修正获取队友问题

src/rooms/logic/Handler/BattleHandler.ts

@@ -60,13 +60,19 @@ export class BattleHandler {
     };
 
     public getFriend(aplayer: PlayerHandler): PlayerHandler{
-        let obj;
+        if(aplayer && aplayer._friend){
+            return aplayer._friend;
+        }
+        // 防止出错冗余处理
+        let res;
         for(let [key, obj] of this._players){
             if(obj._friend == aplayer){
+                aplayer._friend = obj;
+                res = obj;
                 break;
             }
         }
-        return obj;
+        return res;
     };
 
     public petIsValid(pet: PetHandler, players: PlayerHandler[], ct: GameUnitType): boolean{