prevent user from joining a game they're already in

server/src/game_handler.rs

@@ -1,7 +1,9 @@
 use crate::user_handler::*;
 use crate::AppState;
 use crate::GameHandlerMessage::*;
+use crate::SendUserMessage::*;
 use crate::User;
+use crate::UserHandlerMessage::*;
 use anyhow::{Context, Result};
 use lib::*;
 use rand::prelude::IteratorRandom;
@@ -108,6 +110,25 @@ impl GameHandler {
             .unwrap()
             .clone();
 
+        if this_game
+            .read()
+            .unwrap()
+            .players
+            .contains_key(&this_user.read().unwrap().uuid)
+        {
+            self.state
+                .users_tx
+                .send(DmUserAddr {
+                    addr,
+                    message: SendChatMessage(ChatMessage {
+                        text: "You're already in this game!".to_owned(),
+                    }),
+                })
+                .await
+                .unwrap();
+            return;
+        }
+
         // Create player
         this_game.write().unwrap().create_player(this_user);