shift-Fn keys shifted by two in tmux

[Marco]

On Mon, 13 Dec 2021 08:43:01 +0100
Jörg Thümmler <listen at vordruckleitverlag.de> wrote:

> can you check which keycodes are sent by the Shift-Fn-Keys in other
> apps running in tmux? They are correct?

“xev” lists:

  keycode 50 (keysym 0xffe1, Shift_L)
  …
  keycode 71 (keysym 0xffc2, F5)

if I press <shift>-<F5> regardless if launched from within tmux or
not.

> An what happens, if you open another terminal app in tmux and there 
> call mc? Same "keyshifting"?

I'm not sure what you mean by “another terminal app”. Another window
in tmux you mean? Starting a 2nd instance of mc in another window
yields the same result.

I just tried it on the console (no X) and the issue vanishes. This
makes my believe it has nothing to do with mc, rather it's a
misconfiguration of my terminal emulator.

Thanks for the nudge in the right direction.

Marco