dovecot - Dec 2015 - LIST command should not interpret wildcards in reference

Hello everyone,

I believe this is erroneously implemented in Dovecot:


 >>> for i in c.list_folders('deleteme.*.folder', '%'):
...  print(i)
...
((b'\\HasNoChildren',), b'.', 'deleteme.*.folder')
((b'\\HasNoChildren',), b'.',
'deleteme.deleteme.deleteme.folder')


We see here an interactive python session, which launches

LIST "deleteme.*.folder" "%"

over the wire and receives two mailboxes as answer. The response is 
already parsed, but that?s not important for my point: according to 
RFC3501 section 6.3.8 LIST Command, the arguments are ?reference name? 
and ?mailbox name with possible wildcards?.

Both arguments are allowed to contain wildcard characters, but they have 
no special meaning in the reference. Dovecot 2.2.18 doesn?t do that 
right: the second mailbox should not be listed, because it is not a 
subfolder of reference.

Is this a known issue?


Regards,
Robert

Does no-one have an opinion about wildcards in the first argument to LIST?


Robert

On 14/12/15 16:14, Robert Siemer wrote:
> Hello everyone,
>
> I believe this is erroneously implemented in Dovecot:
>
>
>  >>> for i in c.list_folders('deleteme.*.folder',
'%'):
> ...  print(i)
> ...
> ((b'\\HasNoChildren',), b'.', 'deleteme.*.folder')
> ((b'\\HasNoChildren',), b'.',
'deleteme.deleteme.deleteme.folder')
>
>
> We see here an interactive python session, which launches
>
> LIST "deleteme.*.folder" "%"
>
> over the wire and receives two mailboxes as answer. The response is
> already parsed, but that?s not important for my point: according to
> RFC3501 section 6.3.8 LIST Command, the arguments are ?reference name?
> and ?mailbox name with possible wildcards?.
>
> Both arguments are allowed to contain wildcard characters, but they have
> no special meaning in the reference. Dovecot 2.2.18 doesn?t do that
> right: the second mailbox should not be listed, because it is not a
> subfolder of reference.
>
> Is this a known issue?
>
>
> Regards,
> Robert

On 14 Dec 2015, at 17:14, Robert Siemer <Robert.Siemer-lists at
backsla.sh> wrote:
> 
> Hello everyone,
> 
> I believe this is erroneously implemented in Dovecot:
> 
> 
> >>> for i in c.list_folders('deleteme.*.folder',
'%'):
> ...  print(i)
> ...
> ((b'\\HasNoChildren',), b'.', 'deleteme.*.folder')
> ((b'\\HasNoChildren',), b'.',
'deleteme.deleteme.deleteme.folder')
> 
> 
> We see here an interactive python session, which launches
> 
> LIST "deleteme.*.folder" "%"
> 
> over the wire and receives two mailboxes as answer. The response is already
parsed, but that?s not important for my point: according to RFC3501 section
6.3.8 LIST Command, the arguments are ?reference name? and ?mailbox name with
possible wildcards?.
> 
> Both arguments are allowed to contain wildcard characters, but they have no
special meaning in the reference. Dovecot 2.2.18 doesn?t do that right: the
second mailbox should not be listed, because it is not a subfolder of reference.
Well .. I guess ideally Dovecot would behave the way you want it to behave. But
this would require API changes and in general it would complicate the listing
code that is already too complicated. There are also further reasons why
it's not very useful, as mentioned by the 6.3.8 section:

 - Note: The interpretation of the reference argument is implementation-defined.
 - A client SHOULD NOT use such a reference argument except at the explicit
request of the user.
 - It doesn't explicitly mention how wildcards should be handled in
reference argument.

Also it is not an error for IMAP server to return unsolicited replies as part of
any command. So in theory Dovecot could return all the mailboxes as a reply to
any LIST command and still be IMAP-standards compliant, although not a very
optimal one.

So all in all, I don't think this is something that is going to be changed.