fix no video shown

tests/gtest/CMakeLists.txt

@@ -25,6 +25,7 @@ add_executable(olive-gtest
   task_taskmanager_test.cpp
   module_smoke_test.cpp
   shader_resources_test.cpp
+  timebased_widget_test.cpp
   timeline_coordinate_test.cpp
   timeline_workarea_test.cpp
 )

tests/gtest/timebased_widget_test.cpp

@@ -0,0 +1,21 @@
+#include <gtest/gtest.h>
+
+#include "widget/timebased/timebasedwidget.h"
+#include "node/output/viewer/viewer.h"
+
+TEST(TimeBasedWidget, ConnectViewerNodeNullSafe)
+{
+	olive::TimeBasedWidget widget(false, false);
+	widget.ConnectViewerNode(nullptr);
+	EXPECT_EQ(widget.GetConnectedNode(), nullptr);
+}
+
+TEST(TimeBasedWidget, ConnectedNodeClearsOnDelete)
+{
+	olive::TimeBasedWidget widget(false, false);
+	auto *viewer = new olive::ViewerOutput();
+	widget.ConnectViewerNode(viewer);
+	EXPECT_EQ(widget.GetConnectedNode(), viewer);
+	delete viewer;
+	EXPECT_EQ(widget.GetConnectedNode(), nullptr);
+}