[Bug]: Trying to share a calendar in the iOS app breaks it

[user12257]

⚠️ 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

Trying to share a calendar in the iOS app breaks it.

I tried to share a calendar in the iOS app, like you would share an iCloud calendar. I wanted to see if it works.

The result is, that the calendar now is gone. It is not deleted, but not shown anymore. The logs show.

unserialize(): Error at offset 48 of 51 bytes at /var/www/html/apps/dav/lib/DAV/CustomPropertiesBackend.php#560

I assume that the iOS calendar app writes some data that it should not be able to write into the database.

Steps to reproduce

1. Run latest Nextcloud-aio ( Nextcloud AIO v9.7.0)
2. Log into the caldav account on iOS
3. share the calender with an email

Expected behavior

Not to break a calendar and render all entire unavailable and basically deleted, when trying to share the calendar in the iOS app.

Nextcloud Server version

30

Operating system

Other

PHP engine version

Other

Web server

Other

Database engine version

Other

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

Fresh Nextcloud Server install

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

No response

List of activated Apps

No response

Nextcloud Signing status

No response

Nextcloud Logs

unserialize(): Error at offset 48 of 51 bytes at /var/www/html/apps/dav/lib/DAV/CustomPropertiesBackend.php#560

Additional info

( Nextcloud AIO v9.7.0)

I know I am running AIO, but as far as I could track, the responsible code is here. If I should create another Issue in the AIO Repo, I can do this.

For me this is solved, by creating a new calendar, since there was not much in the initial one, but I think that might be a major issue for someone with a lot of things in their calendar, so I thought I have to let someone know.

[AlienPie]

Someone like me. Is there anyway to recover the calendar from your testing?

Adding my system information:

Nextcloud Hub 9 (30.0.2)

NGINX reverse proxy doing TLS Offload

PHP

Version: 8.2.25
Memory limit: 1 GB
Max execution time: 3600
Upload max size: 4 GB
OPcache Revalidate Frequency: 60
Extensions: Core, date, libxml, openssl, pcre, sqlite3, zlib, ctype, curl, dom, fileinfo, filter, hash, iconv, json, mbstring, SPL, session, PDO, pdo_sqlite, standard, posix, random, Reflection, Phar, SimpleXML, tokenizer, xml, xmlreader, xmlwriter, mysqlnd, apache2handler, apcu, bcmath, exif, ftp, gd, gmp, imagick, intl, ldap, memcached, pcntl, pdo_mysql, pdo_pgsql, redis, sodium, sysvsem, zip, Zend OPcache

Database

Type: pgsql
Version: PostgreSQL 14.13 (Debian 14.13-1.pgdg120+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 12.2.0-14) 12.2.0, 64-bit
Size: 297.6 MB

Further Edit:

Not a fix for the bug, but a potential solution for those who, like me, are panicking that they have deleted the entire calendar:

• I used calcardbackup to backup the calendars from the database.
• I then created a new calendar in the web interface and imported the backed up ICS file.
• Finally I used occ dav:list-calendars and occ dav:delete-calendar to identify and remove the broken calendar.