Go to System/Preferences/User Info Settings, and set Maximum length of username to more than the default 10.
what good will that do?
maximum length should actually prevent you from typing more than 10 characters, it should never truncate what you type, that is the whole point of maximum length. is that how password works too? if i type too many characters does it truncate the password? if so then how would i know what my password is because it has been truncated.
seems maximum length is not being used correctly in this case.