doveadm force-resync restore mail (rbox_sync)

[jrse]

Describe the bug

Restored mail exists in 2 mailbox indices but only once in ceph!

To Reproduce
Steps to reproduce the behavior:

1. use imap client to create a new mail and save in it in Drafts folder
2. move mail to INBOX
3. use doveadm force-resync -u INBOX to restore indices.
4. check index of inbox and Drafts folder.

Expected behavior
Mail is only referenced in one mailbox. (we do not support references)

Logfiles, screenshots

doveadm rmb ls -u u1 -

time elapsed loading objects: 64
INDEX: Check
box: INBOX.Drafts
mails total: 1, missing mails in objectstore: 0
box: INBOX
mails total: 1, missing mails in objectstore: 0
box: INBOX.Trash
mails total: 0, missing mails in objectstore: 0
box: INBOX.Spam
mails total: 0, missing mails in objectstore: 0
box: INBOX.Sent
mails total: 0, missing mails in objectstore: 0
mailbox_count: 1

MAILBOX: M(mailbox_guid)=bf31ad1154bfee5bc42d0000d561c877
B(mailbox_orig_name)=Drafts
mail_total=1, mails_displayed=1
mailbox_size=9208787 bytes

     MAIL:   U(uid)=9
             oid = 9848e426abd1f75bb6770000d561c877
             R(receive_time)=2018-11-23 11:08:43
             save_time=2018-11-23 12:29:13
             Z(phy_size)=9208787 V(v_size) = 9334960 stat_size=9208787
             M(mailbox_guid)=bf31ad1154bfee5bc42d0000d561c877
             B(mailbox_orig_name)=Drafts
             G(mail_guid)=9948e426abd1f75bb6770000d561c877
             I(rbox_version): 0.1

Server (please complete the following information):

• OS: ubuntu 18.04
• Ceph Version [luminous]
• Dovecot Version [e.g. 2.2]

Client (please complete the following information):

• used client: thunderbird, doveadm rmb

[jrse]

problem is in : rbox-sync-rebuild.cpp
in case the search for MailboxGUID returns empty Iterator an aditionaly search for objects with the mailboxname is done. (this will add the moved mail to drafts index again)

int search_objects(struct index_rebuild_context *ctx, struct rbox_sync_rebuild_ctx *rebuild_ctx);
librmb::RadosMetadata attr_guid(rbox_metadata_key::RBOX_METADATA_MAILBOX_GUID, guid);
librados::NObjectIterator iter_guid(storage->find_mails(&attr_guid));

if (iter_guid != librados::NObjectIterator::__EndObjectIterator) {
ret = rbox_sync_rebuild_entry(ctx, iter_guid, rebuild_ctx);
} else {
...
librmb::RadosMetadata attr_name(rbox_metadata_key::RBOX_METADATA_ORIG_MAILBOX, rbox->box.name);
// rebuild index.
librados::NObjectIterator iter_name(storage->find_mails(&attr_name));
ret = rbox_sync_rebuild_entry(ctx, iter_name, rebuild_ctx);
}