Fixes the `product_brand_thumbnails` shortcode from the WooCommerce Brands when `show_empty="false"` is used. Prevents double filtering of empty brands in WooCommerce 9.9.4+ by replacing the shortcode handler with a patched version.

fix-product-brand-thumbnails-shortcode.php

/**
 * Fix for WooCommerce product_brand_thumbnails shortcode
 * 
 * This snippet fixes an issue in the WooCommerce Brands where using
 * show_empty="false" parameter breaks the shortcode in WooCommerce versions newer than 9.9.3.
 * 
 * The issue occurs because of double filtering of empty brands in the output_product_brand_thumbnails function.
 * 
 */

if (!function_exists('fix_wc_brands_thumbnails_shortcode')) {
    /**
     * Fix the product_brand_thumbnails shortcode by replacing the original function
     * with a fixed version that doesn't double-filter empty brands.
     */
    function fix_wc_brands_shortcode() {
        // Only run if WC_Brands class exists
        if (!class_exists('WC_Brands')) {
            return;
        }
        
        // Remove the original shortcode
        remove_shortcode('product_brand_thumbnails');
        
        // Add our fixed version of the shortcode
        add_shortcode('product_brand_thumbnails', 'fixed_output_product_brand_thumbnails');
    }
    add_action('init', 'fix_wc_brands_shortcode', 20);
    
    /**
     * Fixed version of the output_product_brand_thumbnails function
     * 
     * This version doesn't apply the remove_terms_with_empty_products filter when hide_empty is already true,
     * which prevents double filtering of empty brands.
     * 
     * @param array $atts Shortcode attributes
     * @return string HTML output
     */
    function fixed_output_product_brand_thumbnails($atts) {
        $args = shortcode_atts(
            array(
                'show_empty'    => true,
                'columns'       => 4,
                'hide_empty'    => 0,
                'orderby'       => 'name',
                'exclude'       => '',
                'number'        => '',
                'fluid_columns' => false,
            ),
            $atts
        );

        $exclude = array_map('intval', explode(',', $args['exclude']));
        $order   = 'name' === $args['orderby'] ? 'asc' : 'desc';

        // Convert show_empty to hide_empty
        if ('true' === $args['show_empty']) {
            $hide_empty = false;
        } else {
            $hide_empty = true;
        }

        // Get terms with hide_empty parameter
        $brands = get_terms(
            'product_brand',
            array(
                'hide_empty' => $hide_empty,
                'orderby'    => $args['orderby'],
                'exclude'    => $exclude,
                'number'     => $args['number'],
                'order'      => $order,
            )
        );

        if (!$brands) {
            return;
        }

        // No need for additional filtering - the hide_empty parameter in get_terms already did this
        // This is the key fix - removing the double filtering

        ob_start();

        wc_get_template(
            'widgets/brand-thumbnails.php',
            array(
                'brands'        => $brands,
                'columns'       => is_numeric($args['columns']) ? intval($args['columns']) : 4,
                'fluid_columns' => wp_validate_boolean($args['fluid_columns']),
            ),
            'woocommerce',
            WC()->plugin_path() . '/templates/brands/'
        );

        return ob_get_clean();
    }
}