From 46e528747bf0473f22af73418af470f3e3e72115 Mon Sep 17 00:00:00 2001
From: Axel Spoerl <axel.spoerl@qt.io>
Date: Fri, 9 Dec 2022 13:45:11 +0100
Subject: [PATCH 070/147] Set geometry property in QXcbWindow after checking
 minimum size

QXcbWindow::create() bound the window's size to windowMinimumSize(),
after its size had been inherited from parent().
QPlatformWindow::setGeometry() was called before that sanity check.

When a fullscreen window is re-mapped from a deactivated screen to the
remaining screen, the call to QPlatformWindow::setGeometry() assigns
an invalid QRect to QPlatformWindowPrivate::rect
The negative int values x2 and/or y2 cause
QXcbBackingStoreImage::flushPixmap to address unmapped memory and
crash.

This patch moves the call to QPlatformWindow::setGeometry() from
before to after bounding to a minimum value. That assures a valid
rectangle to be assigned in all cases.

Fixes: QTBUG-109226
Pick-to: 6.4 6.2 5.15
Change-Id: I349a0f3c721059a9013a275de5b4cb147fbdd7a1
Reviewed-by: Liang Qi <liang.qi@qt.io>
(cherry picked from commit 6a3627b6c5aa5109a80024f3d7b0f938504f7ffe)
---
 src/plugins/platforms/xcb/qxcbwindow.cpp | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/plugins/platforms/xcb/qxcbwindow.cpp b/src/plugins/platforms/xcb/qxcbwindow.cpp
index bffad0fac5..45bac8ee85 100644
--- a/src/plugins/platforms/xcb/qxcbwindow.cpp
+++ b/src/plugins/platforms/xcb/qxcbwindow.cpp
@@ -299,11 +299,6 @@ void QXcbWindow::create()
         return;
     }
 
-    QPlatformWindow::setGeometry(rect);
-
-    if (platformScreen != currentScreen)
-        QWindowSystemInterface::handleWindowScreenChanged(window(), platformScreen->QPlatformScreen::screen());
-
     const QSize minimumSize = windowMinimumSize();
     if (rect.width() > 0 || rect.height() > 0) {
         rect.setWidth(qBound(1, rect.width(), XCOORD_MAX));
@@ -315,6 +310,11 @@ void QXcbWindow::create()
         rect.setHeight(QHighDpi::toNativePixels(int(defaultWindowHeight), platformScreen->QPlatformScreen::screen()));
     }
 
+    QPlatformWindow::setGeometry(rect);
+
+    if (platformScreen != currentScreen)
+        QWindowSystemInterface::handleWindowScreenChanged(window(), platformScreen->QPlatformScreen::screen());
+
     xcb_window_t xcb_parent_id = platformScreen->root();
     if (parent()) {
         xcb_parent_id = static_cast<QXcbWindow *>(parent())->xcb_window();
-- 
2.40.1