[Dovecot] Behavior difference in mbox versus Maildir listing

[Timo Sirainen]

On 21.5.2011, at 23.16, Bruno Prémont wrote:

> The resulting IMAPv4 session is:
>  mb1 LIST "" "#mbox.%"
>  * LIST (\Noselect \HasChildren) "." "#mbox.folder"
>  mb1 OK List completed.
>  mb2 LIST "" "#mbox.folder.%"
>  * LIST (\Noselect \HasChildren) "." "#mbox.folder."
>  * LIST (\NoInferiors \UnMarked) "." "#mbox.folder.folder1a"
>  * LIST (\NoInferiors \UnMarked) "." "#mbox.folder.folder1b"
>  * LIST (\NoInferiors \UnMarked) "." "#mbox.folder.folder1c"
>  mb2 OK List completed.
>  md1 LIST "" "#maildir.%"
>  * LIST (\HasChildren) "." "#maildir.folder"
>  md1 OK List completed.
>  md2 LIST "" "#maildir.folder.%"
>  * LIST (\HasNoChildren) "." "#maildir.folder.folder1a"
>  * LIST (\HasNoChildren) "." "#maildir.folder.folder1b"
>  * LIST (\HasNoChildren) "." "#maildir.folder.folder1c"
>  md2 OK List completed.
> 
> Notice the extra presence of listed folder itself with trailing "."
> in mb2 that has no equivalent in md2!
> 
> Is this expected listing behavior? If so, why the differing behavior
> between both storage engines?

It's expected, although maybe not the best behavior. I'm basically copying UW-IMAP behavior for mbox and Courier/Cyrus behavior for Maildir. There are more detailed reasons for why the "#mbox.folder." should be listed, which are described by Mark Crispin somewhere in imap-protocol mailing list archives I think. I've been thinking about making dbox and Maildir (and maybe mbox) behavior identical though..