Dovecot unified event filtering

[Felix Auringer]

Hello,

I have an issue with debug logging when using a custom plugin for Dovecot. In my plugin, I create a child event of the session's user event:

```c
struct event *plugin_event = event_create(list->ns->user->event);
event_set_name(plugin_event, "oidc_shared_mailboxes_plugin");
event_set_min_log_level(plugin_event, LOG_TYPE_WARNING);
event_set_append_log_prefix(plugin_event, "oidc-shared-mailboxes-plugin: ");
```

I then use passthrough events like the following:

```
e_debug(event_create_passthrough(data->event)->event(), "Modified mailbox_list_iter_init was called.");
e_warning(event_create_passthrough(event)->event(), "Did not find required key 'roles' in the JWT body.");
```

`e_warning` and `e_error` work fine.
If I understand the documentation for the unified event filtering (https://doc.dovecot.org/configuration_manual/event_filter/#unified-filter-language) correctly, I should be able to enable debug logging for with `log_debug = event="oidc_shared_mailboxes_plugin"`. However, this setting has no influence on the logging behavior. The setting I have to set for the debug logging to work is `mail_debug = yes` (I do not have to set `log_debug` at all).

Is this intended behavior or am I doing something wrong?

Best regards,
Felix Auringer


Here is the output of `dovecot -n` (I removed the passdb, userdb, namespace, service, and managesieve settings as they cluttered the output):

```
# 2.3.19 (b3ad6004dc): /etc/dovecot/dovecot.conf
# Pigeonhole version 0.5.19 (4eae2f79)
# OS: Linux 5.10.0-15-amd64 x86_64 Debian 11.6
# Hostname: c3dd5b346d22
auth_mechanisms = plain login xoauth2 oauthbearer
debug_log_path = /dev/stdout
disable_plaintext_auth = no
first_valid_uid = 1000
info_log_path = /dev/stdout
last_valid_uid = 1000
log_debug = event="oidc_shared_mailboxes_plugin"
log_path = /dev/stdout
login_greeting = Hello there! .... GIZ Mail!
mail_location = maildir:~/mail
mail_plugins = " oidc_shared_mailboxes"
plugin {
  oidc_shared_mailboxes_client_id = dovecot-test
}
protocols = imap lmtp
```
---
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