I had hoped no one would ever try to use ACLs with mbox format.. I don't think I want to try to make it work.
And indeed, a file named "dovecot-acl-list" has now been created under
the _mailboxes directory: .. Is such a file supposed to be created there?
It's created to mailbox root directory. With all formats except mbox this is fine. It can't be created to control directory, because it's supposed to be shared and different users may have different control directories.
But I suppose with mbox it's better to create it to control dir rather than have it show up as a mailbox or use some other weird location for it.
http://hg.dovecot.org/dovecot-1.2/rev/f3c6cabae3af http://hg.dovecot.org/dovecot-1.2/rev/4c8175452173
Why does the server seem to expect to find a temp file under ~/ _mboxesctrl/.imap? As well as, more surprisingly, under /usr/local/etc/ dovecot-acls?
Because it just created a .temp. file and then thinks it's a mailbox. This fixes it: http://hg.dovecot.org/dovecot-1.2/rev/bf4f542ec6df
And then finally also a caching fix: http://hg.dovecot.org/dovecot-1.2/rev/5d1a52e8d320