Bug 283631 [CSS] ETabFolder in CTabFolder mode top/bottom keylines differ
bundles/org.eclipse.e4.ui.widgets/src/org/eclipse/e4/ui/widgets/ETabItem.java
int index = 0;
	shape[index++] = x; 
	shape[index++] = y + height + 1;
	shape[index++] = x;
	shape[index++] = y +  height + 1;
	for (int i = 0; i < left.length/2; i++) {
		shape[index++] = x + left[2*i];
		shape[index++] = y + left[2*i+1] + topOffset;
	}
	for (int i = 0; i < right.length/2; i++) {
		shape[index++] = rightEdge - 1 + right[2*i];
		shape[index++] = y + right[2*i+1] + topOffset;
	}
	shape[index++] = rightEdge - 1;
	shape[index++] = y +  height + 1;
	shape[index++] = rightEdge - 1;
	shape[index++] = y +  height + 1;
	
	Rectangle clipping = gc.getClipping();
	Rectangle bounds = getBounds();
	bounds.height += 1;
	if (parent.onBottom) bounds.y -= 1;
	boolean tabInPaint = clipping.intersects(bounds);
	
	if (tabInPaint) {
		
		if (parent.selectionGradientColors != null && !parent.selectionGradientVertical) {
			parent.drawBackground(gc, shape, true);
		} else {
			Color defaultBackground = parent.selectionBackground;