Bug 329930 Resetting a perspective while its active part is not defined in the perspective causes the perspective to not have an active part after the reset
1. Window > Show View > Console 2. Window > Reset Perspective... > OK 3. No parts are active.
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/PartServiceImpl.java
partActivationHistory.prepend(part);
			return;
		}
		
		
		
		
		recordStackActivation(part);
		modelService.bringToTop(part);
		window.getParent().setSelectedElement(window);
		partActivationHistory.activate(part, activateBranch);
		Object object = part.getObject();
		if (object != null && requiresFocus) {
			ContextInjectionFactory.invoke(object, Focus.class, part.getContext(), null);
		}
	}
	/**
	 * Records the specified parent part's selected element in the activation history if the parent
	 * is a stack.
	 * 
	 * @param part
	 *            the part whose parent's selected element should be checked for activation history
	 *            recording
	 */
	private void recordStackActivation(MPart part) {
		MElementContainer<? extends MUIElement> parent = part.getParent();
		if (parent instanceof MGenericStack) {
			recordSelectedActivation(parent);
		} else if (parent == null) {