Bug 63769 Endless loop after Show in Package Explorer
there are situations when you run in an endless loop in show in package explorer when the action is attempting to reveal an element.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
object= filter(object, parent, filters);
				if (object != null)
					return true;
			}
			return false;
		}
		
		
		private Object filter(Object object, Object parent, ViewerFilter[] filters) {
			for (int i = 0; i < filters.length; i++) {
				ViewerFilter filter = filters[i];
				if (!filter.select(fViewer, parent, object))
					return null;
			}
			return object;
		}
	
		/* Checks if a filtered object in essential (ie. is a parent that
		 * should not be removed).
		 */ 
		private boolean isEssential(Object object) {
			try {
				if (!isFlatLayout() && object instanceof IPackageFragment) {
					IPackageFragment fragment = (IPackageFragment) object;
					return !fragment.isDefaultPackage() && fragment.hasSubpackages();
				}
			} catch (JavaModelException e) {
				JavaPlugin.log(e);
			}
			return false;