dovecot - Dec 2015 - autoexpunge creates special_use folder

namespace inbox {
   mailbox Spam {
     special_use = \Spam
     auto = create
     autoexpunge = 30d
   }
}

This creates the "Spam" folder in the filesystem on login/logout, even
though it shouldn't.
If I remove autoexpunge, the folder is not created.

-- 
Tom Sommer

On 11 Dec 2015, at 16:00, Tom Sommer <mail at tomsommer.dk>
wrote:
> 
> namespace inbox {
>  mailbox Spam {
>    special_use = \Spam
>    auto = create
>    autoexpunge = 30d
>  }
> }
> 
> This creates the "Spam" folder in the filesystem on login/logout,
even though it shouldn't.
> If I remove autoexpunge, the folder is not created.
I think this is something that doesn't need to be fixed. The folder will
eventually be created anyway. And adding a check to avoid its creation causes an
extra stat() syscall for most mailbox formats (only LAYOUT=index avoids that).
The extra stat() could even mean extra disk I/O in some cases. So I think
it's better to just have it create the folder since that gives slightly
better overall performance.