Fix influence of decode_format on service events

Decoded CER/CEA messages are passed in events messages that can be
subscribed to using diameter:subscribe/1. A configured decode_format was
not reflected in these, messages always being passed as records.

Clarify that strict_arities only applies to message callbacks.

3 files changed, 43 insertions, 33 deletions

diff --git a/lib/diameter/doc/src/diameter.xml b/lib/diameter/doc/src/diameter.xml
index 3ad24257a5..ad82cafd2f 100644
--- a/lib/diameter/doc/src/diameter.xml
+++ b/lib/diameter/doc/src/diameter.xml
@@ -962,7 +962,8 @@ Defaults to the empty list.</p>
 <item>
 <p>
 Whether or not to require that the number of AVPs in a message or
-grouped AVP agree with those specified in the dictionary in question.
+grouped AVP agree with those specified in the dictionary in question
+when passing messages to &man_app; callbacks.
 If <c>true</c> then mismatches in an outgoing messages cause message
 encoding to fail, while mismatches in an incoming message are reported
 as 5005/5009 errors in the errors field of the diameter_packet record
diff --git a/lib/diameter/src/base/diameter_peer_fsm.erl b/lib/diameter/src/base/diameter_peer_fsm.erl
index 4870b86be5..6c47d8804e 100644
--- a/lib/diameter/src/base/diameter_peer_fsm.erl
+++ b/lib/diameter/src/base/diameter_peer_fsm.erl
@@ -128,9 +128,8 @@
                        %% outgoing DPR; boolean says whether or not
                        %% the request was sent explicitly with
                        %% diameter:call/4.
-         codec :: #{decode_format := record,
+         codec :: #{decode_format := diameter:decode_format(),
                     string_decode := boolean(),
-                    strict_arities => diameter:strict_arities(),
                     strict_mbit := boolean(),
                     rfc := 3588 | 6733,
                     ordered_encode := false},
@@ -260,8 +259,7 @@ i({Ack, WPid, {M, Ref} = T, Opts, {SvcOpts, Nodes, Dict0, Svc}}) ->
                               strict_mbit,
                               rfc,
                               ordered_encode],
-                             SvcOpts#{ordered_encode => false,
-                                      decode_format => record})}.
+                             SvcOpts#{ordered_encode => false})}.
 %% The transport returns its local ip addresses so that different
 %% transports on the same service can use different local addresses.
 %% The local addresses are put into Host-IP-Address avps here when
@@ -812,7 +810,8 @@ handle('DPA' = N,
                  %% service: explicit DPR is counted in the same way
                  %% as other explicitly sent requests.
                  incr(recv, H, Dict0),
-                 incr_rc(recv, diameter_codec:decode(Dict0, Opts, Pkt), Dict0)
+                 {_, RecPkt} = decode(Dict0, Opts, Pkt),
+                 incr_rc(recv, RecPkt, Dict0)
              end,
     diameter_peer:close(TPid),
     {stop, N};
@@ -916,21 +915,30 @@ handle_request(Name,
                = S) ->
     ?LOG(recv, Name),
     incr(recv, H, Dict0),
-    send_answer(Name, diameter_codec:decode(Dict0, Opts, Pkt), S).
+    send_answer(Name, decode(Dict0, Opts, Pkt), S).
+
+%% decode/3
+%%
+%% Decode the message as record for diameter_capx, and in the
+%% configured format for events.
+
+decode(Dict0, Opts, Pkt) ->
+    {diameter_codec:decode(Dict0, Opts, Pkt),
+     diameter_codec:decode(Dict0, Opts#{decode_format := record}, Pkt)}.
 
 %% send_answer/3
 
-send_answer(Type, ReqPkt, #state{transport = TPid,
-                                 dictionary = Dict,
-                                 codec = Opts}
-                          = S) ->
-    incr_error(recv, ReqPkt, Dict),
+send_answer(Type, {DecPkt, RecPkt}, #state{transport = TPid,
+                                           dictionary = Dict,
+                                           codec = Opts}
+                                    = S) ->
+    incr_error(recv, RecPkt, Dict),
 
     #diameter_packet{header = H,
                      transport_data = TD}
-        = ReqPkt,
+        = RecPkt,
 
-    {Msg, PostF} = build_answer(Type, ReqPkt, S),
+    {Msg, PostF} = build_answer(Type, DecPkt, RecPkt, S),
 
     %% An answer message clears the R and T flags and retains the P
     %% flag. The E flag is set at encode.
@@ -958,15 +966,15 @@ eval([F|A], S) ->
 eval(T, _) ->
     close(T).
 
