Bug#845326: debian-installer: When using auto=true priority=critical url=hostname it tries to download from jessie, not stretch

[Bart-Jan Vrielink <bartjan@vrielink.net>]

Title: debian-installer: When using auto=true priority=critical url=hostname it tries to download from jessie, not stretch

Package: debian-installer
Version: 20161031
Severity: normal

Dear Maintainer,

When trying to install a debian stretch VM using virt-install and a preseed
URL, I found out to my surprise that it downloads /d-i/jessie/./preseed.cfg
instead of /d-i/stretch/./preseed.cfg

Actual command line used:
virt-install --connect qemu:///system --name=stretch --file-size=2 \
--vcpus=1,maxvcpus=4 --memory=512,maxmemory=4096 --os-type=linux \
--os-variant=generic --graphics none --console pty,target_type=serial \
--extra-args 'console=ttyS0,115200n8 serial auto=true priority=critical url="" \
--location http://ftp.nl.debian.org/debian/dists/stretch/main/installer-amd64/

I would expect that by using the stretch installer, it would also fetch a
preseed from the stretch directory, and not from jessie.

-- System Information:
Debian Release: 8.6
  APT prefers stable
  APT policy: (700, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.16.0-4-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_GB.utf8, LC_CTYPE=en_GB.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)