Index: wp-includes/post.php
===================================================================
--- wp-includes/post.php	(revision 4636)
+++ wp-includes/post.php	(working copy)
@@ -1423,4 +1423,31 @@
 		return add_post_meta( $post_id, '_wp_attachment_metadata', $data );
 }
 
-?>
+function wp_check_for_changed_slugs($post_id) {
+	if ( !strlen($_POST['wp-old-slug']) )
+		return $post_id;
+
+	$post = &get_post($post_id);
+
+	// we're only concerned with published posts
+	if ( $post->post_status != 'publish' || $post->post_type != 'post' )
+		return $post_id;
+
+	// only bother if the slug has changed
+	if ( $post->post_name == $_POST['wp-old-slug'] )
+		return $post_id;
+
+	$old_slugs = (array) get_post_meta($post_id, '_wp_old_slug');
+
+	// if we haven't added this old slug before, add it now
+	if ( !count($old_slugs) || !in_array($_POST['wp-old-slug'], $old_slugs) )
+		add_post_meta($post_id, '_wp_old_slug', $_POST['wp-old-slug']);
+
+	// if the new slug was used previously, delete it from the list
+	if ( in_array($post->post_name, $old_slugs) )
+		delete_post_meta($post_id, '_wp_old_slug', $post->post_name);
+
+	return $post_id;
+}
+
+?>
\ No newline at end of file
Index: wp-admin/admin-functions.php
===================================================================
--- wp-admin/admin-functions.php	(revision 4636)
+++ wp-admin/admin-functions.php	(working copy)
@@ -1984,34 +1984,6 @@
 }
 
 
-function wp_check_for_changed_slugs($post_id) {
-	if ( !strlen($_POST['wp-old-slug']) )
-		return $post_id;
-
-	$post = &get_post($post_id);
-
-	// we're only concerned with published posts
-	if ( $post->post_status != 'publish' || $post->post_type != 'post' )
-		return $post_id;
-
-	// only bother if the slug has changed
-	if ( $post->post_name == $_POST['wp-old-slug'] )
-		return $post_id;
-
-	$old_slugs = (array) get_post_meta($post_id, '_wp_old_slug');
-
-	// if we haven't added this old slug before, add it now
-	if ( !count($old_slugs) || !in_array($_POST['wp-old-slug'], $old_slugs) )
-		add_post_meta($post_id, '_wp_old_slug', $_POST['wp-old-slug']);
-
-	// if the new slug was used previously, delete it from the list
-	if ( in_array($post->post_name, $old_slugs) )
-		delete_post_meta($post_id, '_wp_old_slug', $post->post_name);
-
-	return $post_id;
-}
-
-
 function wp_remember_old_slug() {
 	global $post;
 	$name = wp_specialchars($post->post_name); // just in case