Bug 329186 'Close All' context menu action can cause parts to be rendered
The 'Close All' action merely unrenders the part in order so as the selection changes from one item to another, it may cause parts to become activated inadvertently.
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/StackRenderer.java
protected void showTab(MUIElement element) {
		super.showTab(element);
		final CTabFolder ctf = (CTabFolder) getParentWidget(element);
		CTabItem cti = findItemForPart(element, null);
		if (cti == null) {
			createTab(element.getParent(), element);
			cti = findItemForPart(element, element.getParent());
		}
		Control ctrl = (Control) element.getWidget();
		if (ctrl != null && ctrl.getParent() != ctf) {
			ctrl.setParent(ctf);
			cti.setControl(ctrl);
		} else if (element.getWidget() == null) {
			Control tabCtrl = (Control) renderer.createGui(element);
			cti.setControl(tabCtrl);
		}
		ignoreTabSelChanges = true;
		ctf.setSelection(cti);
		ignoreTabSelChanges = false;
		
		if (ctf.getTopRight() != null) {
			Control curTB = ctf.getTopRight();
			ctf.setTopRight(null);
			if (!curTB.isDisposed()) {
				MUIElement tbME = (MUIElement) curTB
						.getData(AbstractPartRenderer.OWNING_ME);
				if (tbME instanceof MRenderedToolBar)
					renderer.removeGui(tbME);
				else
					curTB.dispose();