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.

1 files changed, 3 insertions, 4 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, _) ->