Emit inactive when no consumer can be activated

Author: kjnilsson

src/rabbit_fifo.erl

@@ -839,7 +839,7 @@ activate_next_consumer(#?MODULE{consumers = Cons,
                                                              single_active, Effects0),
                     {State, Effects};
                 [] ->
-                    {State0, Effects0}
+                    {State0, [{aux, inactive} | Effects0]}
             end;
         _ ->
                     {State0, Effects0}

test/rabbit_fifo_SUITE.erl

@@ -1025,7 +1025,7 @@ active_flag_not_updated_when_consumer_suspected_unsuspected_and_single_active_co
 
     {State2, _, Effects2} = apply(#{}, {down, Pid1, noconnection}, State1),
     % one monitor and one consumer status update (deactivated)
-    ?assertEqual(2, length(Effects2)),
+    ?assertEqual(3, length(Effects2)),
 
     {_, _, Effects3} = apply(#{index => 1}, {nodeup, node(self())}, State2),
     % for each consumer: 1 effect to monitor the consumer PID