RFC2616 mandates that a proxy MUST return interim (1xx) responses to an HTTP/1.1 client, except where the proxy itself requested the interim response. I'd interpret that slightly liberally, to mean we MUST return an interim response if the Client has asked for one.
Our proxy currently eats all 1xx responses. That's broken. It could possibly have some bearing on that elusive PR 37770. As I see it: (1) 100-Continue should be forwarded to the client if there's an Expect header asking for it. If there isn't, then it really doesn't matter. (2) 101 Switching Protocols needs a framework to plug in a provider for switched protocols. In the absence of one, we should instead return 502. However, since we strip out any Upgrade request header, the question is only one of error-correction, and current behaviour is probably no worse. (3) Any other 1xx is unrecognised, and it's not clear to me whether it's best to return 502 or to forward the interim response. I'm not sure how I should forward an interim response to the client: suggestions welcome. -- Nick Kew Application Development with Apache - the Apache Modules Book http://www.apachetutor.org/