Fix input for SDL_VIDEODRIVER=wayland

zig/sdl/hello_sdl.zig

    const keyboardState = c.SDL_GetKeyboardState(null);
    c.SDL_StartTextInput();
    var quit = false;
    while (!quit) {
        var event: c.SDL_Event = undefined;
        while (c.SDL_PollEvent(&event) != 0) {
            const ctrlPressed = (keyboardState[c.SDL_SCANCODE_LCTRL] != 0);
            switch (event.@"type") {
                c.SDL_QUIT => {
                    quit = true;
                    }
                },
                c.SDL_KEYDOWN => {
                    switch (event.key.keysym.sym) {
                        c.SDLK_ESCAPE => {
                            quit = true;
                        },
                        c.SDLK_BACKSPACE => {
                            pos = if (pos == 0) max_chars - 1 else (pos - 1) % (max_chars - 1);
                            msg[pos] = '_';
                        },
                        c.SDLK_RETURN => {
                            result = runCommand(&msg, gpa);
                            var i: usize = 0;
                            while (i < max_chars) : (i += 1) {
                                msg[i] = ' ';
                            }
                            msg[max_chars] = 0;
                            pos = 0;
                        },
                        else => {},
                    }
                    // ctrl + key combinations
                    if (keyboardState[c.SDL_SCANCODE_LCTRL] != 0) {
                    if (ctrlPressed) {
                        switch (event.key.keysym.sym) {
                            c.SDLK_a => {
                                pos = 0;
                            },
                            else => {},
                        }
                    } else {
                        switch (event.key.keysym.sym) {
                            c.SDLK_ESCAPE => {
                                quit = true;
                            },
                            c.SDLK_BACKSPACE => {
                                pos = if (pos == 0) max_chars - 1 else (pos - 1) % (max_chars - 1);
                                msg[pos] = '_';
                            },
                            c.SDLK_RETURN => {
                                result = runCommand(&msg, gpa);
                                var i: usize = 0;
                                while (i < max_chars) : (i += 1) {
                                    msg[i] = ' ';
                                }
                                msg[max_chars] = 0;
                                pos = 0;
                            },
                            else => {},
                        }
                    }
                },
                c.SDL_TEXTINPUT => {
                    if (event.text.text.len > 0) {
                    if (!ctrlPressed and event.text.text.len > 0) {
                        c.SDL_Log("input: '%s' at %d", event.text.text, pos);
                        msg[pos] = event.text.text[0];
                        pos = (pos + 1) % (max_chars - 1);