Bug 310665 [Browser] 'Web Browser' preference page ignores cancellation
I20100426-0852 1. Window > Preferences > General > Web Browser 2. In Windows XP, I see "Default system web browser", "Firefox", and "Internet Explorer". 3. Select IE. Click the 'Remove' button. 4. Click 'Cancel'. 5. Redo step 1. 6. Window > Preferences 7. IE is gone. :(
bundles/org.eclipse.ui.browser/src/org/eclipse/ui/internal/browser/BrowserManager.java
if (instance == null)
			return;
		instance.dispose();
	}
	protected void dispose() {
	    InstanceScope instanceScope = new InstanceScope();
		IEclipsePreferences prefs = instanceScope.getNode(WebBrowserUIPlugin.PLUGIN_ID);
		prefs.removePreferenceChangeListener(pcl);
	}
	public IBrowserDescriptorWorkingCopy createExternalWebBrowser() {
		return new BrowserDescriptorWorkingCopy();
	}	
	public List getWebBrowsers() {
		if (browsers == null)
			loadBrowsers();
		return new ArrayList(browsers);
	}
	protected void loadBrowsers() {
		Trace.trace(Trace.FINEST, "Loading web browsers"); 
		
		String xmlString = Platform.getPreferencesService().getString
		    (WebBrowserUIPlugin.PLUGIN_ID,  "browsers", null, null); 
		if (xmlString != null && xmlString.length() > 0) {
			browsers = new ArrayList();
			
			try {
				ByteArrayInputStream in = new ByteArrayInputStream(xmlString.getBytes("utf-8")); 
				Reader reader = new InputStreamReader(in, "utf-8"); 
				IMemento memento = XMLMemento.createReadRoot(reader);