Sensible errors on queue durable / auto_delete inequivalence.

2 files changed, 31 insertions, 19 deletions

diff --git a/src/rabbit_amqqueue.erl b/src/rabbit_amqqueue.erl
index 692179fc..5bd93ea2 100644
--- a/src/rabbit_amqqueue.erl
+++ b/src/rabbit_amqqueue.erl
@@ -405,16 +405,14 @@ with_or_die(Name, F) ->
                       ({absent, Q}) -> rabbit_misc:absent(Q)
                   end).
 
-assert_equivalence(#amqqueue{durable     = Durable,
-                             auto_delete = AutoDelete} = Q,
-                   Durable, AutoDelete, RequiredArgs, Owner) ->
-    assert_args_equivalence(Q, RequiredArgs),
-    check_exclusive_access(Q, Owner, strict);
-assert_equivalence(#amqqueue{name = QueueName},
-                   _Durable, _AutoDelete, _RequiredArgs, _Owner) ->
-    rabbit_misc:protocol_error(
-      precondition_failed, "parameters for ~s not equivalent",
-      [rabbit_misc:rs(QueueName)]).
+assert_equivalence(#amqqueue{name        = QName,
+                             durable     = Durable,
+                             auto_delete = AD} = Q,
+                   Durable1, AD1, Args1, Owner) ->
+    rabbit_misc:assert_field_equivalence(Durable, Durable1, QName, durable),
+    rabbit_misc:assert_field_equivalence(AD, AD1, QName, auto_delete),
+    assert_args_equivalence(Q, Args1),
+    check_exclusive_access(Q, Owner, strict).
 
 check_exclusive_access(Q, Owner) -> check_exclusive_access(Q, Owner, lax).
 
diff --git a/src/rabbit_misc.erl b/src/rabbit_misc.erl
index c4148bbf..bd8ba42e 100644
--- a/src/rabbit_misc.erl
+++ b/src/rabbit_misc.erl
@@ -22,7 +22,7 @@
 -export([die/1, frame_error/2, amqp_error/4, quit/1,
          protocol_error/3, protocol_error/4, protocol_error/1]).
 -export([not_found/1, absent/1]).
--export([type_class/1, assert_args_equivalence/4]).
+-export([type_class/1, assert_args_equivalence/4, assert_field_equivalence/4]).
 -export([dirty_read/1]).
 -export([table_lookup/2, set_table_value/4]).
 -export([r/3, r/2, r_arg/4, rs/1]).
@@ -125,6 +125,9 @@
                                     rabbit_framing:amqp_table(),
                                     rabbit_types:r(any()), [binary()]) ->
                                         'ok' | rabbit_types:connection_exit()).
+-spec(assert_field_equivalence/4 ::
+        (any(), any(), rabbit_types:r(any()), atom()) ->
+                                         'ok' | rabbit_types:connection_exit()).
 -spec(dirty_read/1 ::
         ({atom(), any()}) -> rabbit_types:ok_or_error2(any(), 'not_found')).
 -spec(table_lookup/2 ::
@@ -316,11 +319,6 @@ assert_args_equivalence(Orig, New, Name, Keys) ->
 
 assert_args_equivalence1(Orig, New, Name, Key) ->
     {Orig1, New1} = {table_lookup(Orig, Key), table_lookup(New, Key)},
-    FailureFun = fun () ->
-                     protocol_error(precondition_failed, "inequivalent arg '~s'"
-                                    "for ~s: received ~s but current is ~s",
-                                    [Key, rs(Name), val(New1), val(Orig1)])
-                 end,
     case {Orig1, New1} of
         {Same, Same} ->
             ok;
@@ -328,12 +326,22 @@ assert_args_equivalence1(Orig, New, Name, Key) ->
             case type_class(OrigType) == type_class(NewType) andalso
                  OrigVal == NewVal of
                  true  -> ok;
-                 false -> FailureFun()
+                 false -> assert_field_equivalence(OrigVal, NewVal, Name, Key)
             end;
         {_, _} ->
-            FailureFun()
+            assert_field_equivalence(Orig, New, Name, Key)
     end.
 
+assert_field_equivalence(_Orig, _Orig, _Name, _Key) ->
+    ok;
+assert_field_equivalence(Orig, New, Name, Key) ->
+    equivalence_fail(Orig, New, Name, Key).
+
+equivalence_fail(Orig, New, Name, Key) ->
+    protocol_error(precondition_failed, "inequivalent arg '~s' "
+                   "for ~s: received ~s but current is ~s",
+                   [Key, rs(Name), val(New), val(Orig)]).
+
 val(undefined) ->
     "none";
 val({Type, Value}) ->
@@ -341,7 +349,13 @@ val({Type, Value}) ->
                  true  -> "~s";
                  false -> "~w"
              end,
-    format("the value '" ++ ValFmt ++ "' of type '~s'", [Value, Type]).
+    format("the value '" ++ ValFmt ++ "' of type '~s'", [Value, Type]);
+val(Value) ->
+    ValFmt = case is_binary(Value) of
+                 true  -> "~s";
+                 false -> "~w"
+             end,
+    format(ValFmt, [Value]).
 
 %% Normally we'd call mnesia:dirty_read/1 here, but that is quite
 %% expensive due to general mnesia overheads (figuring out table types