Bug 305375 [ui] Many dialogs about unavailable sites
I20100309-0100 I ran a "Check for Updates" immediately after my machine had come out of standby. I don't think the wireless had fully connected yet, and the check for updates failed (fine). However, I got a half dozen nested dialogs about each of the sites that it could not find. They were all stacked on top of one another, and I had to dismiss each one individually. I would expect it to accumulate this into a single dialog rather than one dialog per repository.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/NavigatorContentService.java
*            The viewer id for this content service; normally from the
	 *            <b>org.eclipse.ui.views</b> extension.
	 * @param aViewer
	 *            The viewer that this content service will be associated with.
	 */
	public NavigatorContentService(String aViewerId, StructuredViewer aViewer) {
		this(aViewerId);
		structuredViewerManager = new StructuredViewerManager(aViewer, this);
	}
	public String[] getVisibleExtensionIds() {
		List visibleExtensionIds = new ArrayList();
		NavigatorContentDescriptor[] descriptors = CONTENT_DESCRIPTOR_REGISTRY
				.getAllContentDescriptors();
		for (int i = 0; i < descriptors.length; i++) {
			if (assistant.isVisible(descriptors[i].getId())) {
				visibleExtensionIds.add(descriptors[i].getId());
			}
		}
		if (visibleExtensionIds.isEmpty()) {
			return NO_EXTENSION_IDS;
		}
		return (String[]) visibleExtensionIds
				.toArray(new String[visibleExtensionIds.size()]);
	}
	public INavigatorContentDescriptor[] getVisibleExtensions() {
		List visibleDescriptors = new ArrayList();
		NavigatorContentDescriptor[] descriptors = CONTENT_DESCRIPTOR_REGISTRY
				.getAllContentDescriptors();
		for (int i = 0; i < descriptors.length; i++) {
			if (assistant.isVisible(descriptors[i].getId())) {