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
if (parent != null
						&& parent.getRenderer() == StackRenderer.this) {
					CTabItem cti = findItemForPart(part, parent);
					if (cti != null) {
						updateTab(cti, part, attName, newValue);
					}
					return;
				}
				
				
				List<MPlaceholder> refs = ElementReferenceRenderer
						.getRenderedPlaceholders(part);
				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.Dirtyable.TOPIC,
				UIEvents.Dirtyable.DIRTY), dirtyUpdater);
	}
	protected void updateTab(CTabItem cti, MPart part, String attName,
			Object newValue) {
		if (UIEvents.UILabel.LABEL.equals(attName)) {
			String newName = (String) newValue;