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
fCurrentOrientation= -1;
		
		setOrientation(orientation);
		
		if (fMemento != null) { 
			restoreLinkingEnabled(fMemento);
		}
		fToggleLinkingAction= new ToggleLinkingAction(this);
		
		IActionBars actionBars= getViewSite().getActionBars();
		IMenuManager viewMenu= actionBars.getMenuManager();
		for (int i= 0; i < fToggleOrientationActions.length; i++) {
			viewMenu.add(fToggleOrientationActions[i]);
		}
		viewMenu.add(new Separator(IWorkbenchActionConstants.MB_ADDITIONS));
		viewMenu.add(fShowQualifiedTypeNamesAction);
		viewMenu.add(fToggleLinkingAction);
		
	
		
		ToolBarManager lowertbmanager= new ToolBarManager(methodViewerToolBar);
		lowertbmanager.add(fEnableMemberFilterAction);			
		lowertbmanager.add(new Separator());
		fMethodsViewer.contributeToToolBar(lowertbmanager);
		lowertbmanager.update(true);
							
		
		int nHierarchyViewers= fAllViewers.length; 
		Viewer[] trackedViewers= new Viewer[nHierarchyViewers + 1];
		for (int i= 0; i < nHierarchyViewers; i++) {