From acee56691f1f6f367ffee42ab8ea709a6cf4d6be Mon Sep 17 00:00:00 2001
From: Rob De Reycke <rob_dereycke@hotmail.com>
Date: Thu, 27 Oct 2022 00:37:20 +0200
Subject: [PATCH] xcb: Fix segmentation fault on destruction of QXcbConnection

The same screen was detected twice.

Fixes: QTBUG-104319
Change-Id: Id1f93d68de0306604f2e6a9104962a1d3b0db366
Reviewed-by: Liang Qi <liang.qi@qt.io>
Reviewed-by: Jonas Kvinge <jonas@jkvinge.net>
(cherry picked from commit e39ca06dbc3051c8e82c458ccd7314a2adbff27e)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/plugins/platforms/xcb/qxcbconnection_screens.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/plugins/platforms/xcb/qxcbconnection_screens.cpp b/src/plugins/platforms/xcb/qxcbconnection_screens.cpp
index aa0f2fef658..dc7b5fc632d 100644
--- a/src/plugins/platforms/xcb/qxcbconnection_screens.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection_screens.cpp
@@ -517,7 +517,8 @@ void QXcbConnection::initializeScreensFromMonitor(xcb_screen_iterator_t *it, int
                 old.removeAll(screen);
             }
         }
-        m_screens << screen;
+        if (!m_screens.contains(screen))
+            m_screens << screen;
         siblings << screen;
 
         // similar logic with QXcbConnection::initializeScreensFromOutput()