[core] reduce trace on Upgrade backend connection
reduce trace on Upgrade'd backend connection when ECONNRESET received,
which, for example, apparently might occur if a backend calls close()
on socket without first calling shutdown(fd, SHUT_WR) -- seen on Linux
kernel 5.16.15 where lighttpd received ECONNRESET when trying to read()
(instead of receiving EOF).
@@ -2412,7 +2412,8 @@ static handler_t gw_recv_response_error(gw_handler_ctx * const hctx, request_st
"socket: %s for %s?%.*s, closing connection",
(long long)hctx->wb.bytes_out, proc->connection_name->ptr,
r->uri.path.ptr, BUFFER_INTLEN_PTR(&r->uri.query));
- } else if (!light_btst(r->resp_htags, HTTP_HEADER_UPGRADE)) {
+ } else if (!light_btst(r->resp_htags, HTTP_HEADER_UPGRADE)
+ && !r->h2_connect_ext) {
log_error(r->conf.errh, __FILE__, __LINE__,
"response already sent out, but backend returned error on "
"socket: %s for %s?%.*s, terminating connection",
