gzdoom/wadsrc/static/zscript/actor_inventory.txt

extend class Actor
{
	//============================================================================
	//
	// AActor :: AddInventory
	//
	//============================================================================

	virtual void AddInventory (Inventory item)
	{
		// Check if it's already attached to an actor
		if (item.Owner != NULL)
		{
			// Is it attached to us?
			if (item.Owner == self)
				return;

			// No, then remove it from the other actor first
			item.Owner.RemoveInventory (item);
		}

		item.Owner = self;
		item.Inv = Inv;
		Inv = item;

		// Each item receives an unique ID when added to an actor's inventory.
		// This is used by the DEM_INVUSE command to identify the item. Simply
		// using the item's position in the list won't work, because ticcmds get
		// run sometime in the future, so by the time it runs, the inventory
		// might not be in the same state as it was when DEM_INVUSE was sent.
		Inv.InventoryID = InventoryID++;
	}

}