Fix request_timeout triggering when a request was in the buffer

The problem was that when a request immediately following another
request with a large enough body, the data for the new request
(including headers) would be buffered waiting for more data,
instead of being processed immediately. If no more data came
in on the socket the request_timeout would eventually trigger.
Now the buffer is processed immediately.

src/cowboy_http.erl

@@ -436,8 +436,8 @@ after_parse({data, StreamID, IsFin, Data, State0=#state{opts=Opts, buffer=Buffer
 	end;
 %% No corresponding stream. We must skip the body of the previous request
 %% in order to process the next one.
-after_parse({data, _, IsFin, _, State}) ->
-	loop(set_timeout(State, case IsFin of
+after_parse({data, StreamID, IsFin, _, State=#state{buffer=Buffer}}) ->
+	parse(Buffer, set_timeout(State, case IsFin of
 		fin -> request_timeout;
 		nofin -> idle_timeout
 	end));

test/http_SUITE.erl

@@ -43,6 +43,7 @@ end_per_group(Name, _) ->
 init_dispatch(_) ->
 	cowboy_router:compile([{"localhost", [
 		{"/", hello_h, []},
+		{"/delay_hello", delay_hello_h, #{delay => 1000, notify_received => self()}},
 		{"/echo/:key", echo_h, []},
 		{"/resp/:key[/:arg]", resp_h, []},
 		{"/set_options/:key", set_options_h, []},
@@ -454,6 +455,26 @@ request_timeout_pipeline(Config) ->
 		cowboy:stop_listener(?FUNCTION_NAME)
 	end.
 
+request_timeout_pipeline_delay(Config) ->
+	doc("Ensure the request_timeout does not trigger on requests "
+		"coming in after a large request body."),
+	{ok, _} = cowboy:start_clear(?FUNCTION_NAME, [{port, 0}], #{
+		env => #{dispatch => init_dispatch(Config)},
+		request_timeout => 500
+	}),
+	Port = ranch:get_port(?FUNCTION_NAME),
+	try
+		ConnPid = gun_open([{type, tcp}, {protocol, http}, {port, Port}|Config]),
+		{ok, http} = gun:await_up(ConnPid),
+		StreamRef1 = gun:post(ConnPid, "/", #{}, <<0:8000000>>),
+		StreamRef2 = gun:get(ConnPid, "/delay_hello"),
+		{response, nofin, 200, _} = gun:await(ConnPid, StreamRef1),
+		{response, nofin, 200, _} = gun:await(ConnPid, StreamRef2),
+		{error, {down, {shutdown, closed}}} = gun:await(ConnPid, undefined, 1000)
+	after
+		cowboy:stop_listener(?FUNCTION_NAME)
+	end.
+
 request_timeout_skip_body(Config) ->
 	doc("Ensure the request_timeout drops connections when requests "
 		"fail to come in fast enough after skipping a request body."),