Limit the length of user names?

Then this won’t happen

longName.GIF

Related:

Unfortunately that issue got sidetracked onto the use of email addresses as user names. Although that will tend to cause the problem simply because email addresses are usually long, the problem is certainly not restricted to email addresses. So, IMHO, the disallowance of email addresses as usernames should not have been considered a valid reason to close that issue as fixed.