Elda needs to generate an HTTP Vary response header

[GoogleCodeExporter]

The absence of a Vary header in elda-1.2.5 and earlier cause problems for 
content negotiated content in the presence of downstream web caches.

Elda needs to include a vary header

Vary: Accept

in responses to indicated to downstream caches responses are content 
negotiatied.

Strictly this is only required in the cases where the responses are in fact 
negotiated via Accept headers. Responses selected on the basis of trailing 
extensions (.rdf, .html etc) need not include a "Vary: Accept" header since in 
those cases the accept header does give rise to variation (unless we are also 
generating 406 unacceptable responses if no acceptable response can be 
generated).

The Vary header should include ALL HTTP headers that affect an elda generated 
response - ie result in different responses for the same request URI.

Original issue reported on code.google.com by skwli...@gmail.com on 23 Feb 2012 at 1:02

[GoogleCodeExporter]

This should be a gating criteria on the next Elda release (which should be 
"soon").

Original comment by ehog.he...@googlemail.com on 24 Feb 2012 at 1:41

• Changed state: Accepted

[GoogleCodeExporter]

Original comment by ehog.he...@googlemail.com on 24 Feb 2012 at 2:06

[GoogleCodeExporter]

Elda now includes a `Vary: Accept` header on (most) responses.

Original comment by ehog.he...@googlemail.com on 8 Mar 2012 at 10:23

• Changed state: Fixed