1 files changed, 21 insertions, 10 deletions

diff --git a/src/plugins/platforms/windows/qwindowscontext.cpp b/src/plugins/platforms/windows/qwindowscontext.cpp
index d87804cda2..41d66bdee9 100644
--- a/src/plugins/platforms/windows/qwindowscontext.cpp
+++ b/src/plugins/platforms/windows/qwindowscontext.cpp
@@ -45,6 +45,7 @@
 #include <QtCore/qscopedpointer.h>
 #include <QtCore/quuid.h>
 #include <QtCore/private/qwinregistry_p.h>
+#include <QtCore/private/qfactorycacheregistration_p.h>
 
 #include <QtGui/private/qwindowsguieventdispatcher_p.h>
 
@@ -221,8 +222,12 @@ QWindowsContext::~QWindowsContext()
         DestroyWindow(d->m_powerDummyWindow);
 
     unregisterWindowClasses();
-    if (d->m_oleInitializeResult == S_OK || d->m_oleInitializeResult == S_FALSE)
+    if (d->m_oleInitializeResult == S_OK || d->m_oleInitializeResult == S_FALSE) {
+#ifdef QT_USE_FACTORY_CACHE_REGISTRATION
+        detail::QWinRTFactoryCacheRegistration::clearAllCaches();
+#endif
         OleUninitialize();
+    }
 
     d->m_screenManager.clearScreens(); // Order: Potentially calls back to the windows.
     if (d->m_displayContext)
@@ -264,7 +269,7 @@ void QWindowsContext::registerTouchWindows()
 {
     if (QGuiApplicationPrivate::is_app_running
         && (d->m_systemInfo & QWindowsContext::SI_SupportsTouch) != 0) {
-        for (QWindowsWindow *w : qAsConst(d->m_windows))
+        for (QWindowsWindow *w : std::as_const(d->m_windows))
             w->registerTouchWindow();
     }
 }
@@ -376,8 +381,8 @@ void QWindowsContext::setProcessDpiAwareness(QtWindows::ProcessDpiAwareness dpiA
     const HRESULT hr = SetProcessDpiAwareness(static_cast<PROCESS_DPI_AWARENESS>(dpiAwareness));
     // E_ACCESSDENIED means set externally (MSVC manifest or external app loading Qt plugin).
     // Silence warning in that case unless debug is enabled.
-    if (FAILED(hr) && (hr != E_ACCESSDENIED || lcQpaWindows().isDebugEnabled())) {
-        qWarning().noquote().nospace() << "SetProcessDpiAwareness("
+    if (FAILED(hr) && hr != E_ACCESSDENIED) {
+        qCWarning(lcQpaWindows).noquote().nospace() << "SetProcessDpiAwareness("
             << dpiAwareness << ") failed: " << QWindowsContext::comErrorString(hr)
             << ", using " << QWindowsContext::processDpiAwareness();
     }
@@ -388,12 +393,16 @@ bool QWindowsContext::setProcessDpiV2Awareness()
     qCDebug(lcQpaWindows) << __FUNCTION__;
     const BOOL ok = SetProcessDpiAwarenessContext(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
     if (!ok) {
-        const HRESULT errorCode = GetLastError();
-        qCWarning(lcQpaWindows).noquote().nospace() << "setProcessDpiAwarenessContext(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2) failed: "
-            << QWindowsContext::comErrorString(errorCode);
-        return false;
+        const DWORD dwError = GetLastError();
+        // ERROR_ACCESS_DENIED means set externally (MSVC manifest or external app loading Qt plugin).
+        // Silence warning in that case unless debug is enabled.
+        if (dwError != ERROR_ACCESS_DENIED) {
+            qCWarning(lcQpaWindows).noquote().nospace()
+                << "SetProcessDpiAwarenessContext(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2) failed: "
+                << QWindowsContext::comErrorString(HRESULT(dwError));
+            return false;
+        }
     }
-
     QWindowsContextPrivate::m_v2DpiAware = true;
     return true;
 }
@@ -601,7 +610,7 @@ void QWindowsContext::unregisterWindowClasses()
 {
     const auto appInstance = static_cast<HINSTANCE>(GetModuleHandle(nullptr));
 
-    for (const QString &name : qAsConst(d->m_registeredWindowClassNames)) {
+    for (const QString &name : std::as_const(d->m_registeredWindowClassNames)) {
         if (!UnregisterClass(reinterpret_cast<LPCWSTR>(name.utf16()), appInstance) && QWindowsContext::verbose)
             qErrnoWarning("UnregisterClass failed for '%s'", qPrintable(name));
     }
@@ -733,6 +742,8 @@ static inline bool findPlatformWindowHelper(const POINT &screenPoint, unsigned c
     if (!(cwexFlags & CWP_SKIPTRANSPARENT)
         && (GetWindowLongPtr(child, GWL_EXSTYLE) & WS_EX_TRANSPARENT)) {
         const HWND nonTransparentChild = ChildWindowFromPointEx(*hwnd, point, cwexFlags | CWP_SKIPTRANSPARENT);
+        if (!nonTransparentChild || nonTransparentChild == *hwnd)
+            return false;
         if (QWindowsWindow *nonTransparentWindow = context->findPlatformWindow(nonTransparentChild)) {
             *result = nonTransparentWindow;
             *hwnd = nonTransparentChild;