Set 'node' as front page path and Bartik as default theme if it implicitly was before.
Node module became optional. The default front page path was changed to 'user'. Since 'node' was the implicit default front page path previously and may not have been explicitly configured as such, this update ensures that the old implicit default is still the default.
The default theme for Drupal core was changed from Bartik to Stark. Installation profiles (including Standard and Minimal) were changed to explicitly configure Bartik as default theme. Since Bartik was the default theme by default and may not have been explicitly configured as such previously, this update ensures that the implicit Bartik default is still the default.
http://drupal.org/node/1181776
function system_update_8002() {
$front_page = update_variable_get('site_frontpage');
if (!isset($front_page)) {
update_variable_set('site_frontpage', 'node');
}
$theme = update_variable_get('theme_default');
if (!isset($theme)) {
update_variable_set('theme_default', 'bartik');
}
}