Bug 317180 Screen cheese when starting fresh workspace
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/CTabRendering.java
case PART_HEADER:
			this.drawTabHeader(gc, bounds, state);
			return;
		default:
			if (0 <= part && part < parent.getItemCount()) {
				if (bounds.width == 0 || bounds.height == 0)
					return;
				if ((state & SWT.SELECTED) != 0) {
					drawSelectedTab(part, gc, bounds, state);
					state &= ~SWT.BACKGROUND;
					super.draw(part, state, bounds, gc);
				} else {
					drawUnselectedTab(part, gc, bounds, state);
					if ((state & SWT.HOT) == 0 && !active) {
						gc.setAdvanced(true);
						gc.setAlpha(0x7f);
						state &= ~SWT.BACKGROUND;
						super.draw(part, state, bounds, gc);
						gc.setAdvanced(false);
					} else {
						state &= ~SWT.BACKGROUND;
						super.draw(part, state, bounds, gc);
					}
				}
				return;
			}
		}
		super.draw(part, state, bounds, gc);
	}
	void drawTabHeader(GC gc, Rectangle bounds, int state) {