Bug 33488 [Preferences] [Help] F1 help should always give help about the selected page
build I20030227 - Window / Preferences - focus is in tree at left - F1 - it gives you help about the dialog, not the selected page - give the selected page focus - F1 - it gives you help about the page F1 should always give you help about the selected page. It should also give help about the dialog at the same time, if possible (e.g. a link for the page, and a link for the dialog).
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
return selectedItem;
	}
	/**
	 * Find the TreeItem that has data the same id as the nodeId.
	 * Search the children recursively.
	 * @return TreeItem or null if not found.
	 */
	private TreeItem findNodeMatching(TreeItem[] items, String nodeId) {
		for (int i = 0; i < items.length; i++) {
			Object data = items[i].getData();
			if (data instanceof IPreferenceNode) {
				if (((IPreferenceNode) data).getId().equals(nodeId))
					return items[i];
				else {
					TreeItem selectedChild =
						findNodeMatching(items[i].getItems(), nodeId);
					if (selectedChild != null)
						return selectedChild;
				}
			}
		}
		return null;
	}
	/**
	 * Clear the last selected node. This is so that we not chache
	 * the last selection in case of an error.
	 */
	private void clearSelectedNode() {
		setSelectedNodePreference(null);
	}