Bug 114512 [working sets] Package explorer should only allow working sets that have an updater installed
I20051101-0010 The package explorer started to support working sets different than the Java working set. However, the package explorer must ensure that an working set updater is installed otherwise it will end up showing stale/bogus content.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/workingsets/WorkingSetConfigurationDialog.java
return null;
			Image icon= (Image)fIcons.get(imageDescriptor);
			if (icon == null) {
				icon= imageDescriptor.createImage();
				fIcons.put(imageDescriptor, icon);
			}
			return icon;
		}
		public String getText(Object object) {
			Assert.isTrue(object instanceof IWorkingSet);
			IWorkingSet workingSet= (IWorkingSet)object;
			return workingSet.getName();
		}
	}
	
	private static class Filter extends ViewerFilter {
		public boolean select(Viewer viewer, Object parentElement, Object element) {
			IWorkingSet ws= (IWorkingSet)element;
			String id= ws.getId();
			return HistoryWorkingSetUpdater.ID.equals(id) ||
				OthersWorkingSetUpdater.ID.equals(id) ||
				JavaWorkingSetUpdater.ID.equals(id) || isCompatible(ws);
		}
		private boolean isCompatible(IWorkingSet set) {
			IAdaptable[] elements= set.getElements();
			if (elements.length == 0)
				return false;
			for (int i= 0; i < elements.length; i++) {
				IAdaptable element= elements[i];
				IProject p= (IProject)element.getAdapter(IProject.class);