Mnemonics (accelerators) not in Latin-1 do not work under Linux X11

QList<int> QKeyMapperPrivate::possibleKeysXKBByBaseCode (QKeyEvent *event, KeySym baseKeySym, uint consumedModifiers)
{
#ifndef QT_NO_XKB
    const int xkeycode = event->nativeScanCode();
    const uint xmodifiers = event->nativeModifiers();

    QList<int> result;

    // translate sym -> code
    Qt::KeyboardModifiers baseModifiers = 0;
    int baseCode = -1;
    QByteArray chars;
    int count = 0;
    QString text = translateKeySym(baseKeySym, xmodifiers, baseCode, baseModifiers, chars, count);
    if (baseCode == -1) {
        if (text.isEmpty())
            return QList<int>();
        baseCode = text.at(0).unicode();
    }

    if (baseCode && baseCode < 0xfffe)
        baseCode = QChar(baseCode).toUpper().unicode();
    result += (baseCode | baseModifiers);

    int pos1Bits[MaxBits];
    int num1Bits = 0;

    for (int i = 0; i < MaxBits; ++i) {
        if (consumedModifiers & (1 << i))
            pos1Bits[num1Bits++] = i;
    }

    const int numPerms = (1 << num1Bits);
    // translate the key again using each permutation of consumedModifiers
    for (int i = 1; i < numPerms; ++i) {
        uint val = 0;
        for (int j = 0; j < num1Bits; ++j) {
            if (i & (1 << j))
                val |= (1 << pos1Bits[j]);
        }

        if ((xmodifiers & val) != val)
            continue;

        KeySym sym;
        uint mods;
        if (!XkbLookupKeySym(X11->display, xkeycode, val, &mods, &sym))
            continue;

        // translate sym -> code
        Qt::KeyboardModifiers modifiers = 0;
        int code = -1;
        chars.clear();
        count = 0;
        // mask out the modifiers needed to translate keycode
        text = translateKeySym(sym, xmodifiers & ~val, code, modifiers, chars, count);
        if (code == -1) {
            if (text.isEmpty())
                continue;
            code = text.at(0).unicode();
        }

        if (code && code < 0xfffe)
            code = QChar(code).toUpper().unicode();
        if (code == baseCode)
            continue;

        result += (code | modifiers);
    }
#if 0
    qDebug() << "possibleKeysXKB()" << hex << result;
#endif
    return result;
#else
    Q_UNUSED(event);
    return QList<int>();
#endif // QT_NO_XKB
}

QList<int> QKeyMapperPrivate::possibleKeysXKB(QKeyEvent *event)
{
#ifndef QT_NO_XKB
    const int xkeycode = event->nativeScanCode();
    const uint xmodifiers = event->nativeModifiers();

    // first, translate key only using lock modifiers (there are no Qt equivalents for these, so we must
    // always use them when determining the baseKeySym)
    KeySym baseKeySym;
    uint consumedModifiers;

    QList<int> result;

    if (XkbLookupKeySym(X11->display, xkeycode, (xmodifiers & (LockMask | qt_num_lock_mask)),
                        &consumedModifiers, &baseKeySym))
      result += possibleKeysXKBByBaseCode (event, baseKeySym, consumedModifiers);

    if (event->nativeVirtualKey () != 0)
      result += possibleKeysXKBByBaseCode (event, event->nativeVirtualKey (), event->nativeModifiers ());

    return result.toSet ().toList ();
#else
    Q_UNUSED(event);
    return QList<int>();
#endif // QT_NO_XKB
}