5 files changed, 19 insertions, 6 deletions
diff --git a/src/gui/kernel/qplatformintegration.cpp b/src/gui/kernel/qplatformintegration.cpp
index 3b20d2e7e4..130b479c64 100644
--- a/src/gui/kernel/qplatformintegration.cpp
+++ b/src/gui/kernel/qplatformintegration.cpp
@@ -229,6 +229,11 @@ QPlatformServices *QPlatformIntegration::services() const
     \value ScreenWindowGrabbing The platform supports grabbing window on screen.
     On Wayland, this capability can be reported as \c false. The default implementation
     of hasCapability() returns \c true.
+
+    \value BackingStoreStaticContents The platform backingstore supports static contents.
+    On resize of the backingstore the static contents region is provided, and the backing
+    store is expected to propagate the static content to the resized backing store, without
+    clients needing to repaint the static content region.
  */
 
 /*!
diff --git a/src/gui/kernel/qplatformintegration.h b/src/gui/kernel/qplatformintegration.h
index 71bf23a55c..a18ae821c7 100644
--- a/src/gui/kernel/qplatformintegration.h
+++ b/src/gui/kernel/qplatformintegration.h
@@ -99,7 +99,8 @@ public:
         MaximizeUsingFullscreenGeometry,
         PaintEvents,
         RhiBasedRendering,
-        ScreenWindowGrabbing // whether QScreen::grabWindow() is supported
+        ScreenWindowGrabbing, // whether QScreen::grabWindow() is supported
+        BackingStoreStaticContents
     };
 
     virtual ~QPlatformIntegration() { }
diff --git a/src/gui/painting/qbackingstore.cpp b/src/gui/painting/qbackingstore.cpp
index 586c19885e..2304ee2256 100644
--- a/src/gui/painting/qbackingstore.cpp
+++ b/src/gui/painting/qbackingstore.cpp
@@ -267,6 +267,13 @@ bool QBackingStore::scroll(const QRegion &area, int dx, int dy)
 */
 void QBackingStore::setStaticContents(const QRegion &region)
 {
+    [[maybe_unused]] static const bool didCheckPlatformSupport = []{
+        const auto *integration = QGuiApplicationPrivate::platformIntegration();
+        if (!integration->hasCapability(QPlatformIntegration::BackingStoreStaticContents))
+            qWarning("QBackingStore::setStaticContents(): Platform does not support static contents");
+        return true;
+    }();
+
     d_ptr->staticContents = region;
 }
 
diff --git a/src/plugins/platforms/windows/qwindowsintegration.cpp b/src/plugins/platforms/windows/qwindowsintegration.cpp
index a2dfc18ce8..01d364b0f0 100644
--- a/src/plugins/platforms/windows/qwindowsintegration.cpp
+++ b/src/plugins/platforms/windows/qwindowsintegration.cpp
@@ -286,6 +286,8 @@ bool QWindowsIntegration::hasCapability(QPlatformIntegration::Capability cap) co
         return true;
     case SwitchableWidgetComposition:
         return false; // QTBUG-68329 QTBUG-53515 QTBUG-54734
+    case BackingStoreStaticContents:
+        return true;
     default:
         return QPlatformIntegration::hasCapability(cap);
     }
diff --git a/src/widgets/kernel/qwidgetrepaintmanager.cpp b/src/widgets/kernel/qwidgetrepaintmanager.cpp
index c63f745446..e6b57d9872 100644
--- a/src/widgets/kernel/qwidgetrepaintmanager.cpp
+++ b/src/widgets/kernel/qwidgetrepaintmanager.cpp
@@ -706,7 +706,9 @@ void QWidgetRepaintManager::paintAndFlush()
 
     const QRect tlwRect = tlw->data->crect;
     if (!updatesDisabled && store->size() != tlwRect.size()) {
-        if (hasStaticContents() && !store->size().isEmpty() ) {
+        QPlatformIntegration *integration = QGuiApplicationPrivate::platformIntegration();
+        if (hasStaticContents() && !store->size().isEmpty()
+            && integration->hasCapability(QPlatformIntegration::BackingStoreStaticContents)) {
             // Repaint existing dirty area and newly visible area.
             const QRect clipRect(QPoint(0, 0), store->size());
             const QRegion staticRegion(staticContents(nullptr, clipRect));
@@ -1140,11 +1142,7 @@ void QWidgetRepaintManager::removeStaticWidget(QWidget *widget)
 
 bool QWidgetRepaintManager::hasStaticContents() const
 {
-#if defined(Q_OS_WIN)
     return !staticWidgets.isEmpty();
-#else
-    return !staticWidgets.isEmpty() && false;
-#endif
 }
 
 /*!