SAML `auto_link_ldap_user` trying to find user by uid instead of DN
Zendesk issue: https://gitlab.zendesk.com/agent/tickets/22546
If auto_link_ldap_user
is enabled, SAML authentication should try to find LDAP users and create their user and identity. SAML generally uses the user's DN as the 'uid' from omniauth. We correctly look for existing LDAP identities by DN, but we incorrectly look up LDAP users by uid
if the identity doesn't exist. The bug exists in OAuth::User
in ldap_person
method.
cc/ @patricio