Re: 304 or 412 for If-Modified-Since?

On 30.06.2010 03:29, Cyrus Daboo wrote:
> Hi folks,
> RFC 2616 in Section 14.25 "If-Modified-Since" states that a 304 should
> be returned if the resource is not modified.

Yes.

> RFC 4918 in Section 12.1 "412 Precondition Failed" states that a 412
> should be returned when a conditional header fails to hold.

That should be reported as an RFC 4918 erratum. WebDAV can't override 
normative requirements from HTTP/1.1. (

> So what should clients expect from WebDAV servers?

They should expect that headers defined in RFC 2616 work as advertised 
there.

> Second, does If-Modified-Since make sense for PROPFIND or REPORT requests?

If the resource being addressed responds to GET, and does to with a 
Last-Modified header, then it makes sense for consistency. However, GET 
in a collection *usually* only returns information based on the state of 
the collection and its direct members, so it wouldn't be useful for 
PROPFIND/Depth=Infinity, and might not be useful at all for REPORT.

Of course the same question could be asked about If-None-Match.

I think making PROPFIND/REPORT responses more Web-friendly (adding a way 
to GET those) would help with this issue (hint, hint).

Best regards, Julian