Bug 18229 Walkback when closing ImageAnalyzer
Build 20020527 Win2k 1. Open the ImageAnalyzer SWT example. 2. Load an animated gif. 3. Hit 'animate' 4. Close the window. 5. Walkback
examples/org.eclipse.swt.examples/src/org/eclipse/swt/examples/imageanalyzer/ImageAnalyzer.java
Menu alphaMenu = new Menu(shell, SWT.DROP_DOWN);
		item.setMenu(alphaMenu);
		
		item = new MenuItem(alphaMenu, SWT.NULL);
		item.setText("K");
		item.addSelectionListener(new SelectionAdapter() {
			public void widgetSelected(SelectionEvent event) {
				menuComposeAlpha(ALPHA_CONSTANT);
			}
		});
		
		item = new MenuItem(alphaMenu, SWT.NULL);
		item.setText("(K + x) % 256");
		item.addSelectionListener(new SelectionAdapter() {
			public void widgetSelected(SelectionEvent event) {
				menuComposeAlpha(ALPHA_X);
			}
		});
		
		item = new MenuItem(alphaMenu, SWT.NULL);
		item.setText("(K + y) % 256");
		item.addSelectionListener(new SelectionAdapter() {
			public void widgetSelected(SelectionEvent event) {
				menuComposeAlpha(ALPHA_Y);
			}
		});
	}
	void menuComposeAlpha(int alpha_op) {
		if (image == null) return;
		animate = false;