4.7 Lock mouse to viewport problem

hi , i read source and find problem:

void FInputModeGameOnly::ApplyInputMode(FReply& SlateOperations, class UGameViewportClient& GameViewportClient) const
    {
    	TSharedPtr<SViewport> ViewportWidget = GameViewportClient.GetGameViewportWidget();
    	if (ViewportWidget.IsValid())
    	{
    		TSharedRef<SViewport> ViewportWidgetRef = ViewportWidget.ToSharedRef();
    		SlateOperations.UseHighPrecisionMouseMovement(ViewportWidgetRef);
    		SlateOperations.SetUserFocus(ViewportWidgetRef);
    		SlateOperations.LockMouseToWidget(ViewportWidgetRef);
    		GameViewportClient.SetMouseLockMode(EMouseLockMode::LockOnCapture);

see last line: it use an arbitrary param LockOnCapture, which should be current (last setting) value