Ocsigen_response: Propagate the transfer encoding

In cohttp-eio, the transfer encoding is no longer propagated through the
`Body.t` type. Instead, it must be propagated separately.

Author: Julow

src/server/ocsigen_response.ml

@@ -12,9 +12,8 @@ module Body = struct
       (Transfer.Fixed (Int64.of_int (String.length s)))
       (fun write -> write s)
 
-  let of_cohttp body =
-    ( (fun write -> Cohttp_lwt.Body.write_body write body)
-    , Cohttp_lwt.Body.transfer_encoding body )
+  let of_cohttp ~encoding body =
+    (fun write -> Cohttp_lwt.Body.write_body write body), encoding
 
   let write (w, _) = w
   let transfer_encoding = snd
@@ -26,16 +25,16 @@ type t =
 let make ?(body = Body.empty) ?(cookies = Ocsigen_cookie_map.empty) a_response =
   {a_response; a_body = body; a_cookies = cookies}
 
-let respond ?headers ~status ?(body = Body.empty) () =
+let respond ?headers ~status ~encoding ?(body = Body.empty) () =
   let encoding =
     match headers with
-    | None -> Body.transfer_encoding body
+    | None -> encoding
     | Some headers -> (
       match Cohttp.Header.get_transfer_encoding headers with
-      | Cohttp.Transfer.Unknown -> Body.transfer_encoding body
+      | Cohttp.Transfer.Unknown -> encoding
       | t -> t)
   in
-  let response = Cohttp.Response.make ~status ~encoding ?headers () in
+  let response = Response.make ~status ~encoding ?headers () in
   make ~body response
 
 let respond_string ?headers ~status ~body () =
@@ -57,7 +56,8 @@ let update ?response ?body ?cookies {a_response; a_body; a_cookies} =
   {a_response; a_body; a_cookies}
 
 let of_cohttp ?(cookies = Ocsigen_cookie_map.empty) (a_response, body) =
-  let a_body = Body.of_cohttp body in
+  let encoding = Response.encoding a_response in
+  let a_body = Body.of_cohttp ~encoding body in
   {a_response; a_body; a_cookies = cookies}
 
 (* FIXME: secure *)

src/server/ocsigen_response.mli

@@ -13,7 +13,7 @@ module Body : sig
   (** [make writer] makes a reponse body whose content is generated by
       [writer write]. [write str] blocks until [str] is fully written. *)
 
-  val of_cohttp : Cohttp_lwt.Body.t -> t
+  val of_cohttp : encoding:Cohttp.Transfer.encoding -> Cohttp_lwt.Body.t -> t
   val write : t -> (string -> unit Lwt.t) -> unit Lwt.t
   val transfer_encoding : t -> Cohttp.Transfer.encoding
 end
@@ -27,6 +27,7 @@ val make :
 val respond :
    ?headers:Cohttp.Header.t
   -> status:Http.Status.t
+  -> encoding:Cohttp.Transfer.encoding
   -> ?body:Body.t
   -> unit
   -> t