From 56e5491e5ca9cd5ad5fd987a550bebc5503652c3 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Thu, 9 Jul 2020 23:06:32 -0400
Subject: [PATCH] Ensures safe startup.

---
 OSBindings/Qt/mainwindow.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/OSBindings/Qt/mainwindow.cpp b/OSBindings/Qt/mainwindow.cpp
index ec87b29c6..b059bf561 100644
--- a/OSBindings/Qt/mainwindow.cpp
+++ b/OSBindings/Qt/mainwindow.cpp
@@ -759,7 +759,7 @@ void MainWindow::setWindowTitle() {
 
 void MainWindow::changeEvent(QEvent *event) {
 	// Clear current key state upon any window activation change.
-	if(event->type() == QEvent::ActivationChange) {
+	if(machine && event->type() == QEvent::ActivationChange) {
 		const auto keyboardMachine = machine->keyboard_machine();
 		if(keyboardMachine) {
 			keyboardMachine->clear_all_keys();