HTML Validation fails because of ampersands in RSS link

Question

I use Wordpress' own rss.php to pull in the last 10 items from an external RSS feed. Wordpress automatically adds campaign info to the link like this:

http://domainname.com/postname?utm_source=rss&utm_medium=rss&utm_campaign=postname

Because of the ampersands, the page doesn't validate. Was wondering if I can add anything to the code below to solve it.

---

<!-- if Blog Feed exists-->
<?php $blogfeed = get_post_meta($post->ID, 'blog_feed', true);
    if($blogfeed) : ?>

<div id="slideshow">
<ul>                
    <?php
        include_once(ABSPATH.WPINC.'/rss.php'); // path to include script
        $feed = fetch_rss($blogfeed); // specify feed url
        $items = array_slice($feed->items, 0, 10); // specify first and last item
        ?>

        <?php if (!empty($items)) : ?>
            <?php foreach ($items as $item) : ?>
            <li class="feed-item">
                <h4><a href="<?php echo $item['link']; ?>" target="_blank"><?php echo $item['title']; ?></a></h4>
                <p><?php echo $item['atom_content']; ?></p>
            </li>
        <?php endforeach; ?>

        <?php endif; ?>
</ul>
</div><!-- / #slideshow -->

<?php else : ?>

<?php endif; ?>

Answer 1

You can escape the HTML, so instead of echo $item['link']; you would write:

echo esc_html($item['link']); // This is a WP function
//or 
echo htmlspecialchars($item['link']); //PHP equivalent 

Also important to note your code is depreciated, fetch_rss has been replaced by fetch_feed.

http://codex.wordpress.org/Function_Reference/fetch_feed

ps. You can also use esc_attr which is identical to esc_html in this case.