When running the user-manager KCM in an unprivileged environment/as unprivileged user, user-manager still allows to change attributes and doesn't report any issues when clicking "Apply".

The CLI output clearly shows the issues:
log_user_manager unknown: 0
log_user_manager unknown: 132
log_user_manager unknown: 1000
log_user_manager unknown: Saving on Index:  1
log_user_manager unknown: "org.freedesktop.Accounts.Error.PermissionDenied"
log_user_manager unknown: "Authentication is required"
log_user_manager unknown: "org.freedesktop.Accounts.Error.PermissionDenied"
log_user_manager unknown: "Authentication is required"
log_user_manager unknown: "org.freedesktop.Accounts.Error.PermissionDenied"
log_user_manager unknown: "Authentication is required"
log_user_manager unknown: "org.freedesktop.Accounts.Error.PermissionDenied"
log_user_manager unknown: "Authentication is required"
log_user_manager unknown: "org.freedesktop.Accounts.Error.PermissionDenied"
log_user_manager unknown: "Authentication is required"
log_user_manager unknown: Failed Roles:  (AccountModel::Username, AccountModel::RealName, AccountModel::Email, AccountModel::Administrator, AccountModel::AutomaticLogin)


Those cases should be handled. Either there's a proper way to determine initially whether the permissions are sufficient to disable relevant UI operations or at least when applying the changes (unsucessfully) a message should be shown.

Running:
- all KF5/Plasma 5 components from git and up-to-date
- Qt 5.4.1
- AccountsService 0.6.40
- D-Bus 1.8.16