Logged In: YES 
user_id=752496

I could touch the permissions of the copy to be only
readable, but with os.chmod() it'll be portable only to
Windows and Unix (according to the docs). And in Mac?

Take note that in this very moment, the copy is created via
the open(..., "w") which leaves the copy with the same
permissions that with the patch. We're not creating a
problem... maybe just don't solving it!