fix: if there's nothing to judge, stop immediately

makespec/BUILDVERSION

@@ -1 +1 @@
-186
+187

src/core/contest.cpp

@@ -195,7 +195,8 @@ void Contest::judge(const QVector<std::pair<Contestant *, int>> &judgingTasks) {
 	}
 
 	auto eventLoop = new QEventLoop();
-	connect(controller, &JudgingController::judgeFinished, eventLoop, &QEventLoop::quit);
+	connect(controller, &JudgingController::judgeFinished, eventLoop, &QEventLoop::quit,
+	        Qt::QueuedConnection);
 
 	controller->start();
 

src/core/judgingcontroller.cpp

@@ -53,6 +53,10 @@ void JudgingController::taskFinished() {
 	}
 }
 void JudgingController::start() {
+	if (queuingTasks.size() == 0) {
+		emit judgeFinished();
+		return;
+	}
 	isJudging = 1;
 	while (! queuingTasks.empty() && runningTasks.size() < maxThreads) {
 		assign();