apparmor_parser with --write-cache and --purge-cache should not delete CACHEDIR.TAG

[intrigeri]

See https://bugs.debian.org/883584 for context. This idea was ACK'ed by John Johansen on https://lists.ubuntu.com/archives/apparmor/2018-January/011429.html.

[intrigeri (intrigeri)]

The original problem this bug was about is gone. Actually, now that the multicache went in, we would instead install CACHEDIR.TAG in the cache-loc (/etc/apparmor.d/cache.d/CACHEDIR.TAG). It will apply recursively to all the actual cache sub-directories.

But the same practical problem comes back if using "apparmor_parser --purge-cache", which I would like to do on Debian scripts instead of having to maintain a shell implementation that does the same module it leaves CACHEDIR.TAG alone.

# touch /etc/apparmor.d/cache.d/CACHEDIR.TAG
# apparmor_parser --purge-cache
# ls /etc/apparmor.d/cache.d/CACHEDIR.TAG
ls: cannot access '/etc/apparmor.d/cache.d/CACHEDIR.TAG': No such file or directory

So, could "apparmor_parser --purge-cache" avoid deleting /etc/apparmor.d/cache.d/CACHEDIR.TAG?