QDir::cleanPath does not work as documented

Using QDir:::cleanPath on Windows file names does not results in expected path according to documention, e.g

qDebug() << QString("C:/foo/bar: %0").arg(QDir::cleanPath("C:/foo/bar"));
qDebug() << QString("C:\foo\bar: %0").arg(QDir::cleanPath("C:\foo\bar"));
qDebug() << QString("C:\\foo\\bar: %0").arg(QDir::cleanPath("C:\\foo\\bar"));

shows this output on linux machine

"C:/foo/bar: C:/foo/bar"
"C:\foo\bar: C:\foo\bar"
"C:\\foo\\bar: C:\\foo\\bar"

...and this output on windows machine

"C:/foo/bar: C:/foo/bar"
"C:\foo\bar: C:\foo\bar"
"C:\\foo\\bar: C:/foo/bar"

In the documentation QDir::cleanPath is explained like this:

Returns path with directory separators normalized (converted to "/") and redundant ones removed, and "."s and ".."s resolved (as far as possible).

This is obviously not true and confusing.