[Bug]: Sabre\Xml\ParseException: The input element to parse is empty. Do not attempt to parse #43609

autoantwort · 2024-02-16T01:04:12Z

⚠️ 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

I am using the python caldav lib to search for Events:

import caldav
...

client = caldav.DAVClient(url)
principal = client.principal()
calendars = principal.calendars()
calendars[0].date_search(datetime(2010, 5, 1))

Then I get

[webdav] Fehler: Sabre\Xml\ParseException: The input element to parse is empty. Do not attempt to parse at <<closure>>

0. /var/www/html/3rdparty/sabre/dav/lib/DAV/CorePlugin.php line 685
   Sabre\Xml\Service->parse("", "/remote.php/dav ... /", null)
1. /var/www/html/3rdparty/sabre/event/lib/WildcardEmitterTrait.php line 89
   Sabre\DAV\CorePlugin->httpReport(["Sabre\\HTTP\\Request"], ["Sabre\\HTTP\\Response"])
2. /var/www/html/3rdparty/sabre/dav/lib/DAV/Server.php line 472
   Sabre\DAV\Server->emit("method:REPORT", [["Sabre\\HTTP\\ ... ]])
3. /var/www/html/3rdparty/sabre/dav/lib/DAV/Server.php line 253
   Sabre\DAV\Server->invokeMethod(["Sabre\\HTTP\\Request"], ["Sabre\\HTTP\\Response"])
4. /var/www/html/3rdparty/sabre/dav/lib/DAV/Server.php line 321
   Sabre\DAV\Server->start()
5. /var/www/html/apps/dav/lib/Server.php line 365
   Sabre\DAV\Server->exec()
6. /var/www/html/apps/dav/appinfo/v2/remote.php line 35
   OCA\DAV\Server->exec()
7. /var/www/html/remote.php line 172
   require_once("/var/www/html/a ... p")

REPORT /remote.php/dav/calendars/verwaltung/veranstaltungen/
from 10.72.4.30 by Verwaltung at 2024-02-15T23:42:08+00:00

As Json

{
    "reqId": "QZOqE0VJzuVA91N9NGCw",
    "level": 3,
    "time": "2024-02-15T23:46:15+00:00",
    "remoteAddr": "10.72.4.30",
    "user": "Verwaltung",
    "app": "webdav",
    "method": "REPORT",
    "url": "/remote.php/dav/calendars/verwaltung/veranstaltungen/",
    "message": "The input element to parse is empty. Do not attempt to parse",
    "userAgent": "Mozilla/5.0",
    "version": "27.1.5.1",
    "exception": {
        "Exception": "Sabre\\Xml\\ParseException",
        "Message": "The input element to parse is empty. Do not attempt to parse",
        "Code": 0,
        "Trace": [
            {
                "file": "/var/www/html/3rdparty/sabre/dav/lib/DAV/CorePlugin.php",
                "line": 685,
                "function": "parse",
                "class": "Sabre\\Xml\\Service",
                "type": "->",
                "args": [
                    "",
                    "/remote.php/dav/calendars/verwaltung/veranstaltungen/",
                    null
                ]
            },
            {
                "file": "/var/www/html/3rdparty/sabre/event/lib/WildcardEmitterTrait.php",
                "line": 89,
                "function": "httpReport",
                "class": "Sabre\\DAV\\CorePlugin",
                "type": "->",
                "args": [
                    [
                        "Sabre\\HTTP\\Request"
                    ],
                    [
                        "Sabre\\HTTP\\Response"
                    ]
                ]
            },
            {
                "file": "/var/www/html/3rdparty/sabre/dav/lib/DAV/Server.php",
                "line": 472,
                "function": "emit",
                "class": "Sabre\\DAV\\Server",
                "type": "->",
                "args": [
                    "method:REPORT",
                    [
                        [
                            "Sabre\\HTTP\\Request"
                        ],
                        [
                            "Sabre\\HTTP\\Response"
                        ]
                    ]
                ]
            },
            {
                "file": "/var/www/html/3rdparty/sabre/dav/lib/DAV/Server.php",
                "line": 253,
                "function": "invokeMethod",
                "class": "Sabre\\DAV\\Server",
                "type": "->",
                "args": [
                    [
                        "Sabre\\HTTP\\Request"
                    ],
                    [
                        "Sabre\\HTTP\\Response"
                    ]
                ]
            },
            {
                "file": "/var/www/html/3rdparty/sabre/dav/lib/DAV/Server.php",
                "line": 321,
                "function": "start",
                "class": "Sabre\\DAV\\Server",
                "type": "->",
                "args": []
            },
            {
                "file": "/var/www/html/apps/dav/lib/Server.php",
                "line": 365,
                "function": "exec",
                "class": "Sabre\\DAV\\Server",
                "type": "->",
                "args": []
            },
            {
                "file": "/var/www/html/apps/dav/appinfo/v2/remote.php",
                "line": 35,
                "function": "exec",
                "class": "OCA\\DAV\\Server",
                "type": "->",
                "args": []
            },
            {
                "file": "/var/www/html/remote.php",
                "line": 172,
                "args": [
                    "/var/www/html/apps/dav/appinfo/v2/remote.php"
                ],
                "function": "require_once"
            }
        ],
        "File": "/var/www/html/3rdparty/sabre/xml/lib/Service.php",
        "Line": 122,
        "message": "The input element to parse is empty. Do not attempt to parse",
        "exception": [],
        "CustomMessage": "The input element to parse is empty. Do not attempt to parse"
    },
    "id": "65cea26de7c9a"
}

