Make policy validation aware of the max-priority argument

References #1590.

[#157380396]

Author: michaelklishin

src/rabbit_policies.erl

@@ -41,6 +41,7 @@ register() ->
                           {policy_validator, <<"expires">>},
                           {policy_validator, <<"max-length">>},
                           {policy_validator, <<"max-length-bytes">>},
+                          {policy_validator, <<"max-priority">>},
                           {policy_validator, <<"queue-mode">>},
                           {policy_validator, <<"overflow">>},
                           {operator_policy_validator, <<"expires">>},
@@ -100,6 +101,12 @@ validate_policy0(<<"max-length-bytes">>, Value)
 validate_policy0(<<"max-length-bytes">>, Value) ->
     {error, "~p is not a valid maximum length in bytes", [Value]};
 
+validate_policy0(<<"max-priority">>, Value)
+  when is_integer(Value), Value >= 0, Value =< 255 ->
+    ok;
+validate_policy0(<<"max-priority">>, Value) ->
+    {error, "~p is not a valid max priority (must be an integer in the 1-255 range)", [Value]};
+
 validate_policy0(<<"queue-mode">>, <<"default">>) ->
     ok;
 validate_policy0(<<"queue-mode">>, <<"lazy">>) ->
@@ -117,4 +124,3 @@ merge_policy_value(<<"message-ttl">>, Val, OpVal)      -> min(Val, OpVal);
 merge_policy_value(<<"max-length">>, Val, OpVal)       -> min(Val, OpVal);
 merge_policy_value(<<"max-length-bytes">>, Val, OpVal) -> min(Val, OpVal);
 merge_policy_value(<<"expires">>, Val, OpVal)          -> min(Val, OpVal).
-