Properly handle external exits of request processes

Because the exit reason doesn't include the stacktrace they
were ignored. Now they are properly handled. The error message
was changed slightly to accomodate.

src/cowboy_stream_h.erl

@@ -138,17 +138,16 @@ info(StreamID, Info={'EXIT', Pid, {{request_error, Reason, _HumanReadable}, _}},
 		{error_response, Status, #{<<"content-length">> => <<"0">>}, <<>>},
 		stop
 	], State);
-info(StreamID, Exit={'EXIT', Pid, {Reason, Stacktrace}}, State=#state{ref=Ref, pid=Pid}) ->
+info(StreamID, Exit={'EXIT', Pid, Reason}, State=#state{ref=Ref, pid=Pid}) ->
 	Commands0 = [{internal_error, Exit, 'Stream process crashed.'}],
 	Commands = case Reason of
 		normal -> Commands0;
 		shutdown -> Commands0;
 		{shutdown, _} -> Commands0;
 		_ -> [{log, error,
 				"Ranch listener ~p, connection process ~p, stream ~p "
-				"had its request process ~p exit with reason "
-				"~999999p and stacktrace ~999999p~n",
-				[Ref, self(), StreamID, Pid, Reason, Stacktrace]}
+				"had its request process ~p exit with reason ~0p~n",
+				[Ref, self(), StreamID, Pid, Reason]}
 			|Commands0]
 	end,
 	%% @todo We are trying to send a 500 response before resetting

test/handlers/crash_h.erl

@@ -7,6 +7,9 @@
 -export([init/2]).
 
 -spec init(_, _) -> no_return().
+init(_, external_exit) ->
+	ct_helper:ignore(?MODULE, init, 2),
+	exit(self(), ct_helper_ignore);
 init(_, no_reply) ->
 	ct_helper:ignore(?MODULE, init, 2),
 	error(crash);

test/plain_handler_SUITE.erl

@@ -45,6 +45,7 @@ end_per_group(Name, _) ->
 
 init_dispatch(_) ->
 	cowboy_router:compile([{"localhost", [
+		{"/crash/external_exit", crash_h, external_exit},
 		{"/crash/no_reply", crash_h, no_reply},
 		{"/crash/reply", crash_h, reply}
 	]}]).
@@ -78,3 +79,13 @@ crash_before_reply(Config) ->
 	]),
 	{response, fin, 500, _} = gun:await(ConnPid, Ref),
 	gun:close(ConnPid).
+
+external_exit_before_reply(Config) ->
+	doc("A plain handler exits externally before a response was sent "
+		"results in a 500 response."),
+	ConnPid = gun_open(Config),
+	Ref = gun:get(ConnPid, "/crash/external_exit", [
+		{<<"accept-encoding">>, <<"gzip">>}
+	]),
+	{response, fin, 500, _} = gun:await(ConnPid, Ref),
+	gun:close(ConnPid).