diff --git a/modules/caddyhttp/reverseproxy/reverseproxy.go b/modules/caddyhttp/reverseproxy/reverseproxy.go index 671f42a2..dbbf6471 100644 --- a/modules/caddyhttp/reverseproxy/reverseproxy.go +++ b/modules/caddyhttp/reverseproxy/reverseproxy.go @@ -504,18 +504,14 @@ func (h Handler) prepareRequest(req *http.Request) error { // Remove hop-by-hop headers to the backend. Especially // important is "Connection" because we want a persistent // connection, regardless of what the client sent to us. + // Issue golang/go#46313: don't skip if field is empty. for _, h := range hopHeaders { - hv := req.Header.Get(h) - if hv == "" { - continue - } - if h == "Te" && hv == "trailers" { - // Issue golang/go#21096: tell backend applications that - // care about trailer support that we support - // trailers. (We do, but we don't go out of - // our way to advertise that unless the - // incoming client request thought it was - // worth mentioning) + // Issue golang/go#21096: tell backend applications that care about trailer support + // that we support trailers. (We do, but we don't go out of our way to + // advertise that unless the incoming client request thought it was worth + // mentioning.) + if h == "Te" && httpguts.HeaderValuesContainsToken(req.Header["Te"], "trailers") { + req.Header.Set("Te", "trailers") continue } req.Header.Del(h)