[Bug]: PHP 8.5 - The float is not representable as an int, cast occurred at /nextcloud/3rdparty/deepdiver/zipstreamer/src/Count64.php

⚠️ 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

After the upgrade to PHP 8.5: If someone wants to download a few files or a folder, a zip-file is generated. During this operation, the log get flooded with the following warning: The float 1.8446744069414584E+19 is not representable as an int, cast occurred at nextcloud/3rdparty/deepdiver/zipstreamer/src/Count64.php#112

Steps to reproduce

1. In the GUI mark some files
2. Download them (zip file gets created and downloaded)
3. Watch the logs

Expected behavior

Correct conversion, no warnings in the logs

Nextcloud Server version

33

Operating system

RHEL/CentOS

PHP engine version

PHP 8.5

Web server

Apache (supported)

Database engine version

PostgreSQL

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

None

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": {
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "10.202.72.1",
            "cloud.example.com"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "overwrite.cli.url": "https:\/\/cloud.example.com",
        "overwritehost": "cloud.example.com",
        "overwriteprotocol": "https",
        "htaccess.RewriteBase": "\/",
        "dbtype": "pgsql",
        "version": "33.0.3.2",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbtableprefix": "oc_",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "logtimezone": "Europe\/Vienna",
        "installed": true,
        "mail_sendmailmode": "smtp",
        "mail_smtpmode": "smtp",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "25",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpstreamoptions": {
            "ssl": {
                "allow_self_signed": true,
                "verify_peer": false,
                "verify_peer_name": false
            }
        },
        "default_language": "de_DE",
        "maintenance": false,
        "loglevel": 2,
        "updatechecker": true,
        "has_internet_connection": true,
        "proxy": "proxy.example.com:8080",
        "connectivity_check_domains": [
            "nextcloud.com",
            "download.nextcloud.com"
        ],
        "twofactor_enforced": "true",
        "twofactor_enforced_groups": [],
        "twofactor_enforced_excluded_groups": [],
        "defaultapp": "files",
        "default_locale": "de_AT",
        "default_phone_region": "AT",
        "apps_paths": [
            {
                "path": "\/data\/vhosts\/nextcloud\/apps",
                "url": "\/apps",
                "writable": false
            },
            {
                "path": "\/data\/vhosts\/nextcloud\/custom_apps",
                "url": "\/custom_apps",
                "writable": true
            }
        ],
        "filelocking.enabled": true,
        "memcache.local": "\\OC\\Memcache\\APCu",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "memcache.distributed": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": 6379,
            "password": "***REMOVED SENSITIVE VALUE***"
        },
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "maintenance_window_start": 1,
        "mail_smtpauth": 1,
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "forbidden_filename_basenames": [
            "con",
            "prn",
            "aux",
            "nul",
            "com0",
            "com1",
            "com2",
            "com3",
            "com4",
            "com5",
            "com6",
            "com7",
            "com8",
            "com9",
            "com\u00b9",
            "com\u00b2",
            "com\u00b3",
            "lpt0",
            "lpt1",
            "lpt2",
            "lpt3",
            "lpt4",
            "lpt5",
            "lpt6",
            "lpt7",
            "lpt8",
            "lpt9",
            "lpt\u00b9",
            "lpt\u00b2",
            "lpt\u00b3"
        ],
        "forbidden_filename_characters": [
            "<",
            ">",
            ":",
            "\"",
            "|",
            "?",
            "*",
            "\\",
            "\/"
        ],
        "forbidden_filename_extensions": [
            " ",
            ".",
            ".filepart",
            ".part"
        ],
        "skeletondirectory": "\/data\/nextcloud\/skeleton",
        "trashbin_retention_obligation": "auto,14",
        "app_install_overwrite": [
            "twofactor_admin"
        ],
        "serverid": "1"
    }
}

List of activated Apps

Enabled:
  - activity: 6.0.0
  - admin_audit: 1.23.0
  - bruteforcesettings: 6.0.0
  - circles: 33.0.0
  - cloud_federation_api: 1.17.0
  - comments: 1.23.0
  - contactsinteraction: 1.14.1
  - dav: 1.36.0
  - federatedfilesharing: 1.23.0
  - federation: 1.23.0
  - files: 2.5.0
  - files_downloadlimit: 5.1.0
  - files_external: 1.25.1
  - files_pdfviewer: 6.0.0
  - files_reminders: 1.6.0
  - files_sharing: 1.25.2
  - files_trashbin: 1.23.0
  - files_versions: 1.26.0
  - groupfolders: 21.0.7
  - impersonate: 4.0.0
  - logreader: 6.0.0
  - lookup_server_connector: 1.21.0
  - nextcloud_announcements: 5.0.0
  - notifications: 6.0.0
  - oauth2: 1.21.0
  - password_policy: 5.0.0
  - photos: 6.0.0
  - privacy: 5.0.0
  - profile: 1.2.0
  - provisioning_api: 1.23.0
  - quota_warning: 1.23.0
  - recommendations: 6.0.0
  - related_resources: 4.0.0
  - serverinfo: 5.0.0
  - settings: 1.16.0
  - sharebymail: 1.23.0
  - support: 5.0.0
  - suspicious_login: 11.0.0
  - systemtags: 1.23.0
  - text: 7.0.1
  - theming: 2.8.0
  - twofactor_admin: 4.11.1
  - twofactor_backupcodes: 1.22.0
  - twofactor_totp: 15.0.0
  - updatenotification: 1.23.0
  - user_retention: 1.16.0
  - user_usage_report: 4.0.0
  - viewer: 6.0.0
  - webhook_listeners: 1.5.0
  - workflowengine: 2.15.0
Disabled:
  - app_api: 33.0.0 (installed 32.0.0)
  - dashboard: 7.13.0 (installed 7.1.0)
  - encryption: 2.21.0
  - firstrunwizard: 6.0.0 (installed 4.0.0)
  - sharelisting: 1.3.0 (installed 1.3.0)
  - survey_client: 5.0.0 (installed 1.15.0)
  - testing: 1.23.0
  - twofactor_nextcloud_notification: 7.0.0
  - user_ldap: 1.24.0
  - user_status: 1.13.0 (installed 1.1.1)
  - weather_status: 1.13.0 (installed 1.1.0)

Nextcloud Signing status

No errors have been found.

Nextcloud Logs

{"reqId":"agqzLVJYBVRhi@olqWZFugAAAMw","level":2,"time":"2026-05-18T08:35:30+02:00","remoteAddr":"192.168.2.1","user":"username","app":"PHP","method":"GET","url":"/remote.php/dav/files/username/Temp/?accept=zip&files=%5B%22filename.txt%22%2C%22filename2.txt%22%5D","scriptName":"/remote.php","message":"The float 1.8446744069414584E+19 is not representable as an int, cast occurred at /data/vhosts/nextcloud/3rdparty/deepdiver/zipstreamer/src/Count64.php#112","userAgent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:143.0) Gecko/20100101 Firefox/143.0","version":"33.0.3.2","data":{"app":"PHP"}}

Additional info

OS: Red Hat Enterprise Linux 8.10 (Ootpa)
PHP: PHP 8.5.6 (cli)
Apache: Apache/2.4.37
Nextcloud: 33.0.3.2

As stated, warnings started with the Upgrade from PHP 8.2 to 8.5.

Start with 3rdparty/deepdiver/zipstreamer/src/Count64.php at line 112 and reproduce the warning by downloading multiple files as a ZIP on PHP 8.5. Trace the float-to-integer conversion involved in ZIP generation and verify that the download completes without the warning in the logs.