Calendar event invitee emails and links are incorrect as events are deleted and restored from trash.

[brad2014]

⚠️ 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

Invitation/Cancellation emails for events need to occur when an event is deleted into or restored from the Calendar trash folder, but instead cancellation emails are sent both on "event delete" and again (duplicate) on "trash emptied", but are not being sent on "restored from trash to calendar".

Steps to reproduce

Duplicate Cancellation messages, incorrect token handling of deleted/cancelled event:

1. In the nextcloud calendar app, create an event, invite an external party, save. (invitee receives invitation email)
2. Delete the event via the calendar app UI - notice that Cancellation email is sent.
3. Notice that URL in the original invitation email "more options" link goes to a page asking this user if they accept/decline, even though the event has been canceled.
4. Open the calendar trash bin and empty the trash - a duplicate Cancellation event is incorrectly sent, invitation token is "dangling" (see When a calendar event is deleted, corresponding calendar_invitation entries are not deleted #12387).

Missing Invitation Message when event restored from trash:

1. In the nextcloud calendar app, create an event, and invite an external party.
2. Delete the event via the calendar app UI (notice that Cancelation email is sent, notice that invitation link in recipient).
3. Open the calendar trash bin and restore the event. (notice no "Invitation" email is sent - invitee thinks the event is still canceled)

Expected behavior

• When an event is newly added to the calendar, an "Invitation" email is sent, containing a link to accept/decline (unless config:app:set dav invitation_link_recipients is turned off). This is already correct.

• When an event is moved from the calendar to trash, a single "Cancelled" email should be sent to each invitee, and the STATUS of the attached VEVENT should be changed from CONFIRMED to CANCELLED (per RFC). (The STATUS is optional in the METHOD: CANCEL vevent sent to the invitee - it could be set to CANCELLED in this case, but note that removing an invitee from an event properly sends a CANCEL email to that invitee where the invitation is canceled but the event is not).

• the UI for /apps/dav/invitation/moreOptions/ (and simlilar) should say "This event has been canceled." rather than showing the form for accept/decline a cancelled event.

• When the calendar trash is emptied, no emails should be generated, and as the calendar object is deleted, any calendar_invitation entries that refer to it should be deleted.

Installation method

Community Manual installation with Archive

Operating system

RHEL/CentOS

PHP engine version

PHP 8.0

Web server

Apache (supported)

Database engine version

MySQL

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

No response

List of activated Apps

Enabled:
  - activity: 2.17.0
  - calendar: 4.2.1
  - circles: 25.0.0
  - cloud_federation_api: 1.8.0
  - comments: 1.15.0
  - contacts: 5.0.2
  - contactsinteraction: 1.6.0
  - dashboard: 7.5.0
  - dav: 1.24.0
  - federatedfilesharing: 1.15.0
  - federation: 1.15.0
  - files: 1.20.1
  - 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
  - firstrunwizard: 2.14.0
  - logreader: 2.10.0
  - lookup_server_connector: 1.13.0
  - nextcloud_announcements: 1.14.0
  - notifications: 2.13.1
  - oauth2: 1.13.0
  - password_policy: 1.15.0
  - photos: 2.0.1
  - privacy: 1.9.0
  - provisioning_api: 1.15.0
  - recommendations: 1.4.0
  - related_resources: 1.0.3
  - serverinfo: 1.15.0
  - settings: 1.7.0
  - sharebymail: 1.15.0
  - spreed: 15.0.2
  - support: 1.8.0
  - survey_client: 1.13.0
  - systemtags: 1.15.0
  - tasks: 0.14.5
  - text: 3.6.0
  - theming: 2.0.1
  - twofactor_backupcodes: 1.14.0
  - twofactor_totp: 7.0.0
  - updatenotification: 1.15.0
  - user_external: 3.1.0
  - user_status: 1.5.0
  - viewer: 1.9.0
  - weather_status: 1.5.0
  - workflowengine: 2.7.0
Disabled:
  - admin_audit
  - bruteforcesettings
  - encryption
  - files_external
  - suspicious_login
  - user_ldap

Nextcloud Signing status

No response

Nextcloud Logs

No response

Additional info

No response

[szaimen]

Hi, which nc version?

[nextcloud-command]

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.

[brad2014]

(Apologies for delay @szaimen just noticed your post.)
This is reproducible on NC version 25.0.3.

[SebastianKrupinski]

Duplicate of #12387

[SebastianKrupinski]

Duplicate of #45677