Don't disconnect tmp broker when creating client

Add a comment explaining the weird and messy reason why not, and what potential
side-effects it could have.

kafka/client.go

@@ -42,7 +42,7 @@ func NewClient(id string, host string, port int32) (client *Client, err error) {
 	client.brokers = make(map[int32]*k.Broker)
 	client.leaders = make(map[string]map[int32]int32)
 
-	// add it temporarily so that refreshTopics can find it
+	// add it to the set so that refreshTopics can find it
 	// brokers created through NewBroker() have an ID of -1, which won't conflict with
 	// whatever the metadata request returns
 	client.brokers[tmp.ID()] = tmp
@@ -54,10 +54,12 @@ func NewClient(id string, host string, port int32) (client *Client, err error) {
 		return nil, err
 	}
 
-	// now remove our tmp broker - the successful metadata request will have returned it
-	// with a valid ID, so it will already be in the hash somewhere else and we don't need
-	// the incomplete tmp one anymore
-	client.disconnectBroker(tmp)
+	// So apparently a kafka broker is not required to return its own address in response
+	// to a 'give me *all* the metadata request'... I'm not sure if that's because you're
+	// assumed to have it already or what. Regardless, this means that we can't assume we can
+	// disconnect our tmp broker here, since if it didn't return itself to us we want to keep
+	// it around anyways. The worst that happens is we end up with two connections to the same
+	// broker, one with ID -1 and one with the real ID.
 
 	return client, nil
 }