Issue with QUrl percent encoding in TolerantMode

According to the docs, in TolerantMode: "Any occurrences of a percent character "%" not followed by exactly two hexadecimal characters (e.g., "13% coverage.html") will be replaced by "%25". However, in practice it looks like % is always replaced:

QUrl(QString("http://qt.nokia.com?1 %26 2")).toEncoded();

Expected:
"http://qt.nokia.com?1%20%26%202"

Actual:
"http://qt.nokia.com?1%20%2526%202"

This is causing problems in XmlListModel, see http://lists.trolltech.com/pipermail/qt-qml/2010-October/001368.html for the discussion.