Windows: Prevent registration of timers in shutdown phasev5.4.0-rc1

Do not register new timers after closingDown() has been called. They
might call back into QEventDispatcherWin32 after the object has been
destructed, leading to crashes on exit.

registerSocketNotifier has a similar protection using
QCoreApplication::closingDown(). This however does not work in all cases,
because QEventDispatcher::closingDown() is called in
~QGuiApplication(), while QCoreApplication::is_app_closing is set
in ~QCoreApplication(). In between qt_call_post_routines() is called,
which might trigger new timers to be registered.

Task-number: QTBUG-42772
Change-Id: I91325fb10e38c117c1cbedfee272d0ab6a5ca8fa
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/corelib/kernel/qeventdispatcher_win_p.h b/src/corelib/kernel/qeventdispatcher_win_p.h
index a68f6cfa28..8022299a76 100644
--- a/src/corelib/kernel/qeventdispatcher_win_p.h
+++ b/src/corelib/kernel/qeventdispatcher_win_p.h
@@ -147,6 +147,7 @@ public:
     DWORD threadId;
 
     bool interrupt;
+    bool closingDown;
 
     // internal window handle used for socketnotifiers/timers/etc
     HWND internalHwnd;