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
* Create the KeyListener for doing the refresh on the viewer.
	 */
	private void initKeyListener() {
		fViewer.getControl().addKeyListener(new KeyAdapter() {
			public void keyReleased(KeyEvent event) {
				fActionSet.handleKeyEvent(event);
			}
		});
	}
	/**
	 * An editor has been activated.  Set the selection in this Packages Viewer
	 * to be the editor's input, if linking is enabled.
	 */
	void editorActivated(IEditorPart editor) {
		if (!isLinkingEnabled())  
			return;
		Object input= getElementOfInput(editor.getEditorInput());
		if (input == null) 
			return;
		if (!inputIsSelected(editor.getEditorInput()))
			showInput(input);
	}
	private boolean inputIsSelected(IEditorInput input) {
		IStructuredSelection selection= (IStructuredSelection)fViewer.getSelection();
		if (selection.size() != 1) 
			return false;
		IEditorInput selectionAsInput= null;
		try {
			selectionAsInput= EditorUtility.getEditorInput(selection.getFirstElement());
		} catch (JavaModelException e1) {