Fix for known_atoms decoding

src/msgpack.erl

@@ -129,7 +129,15 @@ unpack_stream(Bin) -> unpack_stream(Bin, []).
 unpack_stream(Bin, Opts0) when is_binary(Bin) ->
     Opts = parse_options(Opts0),
     try
-        msgpack_unpacker:unpack_stream(Bin, Opts)
+        Opts1=Opts?OPTION{
+                     known_atoms=lists:map(
+                                   fun(X) ->
+                                           erlang:atom_to_binary(X, utf8)
+                                   end,
+                                   Opts?OPTION.known_atoms
+                                  )
+                    },
+        msgpack_unpacker:unpack_stream(Bin, Opts1)
     catch
         throw:Exception -> {error, Exception}
     end;

src/msgpack.hrl

@@ -36,7 +36,7 @@
 -record(options_v4, {
           spec = new :: new | old,
           allow_atom = pack  :: none | pack, %% allows atom when packing
-          known_atoms = [] :: [atom()],
+          known_atoms = [] :: [atom()|binary()],
           unpack_str = as_list :: as_binary | as_list | as_tagged_list,
           validate_string = false :: boolean(),
           pack_str = from_list :: from_binary | from_list | from_tagged_list | none,

src/msgpack_unpacker.erl

@@ -237,6 +237,14 @@ unpack_str_or_raw(V, ?OPTION{spec=new,
          as_tagged_list -> {string, unpack_str(V)}
      end, Rest}.
 
+maybe_bin(Bin, ?OPTION{known_atoms=Known}) when Known=/=[] ->
+    case lists:member(Bin,Known) of
+        true ->
+            erlang:binary_to_existing_atom(Bin,utf8);
+        false ->
+            Bin
+    end;
+
 maybe_bin(Bin, _) ->
     Bin.
 

test/msgpack_tests.erl

@@ -379,6 +379,13 @@ binary_test_() ->
       end}
     ].
 
+atom_test_() ->
+    Map1=#{atom1=>atom1,atom2=><<"binary2">>},
+    Bin=msgpack:pack(Map1),
+    ?_assertEqual({ok,#{<<"atom1">>=><<"atom1">>,
+                       <<"atom2">>=><<"binary2">>}}, msgpack:unpack(Bin)),
+    ?_assertEqual({ok,Map1}, msgpack:unpack(Bin,[{known_atoms,[atom1,atom2]}])).
+
 -define(PCNT, 5).
 -define(CNT, 10000).