-- This version of the code is courtesy of Poikilos (January 2024).

local WIN32, DIR_SEP

if os.getenv ("WINDIR") then
    WIN32 = true
    DIR_SEP = "\\"
else
    WIN32 = false
    DIR_SEP = "/"
end

function os.mkdir (dir)
    local f = io.open (dir .. DIR_SEP .. ".placeholder")
    if  f then
        f:close()
        return
    end

    -- minetest.log ("info", "Warning: called deprecated os.mkdir")

    if WIN32 then
        dir = dir:gsub ("/", "\\")
    else
        dir = dir:gsub ("\\", "/")
    end

    if  minetest.mkdir then
        minetest.mkdir (dir)
    else
        os.execute ('mkdir "' .. dir .. '"')
        local f = io.open (dir .. DIR_SEP .. ".placeholder", "w")
        if  f then
            f:write ("DO NOT DELETE!!!\n")
            f:close()
        end
    end
end