Set "include_children" to false for "product_cat" taxonomy queries

relevanssi-include-children.php

<?php

// Add this to theme functions.php

add_filter('relevanssi_modify_wp_query', 'rlv_modify_query');
function rlv_modify_query($query) {
	for ($i = 0; $i < count($query->tax_query->queries); $i++) {
		if (isset($query->tax_query->queries[$i])) {
			$row = $query->tax_query->queries[$i];
			if (isset($row['taxonomy']) && $row['taxonomy'] == "product_cat") {
				$row['include_children'] = false;
				$query->tax_query->queries[$i] = $row;
			}
		}
	}
	return $query;
}