SYSTEM NOTICE: Undefined index 0.

ldap_api - ldap_get_field_from_username()

# Free results / unbind
log_event( LOG_LDAP, "Unbinding from LDAP server" );
ldap_free_result( $t_sr );
ldap_unbind( $t_ds );

START OF FIX

If no matches, return null.

if ( is_array( $t_info ) && isset( $t_info['count'] ) && $t_info['count'] === 0 ) {
    log_event( LOG_LDAP, "No matches found." );
    return null;
}

END OF FIX

# If no matches, return null.
if ( count( $t_info ) == 0 ) {
    log_event( LOG_LDAP, "No matches found." );
    return null;
}