[Ietf-caldav] Dead properties on CalDAV events / folders

[Julian Reschke]

Helge Hess wrote:
> On 16. Dez 2005, at 19:52 Uhr, Wilfredo Sánchez Vega wrote:
>> If you say that a server MUST not modify X- properties then you are 
>> removing the flexibility on the server side that you are requesting on 
>> the client side.
> 
> It must not delete/touch unknown X- properties, it might modify the set 
> of X- properties or change X- properties it knows. This doesn't limit 
> the flexibility on the server side.
> 
> But it has serious consequences if you choose to do any change to 
> PUT'ted entities on the server side. Every subsequent consistent-update 
> [etag] request must fail as per HTTP (even if the change is just a 
> result of the PUT issued by the client).
> 
> Eg a client would show an "someone has changed your item in the server" 
> warning / conflict resolution panel prior submitting _any_ next request. 
> In short: if you want to allow server-side modifications, you should 
> specify that a client MUST immediatly reget the entity after a 
> change/creation request.

This is a known specification issue: it's rather silent what it means to 
return an ETag upon PUT. You seem to think it's for the entity the 
client sent in the PUT request (this is what I thought as well), while 
many people on the HTTP mailing list think it's the ETag you would get 
upon a subsequent GET (see discussion at 
<http://lists.w3.org/Archives/Public/ietf-http-wg/2005OctDec/thread.html#13>). 
I think this question needs to be clarified (by an agreed-upon erratum 
to be included into <http://purl.org/NET/http-errata> before WebDAV or 
related specs are going to make normative statements about this).

> ...


Best regards, Julian