/* Helper function to convert from a null_terminated_array_t<wchar_t> to a null_terminated_array_t<char_t> */
null_terminated_array_t<char> convert_wide_array_to_narrow(const null_terminated_array_t<wchar_t> &wide_arr) {
    const wchar_t *const *arr = wide_arr.get();
    if (! arr)
        return null_terminated_array_t<char>();
        
    std::vector<std::string> list;
    for (size_t i=0; arr[i]; i++) {
        list.push_back(wcs2string(arr[i]));
    }
    return null_terminated_array_t<char>(list);
}

static void update_export_array_if_necessary(bool recalc)
{
    ASSERT_IS_MAIN_THREAD();
    if (recalc && ! get_proc_had_barrier())
    {
        set_proc_had_barrier(true);
        env_universal_barrier();
    }

    if (has_changed_exported)
    {
        std::map<wcstring, wcstring> vals;
        size_t i;

        debug(4, L"env_export_arr() recalc");

        get_exported(top, vals);

        wcstring_list_t uni;
        env_universal_get_names2(uni, 1, 0);
        for (i=0; i<uni.size(); i++)
        {
            const wcstring &key = uni.at(i);
            const wchar_t *val = env_universal_get(key.c_str());

            if (wcscmp(val, ENV_NULL))
            {
                // Note that std::map::insert does NOT overwrite a value already in the map,
                // which we depend on here
                vals.insert(std::pair<wcstring, wcstring>(key, val));
            }
        }

        std::vector<std::string> local_export_buffer;
        export_func(vals, local_export_buffer);
        export_array.set(local_export_buffer);
        has_changed_exported=false;
    }

}