Dup of 781 i think

I believe it isn't a duplicate, but related. 781 was fixed, in that if you get an invite from someone you get the accept/decline buttons. This bug is really a bug to that fix, in that the fix only works if you aren't viewing the calendar of the person who invited you (or maybe other invitees). Basically, I think the logic for an invite is to search for that event in all calendars, if found, don't give accept/decline buttons. The problem is that really you need to narrow that search to that event where you can accept/decline an invitation. And ideally you would always get accept/decline buttons (like in the web interface) where it would show the current status and you could update it if you wanted.

Same here and for us this is far more than a minor bug.
It might even prevent us from getting SOGo accepted into production use!
We make heavy use of subscribing to other users calendars. Usually they are not all visible but subscribed so you can quickly check who's doing what.
If a colleague invites you to a meeting whose calendar you have subscribed to but currently set to invisible you can't see the appointment nor accept it to your own calendar.
VERY annoying and confusing. If there is no quick solution, please keep the message as it is but show the buttons none the less as a workaround.

Is there any way I could quickly change this behavior myself by editing some .js file of the lightning addon?

Yes it isn't dup of 781, we are all our calendars subscribed from everyone, then i can't ever see accept/decline buttons

Fixed with http://mtn.inverse.ca/revision/diff/62428aecc62d07f592f24bea5c7c95be9ebbd33e/with/0783a20aa83c4249f0483151882ca4d7ff6cf4e7

Try out the 1.0b2+105pre1 version from http://inverse.ca/downloads/extensions/nightly/