[education/rkward/testing/win_citest_timeout] rkward: Try to fix thread exit

[Thomas Friedrichsmeier]

Git commit 6a6ad83f122e4e0d23e4423d5f0417c4f68f9bf3 by Thomas Friedrichsmeier.
Committed on 02/10/2022 at 20:07.
Pushed by tfry into branch 'testing/win_citest_timeout'.

Try to fix thread exit

M  +5    -1    rkward/rbackend/rkrbackendprotocol_frontend.cpp
M  +1    -1    rkward/windows/rkwindowcatcher.h

https://invent.kde.org/education/rkward/commit/6a6ad83f122e4e0d23e4423d5f0417c4f68f9bf3

diff --git a/rkward/rbackend/rkrbackendprotocol_frontend.cpp b/rkward/rbackend/rkrbackendprotocol_frontend.cpp
index fd09de28..c152298c 100644
--- a/rkward/rbackend/rkrbackendprotocol_frontend.cpp
+++ b/rkward/rbackend/rkrbackendprotocol_frontend.cpp
@@ -31,10 +31,14 @@ RKRBackendProtocolFrontend::~RKRBackendProtocolFrontend () {
 	RK_ASSERT(_instance == this);
 	terminateBackend ();
 	RKFrontendTransmitter::instance ()->wait(1000);  // Wait for thread to catch the backend's exit request, and exit()
-	RKFrontendTransmitter::instance ()->quit();      // Tell it to quit, otherwise
+	QMetaObject::invokeMethod(RKFrontendTransmitter::instance(), &RKFrontendTransmitter::quit, Qt::QueuedConnection);
+	RK_TRACE (RBACKEND);
 	RKFrontendTransmitter::instance ()->wait(3000);  // Wait for thread to quit and clean up.
+	RK_TRACE (RBACKEND);
 	qApp->processEvents(QEventLoop::AllEvents, 500); // Not strictly needed, but avoids some mem leaks on exit by handling all posted BackendExit events
+	RK_TRACE (RBACKEND);
 	delete RKFrontendTransmitter::instance ();
+	RK_TRACE (RBACKEND);
 	_instance = nullptr;
 }
 
diff --git a/rkward/windows/rkwindowcatcher.h b/rkward/windows/rkwindowcatcher.h
index 6284ccf3..2cc9dc4b 100644
--- a/rkward/windows/rkwindowcatcher.h
+++ b/rkward/windows/rkwindowcatcher.h
@@ -76,7 +76,7 @@ public:
 	/** remove a watch created with registerNameWatcher */
 	void unregisterWatcher (WId watched);
 	static RKWindowCatcher *instance ();
-	static void discardInstance () { delete _instance; };
+	static void discardInstance () { delete _instance; _instance = nullptr; };
 private:
 	void pollWatchedWindowStates ();
 	QTimer poll_timer;