Remove/Add creature from/to map when it changes map.

Note: creatures was never supposed to change map, but now the core allows them to move with transports...

src/server/game/Entities/Creature/Creature.cpp

@@ -2387,22 +2387,15 @@ const char* Creature::GetNameForLocaleIdx(LocaleConstant loc_idx) const
     return GetName();
 }
 
-//TODO: This may cause crash. Creature must be removed from the original grid and added to the new grid.
+//Do not if this works or not, moving creature to another map is very dangerous
 void Creature::FarTeleportTo(Map* map, float X, float Y, float Z, float O)
 {
-    InterruptNonMeleeSpells(true);
-    CombatStop();
-    ClearComboPointHolders();
-    DeleteThreatList();
-    GetMotionMaster()->Clear(false);
-    DestroyForNearbyPlayers();
-
-    RemoveFromWorld();
+    CleanupBeforeRemoveFromMap(false);
+    GetMap()->RemoveFromMap(this, false);
     ResetMap();
+    Relocate(X, Y, Z, O);
     SetMap(map);
-    AddToWorld();
-
-    UpdatePosition(X, Y, Z, O, true);
+    GetMap()->AddToMap(this);
 }
 
 void Creature::SetPosition(float x, float y, float z, float o)

src/server/game/Entities/Unit/Unit.cpp

@@ -13710,7 +13710,7 @@ void Unit::RemoveFromWorld()
     }
 }
 
-void Unit::CleanupsBeforeDelete(bool finalCleanup)
+void Unit::CleanupBeforeRemoveFromMap(bool finalCleanup)
 {
     // This needs to be before RemoveFromWorld to make GetCaster() return a valid pointer on aura removal
     InterruptNonMeleeSpells(true);
@@ -13734,6 +13734,11 @@ void Unit::CleanupsBeforeDelete(bool finalCleanup)
     DeleteThreatList();
     getHostileRefManager().setOnlineOfflineState(false);
     GetMotionMaster()->Clear(false);                    // remove different non-standard movement generators.
+}
+
+void Unit::CleanupsBeforeDelete(bool finalCleanup)
+{
+    CleanupBeforeRemoveFromMap(finalCleanup);
 
     if (Creature* thisCreature = ToCreature())
         if (GetTransport())

src/server/game/Entities/Unit/Unit.h

@@ -1247,6 +1247,7 @@ class Unit : public WorldObject
         void AddToWorld();
         void RemoveFromWorld();
 
+        void CleanupBeforeRemoveFromMap(bool finalCleanup);
         void CleanupsBeforeDelete(bool finalCleanup = true);                        // used in ~Creature/~Player (or before mass creature delete to remove cross-references to already deleted units)
 
         DiminishingLevels GetDiminishing(DiminishingGroup  group);