IMAP4 IDLE does not work. imapd_index == NULL ?

[Alexey Melnikov]

Hi Bernhard,

On 05/02/2015 13:04, Bernhard T wrote:
> Am 2015-02-04 um 12:10 schrieb Bron Gondwana:
>> Sure, you have to select a mailbox if you want to IDLE on it.  If you have selected a mailbox, then imapd_index is that mailbox.
>>
>> Bron.
>>
>>
> Excellent Tip, Thank you!
> Problem Solved. *facepalm*
>
> This time instead of using the imap client's trace functionality,
> I used tcpdump to record the conversation between client and server.
> (and disabled tls, instead using ssh port forward for security)
>
> Turns out, the idling client was misconfigured and instead of selecting
> INBOX it selected '--'.
>
> All other IMAP servers I'm using it with, were very forgiving and
> refused to switch to '--', instead they let the client stay in the
> previously selected 'INBOX'. Thus when the client started 'IDLE' it
> worked as expected.
>
> Cyrus on the other hand, responded 'GDGA6 NO Mailbox does not exist',
> but DID switch the mailbox of the client from 'INBOX' to a
> Mailbox-Does-Not-Exist State.
>
> Thus the following 'IDLE' command did not succeed.
>
>
> So first, thanks for helping me track down this problem.
>
> Second I propose that Cyrus, if given an invalid mailbox name as
> argument to SELECT, stays in the previously selected mailbox if any,
> as this seems to be how other IMAP servers handle it.
This change would be in violation of RFC 3501. Which servers behave in 
the way you describe?