bot: fix long poller stopping logic

bot.go

@@ -174,18 +174,19 @@ func (b *Bot) Start() {
 		// handle incoming updates
 		case upd := <-b.Updates:
 			b.incomingUpdate(&upd)
-
 		// call to stop polling
 		case <-b.stop:
 			stop <- struct{}{}
-
-		// polling has stopped
-		case <-stop:
 			return
 		}
 	}
 }
 
+// Stop gracefully shuts the poller down.
+func (b *Bot) Stop() {
+	b.stop <- struct{}{}
+}
+
 func (b *Bot) incomingUpdate(upd *Update) {
 	if upd.Message != nil {
 		m := upd.Message
@@ -505,11 +506,6 @@ func (b *Bot) handleMedia(m *Message) bool {
 	return true
 }
 
-// Stop gracefully shuts the poller down.
-func (b *Bot) Stop() {
-	b.stop <- struct{}{}
-}
-
 // Send accepts 2+ arguments, starting with destination chat, followed by
 // some Sendable (or string!) and optional send options.
 //

poller.go

@@ -98,12 +98,14 @@ type LongPoller struct {
 
 // Poll does long polling.
 func (p *LongPoller) Poll(b *Bot, dest chan Update, stop chan struct{}) {
-	go func(stop chan struct{}) {
-		<-stop
-		close(stop)
-	}(stop)
-
 	for {
+		select {
+		case <-stop:
+			close(stop)
+			return
+		default:
+		}
+
 		updates, err := b.getUpdates(p.LastUpdateID+1, p.Limit, p.Timeout, p.AllowedUpdates)
 		if err != nil {
 			b.debug(err)