Fix routing key for AMQP 0.9.1 reading from a stream

when message was published to a stream via the stream protocol.

Fixes the following test:
```
./mvnw test -Dtest=AmqpInteroperabilityTest#publishToStreamConsumeFromStreamQueue
```

Author: ansd

deps/rabbit/src/mc.erl

@@ -21,6 +21,7 @@
          correlation_id/1,
          user_id/1,
          message_id/1,
+         property/2,
          timestamp/1,
          priority/1,
          set_ttl/2,
@@ -302,6 +303,14 @@ message_id(#?MODULE{protocol = Proto,
 message_id(BasicMsg) ->
     mc_compat:message_id(BasicMsg).
 
+-spec property(atom(), state()) ->
+    {utf8, binary()} | undefined.
+property(Property, #?MODULE{protocol = Proto,
+                            data = Data}) ->
+    Proto:property(Property, Data);
+property(_Property, _BasicMsg) ->
+    undefined.
+
 -spec set_ttl(undefined | non_neg_integer(), state()) -> state().
 set_ttl(Value, #?MODULE{annotations = Anns} = State) ->
     State#?MODULE{annotations = maps:put(ttl, Value, Anns)};

deps/rabbit/src/mc_amqp.erl

@@ -115,6 +115,8 @@ property(message_id, #msg{properties = #'v1_0.properties'{message_id = MsgId}})
     MsgId;
 property(user_id, #msg{properties = #'v1_0.properties'{user_id = UserId}}) ->
     UserId;
+property(subject, #msg{properties = #'v1_0.properties'{subject = Subject}}) ->
+    Subject;
 property(_Prop, #msg{}) ->
     undefined.
 
@@ -178,13 +180,6 @@ get_property(priority, Msg) ->
                 _ ->
                     undefined
             end
-    end;
-get_property(subject, Msg) ->
-    case Msg of
-        #msg{properties = #'v1_0.properties'{subject = {utf8, Subject}}} ->
-            Subject;
-        _ ->
-            undefined
     end.
 
 convert_to(?MODULE, Msg, _Env) ->
@@ -430,10 +425,6 @@ essential_properties(#msg{message_annotations = MA} = Msg) ->
     Priority = get_property(priority, Msg),
     Timestamp = get_property(timestamp, Msg),
     Ttl = get_property(ttl, Msg),
-    RoutingKeys = case get_property(subject, Msg) of
-                      undefined -> undefined;
-                      Subject -> [Subject]
-                  end,
 
     Deaths = case message_annotation(<<"x-death">>, Msg, undefined) of
                  {list, DeathMaps}  ->
@@ -458,10 +449,8 @@ essential_properties(#msg{message_annotations = MA} = Msg) ->
                  maps_put_truthy(
                    ttl, Ttl,
                    maps_put_truthy(
-                     ?ANN_ROUTING_KEYS, RoutingKeys,
-                     maps_put_truthy(
-                       deaths, Deaths,
-                       #{})))))),
+                     deaths, Deaths,
+                     #{}))))),
     case MA of
         [] ->
             Anns;

deps/rabbit/src/rabbit_amqp_session.erl

@@ -1562,14 +1562,10 @@ incoming_link_transfer(
            [?MODULE, [amqp10_framing:pprint(Section) || Section <- Sections]]),
     case rabbit_exchange_lookup(Exchange) of
         {ok, X = #exchange{name = #resource{name = XNameBin}}} ->
-            Anns0 = #{?ANN_EXCHANGE => XNameBin},
-            Anns = case LinkRKey of
-                       undefined -> Anns0;
-                       _ -> Anns0#{?ANN_ROUTING_KEYS => [LinkRKey]}
-                   end,
+            Anns = #{?ANN_EXCHANGE => XNameBin},
             Mc0 = mc:init(mc_amqp, Sections, Anns),
-            Mc1 = rabbit_message_interceptor:intercept(Mc0),
-            {Mc, RoutingKey} = ensure_routing_key(Mc1),
+            {RoutingKey, Mc1} = ensure_routing_key(LinkRKey, Mc0),
+            Mc = rabbit_message_interceptor:intercept(Mc1),
             check_user_id(Mc, User),
             messages_received(Settled),
             check_write_permitted_on_topic(X, User, RoutingKey),
@@ -1620,19 +1616,24 @@ rabbit_exchange_lookup(X = #exchange{}) ->
 rabbit_exchange_lookup(XName = #resource{}) ->
     rabbit_exchange:lookup(XName).
 
-ensure_routing_key(Mc) ->
-    case mc:routing_keys(Mc) of
-        [RoutingKey] ->
-            {Mc, RoutingKey};
-        [] ->
-            %% Set the default routing key of AMQP 0.9.1 'basic.publish'{}.
-            %% For example, when the client attached to target /exchange/amq.fanout and sends a
-            %% message without setting a 'subject' in the message properties, the routing key is
-            %% ignored during routing, but receiving code paths still expect some routing key to be set.
-            DefaultRoutingKey = <<"">>,
-            Mc1 = mc:set_annotation(?ANN_ROUTING_KEYS, [DefaultRoutingKey], Mc),
-            {Mc1, DefaultRoutingKey}
-    end.
+ensure_routing_key(LinkRKey, Mc0) ->
+    RKey = case LinkRKey of
+               undefined ->
+                   case mc:property(subject, Mc0) of
+                       undefined ->
+                           %% Set the default routing key of AMQP 0.9.1 'basic.publish'{}.
+                           %% For example, when the client attached to target /exchange/amq.fanout and sends a
+                           %% message without setting a 'subject' in the message properties, the routing key is
+                           %% ignored during routing, but receiving code paths still expect some routing key to be set.
+                           <<"">>;
+                       {utf8, Subject} ->
+                           Subject
+                   end;
+               _ ->
+                   LinkRKey
+           end,
+    Mc = mc:set_annotation(?ANN_ROUTING_KEYS, [RKey], Mc0),
+    {RKey, Mc}.
 
 process_routing_confirm([], _SenderSettles = true, _, U) ->
     rabbit_global_counters:messages_unroutable_dropped(?PROTOCOL, 1),