### Godot version

 Latest 4.0.dev (a3a42159e31db27f8ae7c1ecad6a9ed417cb05de)

### System information

Ubuntu 22.04.1 LTS

### Issue description

![image](https://user-images.githubusercontent.com/85438892/214476911-0ce83a43-b959-4b13-88fd-d6b9af0cd63a.png)

### Steps to reproduce

Open any script

### Minimal reproduction project

N/A
KeySym keysym_keycode = 0; 
	KeySym keysym_unicode = 0; 
	
	char str[256] = {};
	XKeyEvent xkeyevent_no_mod = *xkeyevent;
	xkeyevent_no_mod.state &= ~ShiftMask;
	xkeyevent_no_mod.state &= ~ControlMask;
	XLookupString(xkeyevent, str, 255, &keysym_unicode, nullptr);
	String keysym;
	if (xkb_keysym_to_utf32 && xkb_keysym_to_upper) {
		KeySym keysym_unicode_nm = 0; 
		XLookupString(&xkeyevent_no_mod, nullptr, 0, &keysym_unicode_nm, nullptr);
		keysym = String::chr(xkb_keysym_to_utf32(xkb_keysym_to_upper(keysym_unicode_nm)));
	}
	
	if (!xmbstring) {
		
		xmbstring = (char *)memalloc(sizeof(char) * 8);
		xmblen = 8;