From b63615ca6ca1be031c950a3561fb5418c56472a8 Mon Sep 17 00:00:00 2001
From: Christian Ehrlicher <ch.ehrlicher@gmx.de>
Date: Sun, 3 Nov 2024 10:46:09 +0100
Subject: [PATCH] Windows11Style: fix sizehint for QComboBox

The size hint for QComboBox relied on the vista style but the painting
was completely different. Therefore swith to the base windows style and
add the extra margins used in the windows11 style.

Fixes: QTBUG-130824
Task-number: QTBUG-11967
Change-Id: Ic533140793cdd4e640c49f6d73e9bb73bcbb83da
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>
(cherry picked from commit b6ca35f65372cc8519a418d6a5291cafd809f7c8)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/plugins/styles/modernwindows/qwindows11style.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/plugins/styles/modernwindows/qwindows11style.cpp b/src/plugins/styles/modernwindows/qwindows11style.cpp
index 050ac00112a..30a524916f7 100644
--- a/src/plugins/styles/modernwindows/qwindows11style.cpp
+++ b/src/plugins/styles/modernwindows/qwindows11style.cpp
@@ -2066,6 +2066,14 @@ QSize QWindows11Style::sizeFromContents(ContentsType type, const QStyleOption *o
         break;
     }
 #endif
+    case CT_ComboBox:
+        if (const auto *comboBoxOpt = qstyleoption_cast<const QStyleOptionComboBox *>(option)) {
+            contentSize = QWindowsStyle::sizeFromContents(type, option, size, widget);  // don't rely on QWindowsThemeData
+            contentSize += QSize(4, 4);     // default win11 style margins
+            if (comboBoxOpt->subControls & SC_ComboBoxArrow)
+                contentSize += QSize(8, 0); // arrow margins
+        }
+        break;
     default:
         contentSize = QWindowsVistaStyle::sizeFromContents(type, option, size, widget);
         break;