regression in 1.6.13 - wrong http status in logs and stats (no replies)

Hi,

I would like to report a regression in HAProxy 1.6.13 after upgrading from
1.6.9 in production :(

Reproduce with config:

---
global
log 127.0.0.1 local0
log 127.0.0.1 local1 notice
maxconn 4096
chroot /usr/share/haproxy
uid 99
gid 99
daemon

defaults
log global
mode http
option httplog
option dontlognull
option redispatch
stats enable
stats refresh 5s
timeout connect 5s
timeout client 30s
timeout server 30s
balance roundrobin
option forwardfor

listen Statistics
bind 192.168.122.202:7777
mode http
stats refresh 5s
stats uri /

frontend http-in
bind 192.168.122.202:9000

acl is_root_path path /
redirect location /my_custom_page if is_root_path

backend nomatch
redirect location http://www.google.com
---

Send a request with curl -v 192.168.122.202:9000/ - response is OK and has
status code 302 but logs and statistics have 503 instead:

192.168.122.202:37880 [12/Jul/2017:15:54:49.573] http-in http-in/<NOSRV>
0/-1/-1/-1/2 503 305 - - LR-- 0/0/0/0/0 0/0 "GET / HTTP/1.1"

git bisect shows this commit to be the culprit:

commit b12d699543adb84fa543297d12b64fce7ec94803
Author: Christopher Faulet <cfaulet@haproxy.com>
Date: Tue Mar 28 11:51:33 2017 +0200

BUG/MINOR: http: Fix conditions to clean up a txn and to handle the
next request

I also tested 1.7.8 and 1.8-dev2 - they are OK. So it seems it is a
backport issue.

Regards,
Michal