XLookupString return inconsistent

[wettstae at gmail.com]

> Do you have any idea what might be going on?

In libX11, file KeyBind.c, function _XTranslateKeySym, there is the
following piece of code:

    /* only apply Control key if it makes sense, else ignore it */
    if (modifiers & ControlMask) {
        if ((c >= '@' && c < '\177') || c == ' ') c &= 0x1F;
        else if (c == '2') c = '\000';
        else if (c >= '3' && c <= '7') c -= ('3' - '\033');
        else if (c == '8') c = '\177';
        else if (c == '/') c = '_' & 0x1F;
    }

I have no clue what the "sense" is the comment speaks about, but
clearly, the weird behaviour you see was intended.

But I do not think you window manager problem is related to that.  As
Mod4-Shift-2 is a three-key combination, your keyboard hardware might
not be able to handle it properly.  Most keyboards that do not support
"n-key rollover" have this kind of problems, however, the affected
key combinations vary from keyboard model to keyboard model.

Andreas