Check out this default behavior of /bin/cp though:

    $ mkdir a b
    $ echo content > a/file
    $ ln -s non-existing b/file
    $ cp a/file b
    cp: not writing through dangling symlink 'b/file'

Shouldn't shutil.copy*() refuse to write trough a dangling symlink to non-existent
file?  (ATM it seems it just silently creates the file, or fails if it can not be
created).