Calling toCaseFolded twice on a Unicode character results in a different character than a single toCaseFolded

#include <QtGui> 
 
int main() 
{ 
    enum { Count = 2 }; 
    const QChar chars[Count] = { QChar('E'), QChar(1025) }; 
    for (int i=0; i<Count; ++i) { 
        const QChar &unicode = chars[i]; 
        const QChar folded = unicode.toCaseFolded(); 
        const QChar foldedTwice = folded.toCaseFolded(); 
        qDebug() << "haystack" << unicode.unicode() << "haystack folded" << folded.unicode() 
                 << "haystack folded twice" << foldedTwice.unicode(); 
 
        const QString needle = unicode; 
        const QString hayStack = needle.toLower(); 
        qDebug() << "found needle" << hayStack.indexOf(needle, 0, Qt::CaseInsensitive) 
                 << "should be the same" << hayStack.toLower().indexOf(needle.toLower()); 
    } 
    return 0; 
}