I would do something simplier using ID :
<?php $current_id = $post->ID; ?>
<?php query_posts('orderby=name'); ?>
<?php while (have_posts()) : the_post(); ?>
<li>
<?php $current_class = ( $current_id == $post->ID ) ? 'class="current"' : ''; ?>
<a <?php if ( $current_class ) echo $current_class; ?> href="https://wordpress.stackexchange.com/questions/88833/<?php the_permalink() ?>">
<?php the_title() ?>
</a>
</li>
<?php endwhile; ?>
<?php wp_reset_query(); ?>
I didn’t had time to verify code, hope this helps.