*Prevent overriding owners for gameobject.

--HG--
branch : trunk

src/game/GameObject.h

@@ -501,6 +501,14 @@ class TRINITY_DLL_SPEC GameObject : public WorldObject
 
         void SetOwnerGUID(uint64 owner)
         {
+            // Owner already found and different than expected owner - remove object from old owner
+            if (owner && GetOwnerGUID() && GetOwnerGUID() != owner)
+            {
+                if (Unit* owner = GetOwner())
+                    owner->RemoveGameObject(this, false);
+                else
+                    assert(false);
+            }
             m_spawnedByDefault = false;                     // all object with owner is despawned after delay
             SetUInt64Value(OBJECT_FIELD_CREATED_BY, owner);
         }