Hmm, it seems thats depend on the position on whicht test.pl will bes startet, not on the position, doall.log will be saved.
~ = home (uncrypted, local)
~/cmd = crypted,linked to Q:\cmd
test.pl wrote doall.log corrupts
test.pl wrote ../doall.log (in ~) corrupts
cmd/test.pl wrote doall.log ok
cmd/test.pl wrote ../doall.log ok