Bug 283631 [CSS] ETabFolder in CTabFolder mode top/bottom keylines differ
bundles/org.eclipse.e4.ui.widgets/src/org/eclipse/e4/ui/widgets/ETabFolder.java
if (selectedIndex != -1 && selectionGradientColors != null
				&& selectionGradientColors.length > 1
				&& !selectionGradientVertical) {
			drawBackground(gc, shape, true);
		} else if (selectedIndex == -1 && gradientColors != null
				&& gradientColors.length > 1 && !gradientVertical) {
			drawBackground(gc, shape, false);
		} else {
			gc.setBackground(selectedIndex == -1 ? getBackground()
					: selectionBackground);
			gc.fillPolygon(shape);
		}
		
		if (borderLeft > 0) {
			gc.setForeground(borderColor);
			gc.drawPolyline(shape);
		}
		return;
	}
	int x = Math.max(0, borderLeft - 1);
	int y = borderTop;
	int width = size.x - borderLeft - borderRight + 1;
	int height = tabHeight - 1;
	
	int[] left, right;
	if ((getStyle() & SWT.BORDER) != 0) {
		left = E_TOP_LEFT_CORNER;
		right = E_TOP_RIGHT_CORNER;
	} else {