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
public Set findDescriptorsWithPossibleChild(Object anElement,
			boolean toComputeOverrides) {
		
		Set result = new TreeSet(ExtensionSequenceNumberComparator.INSTANCE);
		result.addAll(CONTENT_DESCRIPTOR_REGISTRY
				.findDescriptorsForPossibleChild(anElement, assistant,
						toComputeOverrides));
		return result;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @seeorg.eclipse.ui.internal.navigator.INavigatorContentService#
	 * onExtensionActivation(java.lang.String, java.lang.String, boolean)
	 */
	public void onExtensionActivation(String aViewerId,
			String[] aNavigatorExtensionId, boolean toEnable) {
		synchronized (this) {
			try {
				NavigatorContentDescriptor key;
				NavigatorContentExtension extension;
				for (Iterator iter = contentExtensions.keySet().iterator(); iter
						.hasNext();) {
					key = (NavigatorContentDescriptor) iter.next();
					INavigatorActivationService activation = getActivationService();
					if (!activation.isNavigatorExtensionActive(key.getId())) {
						extension = (NavigatorContentExtension) contentExtensions
								.get(key);
						iter.remove();
						extension.dispose();