UI: Don't call obs_source_get_output_flags on a NULL source

UI/window-basic-main.cpp

@@ -3393,16 +3393,20 @@ void OBSBasic::SourceToolBarActionsSetEnabled()
 
 void OBSBasic::UpdateTransformShortcuts()
 {
+	bool hasVideo = false;
+
 	OBSSource source = obs_sceneitem_get_source(GetCurrentSceneItem());
-	uint32_t flags = obs_source_get_output_flags(source);
-	bool audioOnly = (flags & OBS_SOURCE_VIDEO) == 0;
 
-	ui->actionEditTransform->setEnabled(!audioOnly);
-	ui->actionCopyTransform->setEnabled(!audioOnly);
-	ui->actionPasteTransform->setEnabled(audioOnly ? false
-						       : hasCopiedTransform);
+	if (source) {
+		uint32_t flags = obs_source_get_output_flags(source);
+		hasVideo = (flags & OBS_SOURCE_VIDEO) != 0;
+	}
 
-	ui->actionResetTransform->setEnabled(!audioOnly);
+	ui->actionEditTransform->setEnabled(hasVideo);
+	ui->actionCopyTransform->setEnabled(hasVideo);
+	ui->actionPasteTransform->setEnabled(hasVideo ? hasCopiedTransform
+						      : false);
+	ui->actionResetTransform->setEnabled(hasVideo);
 }
 
 void OBSBasic::UpdateContextBar(bool force)