QQuickPlatformMenu: fix crash on exit with submenus

Ensure that we unparent submenus in destroy(), not just in the
destructor.

Task-number: QTBUG-66889
Change-Id: I18b5fc28ee47a50f511ef4f8cf55cfdcbae9bfec
Reviewed-by: J-P Nurmi <jpnurmi@qt.io>

2 files changed, 17 insertions, 4 deletions

diff --git a/src/imports/platform/qquickplatformmenu.cpp b/src/imports/platform/qquickplatformmenu.cpp
index abbea4e7..0a5ce8e4 100644
--- a/src/imports/platform/qquickplatformmenu.cpp
+++ b/src/imports/platform/qquickplatformmenu.cpp
@@ -216,15 +216,22 @@ QQuickPlatformMenu::~QQuickPlatformMenu()
         m_menuBar->removeMenu(this);
     if (m_parentMenu)
         m_parentMenu->removeMenu(this);
+
+    unparentSubmenus();
+
+    delete m_iconLoader;
+    m_iconLoader = nullptr;
+    delete m_handle;
+    m_handle = nullptr;
+}
+
+void QQuickPlatformMenu::unparentSubmenus()
+{
     for (QQuickPlatformMenuItem *item : qAsConst(m_items)) {
         if (QQuickPlatformMenu *subMenu = item->subMenu())
             subMenu->setParentMenu(nullptr);
         item->setMenu(nullptr);
     }
-    delete m_iconLoader;
-    m_iconLoader = nullptr;
-    delete m_handle;
-    m_handle = nullptr;
 }
 
 QPlatformMenu *QQuickPlatformMenu::handle() const
@@ -277,6 +284,10 @@ void QQuickPlatformMenu::destroy()
     if (!m_handle)
         return;
 
+    // Ensure that all submenus are unparented before we are destroyed,
+    // so that they don't try to access a destroyed menu.
+    unparentSubmenus();
+
     delete m_handle;
     m_handle = nullptr;
 }
diff --git a/src/imports/platform/qquickplatformmenu_p.h b/src/imports/platform/qquickplatformmenu_p.h
index b5c23b61..14f083dd 100644
--- a/src/imports/platform/qquickplatformmenu_p.h
+++ b/src/imports/platform/qquickplatformmenu_p.h
@@ -189,6 +189,8 @@ private Q_SLOTS:
     void updateIcon();
 
 private:
+    void unparentSubmenus();
+
     bool m_complete;
     bool m_enabled;
     bool m_visible;