+/**
+ * Check theme versions against the latest versions hosted on WordPress.org.
+ *
+ * A list of all themes installed in sent to WP. Checks against the
+ * WordPress server at api.wordpress.org. Will only check if WordPress isn't
+ * installing.
+ *
+ * @package WordPress
+ * @since 2.7.0
+ * @uses $wp_version Used to notidy the WordPress version.
+ *
+ * @return mixed Returns null if update is unsupported. Returns false if check is too soon.
+ */
+function wp_update_themes( ) {
+ global $wp_version;
+
+ if ( defined( 'WP_INSTALLING' ) )
+ return false;
+
+ if ( !function_exists( 'get_themes' ) )
+ require_once( ABSPATH . 'wp-includes/theme.php' );
+
+ $installed_themes = get_themes( );
+ $last_update = get_site_transient( 'update_themes' );
+ if ( ! is_object($last_update) )
+ $last_update = new stdClass;
+
+ $timeout = 'load-themes.php' == current_filter() ? 3600 : 43200; //Check for updated every 60 minutes if hitting the themes page, Else, check every 12 hours
+ $time_not_changed = isset( $last_update->last_checked ) && $timeout > ( time( ) - $last_update->last_checked );
+
+ $themes = array();
+ $checked = array();
+ $exclude_fields = array('Template Files', 'Stylesheet Files', 'Status', 'Theme Root', 'Theme Root URI', 'Template Dir', 'Stylesheet Dir', 'Description', 'Tags', 'Screenshot');
+
+ // Put slug of current theme into request.
+ $themes['current_theme'] = get_option( 'stylesheet' );
+
+ foreach ( (array) $installed_themes as $theme_title => $theme ) {
+ $themes[$theme['Stylesheet']] = array();
+ $checked[$theme['Stylesheet']] = $theme['Version'];
+
+ $themes[$theme['Stylesheet']]['Name'] = $theme['Name'];
+ $themes[$theme['Stylesheet']]['Version'] = $theme['Version'];
+
+ foreach ( (array) $theme as $key => $value ) {
+ if ( !in_array($key, $exclude_fields) )
+ $themes[$theme['Stylesheet']][$key] = $value;
+ }
+ }
+
+ $theme_changed = false;
+ foreach ( $checked as $slug => $v ) {
+ $update_request->checked[ $slug ] = $v;
+
+ if ( !isset( $last_update->checked[ $slug ] ) || strval($last_update->checked[ $slug ]) !== strval($v) )
+ $theme_changed = true;
+ }
+
+ if ( isset ( $last_update->response ) && is_array( $last_update->response ) ) {
+ foreach ( $last_update->response as $slug => $update_details ) {
+ if ( ! isset($checked[ $slug ]) ) {
+ $theme_changed = true;
+ break;
+ }
+ }
+ }
+
+ if ( $time_not_changed && !$theme_changed )
+ return false;
+
+ // Update last_checked for current to prevent multiple blocking requests if request hangs
+ $last_update->last_checked = time();
+ set_site_transient( 'update_themes', $last_update );
+
+ $options = array(
+ 'timeout' => ( ( defined('DOING_CRON') && DOING_CRON ) ? 30 : 3),
+ 'body' => array( 'themes' => serialize( $themes ) ),
+ 'user-agent' => 'WordPress/' . $wp_version . '; ' . get_bloginfo( 'url' )
+ );
+
+ $raw_response = wp_remote_post( 'http://api.wordpress.org/themes/update-check/1.0/', $options );
+
+ if ( is_wp_error( $raw_response ) )
+ return false;
+
+ if ( 200 != $raw_response['response']['code'] )
+ return false;
+
+ $new_update = new stdClass;
+ $new_update->last_checked = time( );
+ $response = unserialize( $raw_response['body'] );
+ if ( $response ) {
+ $new_update->checked = $checked;
+ $new_update->response = $response;
+ }
+
+ set_site_transient( 'update_themes', $new_update );
+}
+
+function _maybe_update_core() {
+ global $wp_version;
+
+ $current = get_site_transient( 'update_core' );
+
+ if ( isset( $current->last_checked ) &&
+ 43200 > ( time() - $current->last_checked ) &&
+ isset( $current->version_checked ) &&
+ $current->version_checked == $wp_version )
+ return;
+
+ wp_version_check();
+}
+/**
+ * Check the last time plugins were run before checking plugin versions.
+ *
+ * This might have been backported to WordPress 2.6.1 for performance reasons.
+ * This is used for the wp-admin to check only so often instead of every page
+ * load.
+ *
+ * @since 2.7.0
+ * @access private
+ */