id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	uname	nginx_version
1771	the buffer used to send PROXY protocol header to upstream do not reused in stream module	qlees@…		"function ngx_stream_proxy_init_upstream in ngx_stream_proxy_module.c, line840.

the buffer(cl->buf) used to send PROXY protocol header to upstream, while cl->buf->start and cl->buf->end is set to be zero, so the buffer is unable to reuse.
Is this a feature or mistake? 

{{{
    if (u->proxy_protocol) {
        ngx_log_debug0(NGX_LOG_DEBUG_STREAM, c->log, 0,
                       ""stream proxy add PROXY protocol header"");

        cl = ngx_chain_get_free_buf(c->pool, &u->free);
        if (cl == NULL) {
            ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
            return;
        }

        p = ngx_pnalloc(c->pool, NGX_PROXY_PROTOCOL_MAX_HEADER);
        if (p == NULL) {
            ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
            return;
        }

        cl->buf->pos = p;

        p = ngx_proxy_protocol_write(c, p, p + NGX_PROXY_PROTOCOL_MAX_HEADER);
        if (p == NULL) {
            ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
            return;
        }

        cl->buf->last = p;
        cl->buf->temporary = 1;
        cl->buf->flush = 0;
        cl->buf->last_buf = 0;
        cl->buf->tag = (ngx_buf_tag_t) &ngx_stream_proxy_module;

        cl->next = u->upstream_out;
        u->upstream_out = cl;

        u->proxy_protocol = 0;
    }

}}}
"	defect	closed	trivial		nginx-module	1.15.x	invalid				1.15.12