Nginx clearing all headers

gistfile1.c

    /* clear all the headers */
    ngx_memzero(&r->headers_in, sizeof (ngx_http_headers_in));

    /* reinitialize headers */
    r->headers_in.content_length_n = -1;
    r->headers_in.keep_alive_n = -1;

    /* TODO (mtourne): init to the size of the table passed in param */
    if (ngx_list_init(&r->headers_in.headers, r->pool, 20,
                      sizeof(ngx_table_elt_t))
        != NGX_OK) {

        return luaL_error(L, "out of memory");
    }

    if (ngx_array_init(&r->headers_in.cookies, r->pool, 2,
                       sizeof(ngx_table_elt_t *))
        != NGX_OK) {

        return luaL_error(L, "out of memory");
    }

#if 0
    part = &r->headers_in.headers.part;
    while (part != NULL) {
        part->nelts = 0;
        part = part->next;
    }

    /* clear cookies */
    r->headers_in.cookies.nelts = 0;

    /* clear all the "fixed" headers */
    start = &r->headers_in.host;
    stop = (ngx_table_elt_t **) &r->headers_in.user;

    for (p = start; p < stop; p++) {

        h = *p;

        if (h == NULL) {
            continue;
        }

        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                       "[lua-cf] clearing builtin header: \"%V\"",
                       &h->key);

        h->hash = 0;
        h->value = null_string;
    }

    r->headers_in.server = null_string;
    r->headers_in.content_length_n = -1;
    r->headers_in.chunked = 0;

#endif