Calf (sidechain) gate zero input signal issue

[pedro042]

I started using sidechain gate in Ardour. The gate itself is on Bus 2 and sidechain receives signal from send on Bus 1. The gate works as expected but there is one exception - if the sidechain is muted. If there is some very silent noise for example at -150dBFS, the gate is closed because the input signal doesn't reach threshold level. It's OK. But if the sidechain input is muted (-inf dBFS), the gate is open and it's wrong. The simple gate (without sidechain) behave similar to sidechain gate, but if the gate is open when no signal on the input, it's not serious issue. Opened sidechain gate when zero signal is on the input is a problem. Screenshots attached - the first one is well working gate, because sidechain input signal is about -13 dBFS and threshold is set to -12 dBFS and the gate is closed. On the second screenshot the signal on Bus1 is muted (include pre-fader sends) and the gate is open (zero gain reduction). I think it's definitely a bug. The third attached file is Ardour session (it's very recent version of Ardour). Calf plugins compiled from source - very recent version too. Can someone, please, check this issue and fix it? Thanks a lot in advance. gate-ardour-session.tar.gz