Bug 282947 [CSS] ETabFolder does not draw right with border-visible: false
CTabFolders have always acted odd with respect to borders off and the first tab when selected. It just starts drawing top left. This behaviour seems to be confusing the ETabFolder draw code. It should draw the same curve regardless of whether borders are on or not.
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/workbench/ui/renderers/swt/StackModelFactory.java
* org.eclipse.e4.workbench.ui.renderers.swt.LazyStackFactory#internalChildAdded
	 * (org.eclipse.e4.ui.model.application.MPart,
	 * org.eclipse.e4.ui.model.application.MPart)
	 */
	@Override
	protected void internalChildAdded(MPart parentElement, MPart element) {
		
		super.internalChildAdded(parentElement, element);
		MItemPart<?> itemPart = (MItemPart<?>) element;
		CTabFolder ctf = (CTabFolder) parentElement.getWidget();
		int createFlags = 0;
		
		
		CTabItem cti = findItemForPart(parentElement, element);
		if (cti == null) {
			int index = calcIndexFor(element);
			
			
			cti = new ETabItem(ctf, createFlags, index);
		}
		cti.setData(OWNING_ME, element);
		cti.setText(itemPart.getName());
		cti.setImage(getImage(element));
		cti.setControl((Control) element.getWidget());
		
		hookTabControllerLogic(parentElement, element, cti);
	}
	private int calcIndexFor(final MPart element) {
		int index = 0;