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
if (elementOfInput == null) 
				return false; 
			return tryToReveal(elementOfInput);
		}
		ISelection selection= context.getSelection();
		if (selection != null) {
			selectReveal(selection);
			return true;
		}
		return false;
	}
	/**
	 * Returns the <code>IShowInSource</code> for this view.
	 */
	protected IShowInSource getShowInSource() {
		return new IShowInSource() {
			public ShowInContext getShowInContext() {
				return new ShowInContext(
					getViewer().getInput(),
					getViewer().getSelection());
			}
		};
	}
	/*
	 * @see org.eclipse.ui.views.navigator.IResourceNavigator#setLinkingEnabled(boolean)
	 * @since 2.1
	 */
	public void setLinkingEnabled(boolean enabled) {
		fLinkingEnabled= enabled;
		PreferenceConstants.getPreferenceStore().setValue(PreferenceConstants.LINK_PACKAGES_TO_EDITOR, enabled);