Tweak map-valued decode

Use the same [MsgName | Avps] representation as for the list decode, but
with Avps a map instead of a AVP name/values list. As a result, don't
set the message/AVP name on an additional key in the map, which felt a
bit odd. Messages are [MsgName :: atom() | map()], Grouped AVPs are just
map().

Fix at least one problem in the traffic suite along the way: with
decode_format false, the own decode in to_map/2 didn't know whether or
not to decode strings, resulting on some failures.

3 files changed, 30 insertions, 48 deletions

diff --git a/lib/diameter/src/base/diameter_codec.erl b/lib/diameter/src/base/diameter_codec.erl
index 275e80b9bb..9b21bf4141 100644
--- a/lib/diameter/src/base/diameter_codec.erl
+++ b/lib/diameter/src/base/diameter_codec.erl
@@ -275,9 +275,6 @@ rec2msg(_, [Name|_])
   when is_atom(Name) ->
     Name;
 
-rec2msg(_, #{':name' := Name}) ->
-    Name;
-
 rec2msg(Mod, Rec) ->
     Mod:rec2msg(element(1, Rec)).
 
@@ -383,7 +380,9 @@ decode_avps(MsgName, Mod, AppMod, Opts, Pkt, Avps) ->  %% ... or not
                         errors = Errors,
                         avps = As}.
 
-reformat(MsgName, Avps, #{decode_format := list}) ->
+reformat(MsgName, Avps, #{decode_format := T})
+  when T == map;
+       T == list ->
     [MsgName | Avps];
 
 reformat(_, Msg, _) ->
diff --git a/lib/diameter/src/base/diameter_gen.erl b/lib/diameter/src/base/diameter_gen.erl
index 78d8bd2fa3..597ec143a8 100644
--- a/lib/diameter/src/base/diameter_gen.erl
+++ b/lib/diameter/src/base/diameter_gen.erl
@@ -186,7 +186,7 @@ decode_avps(Name, Recs, #{module := Mod, decode_format := Fmt} = Opts) ->
     %% AM counts the number of top-level AVPs, which missing/4 then
     %% uses when adding 5005 errors.
     Arities = Mod:avp_arity(Name),
-    {reformat(Rec, Arities, Mod, Fmt),
+    {reformat(Name, Rec, Arities, Mod, Fmt),
      Avps,
      Failed ++ missing(Arities, Opts, Mod, AM)}.
 
@@ -752,8 +752,8 @@ newrec(_, _, false = No) ->
 newrec(Mod, Name, record) ->
     newrec(Mod, Name);
 
-newrec(_, Name, _) ->
-    #{':name' => Name}.
+newrec(_, _, _) ->
+    #{}.
 
 %% newrec/2
 
@@ -762,15 +762,14 @@ newrec(Mod, Name) ->
 
 %% reformat/4
 
-reformat(Map, Arities, _Mod, list) ->
+reformat(_, Map, Arities, _Mod, list) ->
     [{F,V} || {F,_} <- Arities, #{F := V} <- [Map]];
 
-reformat(Map, Arities, Mod, record_from_map) ->
-    #{':name' := Name} = Map,
+reformat(Name, Map, Arities, Mod, record_from_map) ->
     RecName = Mod:name2rec(Name),
     list_to_tuple([RecName | [maps:get(F, Map, def(A)) || {F,A} <- Arities]]);
 
-reformat(Rec, _, _, _) ->
+reformat(_, Rec, _, _, _) ->
     Rec.
 
