I have a running Kodi/osmc which is working fine with my remote using lirc.
One question, how can I handle switching the source on my TV?
Because when I switch to a different source watching e.g. DVB-T, in background Kodi interprets each remote key which is pressed and does something uncontrolled I cant see.
Not really enough information about your setup to go on there…
It sounds a bit like you have learnt your TV or Set top boxes remote using irrecord to use with lirc and a GPIO receiver - if so, then yes of course Kodi is going to keep responding to the remote even when your TV is on a different input.
This is not a workable configuration. You should either learn a remote that is not used for another device, or perhaps use CEC, where you use your TV remote, but the TV receives the signal and sends it to Kodi over the HDMI cable rather than separately receiving it with an IR receiver.
Oh thanks and you are right.
The problem ist, that my TV doesn’t support CEC and therefore I was thinking/trying a solution by using irrecord/lirc/GPIO receiver and using also the TV remote.
The solution is working well, when using Kodi 
But when switching to a different input on the TV (e.g. using DVB-T) then Kodi keeps responding to the remote.
You are right, I think I have to look for an unused / different remote 
Before I was thinking about some intelligence when switching the source…
This is a case where the intelligence has to be (at least in part) in the user - to realise what will respond to which device.
In one location I have a satrec with its remote, and a TV with its remote (different makers …), and they both respond to the others volume controls, but in the opposite direction.
Derek