Index: system.admin.inc
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.admin.inc,v
retrieving revision 1.61
diff -u -r1.61 system.admin.inc
--- system.admin.inc	29 Jan 2008 10:56:13 -0000	1.61
+++ system.admin.inc	2 Feb 2008 01:27:38 -0000
@@ -1731,6 +1731,20 @@
 }
 
 /**
+ * Menu callback: forward the request to the theme's shortcut icon.
+ */ 
+function system_shortcut_icon() {
+  init_theme();
+  $favicon = theme_get_setting('favicon', TRUE);
+  if (empty($favicon)) {
+    drupal_not_found();
+  }
+  else {
+    header('Location: '. $favicon);
+  }
+}
+
+/**
  * Theme a SQL result table.
  *
  * @param $data
Index: system.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.module,v
retrieving revision 1.584
diff -u -r1.584 system.module
--- system.module	30 Jan 2008 23:07:41 -0000	1.584
+++ system.module	2 Feb 2008 01:27:38 -0000
@@ -507,6 +507,13 @@
     'type' => MENU_CALLBACK,
     'file' => 'system.admin.inc',
   );
+  // Override favicon.ico to forward to the theme's shortcut icon.
+  $items['favicon.ico'] = array(
+    'page callback' => 'system_shortcut_icon',
+    'access callback' => TRUE,
+    'type' => MENU_CALLBACK,
+    'file' => 'system.admin.inc',
+  );
   return $items;
 }