zero size buf in writer in 1.17.2

[Witold Filipczyk]

Hi,
There is error in log:
2019/07/28 09:46:10 [alert] 2471467#2471467: *407 zero size buf in writer t:1 r:1 f:0 00007F482A259000 00007F482A259000-00007F482A259000 0000000000000000 0-0 while sending response to client, client: 127.0.0.1, server: localhost, request: "GET /Skrypty-m.js HTTP/1.1", host: "localhost"

Reproducible at least on two machines.

#!/bin/bash
set -x
VER=1.17.2
rm -rf nginx-$VER
tar zxvf nginx-$VER.tar.gz
cd nginx-$VER

./configure \
--with-cc-opt="-march=native -mtune=native" \
--conf-path=/etc/nginx/nginx.conf \
--error-log-path=/var/log/nginx/error.log \
--pid-path=/var/run/nginx.pid \
--lock-path=/var/lock/nginx.lock \
--http-log-path=/var/log/nginx/access.log \
--http-client-body-temp-path=/var/lib/nginx/body \
--http-proxy-temp-path=/var/lib/nginx/proxy \
--http-fastcgi-temp-path=/var/lib/nginx/fastcgi \
--with-http_stub_status_module \
--without-http_geo_module \
--without-http_memcached_module \
--without-http_scgi_module \
--without-http_autoindex_module \
--without-http_ssi_module \
--without-http_browser_module \
--with-pcre-jit \
--with-http_ssl_module \
--with-http_sub_module \
--with-http_addition_module \
--with-http_auth_request_module \
--with-threads \
--with-http_v2_module \
--with-http_gzip_static_module

nginx.conf:

user            nginx http;
error_log        /var/log/nginx/error.log debug;
pid            /var/run/nginx-standard.pid;

events {
    worker_connections    48;
    use epoll;
}

http {
    include /etc/nginx/mime.types;
    include /etc/nginx/fastcgi_params;

    default_type text/plain;

    gzip  on;
    gzip_http_version 1.1;
    gzip_vary on;
    gzip_comp_level 6;
    gzip_proxied any;
    gzip_min_length 1024;
    gzip_buffers 32 4k;
    gzip_types text/plain text/css application/javascript application/x-javascript text/xml application/xml application/xml+rss text/javascript application/font-sfnt;

    server {
        listen 80;

        server_name    localhost;
        access_log    /var/log/nginx/nginx-standard_access.log main;

        location = /Skrypty-m.js {
            root /var/www;
        }
    }
}

Skrypty-m.js in the attachment.
The error does not occur in 1.17.1 and earlier.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Skrypty-m.js
Type: application/javascript
Size: 14920 bytes
Desc: not available
URL: <http://mailman.nginx.org/pipermail/nginx-devel/attachments/20190728/099c99ac/attachment.js>