Added abit more defense programming, should be needed still ..why not

https://github.com/liyunfan1223/mod-playerbots/issues/1490

src/Playerbots.cpp

@@ -209,16 +209,30 @@ public:
 
     void OnPlayerGiveXP(Player* player, uint32& amount, Unit* /*victim*/, uint8 /*xpSource*/) override
     {
-        if (!player->GetSession()->IsBot())
-            return;
-        
-        if (!sRandomPlayerbotMgr->IsRandomBot(player))
+        // early return
+        if (sPlayerbotAIConfig->randomBotXPRate == 1.0 || !player)
             return;
 
-        if (sPlayerbotAIConfig->randomBotXPRate != 1.0)
+        // no XP multiplier, when player is no bot.
+        if (!player->GetSession()->IsBot() || !sRandomPlayerbotMgr->IsRandomBot(player))
+            return;
+
+        // no XP multiplier, when bot has group where leader is a real player.
+        if (Group* group = player->GetGroup())
         {
-            amount = static_cast<uint32>(std::round(static_cast<float>(amount) * sPlayerbotAIConfig->randomBotXPRate));
+            Player* leader = group->GetLeader();
+            if (leader && leader != player)
+            {
+                if (PlayerbotAI* leaderBotAI = GET_PLAYERBOT_AI(leader))
+                {
+                    if (leaderBotAI->HasRealPlayerMaster())
+                        return;
+                }
+            }
         }
+
+        // otherwise apply bot XP multiplier.
+        amount = static_cast<uint32>(std::round(static_cast<float>(amount) * sPlayerbotAIConfig->randomBotXPRate));
     }
 };