Redmine

• redmine:latest
• redmine:4.1.3
• redmine:4.0.9

from DockerHub and issue occurs there.

That's strange: i've tested ALL versions of redmine and no one can create users with Cyrillic logins.
But how we are using redmine with Cyrillic login users for years?!

Restored old backup of version 4.0.1 and dont have this issue.
But on fresh 4.0.1 (via bitnami or docker image) I have this issue.

I totally dont understand whats going on.

unfortunatelly Cyrillic logins aren't allowed for more then 13 years

# Login must contain letters, numbers, underscores only
validates_format_of :login, :with => /\A[a-z0-9_\-@\.]*\z/i

and LDAP logins also triggers validation
https://github.com/redmine/redmine/blob/master/app/models/user.rb#L253

so the only way to bypass the validation should be altering the source code, 3rd party plugins, or of course direct import to the database. Nothing official.

https://www.redmine.org/issues/6166 is basically the same problem with german characters, but no one seems to be interested.

maybe UTF-8 (and Ruby support) wasn't so common 13 years ago.

I don't see any valid reason why not to make it less strict and allow such characters, but I'm not a Redmine's maintainer...