##### SUMMARY

I'm currently using ansible 2.9.9 (latest available on debian testing), with python 3.8.5
I used a playbook developed with ansible 2.7.7 (latest on debian stable), and I've been kick out of all my servers because the salt used in the password_hash() function contains specials caracters.

I dont know if this is intentional, an element missing in the documentation or if I was simply not aware of that fact, in any case, I think that it could be interessting to warn other about this.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
User (password_hash)

##### ANSIBLE VERSION
2.9.9

##### STEPS TO REPRODUCE
```---
- name:
  hosts:
    - localhost
  gather_facts: false
  tasks:
    - debug:
        msg: "{{ 'password' | password_hash( 'sha512', 65534 | random( seed=inventory_hostname ) | string ) }}"
        
    - debug:
        msg: "{{ 'password' | password_hash( 'sha512', 'salt' ) }}"
        
    - debug:
        msg: "{{ 'password' | password_hash( 'sha512', 'salt-' ) }}"
        
    - debug:
        msg: "{{ 'password' | password_hash( 'sha512', 'salt_' ) }}"
```

##### ACTUAL RESULTS
```
[WARNING]: Unable to parse /home/.../ansible/inventory as an inventory source
[WARNING]: No inventory was parsed, only implicit localhost is available
[WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match 'all'

PLAY [localhost] *******************************************************************************************************************************************

TASK [debug] ***********************************************************************************************************************************************
ok: [localhost] => {
    "msg": "$6$43927$59/6eFzcpI0IigUdbYePA2OeIEwIkyqe9VJzYswDQhl6cD7I4SoZehr004rG.k4xB8/C5F7A4k9dU5LC1RdGn."
}

TASK [debug] ***********************************************************************************************************************************************
ok: [localhost] => {
    "msg": "$6$salt$IxDD3jeSOb5eB1CX5LBsqZFVkJdido3OUILO5Ifz5iwMuTS4XMS130MTSuDDl3aCI6WouIL9AjRbLCelDCy.g."
}

TASK [debug] ***********************************************************************************************************************************************
ok: [localhost] => {
    "msg": "*0"
}

TASK [debug] ***********************************************************************************************************************************************
ok: [localhost] => {
    "msg": "*0"
}

PLAY RECAP *************************************************************************************************************************************************
localhost                  : ok=4    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0
```

##### EXPECTED RESULTS
Not "*0" for the password hashed.

def __init__(self):
        self.orig = encrypt.PASSLIB_AVAILABLE
    def __enter__(self):
        encrypt.PASSLIB_AVAILABLE = False
        return self
    def __exit__(self, exception_type, exception_value, traceback):
        encrypt.PASSLIB_AVAILABLE = self.orig
def assert_hash(expected, secret, algorithm, **settings):
    if encrypt.PASSLIB_AVAILABLE:
        assert encrypt.passlib_or_crypt(secret, algorithm, **settings) == expected
        assert encrypt.PasslibHash(algorithm).hash(secret, **settings) == expected
    else:
        assert encrypt.passlib_or_crypt(secret, algorithm, **settings) == expected
        with pytest.raises(AnsibleError) as excinfo:
            encrypt.PasslibHash(algorithm).hash(secret, **settings)
        assert excinfo.value.args[0] == "passlib must be installed to hash with '%s'" % algorithm
@pytest.mark.skipif(sys.platform.startswith('darwin'), reason='macOS requires passlib')
def test_encrypt_with_rounds_no_passlib():
    with passlib_off():
        assert_hash("$5$12345678$uAZsE3BenI2G.nA8DpTl.9Dc8JiqacI53pEqRr5ppT7",
                    secret="123", algorithm="sha256_crypt", salt="12345678", rounds=5000)
        assert_hash("$5$rounds=10000$12345678$JBinliYMFEcBeAXKZnLjenhgEhTmJBvZn3aR8l70Oy/",
                    secret="123", algorithm="sha256_crypt", salt="12345678", rounds=10000)
        assert_hash("$6$12345678$LcV9LQiaPekQxZ.OfkMADjFdSO2k9zfbDQrHPVcYjSLqSdjLYpsgqviYvTEP/R41yPmhH3CCeEDqVhW1VHr3L.",
                    secret="123", algorithm="sha512_crypt", salt="12345678", rounds=5000)
@pytest.mark.skipif(not encrypt.PASSLIB_AVAILABLE, reason='passlib must be installed to run this test')
def test_encrypt_with_rounds():