When RabbitMQ fails to publish a message to an exchange, and it isn't a return, signal a connection error so that it retries

Author: phatboyg

src/Transports/MassTransit.RabbitMqTransport/RabbitMqTransport/RabbitMqChannelContext.cs

@@ -54,6 +54,10 @@ async Task WaitAck()
                     {
                         throw new MessageReturnedException("The message was returned by RabbitMQ", exception);
                     }
+                    catch (PublishException exception)
+                    {
+                        throw new RabbitMqConnectionException("BasicPublishAsync failed", exception);
+                    }
                 }
 
                 return awaitAck ? WaitAck() : Task.CompletedTask;

src/Transports/MassTransit.RabbitMqTransport/RabbitMqTransport/RabbitMqSendTransportContext.cs

@@ -185,16 +185,12 @@ static void SetHeaders(IDictionary<string, object> dictionary, SendHeaders heade
             {
                 if (header.Value == null)
                 {
-                    if (dictionary.ContainsKey(header.Key))
-                        dictionary.Remove(header.Key);
+                    dictionary.Remove(header.Key);
 
                     continue;
                 }
 
-                if (header.Key == RabbitMqHeaders.Exchange
-                    || header.Key == RabbitMqHeaders.RoutingKey
-                    || header.Key == RabbitMqHeaders.DeliveryTag
-                    || header.Key == RabbitMqHeaders.ConsumerTag)
+                if (header.Key is RabbitMqHeaders.Exchange or RabbitMqHeaders.RoutingKey or RabbitMqHeaders.DeliveryTag or RabbitMqHeaders.ConsumerTag)
                     continue;
 
                 if (dictionary.ContainsKey(header.Key))