Created attachment 4531
Slimlock  is a new screen locker gaining in popularity among Arch and Gentoo XFCE users; it has been in AUR, and was just added to Gentoo Portage tree a few days ago.
To fully integrate with XFCE (e.g., locking on sleep through the power manager), slimlock must be suppored by xflock4 in xfce4-session. I am attaching a patch against 4.10.0 to accomplish this. Slimlock is invoked in the same manner as slock.
Will this patch be added? It's been two years since the bug report was opened!
Many users use slimlock and this will help them a lot.
See also bug #11324.
This bug is obsolete as any distribution can set their default locker easily by setting the /general/LockCommand property in the xfce4-session channel of xfconf (it's integrated in xflock4).
Users who switch to a different lockscreen can consequently also easily fix this. It's arguably not a very discoverable feature, but changing the default lockscreen of a distribution is also not a very every-day "normal" operation imo.
The main reason - from my point of view - xflock4 was still extended by distros with patches was because they had a default locker that was not in the list.