Comment 7 for bug 1794053

xenial
======

With 1.2.27
-----------

root@glowing-mastodon:~# python3 a.py
total 0
[...]
lrwx------ 1 root root 64 Oct 18 12:15 3 -> /var/lib/dpkg/lock
l-wx------ 1 root root 64 Oct 18 12:15 6 -> pipe:[27632799]
Reading package lists... Done
Building dependency tree
Reading state information... Done
total 0
[...]
l-wx------ 1 root root 64 Oct 18 12:15 6 -> pipe:[27632799]
Traceback (most recent call last):
  File "a.py", line 13, in <module>
    apt_pkg.pkgsystem_unlock()
SystemError: E:Not locked

=> broken as expected

With 1.2.29
-----------

root@glowing-mastodon:~# python3 a.py
total 0
[...]
lrwx------ 1 root root 64 Oct 18 12:17 3 -> /var/lib/dpkg/lock-frontend
lrwx------ 1 root root 64 Oct 18 12:17 4 -> /var/lib/dpkg/lock
l-wx------ 1 root root 64 Oct 18 12:17 6 -> pipe:[27632799]
Reading package lists... Done
Building dependency tree
Reading state information... Done
total 0
[...]
lrwx------ 1 root root 64 Oct 18 12:17 3 -> /var/lib/dpkg/lock-frontend
lrwx------ 1 root root 64 Oct 18 12:17 4 -> /var/lib/dpkg/lock
l-wx------ 1 root root 64 Oct 18 12:17 6 -> pipe:[27632799]
root@glowing-mastodon:~#

=> lock is still held at second ls, and releasing it worked fine.