Re: [imapext] SEARCHRES RFC5182

[Alexey Melnikov <[e-mail]>]

Hi Adrien,

On 09/03/2021 23:21, Adrien de Croy wrote:
> Hi Everyone
>
> I've been looking into this extension, but it has a number of problems 
> and uncertainties in the spec especially:
>
> * in relation to storing results of ESEARCH extensions, it refers to 
> them as messages).

Can you elaborate/quote specific text which is confusing?

> * in relation to reporting errors if the saved results are 
> incompatible (e.g. stored SEQ but asked to use as UID or vice versa)

The document is quite clear that $ references message numbers or UIDs as 
appropriate in the corresponding context. So a saved result is never 
incompatible.

You can see this in the last paragraph of section 2.1:

    Implementation note: server implementors should note that "$" can
    reference IMAP message sequences or UID sequences, depending on the
    context where it is used.  For example, the "$" marker can be set as
    a result of a SEARCH (SAVE) command and used as a parameter to a UID
    FETCH command (which accepts a UID sequence, not a message sequence),
    or the "$" marker can be set as a result of a UID SEARCH (SAVE)
    command and used as a parameter to a FETCH command (which accepts a
    message sequence, not a UID sequence).

> * dealing with expunging of messages.

I think this is also clear, from Section 2.1:

    When a message listed in the search result variable is EXPUNGEd, it
    is automatically removed from the list.  Implementors are reminded
    that if the server stores the list as a list of message numbers, it
    MUST automatically adjust them when notifying the client about
    expunged messages, as described in Section 7.4.1 of [IMAP4].


If it helps, the best way of implementing this (IMHO) is to store a list 
of UIDs in some form and translate them to sequence numbers in the 
server, when needed. When messages are expunged, this list is purged of 
expunged messages.

> So my first question relates to whether I'm even wasting my time.  The 
> imapwiki shows very few servers support it, but are any clients known 
> to support it?
I don't know the answer to this.


Best Regards,

Alexey