Re: Content negotiation for request bodies

Brian Smith wrote:
> > I don't see much difference between "try it, and if it fails..." and 
> > sending an Expects header.  Don't they amount to the same thing?
> 
> > I guess the difference is in the amount of resource that may have 
> > already been sent before a failure comes back
> 
> The other difference is that the client can implement a policy "if
> the server is too dumb to understand Expect: 100-continue, then it is
> also probably too dumb to understand Content-Encoding or other
> advanced features I would like to use in this request, so let's back
> off and use something simpler." In particular, the client might assume
> that the lack of a 100-continue response means that there is an
> ancient (HTTP 1.0) proxy or server involved somewhere.

Is "Expect: deflate" of any use here?

I'm thinking if you send a compressed request body (for example), in
the hope that a server which doesn't understand it will reject it
safely, there is a possibility of unintended side effects as the
server might interpret the body in a way that's not intended.

-- Jamie