Cannot change username with SSO enabled

[andrei (Andrei Prigorshnev)]

@fefrei

I found it: sso overrides username prevents the name change.

I still consider this situation a bug. Enabling this setting should either hide the Change Username button from the administrator panel and disable the users/.../preferences/username page, or still allow username changes for admins (possibly with a warning).

Turned out it’s already fixed. We hide this pencil when the setting is turned on:

Also, we show this if an admin is trying to change username of some user: