Re: [xmpp] <optional> and <required/>

[Waqas Hussain <[e-mail]>]

On Wed, Mar 9, 2011 at 8:03 AM, Peter Saint-Andre <[e-mail]> wrote:
> On 3/8/11 7:47 PM, Kim Alvefur wrote:
>> Hi!
>>
>> Just to point out that these sections[1][2] seems to conflict with this
>> tread[3]. Otherwise, how does it make sense for roster versioning to be
>> required?
>>
>> [1]: http://tools.ietf.org/html/draft-ietf-xmpp-3920bis-22#section-4.9.3.23
>> [2]: http://tools.ietf.org/html/draft-ietf-xmpp-3921bis-20#section-2.6.1
>> [3]: http://www.ietf.org/mail-archive/web/xmpp/current/msg01125.html
>
> There are two different topics here:
>
> 1. Whether any given feature is mandatory-to-negotiate or
> voluntary-to-negotiate.
>
> 2. Whether to define a generalized mechanism for such signalling, which
> would apply to all features.
>
> The mailing list post you've cited applies to #2. Section 2.6.1 of
> 3921bis applies to #1.
>
> I see your point about the <unsupported-feature/> stream error: it might
> not make much sense to define such an error condition if there is no
> generalized mechanism for signalling that any given feature is
> mandatory-to-negotiate...
>
> Peter
>

I think the <optional/> in 3921bis should go.

3921bis defines two stream features. Both are optional. One wants
<optional/> inside, the other doesn't. I think this <optional/> is a
leftover from when we tried having a generalized mechanism for
required features, and the only purpose it serves in this instance is
to add redundant inconsistency.

--
Waqas Hussain