local inv = player:get_inventory()
	local inv_src = inv:get_list("craft")
	local inv_dst = inv:get_list("main")

	local index1 = 1
	local index2 = 1

	while (index1 <= #inv_src) and (index2 <= #inv_dst) do
		if (inv_src[index1] and not inv_src[index1]:is_empty())
		 and (not (inv_dst[index2] or inv_dst[index2]:is_empty())) then
			inv_dst[index2] = inv_src[index1]
			inv_src[index1] = nil
			index2 = index2 + 1
		end
		index1 = index1 + 1
	end