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/NavigatorContentServiceContentProvider.java
* {@link CommonViewer}, the client must ensure that this method is called
	 * when finished. </b>
	 * </p>
	 * 
	 * @see org.eclipse.jface.viewers.IContentProvider#dispose()
	 */
	public synchronized void dispose() {
		if (disposeContentService) {
			contentService.dispose();
		}
	}
	/**
	 * Get the element from an element or tree path argument.
	 * 
	 * @param parentElementOrPath
	 *            the element or tree path
	 * @return the element
	 */
	private Object internalAsElement(Object parentElementOrPath) {
		if (parentElementOrPath instanceof TreePath) {
			TreePath tp = (TreePath) parentElementOrPath;
			if (tp.getSegmentCount() > 0) {
				return tp.getLastSegment();
			}
			
			return viewer.getInput();
		}
		return parentElementOrPath;
	}
	class CyclicPathException extends Exception {