I know that since 12.04, we need to add a policykit rule to enable hibernation (see question How to enable hibernation? and the Official Documentation).

I can successfully bring my laptop into hibernation mode with sudo pm-hibernate or sudo s2disk, so the rule is in place and works, but the hibernation entry is still missing in the menu.

I can tell from looking through the source of the indicator-session package (but not understanding the whole code) that there is still a hibernation menu entry in the code and it should be displayed when the system is capable of hibernating. Please calm down if you're enraged by this. This is very unlikely to be a conspiracy, but rather a bug/regression on a deeper level, which can happen when you move code around or replace it.

Question: What needs to be done in 13.10 to properly tell indicator-session that the system can hibernate?

Possible duplicate: Hibernation still not available - No activity, because saucy was in development at that time, so out of scope for AskUbuntu.

Related bug report: https://bugs.launchpad.net/ubuntu/+source/indicator-session/+bug/1232814