Unable to rename recordings over HTSP
XBMC has a "Rename recording" feature which currently does not work. There's a bug in XBMC that makes it look like nothing happened when you renamed something, but the command is actually sent to the backend. However, tvheadend discards any updates to existing recordings (e.g. not timers). I believe this is due to https://github.com/tvheadend/tvheadend/blob/master/src/dvr/dvr_db.c#L736. I suggest some properties such as title can be updated regardless of recording state (it makes no sense to change the start/stop time of a recording that is already completed).