Re: #241: clarify eval order/interaction of conditional headers

On Jul 12, 2012, at 12:08 AM, Julian Reschke wrote:

> On 2012-07-03 09:37, Mark Nottingham wrote:
>> <http://trac.tools.ietf.org/wg/httpbis/trac/ticket/241>
>> 
>> Roy documented the evaluation order for conditional that Apache uses (which, he pointed out, is the only logical way to do it, once you look at it):
>> 
>> <http://trac.tools.ietf.org/wg/httpbis/trac/ticket/241#comment:4>
>> ...
> 
> I'd like to avoid to include pseudo-code like that *unless* it's really needed.

So would I ... the text provided is just the comments from the code.
Once the result is agreed, we can work on text.

> Do we really need to define the evaluation order? In what real-world situations well there be more than one condition?
> 
> Wouldn't it be simpler to:
> 
> 1) Formally define the condition expressed by each header field,
> 
> and
> 
> 2) State that all conditions must be met, otherwise a 412 will be returned (with the 304 variant special-cased).

No, because it isn't true in practice (nor desired).  We actually
do want an etag to override last-modified even when IMS is false.

....Roy

Received on Thursday, 12 July 2012 18:38:53 UTC