* sec_acl.cc (setacl): Never set DELETE permission. Set
FILE_DELETE_CHILD only on readable and executable directories.
* sec_helper.cc: Add constructor for `well_known_null_sid'.
* security.cc (get_nt_attribute): Set S_ISVTX for directories if
FILE_WRITE_DATA and FILE_EXECUTE but not FILE_DELETE_CHILD is set.
Add evaluation of S_ISVTX, S_ISGID and S_ISUID from NULL ACE.
(alloc_sd): Never set DELETE permission. Set FILE_DELETE_CHILD
only on readable and executable directories.
Add creation of NULL ACE for S_ISVTX, S_ISGID and S_ISUID permissions.
* security.h: Add extern declaration for `well_known_null_sid'.
3a157c0d0d