 %% def/1
diff --git a/lib/diameter/src/base/diameter_traffic.erl b/lib/diameter/src/base/diameter_traffic.erl
index f684f60cb7..e9c422d6ab 100644
--- a/lib/diameter/src/base/diameter_traffic.erl
+++ b/lib/diameter/src/base/diameter_traffic.erl
@@ -621,16 +621,10 @@ is_answer_message(#diameter_packet{msg = Msg}, Dict0) ->
 is_answer_message([#diameter_header{is_request = R, is_error = E} | _], _) ->
     E andalso not R;
 
-%% Message sent as a tagged avp/value list.
+%% Message sent as a map or tagged avp/value list.
 is_answer_message([Name | _], _) ->
     Name == 'answer-message';
 
-%% Message sent as a map.
-is_answer_message(Map, _)
-  when is_map(Map) ->
-    #{':name' := Name} = Map,
-    Name == 'answer-message';
-
 %% Message sent as a record.
 is_answer_message(Rec, Dict) ->
     try
@@ -875,15 +869,13 @@ reset(Msg, [RC | Avps], Dict) ->
 
 %% set/3
 
-%% Reply as name and tuple list ...
+%% Reply as name/values list ...
+set([Name|As], Avps, _)
+  when is_map(As) ->
+    [Name | maps:merge(As, maps:from_list(Avps))];
 set([_|_] = Ans, Avps, _) ->
     Ans ++ Avps;  %% Values nearer tail take precedence.
 
-%% ... a map ...
-set(Ans, Avps, _)
-  when is_map(Ans) ->
-    maps:merge(Ans, maps:from_list(Avps));
-
 %% ... or record.
 set(Rec, Avps, Dict) ->
     Dict:'#set-'(Avps, Rec).
@@ -902,9 +894,6 @@ rc([MsgName | _], RC, Dict) ->
         _     -> []
     end;
 
-rc(#{':name' := Name}, RC, Dict) ->
-    rc([Name], RC, Dict);
-
 rc(Rec, RC, Dict) ->
     rc([Dict:rec2msg(element(1, Rec))], RC, Dict).
 
@@ -937,10 +926,6 @@ failed(Msg, FailedAvp, Dict) ->
 msg2rec([MsgName | _], Dict) ->
     Dict:msg2rec(MsgName);
 
-%% ... map ...
-msg2rec(#{':name' := MsgName}, Dict) ->
-    Dict:msg2rec(MsgName);
-
 %% ... or record.
 msg2rec(Rec, _) ->
     element(1, Rec).
@@ -949,12 +934,11 @@ msg2rec(Rec, _) ->
 
 %% Message as name/values list ...
 values([_ | Avps], F, _) ->
-    proplists:get_value(F, Avps, []);
-
-%% ... map ...
-values(Msg, F, _)
-  when is_map(Msg) ->
-    maps:get(F, Msg, []);
+    if is_map(Avps) ->
+            maps:get(F, Avps, []);
+       is_list(Avps) ->
+            proplists:get_value(F, Avps, [])
+    end;
 
 %% ... or record.
 values(Rec, F, Dict) ->
@@ -1906,23 +1890,13 @@ get_avp(Dict, Name, [#diameter_header{} | Avps]) ->
 
 %% Message as name/values list ...
 get_avp(_, Name, [_MsgName | Avps]) ->
-    case lists:keyfind(Name, 1, Avps) of
+    case find(Name, Avps) of
         {_, V} ->
             #diameter_avp{name = Name, value = V};
         _ ->
             undefined
     end;
 
-%% ... map ...
-get_avp(_, Name, Map)
-  when is_map(Map) ->
-    case maps:find(Name, Map) of
-        {ok, V} ->
-            #diameter_avp{name = Name, value = V};
-        error ->
-            undefined
-    end;
-
 %% ... or record (but not necessarily).
 get_avp(Dict, Name, Rec) ->
     try
@@ -1932,6 +1906,16 @@ get_avp(Dict, Name, Rec) ->
             undefined
     end.
 
+%% find/2
+
+find(Key, Map)
+  when is_map(Map) ->
+    maps:find(Key, Map);
+
+find(Key, List)
+  when is_list(List) ->
+    lists:keyfind(Key, 1, List).
+
 %% get_avp_value/3
 
 get_avp_value(Dict, Name, Msg) ->