Request body: do not create temp file if there's nothing to write. Do this only when the entire request body is empty and r->request_body_in_file_only is set. The issue manifested itself with missing warning "a client request body is buffered to a temporary file" when the entire rb->buf is full and all buffers are delayed by a filter.

# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


cat << END >> $NGX_AUTO_CONFIG_H

#ifndef $have
#define $have  0
#endif

END