Steps to reproduce

pip install caldav

import caldav
...

client = caldav.DAVClient(url)
principal = client.principal()
calendars = principal.calendars()
calendars[0].date_search(datetime(2010, 5, 1))

Expected behavior

No error

Installation method

Official All-in-One appliance

Nextcloud Server version

27

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.1

Web server

Apache (supported)

Database engine version

PostgreSQL

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

Upgraded to a MAJOR version (ex. 22 to 23)

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

docker exec --user www-data -it nextcloud-aio-nextcloud php occ config:list system     
{
    "system": {
        "one-click-instance": true,
        "one-click-instance.user-limit": 100,
        "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
            }
        ],
        "appsallowlist": [],
        "check_data_directory_permissions": false,
        "memcache.distributed": "\\OC\\Memcache\\Redis",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "password": "***REMOVED SENSITIVE VALUE***",
            "port": 6379
        },
        "overwritehost": "cloud.hilton.rwth-aachen.de",
        "overwriteprotocol": "https",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "localhost",
            "cloud.hilton.rwth-aachen.de"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "pgsql",
        "version": "27.1.5.1",
        "overwrite.cli.url": "https:\/\/cloud.hilton.rwth-aachen.de\/",
        "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***",
        "maintenance": false,
        "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",
            "7": "OC\\Preview\\Krita",
            "0": "OC\\Preview\\Imaginary"
        },
        "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": "\/Shared",
        "one-click-instance.link": "https:\/\/nextcloud.com\/all-in-one\/",
        "upgrade.cli-upgrade-link": "https:\/\/github.com\/nextcloud\/all-in-one\/discussions\/2726",
        "updatedirectory": "\/nc-updater",
        "allow_local_remote_servers": true,
        "davstorage.request_timeout": 3600,
        "htaccess.RewriteBase": "\/",
        "dbpersistent": false,
        "files_external_allow_create_new_local": false,
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "ldapProviderFactory": "OCA\\User_LDAP\\LDAPProviderFactory",
        "mail_smtpsecure": "tls",
        "mail_sendmailmode": "smtp",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "587",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpauth": 1,
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpauthtype": "LOGIN",
        "preview_imaginary_url": "http:\/\/nextcloud-aio-imaginary:9000",
        "app_install_overwrite": [
            "files_3d"
        ]
    }
}

