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
while (iter.hasPrevious()) {
			INavigatorContentDescriptor child = (INavigatorContentDescriptor) iter.previous();
			if (assistant.isVisibleAndActive(child) && child.isPossibleChild(anElement)) {
				findOverridingLabelExtensions(anElement, child, contributors);
			}
		}
		contributors.add(getExtension(descriptor));
	}
	
	/**
	 * 
	 * The label provider that is are enabled for the given element.
	 * A label provider is 'enabled' if its corresponding content provider
	 * returned the element.
	 * 
	 * @param anElement
	 *            An element from the tree (any element contributed to the
	 *            tree).
	 * @return The label provider
	 */
	public ILabelProvider[] findRelevantLabelProviders(Object anElement) {
		Collection extensions = findPossibleLabelExtensions(anElement);
		
		if (extensions.size() == 0) {
			return NO_LABEL_PROVIDERS;
		}
		List resultProvidersList = new ArrayList();
		for (Iterator itr = extensions.iterator(); itr.hasNext();) {
			resultProvidersList.add(((NavigatorContentExtension) itr.next()).getLabelProvider());
		}