Core/Transports: Fixed crashes when instance with transports unloads

Closes #11056

src/server/game/Battlegrounds/Zones/BattlegroundIC.cpp

@@ -58,8 +58,17 @@ BattlegroundIC::BattlegroundIC()
 
 BattlegroundIC::~BattlegroundIC()
 {
-    delete gunshipHorde;
-    delete gunshipAlliance;
+    if (gunshipHorde)
+    {
+        gunshipHorde->RemoveFromWorld();
+        delete gunshipHorde;
+    }
+
+    if (gunshipAlliance)
+    {
+        gunshipAlliance->RemoveFromWorld();
+        delete gunshipAlliance;
+    }
 }
 
 void BattlegroundIC::HandlePlayerResurrect(Player* player)

src/server/game/Entities/Transport/Transport.cpp

@@ -39,6 +39,7 @@ Transport::Transport() : GameObject(),
 
 Transport::~Transport()
 {
+    UnloadStaticPassengers();
 }
 
 bool Transport::Create(uint32 guidlow, uint32 entry, uint32 mapid, float x, float y, float z, float ang, uint32 animprogress)

src/server/game/Entities/Transport/Transport.h

@@ -67,6 +67,8 @@ class Transport : public GameObject, public TransportBase
 
         void EnableMovement(bool enabled);
 
+        TransportTemplate const* GetTransportTemplate() const { return _transportInfo; }
+
     private:
         void MoveToNextWaypoint();
         float CalculateSegmentPos(float perc);

src/server/game/Maps/Map.cpp

@@ -63,6 +63,17 @@ Map::~Map()
         obj->ResetMap();
     }
 
+    for (TransportsContainer::iterator itr = _transports.begin(); itr != _transports.end(); ++itr)
+    {
+        Transport* transport = *itr;
+        // Destroy local transports
+        if (transport->GetTransportTemplate()->inInstance)
+        {
+            transport->RemoveFromWorld();
+            delete transport;
+        }
+    }
+
     if (!m_scriptSchedule.empty())
         sScriptMgr->DecreaseScheduledScriptCount(m_scriptSchedule.size());