Provide more descriptive type spec

Author: ansd

deps/rabbit/include/mc.hrl

@@ -1,13 +1,11 @@
--type death_key() :: {Queue :: rabbit_misc:resource_name(), rabbit_dead_letter:reason()}.
+-type death_key() :: {SourceQueue :: rabbit_misc:resource_name(), rabbit_dead_letter:reason()}.
 -type death_anns() :: #{first_time := non_neg_integer(), %% the timestamp of the first
                         last_time := non_neg_integer(), %% the timestamp of the last
-                        ttl => non_neg_integer()}.
--record(death, {
-                exchange :: rabbit_misc:resource_name(),
-                routing_keys = [] :: [rabbit_types:routing_key()],
+                        ttl => OriginalExpiration :: non_neg_integer()}.
+-record(death, {exchange :: OriginalExchange :: rabbit_misc:resource_name(),
+                routing_keys = [] :: OriginalRoutingKeys :: [rabbit_types:routing_key()],
                 count = 0 :: non_neg_integer(),
-                anns :: death_anns()
-               }).
+                anns :: death_anns()}).
 
 -record(deaths, {first :: death_key(),
                  last :: death_key(),

deps/rabbit/src/mc_amqp.erl

@@ -399,7 +399,7 @@ recover_deaths([], Acc) ->
     Acc;
 recover_deaths([{map, Kvs} | Rem], Acc) ->
     Queue = key_find(<<"queue">>, Kvs),
-    Reason = binary_to_atom(key_find(<<"reason">>, Kvs)),
+    Reason = binary_to_existing_atom(key_find(<<"reason">>, Kvs)),
     DA0 = case key_find(<<"original-expiration">>, Kvs) of
               undefined ->
                   #{};
@@ -431,8 +431,8 @@ essential_properties(#msg{message_annotations = MA} = Msg) ->
                      {utf8, FstR} = message_annotation(<<"x-first-death-reason">>, Msg, Def),
                      {utf8, LastQ} = message_annotation(<<"x-last-death-queue">>, Msg, Def),
                      {utf8, LastR} = message_annotation(<<"x-last-death-reason">>, Msg, Def),
-                     #deaths{first = {FstQ, binary_to_atom(FstR)},
-                             last = {LastQ, binary_to_atom(LastR)},
+                     #deaths{first = {FstQ, binary_to_existing_atom(FstR)},
+                             last = {LastQ, binary_to_existing_atom(LastR)},
                              records = recover_deaths(DeathMaps, #{})};
                  _ ->
                      undefined