static void add_trailer_line(const char * key, const char *val, apr_pool_t *p,

                             apr_bucket_alloc_t *bucket_alloc,

                             apr_bucket_brigade *bb)

{

    apr_bucket *e;

    char *buf;

    buf = apr_pstrcat(p, key, ": ", val, CRLF, NULL);

    ap_xlate_proto_to_ascii(buf, strlen(buf));

    e = apr_bucket_immortal_create(buf, strlen(buf), bucket_alloc);

    APR_BRIGADE_INSERT_TAIL(bb, e);

}

static void forward_declared_trailers(apr_pool_t *p, const request_rec *r,

                                      apr_bucket_alloc_t *bucket_alloc,

                                      apr_bucket_brigade *bb)

{

    const char *declared_trailers = apr_table_get(r->headers_in, "Trailer");

    if (declared_trailers) {

        char *mod_trailers = apr_pstrcat(p, declared_trailers, NULL);

        char *key;

        char *last = NULL;

        while ((key = apr_strtok(mod_trailers, ", ", &last))) {

            const char *value = apr_table_get(r->trailers_in, key);

            if (value) {

                add_trailer_line(key, value, p, bucket_alloc, bb);

            }

            mod_trailers = last;

        }

    }

}

    /** pass tailer header and enforce chunked */

    if (*old_te_val) {

        const char *trailer = apr_table_get(r->headers_in, "Trailer");

        if (trailer) {

            char *buf = apr_pstrcat(p, "Trailer: ", trailer, CRLF, NULL);

            ap_xlate_proto_to_ascii(buf, strlen(buf));

            APR_BRIGADE_INSERT_TAIL(header_brigade,

                                    apr_bucket_pool_create(buf, strlen(buf),

                                                           p, bucket_alloc));

            *rb_method = RB_STREAM_CHUNKED;

        }

    }