  - circles: 25.0.0
  - cloud_federation_api: 1.8.0
  - comments: 1.15.0
  - contacts: 5.2.0
  - contactsinteraction: 1.6.0
  - dashboard: 7.5.0
  - dav: 1.24.0
  - deck: 1.8.5
  - federatedfilesharing: 1.15.0
  - files: 1.20.1
  - files_external: 1.17.0
  - files_fulltextsearch: 25.0.0
  - files_pdfviewer: 2.6.0
  - files_rightclick: 1.4.0
  - files_sharing: 1.17.0
  - files_trashbin: 1.15.0
  - files_versions: 1.18.0
  - fulltextsearch: 25.0.0
  - fulltextsearch_elasticsearch: 25.0.0
  - groupfolders: 13.1.3
  - logreader: 2.10.0
  - lookup_server_connector: 1.13.0
  - nextcloud-aio: 0.3.0
  - nextcloud_announcements: 1.14.0
  - notifications: 2.13.1
  - notify_push: 0.6.3
  - oauth2: 1.13.0
  - password_policy: 1.15.0
  - privacy: 1.9.0
  - provisioning_api: 1.15.0
  - recommendations: 1.4.0
  - related_resources: 1.0.4
  - richdocuments: 7.1.4
  - serverinfo: 1.15.0
  - settings: 1.7.0
  - sharebymail: 1.15.0
  - spreed: 15.0.6
  - support: 1.8.0
  - survey_client: 1.13.0
  - systemtags: 1.15.0
  - tasks: 0.15.0
  - text: 3.6.0
  - theming: 2.0.1
  - twofactor_backupcodes: 1.14.0
  - twofactor_totp: 7.0.0
  - user_ldap: 1.15.0
  - viewer: 1.9.0
  - workflowengine: 2.7.0
Disabled:
  - bruteforcesettings
  - encryption
  - federation: 1.15.0
  - firstrunwizard: 2.14.0
  - photos: 2.0.1
  - suspicious_login
  - user_status: 1.5.0
  - weather_status: 1.5.0

Nextcloud Signing status

No response

Nextcloud Logs

No response

Additional info

No response

Start in lib/private/User/Manager.php at countSeenUsers(), then compare its database query with the users returned by the php occ user:list entry point. Use the provided PostgreSQL queries to reproduce the discrepancy and verify that deleted LDAP users are excluded from the resulting count.