List of activated Apps

docker exec --user www-data -it nextcloud-aio-nextcloud php occ app:list                  
Enabled:
  - activity: 2.19.0
  - admin_audit: 1.17.0
  - calendar: 4.6.4
  - camerarawpreviews: 0.8.4
  - cloud_federation_api: 1.10.0
  - comments: 1.17.0
  - contactsinteraction: 1.8.0
  - dav: 1.27.0
  - deck: 1.11.3
  - federatedfilesharing: 1.17.0
  - federation: 1.17.0
  - files: 1.22.0
  - files_pdfviewer: 2.8.0
  - files_reminders: 1.0.0
  - files_rightclick: 1.6.0
  - files_sharing: 1.19.0
  - files_trashbin: 1.17.0
  - files_versions: 1.20.0
  - forms: 3.4.5
  - group_everyone: 0.1.13
  - groupfolders: 15.3.4
  - logreader: 2.12.0
  - lookup_server_connector: 1.15.0
  - nextcloud-aio: 0.4.0
  - notifications: 2.15.0
  - notify_push: 0.6.9
  - oauth2: 1.15.1
  - photos: 2.3.0
  - privacy: 1.11.0
  - provisioning_api: 1.17.0
  - quota_warning: 1.18.0
  - recommendations: 1.6.0
  - related_resources: 1.2.0
  - richdocuments: 8.2.4
  - serverinfo: 1.17.0
  - settings: 1.9.0
  - sharebymail: 1.17.0
  - spreed: 17.1.5
  - support: 1.10.0
  - systemtags: 1.17.0
  - text: 3.8.0
  - theming: 2.2.0
  - theming_customcss: 1.15.0
  - twofactor_backupcodes: 1.16.0
  - user_ldap: 1.17.0
  - user_status: 1.7.0
  - viewer: 2.1.0
  - weather_status: 1.7.0
  - workflowengine: 2.9.0
Disabled:
  - apporder: 0.15.0 (installed 0.15.0)
  - bruteforcesettings: 2.7.0
  - circles: 27.0.1 (installed 27.0.1)
  - dashboard: 7.7.0 (installed 7.1.0)
  - encryption: 2.15.0
  - files_external: 1.19.0
  - firstrunwizard: 2.16.0 (installed 2.10.0)
  - nextcloud_announcements: 1.16.0 (installed 1.10.0)
  - password_policy: 1.17.0 (installed 1.11.0)
  - survey_client: 1.15.0 (installed 1.9.0)
  - suspicious_login: 5.0.0 (installed 4.1.0)
  - tasks: 0.15.0 (installed 0.15.0)
  - twofactor_totp: 9.0.0

Nextcloud Signing status

No errors have been found.

Nextcloud Logs

{
    "reqId": "QZOqE0VJzuVA91N9NGCw",
    "level": 3,
    "time": "2024-02-15T23:46:15+00:00",
    "remoteAddr": "10.72.4.30",
    "user": "Verwaltung",
    "app": "webdav",
    "method": "REPORT",
    "url": "/remote.php/dav/calendars/verwaltung/veranstaltungen/",
    "message": "The input element to parse is empty. Do not attempt to parse",
    "userAgent": "Mozilla/5.0",
    "version": "27.1.5.1",
    "exception": {
        "Exception": "Sabre\\Xml\\ParseException",
        "Message": "The input element to parse is empty. Do not attempt to parse",
        "Code": 0,
        "Trace": [
            {
                "file": "/var/www/html/3rdparty/sabre/dav/lib/DAV/CorePlugin.php",
                "line": 685,
                "function": "parse",
                "class": "Sabre\\Xml\\Service",
                "type": "->",
                "args": [
                    "",
                    "/remote.php/dav/calendars/verwaltung/veranstaltungen/",
                    null
                ]
            },
            {
                "file": "/var/www/html/3rdparty/sabre/event/lib/WildcardEmitterTrait.php",
                "line": 89,
                "function": "httpReport",
                "class": "Sabre\\DAV\\CorePlugin",
                "type": "->",
                "args": [
                    [
                        "Sabre\\HTTP\\Request"
                    ],
                    [
                        "Sabre\\HTTP\\Response"
                    ]
                ]
            },
            {
                "file": "/var/www/html/3rdparty/sabre/dav/lib/DAV/Server.php",
                "line": 472,
                "function": "emit",
                "class": "Sabre\\DAV\\Server",
                "type": "->",
                "args": [
                    "method:REPORT",
                    [
                        [
                            "Sabre\\HTTP\\Request"
                        ],
                        [
                            "Sabre\\HTTP\\Response"
                        ]
                    ]
                ]
            },
            {
                "file": "/var/www/html/3rdparty/sabre/dav/lib/DAV/Server.php",
                "line": 253,
                "function": "invokeMethod",
                "class": "Sabre\\DAV\\Server",
                "type": "->",
                "args": [
                    [
                        "Sabre\\HTTP\\Request"
                    ],
                    [
                        "Sabre\\HTTP\\Response"
                    ]
                ]
            },
            {
                "file": "/var/www/html/3rdparty/sabre/dav/lib/DAV/Server.php",
                "line": 321,
                "function": "start",
                "class": "Sabre\\DAV\\Server",
                "type": "->",
                "args": []
            },
            {
                "file": "/var/www/html/apps/dav/lib/Server.php",
                "line": 365,
                "function": "exec",
                "class": "Sabre\\DAV\\Server",
                "type": "->",
                "args": []
            },
            {
                "file": "/var/www/html/apps/dav/appinfo/v2/remote.php",
                "line": 35,
                "function": "exec",
                "class": "OCA\\DAV\\Server",
                "type": "->",
                "args": []
            },
            {
                "file": "/var/www/html/remote.php",
                "line": 172,
                "args": [
                    "/var/www/html/apps/dav/appinfo/v2/remote.php"
                ],
                "function": "require_once"
            }
        ],
        "File": "/var/www/html/3rdparty/sabre/xml/lib/Service.php",
        "Line": 122,
        "message": "The input element to parse is empty. Do not attempt to parse",
        "exception": [],
        "CustomMessage": "The input element to parse is empty. Do not attempt to parse"
    },
    "id": "65cea26de7c9a"
}

