[Reg 6.2.3 -> 6.2.4] Resizing QTableView header freezes application when using event loop from QMfcApp::pluginInstance()

Example Code

#include <qmfcapp.h>
#include <windows.h>
#include <QTableView>
#include <QFileSystemModel>

BOOL WINAPI DllMain( HINSTANCE hInstance, DWORD dwReason, LPVOID /*lpvReserved*/ )
{
    static bool ownApplication = FALSE;

    if ( dwReason == DLL_PROCESS_ATTACH )
        ownApplication = QMfcApp::pluginInstance( hInstance );
    if ( dwReason == DLL_PROCESS_DETACH && ownApplication )
        delete qApp;

    return TRUE;
}

extern "C" __declspec(dllexport) bool showDialog( HWND parent )
{
    Q_UNUSED(parent)
    auto model = new QFileSystemModel;
    model->setRootPath("C:/");

    auto tableView = new QTableView;
    tableView->setModel(model);

    tableView->setWindowTitle("Freezing Header Example");
    tableView->resize(640, 480);
    tableView->show();

    return TRUE;
}

Steps to reproduce

1. Check out https://codereview.qt-project.org/c/qt-solutions/qt-solutions/+/427169 to enable Qt 6 builds
2. Replace qtwinmigrate/examples/qtdll/main.cpp [1] with the example above (e.g. by applying qtbug-105719-example.diff)
3. Build qtwinmigrate and its examples with Qt 6.2.4 or newer (cd qtwinmigrate && configure.bat && qmake && nmake)
4. Run windeployqt.exe on qtwinmigrate/examples/qtdll/release/qtdialog.dll
5. Open qtwinmigrate/examples/mfc/step1/QtMfc.dsp [2] in Visual Studio and build it
6. Move QtMfc.exe to qtwinmigrate/examples/qtdll/release/ and run it
7. Click "Help" > "About QtMfc..." to launch the QTableView
8. Keep resizing the column header

After doing the final step for a short while, the application will hang and one CPU core will run at 100% (see attached animation)

[1] https://github.com/qtproject/qt-solutions/tree/master/qtwinmigrate/examples/qtdll
[2] https://github.com/qtproject/qt-solutions/tree/master/qtwinmigrate/examples/mfc/step1

Notes

• Qt 6.2.3 does not have this issue. Reverting https://codereview.qt-project.org/c/qt/qtbase/+/387409 makes the issue disappear (tested on Qt 6.2.4)
• Resizing QTreeView's header does not seem to cause this issue