Re: Response for unsupported conditional request

On 30.01.2025 01:01, Mark Nottingham wrote:
> Hmm. I'm trying to page in the discussions we had around this section, but it seems like there's a contradiction here.
>
> Each of the preconditions defined in Section 13.1 have language like this:
>
>> When an origin server receives a request that selects a representation and that request includes an If-Unmodified-Since header field without an If-Match header field, the origin server MUST evaluate the If-Unmodified-Since condition per Section 13.2 prior to performing the method.
>
> 13.2.1 specifies a number of situations where the field can be ignored (e.g., by non-authoritative servers, by methods that don't select a representation), and then goes on to define the algorithm in 13.2.2. A server that does not support one of these fields would not execute at least part of the algorithm, violating the MUST.
>
> However, 13.1 says two things that imply that entire precondition fields can be ignored in certain circumstances:
>
>> For instance, the "If" header field in WebDAV can make a request conditional on various aspects of multiple resources, such as locks, if the recipient understands and implements that field ([WEBDAV], Section 10.4).


Yes, that applies to conditional fields not defined in the base specs.
So "If" in WebDAV, and future extensions.

This just follows from the rule that extensions can not add new
requirements (their use would need to be negotiated, as it happens in
WebDAV).

> ...

Best regards, Julian

Received on Thursday, 30 January 2025 05:17:12 UTC