Do not add messages without ID to cache

bridge/gitter/gitter.go

@@ -105,8 +105,8 @@ func (b *Bgitter) Send(msg config.Message) (string, error) {
 		flog.Errorf("Could not find roomID for %v", msg.Channel)
 		return "", nil
 	}
-	// add ZWSP because gitter echoes our own messages
 	if msg.ID != "" {
+		flog.Debugf("updating message with id %s", msg.ID)
 		_, err := b.c.UpdateMessage(roomID, msg.ID, msg.Username+msg.Text)
 		if err != nil {
 			return "", err

gateway/gateway.go

@@ -186,7 +186,9 @@ func (gw *Gateway) handleMessage(msg config.Message, dest *bridge.Bridge) []*BrM
 			fmt.Println(err)
 		}
 		// append the message ID (mID) from this bridge (dest) to our brMsgIDs slice
-		brMsgIDs = append(brMsgIDs, &BrMsgID{dest, mID})
+		if mID != "" {
+			brMsgIDs = append(brMsgIDs, &BrMsgID{dest, mID})
+		}
 	}
 	return brMsgIDs
 }

gateway/router.go

@@ -103,7 +103,7 @@ func (r *Router) handleReceive() {
 					msgIDs = append(msgIDs, gw.handleMessage(msg, br)...)
 				}
 				// only add the message ID if it doesn't already exists
-				if _, ok := gw.Messages.Get(msg.ID); !ok {
+				if _, ok := gw.Messages.Get(msg.ID); !ok && msg.ID != "" {
 					gw.Messages.Add(msg.ID, msgIDs)
 				}
 			}