test for noncharacters, fixed bug discovered by test

src/jsx.erl

@@ -232,7 +232,9 @@ decode_loop({jsx, end_json, _Next}, Acc) ->
 decode_loop({jsx, incomplete, More}, Acc) ->
     decode_loop(More(end_stream), Acc);
 decode_loop({jsx, E, Next}, Acc) ->
-    decode_loop(Next(), [E] ++ Acc).
+    decode_loop(Next(), [E] ++ Acc);
+decode_loop({error, {badjson, _Error}}, _Acc) ->
+    {error, badjson}.
 
     
 incremental_decode(<<C:1/binary, Rest/binary>>, Flags) ->
@@ -249,6 +251,17 @@ incremental_decode_loop({jsx, Event, Next}, Rest, Acc) ->
 	incremental_decode_loop(Next(), Rest, [Event] ++ Acc).
 
 
+bad_escapes_test_() ->
+    [
+        {"null byte",
+            ?_assertEqual({error, badjson}, decode(<<"\"\\u0000\"">>, []))
+        },
+        {"escaped noncharacter",
+            ?_assertEqual({error, badjson}, decode(<<"\"\\ud83f\\udfff\"">>, []))
+        }
+    ].
+
+
 multi_decode_test_() ->
     [
         {"multiple values in a single stream", ?_assert(
@@ -291,4 +304,5 @@ multi_test_result() ->
 
 
 
+    
 -endif.

src/jsx_decoder.hrl

@@ -542,9 +542,10 @@ low_surrogate(<<D/?utfx, Rest/binary>>, Stack, Opts, String, [C, B, A], High)
         X when X >= 16#dc00, X =< 16#dfff ->
             V = surrogate_to_codepoint(High, X),
             case V rem 16#10000 of
-                X when X == 16#fffe; X == 16#ffff ->
+                Y when Y == 16#fffe; Y == 16#ffff ->
                     {error, {badjson, <<D/?utfx, Rest/binary>>}}
-                ; _ ->
+                ; Y ->
+                    io:format("~p ~p~n", [V, Y]),
                     string(Rest, Stack, Opts, <<String/binary, V/utf8>>)
             end
         %% not a low surrogate, bad bad bad