[PATCH] Not Modified: prefer entity tags over date validators

[Maxim Dounin]

Hello!

On Wed, Nov 19, 2014 at 12:50:20PM -0800, Piotr Sikora wrote:

> Hey Maxim,
> 
> > Current nginx behaviour is to respect both, and I don't see real
> > reasons to change the behaviour.
> 
> How about adhering to RFC standards? RFC7232 clearly describes the
> precedence for evaluation of conditional requests (section 6) and puts
> even more emphasis on it by saying that If-(Un)modified-Since headers
> MUST (not SHOULD, MUST) be ignored when If-(None-)Match headers are
> present (section 3).

Sure.  We do adhere RFC2616 here.  The problem is that RFC7232 is 
different, and there are no known reasons why it should.  After 
HTTPbis working group switched to working on HTTP/2 and introduced 
GTFO frame, I tend to be very sceptical about their work.

> > A while ago I've tried to dig
> > into HTTPbis VCS and tracker to find out why this part of the
> > specification was changed from RFC2616, but failed.
> 
> ETag is stronger validator than date, that's it.

The same applies to RFC2616, but it mandates different behaviour.  
So what's the problem with checking both date and ETag?

-- 
Maxim Dounin
http://nginx.org/