-%% build_answer/3
+%% build_answer/4
 
 build_answer('CER',
+             DecPkt,
              #diameter_packet{msg = CER,
                               header = #diameter_header{version
                                                         = ?DIAMETER_VERSION,
                                                         is_error = false},
-                              errors = []}
-             = Pkt,
+                              errors = []},
              #state{dictionary = Dict0}
              = S) ->
     {SupportedApps, RCaps, CEA} = recv_CER(CER, S),
@@ -984,25 +992,25 @@ build_answer('CER',
             orelse ?THROW(4003),  %% DIAMETER_ELECTION_LOST
         caps_cb(Caps)
     of
-        N -> {cea(CEA, N, Dict0), [fun open/5, Pkt,
+        N -> {cea(CEA, N, Dict0), [fun open/5, DecPkt,
                                                SupportedApps,
                                                Caps,
                                                {accept, inband_security(IS)}]}
     catch
         ?FAILURE(Reason) ->
-            rejected(Reason, {'CER', Reason, Caps, Pkt}, S)
+            rejected(Reason, {'CER', Reason, Caps, DecPkt}, S)
     end;
 
 %% The error checks below are similar to those in diameter_traffic for
 %% other messages. Should factor out the commonality.
 
 build_answer(Type,
+             DecPkt,
              #diameter_packet{header = H,
-                              errors = Es}
-             = Pkt,
+                              errors = Es},
              S) ->
     {RC, FailedAVP} = result_code(Type, H, Es),
-    {answer(Type, RC, FailedAVP, S), post(Type, RC, Pkt, S)}.
+    {answer(Type, RC, FailedAVP, S), post(Type, RC, DecPkt, S)}.
 
 inband_security([]) ->
     ?NO_INBAND_SECURITY;
@@ -1174,12 +1182,10 @@ handle_CEA(#diameter_packet{header = H}
            = S) ->
     incr(recv, H, Dict0),
 
-    #diameter_packet{}
-        = DPkt
-        = diameter_codec:decode(Dict0, Opts, Pkt),
+    {DecPkt, RecPkt} = decode(Dict0, Opts, Pkt),
 
-    RC = result_code(incr_rc(recv, DPkt, Dict0)),
-    {SApps, IS, RCaps} = recv_CEA(DPkt, S),
+    RC = result_code(incr_rc(recv, RecPkt, Dict0)),
+    {SApps, IS, RCaps} = recv_CEA(RecPkt, S),
 
     #diameter_caps{origin_host = {OH, DH}}
         = Caps
@@ -1202,9 +1208,9 @@ handle_CEA(#diameter_packet{header = H}
             orelse ?THROW(election_lost),
         caps_cb(Caps)
     of
-        _ -> open(DPkt, SApps, Caps, {connect, hd([_] = IS)}, S)
+        _ -> open(DecPkt, SApps, Caps, {connect, hd([_] = IS)}, S)
     catch
-        ?FAILURE(Reason) -> close({'CEA', Reason, Caps, DPkt})
+        ?FAILURE(Reason) -> close({'CEA', Reason, Caps, DecPkt})
     end.
 %% Check more than the result code since the peer could send success
 %% regardless. If not 2001 then a peer_up callback could do anything
diff --git a/lib/diameter/test/diameter_event_SUITE.erl b/lib/diameter/test/diameter_event_SUITE.erl
index 57d3427037..a291dde6be 100644
--- a/lib/diameter/test/diameter_event_SUITE.erl
+++ b/lib/diameter/test/diameter_event_SUITE.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2013-2016. All Rights Reserved.
+%% Copyright Ericsson AB 2013-2017. All Rights Reserved.
 %%
 %% Licensed under the Apache License, Version 2.0 (the "License");
 %% you may not use this file except in compliance with the License.
@@ -63,7 +63,8 @@
          {'Host-IP-Address', [?ADDR]},
          {'Vendor-Id', 12345},
          {'Product-Name', "OTP/diameter"},
-         {'Acct-Application-Id', [D:id() || D <- Dicts]}
+         {'Acct-Application-Id', [D:id() || D <- Dicts]},
+         {decode_format, map}
          | [{application, [{dictionary, D},
                            {module, #diameter_callback{}}]}
             || D <- Dicts]]).
@@ -111,7 +112,8 @@ up(Config) ->
     {Svc, Ref} = connect(Config, [{connect_timer, 5000},
                                   {watchdog_timer, 15000}]),
     start = event(Svc),
-    {up, Ref, {TPid, Caps}, Cfg, #diameter_packet{}} = event(Svc),
+    {up, Ref, {TPid, Caps}, Cfg, #diameter_packet{msg = M}} = event(Svc),
+    ['CEA' | #{}] = M,  %% assert
     {watchdog, Ref, _, {initial, okay}, _} = event(Svc),
     %% Kill the transport process and see that the connection is
     %% reestablished after a watchdog timeout, not after connect_timer
@@ -131,8 +133,9 @@ down(Config) ->
                                   {connect_timer, 5000},
                                   {watchdog_timer, 20000}]),
     start = event(Svc),
-    {closed, Ref, {'CEA', ?NO_COMMON_APP, _, #diameter_packet{}}, _}
+    {closed, Ref, {'CEA', ?NO_COMMON_APP, _, #diameter_packet{msg = M}}, _}
         = event(Svc),
+    ['CEA' | #{}] = M,  %% assert
     {reconnect, Ref, _} = event(Svc, 4000, 10000).
 
 %% Connect with matching capabilities but have the server delay its