I cant get XCreateIC to work properly

[proxin187]

Im currently writting my own terminal emulator for fun and im currently in the work of implementing utf-8 input support, for this i need to use Xutf8LookupString(), this function requires that i use XCreateIC to create a input context.

The problem is that XCreateIC returns a null pointer when i pass the same arguments as in x.c - st - simple terminal (except XNDestroyCallback which shouldnt matter).

this happends either when "A required argument was not set", "A read-only argument was set", "The argument name is not recognized" or "The input method encountered an input method implementation-dependent error" but i cant seem find any of these problems in my code.

I found a similar issue here but it doesnt seem to fix any of my issues.

Example code bellow:

    pub fn open() -> Result<Display, Box<dyn std::error::Error>> {
        let dpy = unsafe { xlib::XOpenDisplay(ptr::null()) };

        if dpy.is_null() {
            Err("failed to open display".into())
        } else {
            unsafe {
                let bg = Color::new(0, 0, 0).encode();
                let window = xlib::XCreateSimpleWindow(
                    dpy,
                    xlib::XDefaultRootWindow(dpy),
                    0,
                    0,
                    500,
                    500,
                    0,
                    bg,
                    bg
                );

                let screen = xlib::XDefaultScreen(dpy);

                let mut values: xlib::XGCValues = mem::zeroed();

                let gc = xlib::XCreateGC(dpy, window, 0, &mut values);
                let back_buffer = xlib::XCreatePixmap(dpy, window, 945, 1020, 24);
                let draw = xft::XftDrawCreate(dpy, back_buffer, xlib::XDefaultVisual(dpy, screen), xlib::XDefaultColormap(dpy, screen));

                xlib::XSetLocaleModifiers("\0".as_ptr() as *const i8);

                let xim = xlib::XOpenIM(dpy, 0 as xlib::XrmDatabase, 0 as *mut ffi::c_char, 0 as *mut ffi::c_char);

                println!("xim: {:?}", xim);

                let xn_input_style = ffi::CString::new(xlib::XNInputStyle)?;
                let xn_client_window = ffi::CString::new(xlib::XNClientWindow)?;

                let xic = xlib::XCreateIC(
                    xim,
                    xn_input_style.as_ptr(), xlib::XIMPreeditNone | xlib::XIMStatusNothing,
                    xn_client_window.as_ptr(), window as ffi::c_ulong,
                    ptr::null_mut::<ffi::c_void>()
                );

                println!("xic: {:?}", xic);

                xlib::XSync(dpy, xlib::False);

                Ok(Display {
                    dpy,
                    gc,
                    xim,
                    xic,
                    draw,
                    back_buffer,
                    window,
                    screen,
                })
            }
        }
    }