[Bug]: Individual calendar share removal leads to group unshare #49907

⚠️ 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

Unsharing an individual shared calendar leads to not seeing it, even though it is still shared via group.

Steps to reproduce

1. have a calendar shared to group "users" readonly
2. create user1, add user1 to group "users"
3. add individual share to user1 with read-write permission
4. use it
5. remove individual share
6. user1 cannot see calendar

Expected behavior

Calendar should remain read-only, as it is shared via group.

Nextcloud Server version

30

Operating system

None

PHP engine version

None

Web server

None

Database engine version

None

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

None

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

happened on c.n.c

List of activated Apps

Nextcloud Signing status

Nextcloud Logs

Additional info

No response