Merge bug 24392

Author: Simon MacMullen

src/rabbit_misc.erl

@@ -250,18 +250,23 @@ assert_args_equivalence(Orig, New, Name, Keys) ->
     ok.
 
 assert_args_equivalence1(Orig, New, Name, Key) ->
-    case {table_lookup(Orig, Key), table_lookup(New, Key)} of
+    {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;
-        {{OrigType, OrigVal} = Orig1, {NewType, NewVal} = New1} ->
+        {{OrigType, OrigVal}, {NewType, NewVal}} ->
             case type_class(OrigType) == type_class(NewType) andalso
                  OrigVal == NewVal of
                  true  -> ok;
-                 false -> protocol_error(precondition_failed, "inequivalent arg"
-                                         " '~s' for ~s: received ~s but current"
-                                         " is ~s",
-                                         [Key, rs(Name), val(New1), val(Orig1)])
-            end
+                 false -> FailureFun()
+            end;
+        {_, _} ->
+            FailureFun()
     end.
 
 val(undefined) ->