From 23d71340c9359842e673ed9f0298a0bd994d1438 Mon Sep 17 00:00:00 2001
From: David Markowitz <39972741+EmosewaMC@users.noreply.github.com>
Date: Sun, 22 Oct 2023 14:53:54 -0700
Subject: [PATCH] Scripts: Fix possible nullptr access (#1232)

unsure how to reproduce the actual bug, however we can see that with the following crash dump
```
Entity::GetComponent(eReplicaComponentType) const(+0x4) [0x56095665e634]
BossSpiderQueenEnemyServer::OnDie(Entity*, Entity*)(+0x28d) [0x560956795d0d]
Entity::Kill(Entity*)(+0xf8) [0x5609566637a8]
ZoneAgProperty::BaseTimerDone(Entity*, std::string const&)(+0x89b) [0x56095683736b]
Entity::Update(float)(+0x2b6) [0x560956662676]
EntityManager::UpdateEntities(float)(+0x2e) [0x56095667305e]
```
that the actual crash issue starts at
```
Entity::Kill(Entity*)(+0xf8) [0x5609566637a8]
ZoneAgProperty::BaseTimerDone(Entity*, std::string const&)
```
BaseTimerDone calls Kill, and there is only 1 call to Kill in the function which calls Kill no arguments, meaning the killer is a nullptr.  This propogates its way to the BossSpiderQueenEnemyServer::OnDie wherein we blindly check the killer pointer without verifying that the pointer is actually valid.

This patch simply checks that killer is valid before access to address the hole.
---
 dScripts/02_server/Enemy/AG/BossSpiderQueenEnemyServer.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dScripts/02_server/Enemy/AG/BossSpiderQueenEnemyServer.cpp b/dScripts/02_server/Enemy/AG/BossSpiderQueenEnemyServer.cpp
index 49359ed1..36923cad 100644
--- a/dScripts/02_server/Enemy/AG/BossSpiderQueenEnemyServer.cpp
+++ b/dScripts/02_server/Enemy/AG/BossSpiderQueenEnemyServer.cpp
@@ -52,7 +52,7 @@ void BossSpiderQueenEnemyServer::OnStartup(Entity* self) {
 }
 
 void BossSpiderQueenEnemyServer::OnDie(Entity* self, Entity* killer) {
-	if (Game::zoneManager->GetZoneID().GetMapID() == instanceZoneID) {
+	if (Game::zoneManager->GetZoneID().GetMapID() == instanceZoneID && killer) {
 		auto* missionComponent = killer->GetComponent<MissionComponent>();
 		if (missionComponent == nullptr)
 			return;