MM-24575 handle auto-respond to self (#14410)

app/auto_responder.go

@@ -18,6 +18,10 @@ func (a *App) SendAutoResponseIfNecessary(channel *model.Channel, sender *model.
 	}
 
 	receiverId := channel.GetOtherUserIdForDM(sender.Id)
+	if receiverId == "" {
+		// User direct messaged themself, let them test their auto-responder.
+		receiverId = sender.Id
+	}
 
 	receiver, err := a.GetUser(receiverId)
 	if err != nil {

app/post.go

@@ -419,12 +419,14 @@ func (a *App) handlePostEvents(post *model.Post, user *model.User, channel *mode
 		return err
 	}
 
-	a.Srv().Go(func() {
-		_, err := a.SendAutoResponseIfNecessary(channel, user)
-		if err != nil {
-			mlog.Error("Failed to send auto response", mlog.String("user_id", user.Id), mlog.String("post_id", post.Id), mlog.Err(err))
-		}
-	})
+	if post.Type != model.POST_AUTO_RESPONDER { // don't respond to an auto-responder
+		a.Srv().Go(func() {
+			_, err := a.SendAutoResponseIfNecessary(channel, user)
+			if err != nil {
+				mlog.Error("Failed to send auto response", mlog.String("user_id", user.Id), mlog.String("post_id", post.Id), mlog.Err(err))
+			}
+		})
+	}
 
 	if triggerWebhooks {
 		a.Srv().Go(func() {