ACL set to numeric usernames will be treated as uid.

Issue

• ACL's set to numeric username are not obeyed:

# useradd 123
# useradd test

# mkdir /testdir

# getfacl /testdir/
getfacl: Removing leading '/' from absolute path names
# file: testdir/
# owner: root
# group: root
user::rwx
group::r-x
other::r-x

# setfacl -m u:test:rwx /testdir
# getfacl /testdir/
getfacl: Removing leading '/' from absolute path names
# file: testdir/
# owner: root
# group: root
user::rwx
user:test:rwx
group::r-x
mask::rwx
other::r-x

# setfacl -m u:123:rwx /testdir/
# getfacl /testdir/
getfacl: Removing leading '/' from absolute path names
# file: testdir/
# owner: root
# group: root
user::rwx
user:123:rwx
user:test:rwx
group::r-x
mask::rwx
other::r-x

# su - test
# cd  /testdir
# touch file
#[testdir]$ ll
total 0
-rw-rw-r-- 1 test test 0 Jul 12 11:43 file  ---->> Non numeric username users are able to touch files

# su - 123
# cd /testdir
#[testdir]$ touch file1
touch: cannot touch `file1': Permission denied

• The numeric user is not allowed to touch files.