unable to log in with Shibboleth plugin 1.10.x
not all required globals are set correctly to login with Shibboleth login procedure
main/auth/Shibboleth/lib/Shibboleth_session_class-php / method login($uid) line 69 :
$this->logout();// logout clears user's session data and does platform logout with online_logout
session is restored by further procedure, but some required parameters are not set.
unselective fix can be reached with conditional logout() execution :
if( $this->is_logged_in() ) $this->logout();
but this can affect on logging done by onlide_logout() from inc/lib/online.inc.php so i rather let Laurent to look at this