From 8d6e825ddfa14f75959ae20a76e4e1a34f4faec2 Mon Sep 17 00:00:00 2001
From: Oliver Wolff <oliver.wolff@qt.io>
Date: Thu, 30 Sep 2021 11:04:48 +0200
Subject: [PATCH] windows qpa: Handle invisible child windows gracefully on dpi
 changes
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Fixes: QTBUG-96466
Pick-to: 6.2
Change-Id: I58d90e85b4bb837df2dc5fd89abe984dadcd468d
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>
---
 src/plugins/platforms/windows/qwindowscontext.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/plugins/platforms/windows/qwindowscontext.cpp b/src/plugins/platforms/windows/qwindowscontext.cpp
index 433e58a97a..bbdf1ad692 100644
--- a/src/plugins/platforms/windows/qwindowscontext.cpp
+++ b/src/plugins/platforms/windows/qwindowscontext.cpp
@@ -1474,6 +1474,8 @@ bool QWindowsContext::windowsProc(HWND hwnd, UINT message,
         // Scale child QPlatformWindow size. Windows sends WM_DPICHANGE to top-level windows only.
         for (QWindow *childWindow : platformWindow->window()->findChildren<QWindow *>()) {
             QWindowsWindow *platformChildWindow = static_cast<QWindowsWindow *>(childWindow->handle());
+            if (!platformChildWindow)
+                continue;
             QRect currentGeometry = platformChildWindow->geometry();
             QRect scaledGeometry = QRect(currentGeometry.topLeft() * scale, currentGeometry.size() * scale);
             platformChildWindow->setGeometry(scaledGeometry);