Bug 32384 Cannot open type hierarchy after a cancel
JUnit setup 1) open the type hierarchy on TestCase 2) press F4 on Object 3) cancel in progress bar 4) press F4 on Object again ->nothing happens
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/TypeHierarchyViewPart.java
int nSelected= selected.size();
			if (fIsEnableMemberFilter) {
				IMember[] memberFilter= null;
				if (nSelected > 0) {
					memberFilter= new IMember[nSelected];
					selected.toArray(memberFilter);
				}
				setMemberFilter(memberFilter);
				updateHierarchyViewer(true);
				updateTitle();
				internalSelectType(fSelectedType, true);	
			}
			if (nSelected == 1) {
				revealElementInEditor(selected.get(0), fMethodsViewer);
			}
		}
	}
	
	private void typeSelectionChanged(ISelection sel) {
		if (sel instanceof IStructuredSelection) {
			List selected= ((IStructuredSelection)sel).toList();
			int nSelected= selected.size();
			if (nSelected != 0) {
				List types= new ArrayList(nSelected);
				for (int i= nSelected-1; i >= 0; i--) {
					Object elem= selected.get(i);
					if (elem instanceof IType && !types.contains(elem)) {
						types.add(elem);
					}
				}