RE: NFC normalization rename errors after 2.3 to 2.4 upgrade (mdbox)

Hi,

I tested the patch. The NFC error is gone.

I copied one affected user to a test user. The problem was reproducible on two different servers. After running with the patched version, the NFC error disappeared. After migrating the mailbox back to an unpatched server, the NFC error was still gone. So the patch seems to change something persistent.

However, I still get more subscribed mailbox names than real mailboxes. Before the test on the unpatched server 'mailbox list -s‘ returned 50 mailbox names and 9 errors.

Without -s I get 50 mailboxes. With -s I get 68 names, but only 50 mailboxes really exist. The additional names have a GUID-like suffix. I don't know if they are related to this issue or if they are old subscription entries.

Would it make sense to remove the affected subscription entries automatically?

Regards, Jens

Von: Timo Sirainen <timo@sirainen.com> Datum: Freitag, 10. Juli 2026 um 16:28 An: Michael Goth <mg@webflow.de>; dovecot@dovecot.org <dovecot@dovecot.org>; Jens Urban <Jens.Urban@freenet.ag> Betreff: Re: NFC normalization rename errors after 2.3 to 2.4 upgrade (mdbox)

On 6. Jul 2026, at 21.53, Timo Sirainen via dovecot <dovecot@dovecot.org> wrote:

On 6. Jul 2026, at 8.39, Michael Goth via dovecot <dovecot@dovecot.org> wrote:

So I think updating the mailbox name to NFC should also update any
matching subscriptions of the user. Otherwise, the subscription gets
lost and we get constant errors in the logs.

I thought this was already fixed, but looks like accidentally the test was using mailbox_list_utf8=yes. With the default =no it was broken. Attached a fix.

I guess nobody looked at the accidentally wrong diff :) But the fix is now committed:

Hi, I tested the patch. The NFC error is gone. I copied one affected user to a test user. The problem was reproducible on two different servers. After running with the patched version, the NFC error disappeared. After migrating the mailbox back to an unpatched server, the NFC error was still gone. So the patch seems to change something persistent. However, I still get more subscribed mailbox names than real mailboxes. Before the test on the unpatched server 'mailbox list -saEUR~ returned 50 mailbox names and 9 errors. Without -s I get 50 mailboxes. With -s I get 68 names, but only 50 mailboxes really exist. The additional names have a GUID-like suffix. I don't know if they are related to this issue or if they are old subscription entries. Would it make sense to remove the affected subscription entries automatically? Regards, Jens Von: Timo Sirainen <timo@sirainen.com> Datum: Freitag, 10. Juli 2026 um 16:28 An: Michael Goth <mg@webflow.de>; dovecot@dovecot.org <dovecot@dovecot.org>; Jens Urban <Jens.Urban@freenet.ag> Betreff: Re: NFC normalization rename errors after 2.3 to 2.4 upgrade (mdbox) On 6. Jul 2026, at 21.53, Timo Sirainen via dovecot <dovecot@dovecot.org> wrote:

On 6. Jul 2026, at 8.39, Michael Goth via dovecot

<dovecot@dovecot.org>

wrote:

So I think updating the mailbox name to NFC should also update any
matching subscriptions of the user. Otherwise, the subscription gets
lost and we get constant errors in the logs.

I thought this was already fixed, but looks like accidentally the test was using mailbox_list_utf8=yes. With the default =no it was broken. Attached a fix.

I guess nobody looked at the accidentally wrong diff :) But the fix is now committed: