Fixing the fix for issue yrashk#57

The previous fix would mess up some escaping in different
circumstances. This commit should get rid of the problems by
adding smarter escaping.

src/socketio_transport_polling.erl

@@ -297,7 +297,7 @@ send_message(Message, Req, Index, ServerModule, Sup) ->
 send_message_1(Headers, Message, Req, Index, ServerModule) ->
     Headers0 = [{"Content-Type", "text/javascript; charset=UTF-8"}|Headers],
     Message0 = unicode:characters_to_list(jsx:format(jsx:term_to_json(list_to_binary(Message), [{strict, false}]))),
-    Message1 = "io.JSONP["++Index++"]._(" ++ Message0 ++ ");",
+    Message1 = "io.JSONP["++Index++"]._(\"" ++ escape(tl(Message0)) ++ ");",
     apply(ServerModule, respond, [Req, 200, Headers0, Message1]).
 
 cors_headers(Headers, Sup) ->
@@ -325,3 +325,10 @@ reset_duration({TimerRef, Time}) ->
     erlang:cancel_timer(TimerRef),
     NewRef = erlang:start_timer(Time, self(), polling),
     {NewRef, Time}.
+
+%% THis should deal with only one level of depth -- the rest is assumed to
+%% have been escaped correctly by jsx.
+escape([$"]) -> [$"];
+escape([$"|Rest]) -> [$\\, $" | escape(Rest)];
+escape([$\\|Rest]) -> [$\\,$\\ | escape(Rest)];
+escape([CodePoint|Rest]) -> [CodePoint | escape(Rest)].

test/socketio_transport_tests.erl

@@ -47,7 +47,7 @@ transport_tests(Browser, Transport) ->
                   ets:insert(socketio_tests, {transport, Transport}),
                   error_logger:delete_report_handler(error_logger_tty_h), %% suppress annoying kernel logger
                   application:start(misultin),
-		  application:start(socketio),
+                  application:start(socketio),
                   {ok, Pid} = socketio_listener:start([{http_port, 8989}, 
                                                        {default_http_handler, ?MODULE}]),
                   EventMgr = socketio_listener:event_manager(Pid),