Reminders of group events get send to not only attendees of said event but to everyone in the group.

[dzatoah]

First of all, you're all doing a great job. ^^

I wanted to say this is my first contribution and I'm not 100% sure of the terminology. ^^

Steps to reproduce

1. Create a group with the following members:

• peter@example.com
• max@example.com

2. Create new calendar and share calendar with the new group (with write-access.)
3. Create a new event in the new calendar.
4. Activate a reminder: 5 mins before the event.
5. Under attendees: Invite the following people:

• john@example.com
• jane@example.com

Expected behaviour

• john@example.com & jane@example.com should receive an invitation.
• john@example.com & jane@example.com should receive a reminder e-mail 5 minutes before the event.

Actual behaviour

• john@example.com & jane@example.com receive an invitation.
• john@example.com &
• jane@example.com &
• peter@example.com &
• max@example.com receive a reminder e-mail 5 minutes before the event.

Calendar app

Cloned via git. 3.1.0-alpha.1 f89c089 https://github.com/nextcloud/calendar.git

Server configuration

Apache2 on Debian 11
Database: SQLite
PHP version: 7.4.25
Nextcloud Version: cloned via git. c605ef1f432dcd48ba4b3b8cc82551c234dc4f64 https://github.com/nextcloud/server.git

List of activated apps:

Enabled:
  - accessibility: 1.10.0
  - calendar: 3.1.0-alpha.1
  - cloud_federation_api: 1.7.0
  - comments: 1.14.0
  - contactsinteraction: 1.5.0
  - dashboard: 7.4.0
  - dav: 1.22.0
  - federatedfilesharing: 1.14.0
  - federation: 1.14.0
  - files: 1.19.0
  - files_sharing: 1.16.0
  - files_trashbin: 1.14.0
  - files_versions: 1.17.0
  - lookup_server_connector: 1.12.0
  - oauth2: 1.12.0
  - provisioning_api: 1.14.0
  - settings: 1.6.0
  - sharebymail: 1.14.0
  - systemtags: 1.14.0
  - theming: 1.15.0
  - twofactor_backupcodes: 1.13.0
  - updatenotification: 1.14.0
  - user_status: 1.4.0
  - weather_status: 1.4.0
  - workflowengine: 2.6.0
Disabled:
  - admin_audit
  - bruteforcesettings
  - encryption
  - files_external
  - testing
  - user_ldap

Nextcloud configuration:

config.php

<?php
$CONFIG = array (
  'instanceid' => 'oc2cnl5cuc6p',
  'passwordsalt' => '***',
  'secret' => '***',
  'trusted_domains' => 
  array (
    0 => '10.0.2.5',
  ),
  'datadirectory' => '/var/www/nextcloud/data',
  'dbtype' => 'sqlite3',
  'version' => '24.0.0.4',
  'overwrite.cli.url' => 'http://10.0.2.5',
  'dbname' => 'nextcloud',
  'dbhost' => 'localhost',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'installed' => true,
  'debug' => true,
  'app_install_overwrite' => 
  array (
    0 => 'richdocuments',
    1 => 'richdocumentscode',
    2 => 'announcementcenter',
  ),
  'mail_smtpmode' => 'smtp',
  'mail_smtpauthtype' => 'LOGIN',
  'mail_sendmailmode' => 'smtp',
  'mail_smtpauth' => 1,
  'mail_smtpsecure' => 'tls',
  'mail_from_address' => 'daniel',
  'mail_domain' => 'example.com',
  'mail_smtphost' => '***',
  'mail_smtpname' => '***',
  'mail_smtppassword' => '***,
  'force_language' => 'en',
);

We thought of a new settings option for this issue. (Second option from the bottom)

[ChristophWurst]

First of all, you're all doing a great job. ^^

🙏

---

So I think this might be a mix of things. First, the calendar sharing currently has a few quirks. nextcloud/server#26668 will tackle this. Not sure if it has influence for (shared) calendars and reminders.

Otherwise this could also be related to nextcloud/server#21370. Again, not sure.

[dzatoah]

Hey, thanks for your answer.

I'm new to Nextcloud but I think nextcloud/server#21370 is not related to this problem since

1. They are talking about non-shared calendars.
2. There is already a fix 6497 but I could reproduce my issue using latest master branch.

Also do you think the default behavior should be changed or should it be possible to switch behaviors like shown above?

Can I somehow help, fixing this issues?

[dzatoah]

I think we'll have to change the behavior in here:

https://github.com/nextcloud/server/blob/0447b53bda9fe95ea0cbed765aa332584605d652/apps/dav/lib/CalDAV/Reminder/ReminderService.php#L144

We don't need all users with write access, but only attendees.

[dzatoah]

I would say this issue can be closed since it's not actually an issue of calendar but core.