Fix segfault when closing widget and destroying window in QDialog::done

On OpenSUSE we seem to get an Enter event after or while the QWindow is
closed, and that appears to reset the currentMouseWindow after we
cleared it in QWindowPrivate::destroy. Apply a workaround similar to the
focus_window to make sure that currentMouseWindow and
currentMousePressWindow don't point to destroyed objects.

Change-Id: I61afdaa7d8d1d437058624012319460be2f2567f
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
(cherry picked from commit e9e8d67e31b8b6a8348b5dae3225be2dbd87ffd2)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 7 insertions, 3 deletions

diff --git a/src/gui/kernel/qwindow.cpp b/src/gui/kernel/qwindow.cpp
index 83c776a485..15fcceb9c1 100644
--- a/src/gui/kernel/qwindow.cpp
+++ b/src/gui/kernel/qwindow.cpp
@@ -223,11 +223,15 @@ QWindow::~QWindow()
     if (!QGuiApplicationPrivate::is_app_closing)
         QGuiApplicationPrivate::instance()->modalWindowList.removeOne(this);
 
-    // focus_window is normally cleared in destroy(), but the window may in
-    // some cases end up becoming the focus window again. Clear it again
-    // here as a workaround. See QTBUG-75326.
+    // thse are normally cleared in destroy(), but the window may in
+    // some cases end up becoming the focus window again, or receive an enter
+    // event. Clear it again here as a workaround. See QTBUG-75326.
     if (QGuiApplicationPrivate::focus_window == this)
         QGuiApplicationPrivate::focus_window = nullptr;
+    if (QGuiApplicationPrivate::currentMouseWindow == this)
+        QGuiApplicationPrivate::currentMouseWindow = nullptr;
+    if (QGuiApplicationPrivate::currentMousePressWindow == this)
+        QGuiApplicationPrivate::currentMousePressWindow = nullptr;
 }
 
 void QWindowPrivate::init(QScreen *targetScreen)