Fix transfer-encoding precedence over content-length

2 files changed, 39 insertions, 15 deletions

diff --git a/src/gun_http.erl b/src/gun_http.erl
index 164ede8..ec459a3 100644
--- a/src/gun_http.erl
+++ b/src/gun_http.erl
@@ -522,22 +522,20 @@ response_io_from_headers(<<"HEAD">>, _, _, _) ->
 response_io_from_headers(_, _, Status, _) when (Status =:= 204) or (Status =:= 304) ->
 	head;
 response_io_from_headers(_, Version, _Status, Headers) ->
-	case lists:keyfind(<<"content-length">>, 1, Headers) of
-		{_, <<"0">>} ->
-			head;
-		{_, Length} ->
-			{body, cow_http_hd:parse_content_length(Length)};
-		_ when Version =:= 'HTTP/1.0' ->
-			body_close;
+	case lists:keyfind(<<"transfer-encoding">>, 1, Headers) of
+		{_, TE} when Version =:= 'HTTP/1.1' ->
+			case cow_http_hd:parse_transfer_encoding(TE) of
+				[<<"chunked">>] -> body_chunked;
+				[<<"identity">>] -> body_close
+			end;
 		_ ->
-			case lists:keyfind(<<"transfer-encoding">>, 1, Headers) of
-				false ->
-					body_close;
-				{_, TE} ->
-					case cow_http_hd:parse_transfer_encoding(TE) of
-						[<<"chunked">>] -> body_chunked;
-						[<<"identity">>] -> body_close
-					end
+			case lists:keyfind(<<"content-length">>, 1, Headers) of
+				{_, <<"0">>} ->
+					head;
+				{_, Length} ->
+					{body, cow_http_hd:parse_content_length(Length)};
+				_ ->
+					body_close
 			end
 	end.
 
diff --git a/test/rfc7230_SUITE.erl b/test/rfc7230_SUITE.erl
index c7aa63d..07d6b13 100644
--- a/test/rfc7230_SUITE.erl
+++ b/test/rfc7230_SUITE.erl
@@ -18,6 +18,7 @@
 
 -import(ct_helper, [doc/1]).
 -import(gun_test, [init_origin/2]).
+-import(gun_test, [init_origin/3]).
 -import(gun_test, [receive_from/1]).
 
 all() ->
@@ -56,3 +57,28 @@ do_host_port(Transport, DefaultPort, HostHeaderPort) ->
 	[<<"host: localhost", Rest/bits>>] = [L || <<"host: ", _/bits>> = L <- Lines],
 	HostHeaderPort = Rest,
 	gun:close(ConnPid).
+
+transfer_encoding_overrides_content_length(_) ->
+	doc("When both transfer-encoding and content-length are provided, "
+		"content-length must be ignored. (RFC7230 3.3.3)"),
+	{ok, _, OriginPort} = init_origin(tcp, http,
+		fun(_, ClientSocket, ClientTransport) ->
+			{ok, _} = ClientTransport:recv(ClientSocket, 0, 1000),
+			ClientTransport:send(ClientSocket,
+				"HTTP/1.1 200 OK\r\n"
+				"content-length: 12\r\n"
+				"transfer-encoding: chunked\r\n"
+				"\r\n"
+				"6\r\n"
+				"hello \r\n"
+				"6\r\n"
+				"world!\r\n"
+				"0\r\n\r\n"
+			)
+		end),
+	{ok, ConnPid} = gun:open("localhost", OriginPort),
+	{ok, http} = gun:await_up(ConnPid),
+	StreamRef = gun:get(ConnPid, "/"),
+	{response, nofin, 200, _} = gun:await(ConnPid, StreamRef),
+	{ok, <<"hello world!">>} = gun:await_body(ConnPid, StreamRef),
+	gun:close(ConnPid).