Bug 299685 Empty iconURI's cause 'MalformedURLException' failures rather than being ignored
One of the issues Lars' found is that if you fill in a field (i.e. iconURI) and subsequently clear it you don't end up in the same model state. Once the value has been set in the editor it will never be 'null' again, clearing the field just sets it to an empty string.
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/workbench/ui/renderers/swt/WBWRenderer.java
}
		}
		return newWidget;
	}
	@Override
	public void hookControllerLogic(MUIElement me) {
		super.hookControllerLogic(me);
		Widget widget = (Widget) me.getWidget();
		if (widget instanceof Shell && me instanceof MWindow) {
			final Shell shell = (Shell) widget;
			final MWindow w = (MWindow) me;
			shell.addControlListener(new ControlListener() {
				public void controlResized(ControlEvent e) {
					try {
						ignoreSizeChanges = true;
						w.setWidth(shell.getSize().x);
						w.setHeight(shell.getSize().y);
					} finally {
						ignoreSizeChanges = false;
					}
				}
				public void controlMoved(ControlEvent e) {
					try {
						ignoreSizeChanges = true;
						w.setX(shell.getLocation().x);
						w.setY(shell.getLocation().y);
					} finally {
						ignoreSizeChanges = false;
					}
				}