This should an issue with using external authentication. When a user logs in it updates their attributes, and I am guessing during this process during the upgrade it is also updating the users signature, modify your code as needed.
You can see from the below how it updates.
Also check here, there is some chat about if you are using auto login it looks like signature is updated with username, youll need to mod the code.
http://www.mediawiki.org/wiki/Extension_talk:LDAP_Authentication/Archive_2#Signature_with_Real_Name
In LdapAuthentication.php
/**
* When a user logs in, update user with information from LDAP.
*
* @param User $user
* @access public
* TODO: fix the setExternalID stuff
*/
function updateUser( &$user ) {
global $wgLDAPRetrievePrefs;
global $wgLDAPUseLDAPGroups;
global $wgLDAPUniqueBlockLogin, $wgLDAPUniqueRenameUser;
$this->printDebug( "Entering updateUser", NONSENSITIVE );
if ($this->authFailed) {
$this->printDebug( "User didn't successfully authenticate, exiting.", NONSENSITIVE );
return;
}
$saveSettings = false;
//If we aren't pulling preferences, we don't want to accidentally
//overwrite anything.
if ( isset( $wgLDAPRetrievePrefs[$_SESSION['wsDomain']] ) && $wgLDAPRetrievePrefs[$_SESSION['wsDomain']] ) {
$this->printDebug( "Setting user preferences.", NONSENSITIVE );
if ( '' != $this->lang ) {
$user->setOption( 'language', $this->lang );
}
if ( '' != $this->nickname ) {
$user->setOption( 'nickname', $this->nickname );
}
if ( '' != $this->realname ) {
$user->setRealName( $this->realname );
}
if ( '' != $this->email ) {
$user->setEmail( $this->email );
}
if ( ( isset( $wgLDAPUniqueBlockLogin[$_SESSION['wsDomain']] ) && $wgLDAPUniqueBlockLogin[$_SESSION['wsDomain']] )
|| ( isset( $wgLDAPUniqueRenameUser[$_SESSION['wsDomain']] ) && $wgLDAPUniqueRenameUser[$_SESSION['wsDomain']] ) ) {
if ( '' != $this->externalid ) {
$user->setExternalID( $this->externalid );
}
}
$saveSettings = true;
}
if ( isset( $wgLDAPUseLDAPGroups[$_SESSION['wsDomain']] ) && $wgLDAPUseLDAPGroups[$_SESSION['wsDomain']] ) {
$this->printDebug( "Setting user groups.", NONSENSITIVE );
$this->setGroups( $user );
$saveSettings = true;
}
if ( $saveSettings ) {
$this->printDebug( "Saving user settings.", NONSENSITIVE );
$user->saveSettings();
}
}