(for me, I am using hangul(Korean))
Environment : Fedora 31, using fcitx+fcitx-hangul as an input method
try to change language (to hangul)
=> It doesn't change, No message on terminal.
(If trying to change with hangul key on keyboard, getting The key you just pressed is not recognized by SDL. To help get this fixed, please report this to the SDL forums/mailing list <https://discourse.libsdl.org/> X11 KeyCode 130 (122), X11 KeySym 0xFF31 (Hangul).
It looks like @JGRennison added IME support to the SDL 2 driver (which wasn't possible in SDL 1). It would be great to get this into OpenTTD-master. I don't have any experience with IME or fcitx. It looks like his changes to the SDL driver may also fix #7816.
#7816 is really the same as #7783, which does not require anything complicated to fix.
The fcitx IME changes I made were notably more non-trivial than I expected when I started, and may not necessarily be the approach you want to take with trunk.
The IME support already in SDL2 is more limited in various ways but is not that complicated to use.