From 1cc15c4b6d65a22ab4018226a96baf843feb1f00 Mon Sep 17 00:00:00 2001
From: J-P Nurmi <jpnurmi@qt.io>
Date: Fri, 2 Feb 2018 10:00:27 +0100
Subject: [PATCH] QComboBoxPrivate::showNativePopup(): Scale target rectangle

The QPlatform* classes operate in native pixels.

Task-number: QTBUG-55251
Change-Id: I80490fa802fbc77a1e02c176528cc047630f9a7d
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
---
 src/widgets/widgets/qcombobox.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/widgets/widgets/qcombobox.cpp b/src/widgets/widgets/qcombobox.cpp
index e0bc198d2e..7ab3565a00 100644
--- a/src/widgets/widgets/qcombobox.cpp
+++ b/src/widgets/widgets/qcombobox.cpp
@@ -66,6 +66,7 @@
 #include <qabstractproxymodel.h>
 #include <qstylehints.h>
 #include <private/qguiapplication_p.h>
+#include <private/qhighdpiscaling_p.h>
 #include <private/qapplication_p.h>
 #include <private/qcombobox_p.h>
 #include <private/qabstractitemmodel_p.h>
@@ -2550,7 +2551,8 @@ bool QComboBoxPrivate::showNativePopup()
     else if (q->testAttribute(Qt::WA_MacMiniSize))
         offset = QPoint(-2, 6);
 
-    m_platformMenu->showPopup(tlw, QRect(tlw->mapFromGlobal(q->mapToGlobal(offset)), QSize()), currentItem);
+    const QRect targetRect = QRect(tlw->mapFromGlobal(q->mapToGlobal(offset)), QSize());
+    m_platformMenu->showPopup(tlw, QHighDpi::toNativePixels(targetRect, tlw), currentItem);
 
 #ifdef Q_OS_OSX
     // The Cocoa popup will swallow any mouse release event.