Additional info

Nextcloud all in one 27.1.5

The text was updated successfully, but these errors were encountered:

autoantwort · 2024-03-21T18:16:54Z

Same error with 28.0.3

autoantwort · 2024-04-03T13:12:13Z

I have finally found the "Bug": My server uses https (or the proxy), but i used http://Verwaltung:***@***.de/remote.php/dav/calendars/verwaltung/' as url. If I change that to httpsI don't get errors.

autoantwort · 2024-04-03T13:13:05Z

The question is if that is intended behavior and if no, who is to blame.

joshtrichards · 2024-04-04T20:57:25Z

According to this part of the stack trace, the body sent with the REPORT HTTP request is empty (i.e. the first argument is empty):

            {
                "file": "/var/www/html/3rdparty/sabre/dav/lib/DAV/CorePlugin.php",
                "line": 685,
                "function": "parse",
                "class": "Sabre\\Xml\\Service",
                "type": "->",
                "args": [
                    "",
                    "/remote.php/dav/calendars/verwaltung/veranstaltungen/",
                    null
                ]
            },

And I don't see any indications that we modify it or anything before that. That's the first time we try to retrieve it. So maybe that library and the http versus https handling resulted in only a partial HTTP transaction. The ParseException saying The input element to parse is empty. Do not attempt to parse is just a reflection of the body being empty.

autoantwort · 2024-04-04T21:01:57Z

Maybe https://github.com/nextcloud/all-in-one does the redirection wrong or the caldav python lib forgets to resend the body after redirection.

autoantwort · 2024-04-05T02:21:40Z

I have debugged the code and caldav uses python requests to make the http requests. Nextcloud return 301 Found for the http url and request with follow_redirects does not send the body again after the redirect

nextcloud-command · 2024-05-06T00:15:05Z

This issue has been automatically marked as stale because it has not had recent activity and seems to be missing some essential information. It will be closed if no further activity occurs. Thank you for your contributions.

autoantwort added 0. Needs triage Pending check for reproducibility or if it fits our roadmap bug labels Feb 16, 2024

szaimen added the 27-feedback label Feb 16, 2024

joshtrichards added the feature: caldav Related to CalDAV internals label Feb 17, 2024

autoantwort mentioned this issue Feb 23, 2024

Unable to use the calendar app juliushaertl/nextcloud-docker-dev#308

Closed

joshtrichards added the needs info label Apr 4, 2024

autoantwort mentioned this issue Apr 5, 2024

After a redirect the body must still be send to the server python-caldav/caldav#389

Open

nextcloud-command added the stale Ticket or PR with no recent activity label May 6, 2024

nextcloud-command closed this as not planned Won't fix, can't repro, duplicate, stale May 20, 2024

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[Bug]: Sabre\Xml\ParseException: The input element to parse is empty. Do not attempt to parse #43609

[Bug]: Sabre\Xml\ParseException: The input element to parse is empty. Do not attempt to parse #43609

autoantwort commented Feb 16, 2024

autoantwort commented Mar 21, 2024

autoantwort commented Apr 3, 2024

autoantwort commented Apr 3, 2024

joshtrichards commented Apr 4, 2024

autoantwort commented Apr 4, 2024

autoantwort commented Apr 5, 2024

nextcloud-command commented May 6, 2024

[Bug]: Sabre\Xml\ParseException: The input element to parse is empty. Do not attempt to parse #43609

[Bug]: Sabre\Xml\ParseException: The input element to parse is empty. Do not attempt to parse #43609

Comments

autoantwort commented Feb 16, 2024

⚠️ This issue respects the following points: ⚠️

Bug description

Steps to reproduce

Expected behavior

Installation method

Nextcloud Server version

Operating system

PHP engine version

Web server

Database engine version

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

Are you using the Nextcloud Server Encryption module?

What user-backends are you using?

Configuration report

List of activated Apps

Nextcloud Signing status

Nextcloud Logs

Additional info

autoantwort commented Mar 21, 2024

autoantwort commented Apr 3, 2024

autoantwort commented Apr 3, 2024

joshtrichards commented Apr 4, 2024

autoantwort commented Apr 4, 2024

autoantwort commented Apr 5, 2024

nextcloud-command commented May 6, 2024