macOS: Unregister screen notification handlers on QGuiApplication shutdown

In the case of a plugin, the plugin might be unloaded, and destroy its
QGuiApplication. We don't want the screen notification handlers to outlive
the application, as that results in crashes.

Fixes: QTBUG-91919
Done-with: Yang Yang
Change-Id: I3a4c0fcf97b785357516d1dac34489511400f154
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
(cherry picked from commit 96469ae338c3146f4efea3fabaaae5bc6ecd6a59)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

2 files changed, 16 insertions, 3 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoascreen.h b/src/plugins/platforms/cocoa/qcocoascreen.h
index b109c24f63..0eb6d114e2 100644
--- a/src/plugins/platforms/cocoa/qcocoascreen.h
+++ b/src/plugins/platforms/cocoa/qcocoascreen.h
@@ -43,6 +43,7 @@
 #include "qcocoacursor.h"
 
 #include <qpa/qplatformintegration.h>
+#include <QtCore/private/qcore_mac_p.h>
 
 #include <CoreGraphics/CoreGraphics.h>
 #include <CoreVideo/CoreVideo.h>
@@ -102,6 +103,9 @@ private:
     static void updateScreens();
     static void cleanupScreens();
 
+    static QMacNotificationObserver s_screenParameterObserver;
+    static CGDisplayReconfigurationCallBack s_displayReconfigurationCallBack;
+
     static bool updateScreensIfNeeded();
     static NSArray *s_screenConfigurationBeforeUpdate;
 
diff --git a/src/plugins/platforms/cocoa/qcocoascreen.mm b/src/plugins/platforms/cocoa/qcocoascreen.mm
index 61f7476159..d326d149f1 100644
--- a/src/plugins/platforms/cocoa/qcocoascreen.mm
+++ b/src/plugins/platforms/cocoa/qcocoascreen.mm
@@ -75,12 +75,14 @@ namespace CoreGraphics {
 }
 
 NSArray *QCocoaScreen::s_screenConfigurationBeforeUpdate = nil;
+QMacNotificationObserver QCocoaScreen::s_screenParameterObserver;
+CGDisplayReconfigurationCallBack QCocoaScreen::s_displayReconfigurationCallBack = nullptr;
 
 void QCocoaScreen::initializeScreens()
 {
     updateScreens();
 
-    CGDisplayRegisterReconfigurationCallback([](CGDirectDisplayID displayId, CGDisplayChangeSummaryFlags flags, void *userInfo) {
+    s_displayReconfigurationCallBack = [](CGDirectDisplayID displayId, CGDisplayChangeSummaryFlags flags, void *userInfo) {
         Q_UNUSED(userInfo);
 
         // Displays are reconfigured in batches, and we want to update our screens
@@ -131,9 +133,10 @@ void QCocoaScreen::initializeScreens()
                 updateScreensIfNeeded();
             }
         }
-    }, nullptr);
+    };
+    CGDisplayRegisterReconfigurationCallback(s_displayReconfigurationCallBack, nullptr);
 
-    static QMacNotificationObserver screenParameterObserver(NSApplication.sharedApplication,
+    s_screenParameterObserver = QMacNotificationObserver(NSApplication.sharedApplication,
         NSApplicationDidChangeScreenParametersNotification, [&]() {
             qCDebug(lcQpaScreen) << "Received screen parameter change notification";
             updateScreensIfNeeded(); // As a last resort we update screens here
@@ -241,6 +244,12 @@ void QCocoaScreen::cleanupScreens()
     // Remove screens in reverse order to avoid crash in case of multiple screens
     for (QScreen *screen : backwards(QGuiApplication::screens()))
         static_cast<QCocoaScreen*>(screen->handle())->remove();
+
+    Q_ASSERT(s_displayReconfigurationCallBack);
+    CGDisplayRemoveReconfigurationCallback(s_displayReconfigurationCallBack, nullptr);
+    s_displayReconfigurationCallBack = nullptr;
+
+    s_screenParameterObserver.remove();
 }
 
 void QCocoaScreen::remove()