CORE PANEL

EDIT :: mod_upgrade.php

<?php
define( 'YOURLS_ADMIN', true );
define( 'YOURLS_UPGRADING', true );
require_once( dirname( __DIR__ ).'/includes/load-yourls.php' );
if(empty($_POST['softlogin'])){
	yourls_maybe_require_auth();
}

yourls_html_head( 'upgrade', yourls__( 'Upgrade YOURLS' ) );
yourls_html_logo();
yourls_html_menu();
?>
        <h2><?php yourls_e( 'Upgrade YOURLS' ); ?></h2>
<?php

// Check if upgrade is needed
if ( !yourls_upgrade_is_needed() ) {
    echo '<p>' . yourls_s( 'Upgrade not required. Go <a href="%s">back to play</a>!', yourls_admin_url('index.php') ) . '</p>';

} else {
    /*
    step 1: create new tables and populate them, update old tables structure,
    step 2: convert each row of outdated tables if needed
    step 3: - if applicable finish updating outdated tables (indexes etc)
            - update version & db_version in options, this is all done!
    */

// From what are we upgrading?
    if ( isset( $_GET['oldver'] ) && isset( $_GET['oldsql'] ) ) {
        $oldver = yourls_sanitize_version($_GET['oldver']);
        $oldsql = intval($_GET['oldsql']);
    } else {
        list( $oldver, $oldsql ) = yourls_get_current_version_from_sql();
    }

// To what are we upgrading ?
    $newver = YOURLS_VERSION;
    $newsql = YOURLS_DB_VERSION;

// Verbose & ugly details
    yourls_debug_mode(true);

// Let's go
    $step = ( isset( $_GET['step'] ) ? intval( $_GET['step'] ) : 0 );
    switch( $step ) {

default:
        case 0:
            ?>
            <p><?php yourls_e( 'Your current installation needs to be upgraded.' ); ?></p>
            <p><?php yourls_e( 'Please, pretty please, it is recommended that you <strong>backup</strong> your database<br/>(you should do this regularly anyway)' ); ?></p>
            <p><?php yourls_e( "Nothing awful <em>should</em> happen, but this doesn't mean it <em>won't</em> happen, right? ;)" ); ?></p>
            <p><?php yourls_e( "On every step, if <span class='error'>something goes wrong</span>, you'll see a message and hopefully a way to fix." ); ?></p>
            <p><?php yourls_e( 'If everything goes too fast and you cannot read, <span class="success">good for you</span>, let it go :)' ); ?></p>
            <p><?php yourls_e( 'Once you are ready, press "Upgrade" !' ); ?></p>
            <?php
            echo "
            <form action='upgrade.php?' method='get'>
            <input type='hidden' name='step' value='1' />
            <input type='hidden' name='oldver' value='$oldver' />
            <input type='hidden' name='newver' value='$newver' />
            <input type='hidden' name='oldsql' value='$oldsql' />
            <input type='hidden' name='newsql' value='$newsql' />
            <input type='submit' class='primary' value='" . yourls_esc_attr__( 'Upgrade' ) . "' />
            </form>";

break;

case 1:
        case 2:
            $upgrade = yourls_upgrade( $step, $oldver, $newver, $oldsql, $newsql );
            break;

case 3:
            $upgrade = yourls_upgrade( 3, $oldver, $newver, $oldsql, $newsql );
            echo '<p>' . yourls__( 'Your installation is now up to date ! ' ) . '</p>';
            echo '<p>' . yourls_s( 'Go back to <a href="%s">the admin interface</a>', yourls_admin_url('index.php') ) . '</p>';
    }

}

<?php yourls_html_footer(); ?>

CANCEL

// SYSTEM PANEL //

EDIT :: mod_upgrade.php