From 9cbfe495b7bba23e5a9b0debaa6048d8ba3ef0c3 Mon Sep 17 00:00:00 2001
From: Yuhang Zhao <2546789017@qq.com>
Date: Tue, 7 Jun 2022 10:43:26 +0800
Subject: [PATCH] win32: fix crash in rare cases

Signed-off-by: Yuhang Zhao <2546789017@qq.com>
---
 src/core/framelesshelper_win.cpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/core/framelesshelper_win.cpp b/src/core/framelesshelper_win.cpp
index 5d8d3bd..6752d5e 100644
--- a/src/core/framelesshelper_win.cpp
+++ b/src/core/framelesshelper_win.cpp
@@ -1095,9 +1095,12 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
         }
     }
     if (systemThemeChanged) {
+        // In some rare cases the FramelessManager instance may be destroyed already.
         FramelessManager *manager = FramelessManager::instance();
-        FramelessManagerPrivate *managerPriv = FramelessManagerPrivate::get(manager);
-        managerPriv->notifySystemThemeHasChangedOrNot();
+        if (manager) {
+            FramelessManagerPrivate *managerPriv = FramelessManagerPrivate::get(manager);
+            managerPriv->notifySystemThemeHasChangedOrNot();
+        }
     }
     return false;
 }