[Prestashop - remove default lang from url] #prestashop

sample.php

class Link extends LinkCore
{
    protected function getLangLink($id_lang = null, Context $context = null, $id_shop = null)
    {
        $parent_result = parent::getLangLink($id_lang, $context, $id_shop);

        if ($parent_result) {
            if ($id_lang == Configuration::get('PS_LANG_DEFAULT')) {
                return '';
            } else {
                return $parent_result;
            }
        }
    }
}

/*---------------*/
class Tools extends ToolsCore
{
    public static function setCookieLanguage($cookie = null)
    {
        parent::setCookieLanguage($cookie);

        if (!$cookie) {
            $cookie = Context::getContext()->cookie;
        }

        if(!Tools::getValue('isolang') && !Tools::getValue('id_lang') && !Tools::isSubmit('id_category_layered')) {
            $cookie->id_lang = Configuration::get('PS_LANG_DEFAULT');
            Context::getContext()->language = new Language($cookie->id_lang);
        }

        /* If language file not present, you must use default language file */
        if (!$cookie->id_lang || !Validate::isUnsignedId($cookie->id_lang)) {
            $cookie->id_lang = (int)Configuration::get('PS_LANG_DEFAULT');
            Context::getContext()->language = new Language($cookie->id_lang);
        }

        $iso = Language::getIsoById((int)$cookie->id_lang);
        @include_once(_PS_THEME_DIR_.'lang/'.$iso.'.php');

        return $iso;
    }
}