#include <QtCore/QDebug>
#include <QtCore/QFileInfo>
#include <QtWidgets/QApplication>
#include <QtWidgets/QFileSystemModel>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    // Before running, execute "cd C:\Windows" at the command prompt

    QFileSystemModel fileSystemModel;
    auto index = fileSystemModel.index("C:/");
    qDebug() << fileSystemModel.filePath(index)
             << fileSystemModel.fileInfo(index).absoluteFilePath()
             << QFileInfo("C:/").absoluteFilePath();

    // Output:
    // "C:/" "C:/Windows" "C:/"

    // Expected:
    // "C:/" "C:/" "C:/"
}