Bug 326087 StackRenderer arbitrarily changes selected element when MPartStack is being unrendered
1. Open two files. 2. Activate the editor in the back. 3. Restart 4. The file in the wrong is active now. :O
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/StackRenderer.java
.getRenderedPlaceholders(element);
				for (MPlaceholder ref : refs) {
					MElementContainer<MUIElement> refParent = ref.getParent();
					if (refParent.getRenderer() instanceof StackRenderer) {
						CTabItem cti = findItemForPart(ref, refParent);
						if (cti != null) {
							updateTab(cti, part, attName, newValue);
						}
					}
				}
			}
		};
		eventBroker.subscribe(UIEvents.buildTopic(UIEvents.UILabel.TOPIC),
				itemUpdater);
		dirtyUpdater = new EventHandler() {
			public void handleEvent(Event event) {
				Object objElement = event
						.getProperty(UIEvents.EventTags.ELEMENT);
				
				if (!(objElement instanceof MPart)) {
					return;
				}
				
				MPart part = (MPart) objElement;
				String attName = (String) event
						.getProperty(UIEvents.EventTags.ATTNAME);
				Object newValue = event
						.getProperty(UIEvents.EventTags.NEW_VALUE);
				
				MElementContainer<MUIElement> parent = part.getParent();