Remove 2+ empty lines in WooCommerce Product Descriptions

cleanup-blanks.php

// Removes empty lines in Woo Product Long + Short Descr when 2 or more occur together
// Removes empty spaces at beginning or end of descriptions
// Fires on Post Update (works with Quick Edit)

add_action('save_post_product', 'ni_clean_up_product_content', 10, 3);

function ni_clean_up_product_content($post_ID, $post, $update) {
    // Check if it's an update
    if ($update) {
        // Get the content and short description
        $content = $post->post_content;
        $short_description = get_post_meta($post_ID, '_excerpt', true);

        // Replace lines with only ' ' with an empty string
        $content = preg_replace("/^ \s*$/m", "", $content);
        $short_description = preg_replace("/^ \s*$/m", "", $short_description);

        // Remove multiple empty lines but keep a single empty line
        $content = preg_replace("/(\n\s*){3,}/", "\n\n", $content);
        $short_description = preg_replace("/(\n\s*){3,}/", "\n\n", $short_description);

        // Remove trailing and leading empty lines
        $content = trim($content);
        $short_description = trim($short_description);

        // Update the product content and short description without calling save_post again
        remove_action('save_post_product', 'clean_up_product_content', 10);
        wp_update_post(array('ID' => $post_ID, 'post_content' => $content));
        update_post_meta($post_ID, '_excerpt', $short_description);
        add_action('save_post_product', 'clean_up_product_content', 10, 3);
    }
}