Ubiquity at install must warn when an invalid user name is entered

[marcobra (Marco Braida)]

Binary package hint: ubiquity

At install if the user specify an invalid user name
Ubiquity don't give back to the user any warning or other informative message.

Thank you

[Marcus E (marcus+e)]

The installer does not warn the user when a non-usable user name is entered on the "who are you" screen, nor does it show information about its requirements, instead it just refused to continue by not activiating the "forward" button which makes the text "ready when you are" seem like somewhat of a joke. This is in the 10.10 live desktop installer.

[Colin Watson (cjwatson)]

Marco, thanks for escalating this from the answers tracker, but I had already dealt with it as bug 555896 in response to other questions asked there. Marking as a duplicate.