Ticket #17323: 17323.2.diff

Index: wp-admin/includes/update.php
===================================================================
--- wp-admin/includes/update.php        (revision 17792)
+++ wp-admin/includes/update.php        (working copy)
@@ -309,4 +309,53 @@
 }
 add_action( 'admin_notices', 'maintenance_nag' );
 
+/**
+ * Display a nag in the footer if the user is using an outdated browser.  If
+ * that browser is IE < 8 mention that it is insecure
+ *
+ * @since 3.1.2
+ */
+function browser_upgrade_nag() {
+       $key = md5( $_SERVER['HTTP_USER_AGENT'] );
+
+       if ( false !== ($response = get_site_transient('browsehappy_' . $key) ) ) {
+
+               $options = array(
+                       'body'                  => array( 'useragent' => $_SERVER['HTTP_USER_AGENT'] ),
+                       'user-agent'    => 'WordPress/' . $wp_version . '; ' . get_bloginfo( 'url' )
+               );
+
+               $raw_response = wp_remote_post( 'http://api.wordpress.org/core/browse-happy/1.0/', $options );
+
+               if ( is_wp_error( $raw_response ) || 200 != $raw_response['response']['code'] )
+                       return;
+
+               /**
+                * Response should be an array with:
+                *  'name' - string- A user friendly browser name
+                *  'version' - string - The most recent version of the browser
+                *  'upgrade' - boolean - Whether the browser needs an upgrade
+                *  'insecure' - boolean - Whether the browser is deemed insecure
+                */
+               $response = unserialize( $raw_response['body'] );
+
+               if ( ! $response )
+                       return;
+
+               set_site_transient( 'browsehappy_' . $key, $response, 604800 ); // cache for 1 week
+       }
+
+       if ( ! $response['upgrade'] )
+               return;
+
+       if ( $response['insecure'] ) {
+               $msg = sprintf( __( 'Your version of %s is insecure.  WordPress recommends an update.' ), $response['name'] );
+       } else {
+               $msg = sprintf( __( 'Your version of %s is out of date.  WordPress recommends an update.' ), $response['name'] );
+       }
+
+       echo apply_filters( 'browse-happy-notice', '<div id="bh"><a href="http://browsehappy.com/" title="' . esc_attr__( 'Browse Happy' ) . '">' . esc_html( $msg ) . '</a></div>' );
+}
+add_action( 'admin_footer', 'browser_upgrade_nag' );
+
 ?>