Description of problem:

Sometime between redhat-config-users and now, this bit of code

        if i == "_" or i == "-":
            #specifically allow "_" and "-"
            return 1
        
was added to isUsernameOk() from asciiCheck.py. This is in a loop
which checks each character for okayness. The problem: if a - or _
occurs anywhere in the given username, the entire rest of the name is
passed without checking. So, one can give a username like "foo- b a
r", resulting in a runtime error (I assume from libuser) and a hung GUI.

Version-Release number of selected component (if applicable):

Not sure when this started, but it's in the test2 package, and it's in
1.2.11-4, which is the latest in the development tree.

How reproducible:

always

Steps to Reproduce:
1. hit the Add User button
2. enter "- blah" for a username
3. enter some password
4. hit OK
5. Boom!
  
Actual results:

Dialog goes gray and freezes; RuntimeError on console.

Expected results:

A pretty "don't do that!" warning message.

Additional info:

An alternate approach... instead of the whole new check, modify the
"if i in string.punctuation" one and either reduce what
string.punctuation is or add a second "oh except" check.