Bug 314317 Cannot re-create a previously closed MWindow instance
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/workbench/ui/renderers/swt/WBWRenderer.java
super();
	}
	MPart activePart = null;
	@Inject
	void trackActivePart(@Optional @Named(IServiceConstants.ACTIVE_PART) MPart p) {
		if (activePart != null) {
			activePart.getTags().remove("active"); 
			MUIElement parent = activePart.getParent();
			if (parent == null && activePart.getCurSharedRef() != null) {
				MPlaceholder ph = activePart.getCurSharedRef();
				parent = ph.getParent();
			}
			if (parent instanceof MPartStack) {
				parent.getTags().remove("active"); 
				if (parent.getWidget() != null)
					setCSSInfo(parent, parent.getWidget());
			} else {
				if (activePart.getWidget() != null)
					setCSSInfo(activePart, activePart.getWidget());
			}
		}
		activePart = p;
		if (activePart != null) {
			activePart.getTags().add("active"); 
			MUIElement parent = activePart.getParent();
			if (parent == null && activePart.getCurSharedRef() != null) {
				MPlaceholder ph = activePart.getCurSharedRef();
				parent = ph.getParent();
			}
			if (parent instanceof MPartStack && parent.getWidget() != null) {