QFileSystemModel with wrong path of top-directory of a drive

   // EXAMPLE:     BUG: you want C:\  but you get the current working directory
   SetCurrentDirectory(L"C:\\Windows");  
   QFileSystemModel* pModel = new QFileSystemModel(nullptr);
   QFileInfo  buggyInfo     = pModel->fileInfo(pModel->index("C:\\", 0)); // try to get fileInfo of C:\   (top-directory)
   // buggyInfo:  fileEntry.m_filePath="C:"  /  fileEntry.m_nativeFilePath="\\?\C:\Windows"
   QString    txtWrongPath  = buggyInfo.absoluteFilePath();  // "C:/Windows"
   delete pModel;

   // second example
   // the parent of "C:/Windows"  should not be "C:/Solutions/250204_qt_FileSystemModel"
   QFileSystemModel* pModel = new QFileSystemModel(nullptr);
   pModel->setRootPath("");
   pModel->sort(0, Qt::AscendingOrder);
   QModelIndex testIndex     = pModel->index("C:\\Windows", 0);
   QFileInfo   correctInfo   = pModel->fileInfo(testIndex);
   QString     txtPath       = correctInfo.absoluteFilePath(); // "C:/Windows"
   QFileInfo   infoParent    = pModel->fileInfo(testIndex.parent());
   QString     txtParentFile = infoParent.absoluteFilePath(); //  "C:/Solutions/250204_qt_FileSystemModel/QtFileSystemModelTest"
   QString     txtParentPath = infoParent.absolutePath();     //  "C:/Solutions/250204_qt_FileSystemModel"

qtbase-v5.15.13\src\widgets\dialogs\qfilesystemmodel.cpp
QFileSystemModelPrivate::QFileSystemNode *QFileSystemModelPrivate::node(const QString &path, bool fetch) 
  with path = "c:\"   results in
  node->info->mFileInfo.d_ptr.d->fileEntry.m_filePath = "C:"
  node->info->mFileInfo.d_ptr.d->fileEntry.m_nativeFilePath = "\\?\C:\Users\XXX\AppData\Roaming\XXX"