add user agent header and fix host/content-length httpun headers

Author: maxtori

src/common/req.ml

@@ -92,3 +92,5 @@ let header_params ?(debug=false) s =
           acc
       ) [] l in
     value, params
+
+let user_agent_header = ref (Some ("user-agent", "ez_api/2.1.1"))

src/request/ezRequest.ml

@@ -119,6 +119,12 @@ module Make(S : Interface) : S = struct
       let meth = Service.meth service.s in
       let input_encoding = Service.input service.s in
       let url = forge api service arg params in
+      let headers = match !Req.user_agent_header, headers with
+        | None, _ -> headers
+        | Some h, None -> Some [ h ]
+        | Some h, Some l ->
+          if List.exists (fun (k, _) -> String.lowercase_ascii k = "user-agent") l then Some l
+          else Some (h :: l) in
       match input_encoding with
       | Empty ->
         if post then

src/request/ezRequest_lwt.ml

@@ -113,6 +113,12 @@ module Make(S : Interface) : S = struct
       let meth = Service.meth service.s in
       let input_encoding = Service.input service.s in
       let url = forge api service arg params in
+      let headers = match !Req.user_agent_header, headers with
+        | None, _ -> headers
+        | Some h, None -> Some [ h ]
+        | Some h, Some l ->
+          if List.exists (fun (k, _) -> String.lowercase_ascii k = "user-agent") l then Some l
+          else Some (h :: l) in
       begin match input_encoding with
         | Empty ->
           if post then

src/request/unix/httpun/httpun_client.ml

@@ -125,9 +125,10 @@ let perform ?msg ?meth ?content ?content_type ?(headers=[]) ?timeout handler url
     let> addresses = Lwt_unix.getaddrinfo hostname (Int.to_string port) [Unix.(AI_FAMILY PF_INET)] in
     let socket = Lwt_unix.socket Unix.PF_INET Unix.SOCK_STREAM 0 in
     let> () = Lwt_unix.connect socket (List.hd addresses).Unix.ai_addr in
+    let host = if (port <> 80 && port <> 443) then Format.sprintf "%s:%d" hostname port else hostname in
     let headers = Headers.of_list @@
-      [ "host", hostname ] @ headers @
-      Option.fold ~none:[] ~some:(fun c -> [ "content-length", string_of_int (String.length c)]) content @
+      [ "host", host ] @ headers @
+      Option.fold ~none:[ "content-length", "0" ] ~some:(fun c -> [ "content-length", string_of_int (String.length c)]) content @
       Option.fold ~none:[] ~some:(fun c -> [ "content-type", c]) content_type in
     let req = Request.create ~headers meth path in
     let error_handler = error_handler (Lwt.wakeup_later notify) in