Bug 41927 [Dialogs] Selecting in PreferenceDialog generates too many invalid entries
20030825 If you select an entry, close the dialog and then reopen it selecting anotehr entry will result in a "this page has invalid values" although you selected nothing.
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
protected void selectSavedItem() {
		if (tree != null) {
			int count = tree.getItemCount();
			if (count > 0) {
				TreeItem selectedItem = getLastSelectedNode(tree.getItems());
				Object data = selectedItem.getData();
				if (data instanceof IPreferenceNode) {
					tree.setSelection(new TreeItem[] { selectedItem });
					currentTreeItem = selectedItem;
					showPage((IPreferenceNode) data);
					
					tree.setFocus();
				}
			}
		}
	}
	/**
	 * Get the name of the selected item preference
	 */
	protected String getSelectedNodePreference() {
		return lastPreferenceId;
	}
	/**
	 * Get the name of the selected item preference
	 */
	protected void setSelectedNodePreference(String pageId) {
		lastPreferenceId = pageId;
	}
	/**
	 * Get the node that was last selected in the dialog store.